//! The JSON API (hub spec §12.1) under `/api/v1`: bearer tokens, RFC 7807
//! problems, the same shapes as `oxy --json` where one exists. Reads need
//! `repo:read` (anonymous for public repositories); writes the scope named
//! on each handler.

use crate::auth::{self, Access, Role};
use crate::db::{self, accounts::Account};
use crate::repos::{view, RepoError, RepoName};
use crate::Shared;
use axum::extract::{Path, Query, State};
use axum::http::{HeaderMap, StatusCode};
use axum::response::{IntoResponse, Response};
use axum::routing::{get, post};
use axum::{Json, Router};
use hub_api::*;
use serde::Deserialize;

mod projects;

/// Any other path under `/api/v1`: a problem document, not the site's page.
async fn no_route() -> ApiError {
    ApiError(StatusCode::NOT_FOUND, "no such API route".into())
}

pub fn router() -> Router<Shared> {
    Router::new()
        .fallback(no_route)
        .route("/flow/claim", post(crate::flow::claim))
        .route("/flow/jobs/{id}/log", post(crate::flow::log))
        .route("/flow/jobs/{id}/finish", post(crate::flow::finish))
        .route("/projects/{owner}", get(projects::list).post(projects::create))
        .route("/projects/{owner}/{number}", get(projects::board).patch(projects::edit))
        .route("/projects/{owner}/{number}/cards", post(projects::add_card))
        .route("/projects/{owner}/{number}/cards/{id}", axum::routing::patch(projects::move_card).delete(projects::remove_card))
        .route("/user", get(me))
        .route("/notifications", get(notifications))
        .route("/notifications/read", post(notifications_read_all))
        .route("/notifications/{id}/read", post(notification_read))
        .route("/users/{name}", get(user))
        .route("/orgs/{name}", get(org))
        .route("/search", get(search))
        .route("/repos", get(list_repos).post(create_repo))
        .route("/repos/{owner}/{name}", get(get_repo))
        .route("/repos/{owner}/{name}/bookmarks", get(bookmarks))
        .route("/repos/{owner}/{name}/tags", get(tags))
        .route("/repos/{owner}/{name}/history/{r}", get(history))
        .route("/repos/{owner}/{name}/changes/{hash}", get(change))
        .route("/repos/{owner}/{name}/tree/{r}", get(tree_root))
        .route("/repos/{owner}/{name}/tree/{r}/{*path}", get(tree))
        .route("/repos/{owner}/{name}/file/{r}/{*path}", get(file))
        .route("/repos/{owner}/{name}/blame/{r}/{*path}", get(blame))
        .route("/repos/{owner}/{name}/conflicts", get(conflicts))
        .route("/repos/{owner}/{name}/trust", get(trust))
        .route("/repos/{owner}/{name}/pushes", get(pushes))
        .route("/repos/{owner}/{name}/proposals", get(proposals).post(create_proposal))
        .route("/repos/{owner}/{name}/proposals/{number}", get(proposal))
        .route("/repos/{owner}/{name}/proposals/{number}/comments", get(proposal_comments).post(proposal_comment))
        .route("/repos/{owner}/{name}/proposals/{number}/reviews", get(proposal_reviews).post(proposal_review))
        .route("/repos/{owner}/{name}/proposals/{number}/checks", get(proposal_checks))
        .route("/repos/{owner}/{name}/proposals/{number}/files", get(proposal_files))
        .route("/repos/{owner}/{name}/proposals/{number}/content/{side}/{*path}", get(proposal_content))
        .route("/repos/{owner}/{name}/issues", get(issues).post(create_issue))
        .route("/repos/{owner}/{name}/issues/{number}", get(issue).post(issue_state).patch(issue_edit))
        .route("/repos/{owner}/{name}/issues/{number}/comments", get(issue_comments).post(issue_comment))
        .route("/repos/{owner}/{name}/labels", get(labels).post(create_label))
        .route("/repos/{owner}/{name}/labels/{label}", axum::routing::delete(delete_label))
        .route("/repos/{owner}/{name}/milestones", get(milestones))
        .route("/repos/{owner}/{name}/hooks", get(hooks).post(create_hook))
        .route("/repos/{owner}/{name}/hooks/{id}/delete", post(delete_hook))
        .route("/repos/{owner}/{name}/checks", post(post_check))
        .route("/repos/{owner}/{name}/flow/runs", get(flow_runs).post(start_flow_run))
        .route("/repos/{owner}/{name}/flow/runs/{number}", get(flow_run))
        .route("/repos/{owner}/{name}/flow/runs/{number}/jobs/{job}/log", get(flow_job_log))
        .route("/repos/{owner}/{name}/flow/runs/{number}/rerun", post(rerun_flow_run))
        .route("/repos/{owner}/{name}/checks/required", get(required_checks).put(set_required_checks))
        .route("/repos/{owner}/{name}/checks/{state}", get(checks_for_state))
        .route("/repos/{owner}/{name}/releases", get(releases).post(create_release))
        .route("/repos/{owner}/{name}/releases/{tag}/assets", post(upload_asset))
}

async fn releases(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name)): Path<(String, String)>,
) -> Result<Json<Vec<Release>>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (repo, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    Ok(Json(crate::web::releases::api_views(&app, &repo, &row).await?))
}

async fn create_release(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name)): Path<(String, String)>,
    Json(body): Json<NewRelease>,
) -> Result<(StatusCode, Json<Release>), ApiError> {
    let c = caller(&app, &headers).await?;
    let me = c.require("repo:write")?.clone();
    let (repo, row, _) = reach(&app, &c, &owner, &name, Access::Write).await?;
    crate::web::releases::create_release(&app, &repo, &row, &me, &body.tag, &body.title, body.notes, body.prerelease)
        .await
        .map_err(|m| ApiError(StatusCode::BAD_REQUEST, m))?;
    let r = crate::web::releases::api_views(&app, &repo, &row)
        .await?
        .into_iter()
        .find(|r| r.tag == body.tag)
        .ok_or_else(|| not_found("no such release"))?;
    Ok((StatusCode::CREATED, Json(r)))
}

#[derive(Deserialize)]
struct AssetQuery {
    name: String,
}

/// `POST …/releases/{tag}/assets?name=file.tar.gz` with the file as the body.
async fn upload_asset(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, tag)): Path<(String, String, String)>,
    Query(q): Query<AssetQuery>,
    body: axum::body::Bytes,
) -> Result<(StatusCode, Json<Release>), ApiError> {
    let c = caller(&app, &headers).await?;
    c.require("repo:write")?;
    let (repo, row, _) = reach(&app, &c, &owner, &name, Access::Write).await?;
    let r = db::releases::get(&app.db, row.id, &tag).await?.ok_or_else(|| not_found("no such release"))?;
    let ct = headers.get(axum::http::header::CONTENT_TYPE).and_then(|v| v.to_str().ok()).unwrap_or("application/octet-stream").to_string();
    crate::web::releases::store_asset(&app, r.id, &q.name, &ct, &body).await.map_err(|m| ApiError(StatusCode::BAD_REQUEST, m))?;
    let r = crate::web::releases::api_views(&app, &repo, &row)
        .await?
        .into_iter()
        .find(|r| r.tag == tag)
        .ok_or_else(|| not_found("no such release"))?;
    Ok((StatusCode::CREATED, Json(r)))
}

pub struct ApiError(pub StatusCode, pub String);

impl IntoResponse for ApiError {
    fn into_response(self) -> Response {
        let body = Problem { status: self.0.as_u16(), title: self.0.canonical_reason().unwrap_or("error").into(), detail: self.1 };
        (self.0, [("content-type", "application/problem+json")], Json(body)).into_response()
    }
}

impl From<RepoError> for ApiError {
    fn from(e: RepoError) -> ApiError {
        match e {
            RepoError::NotFound => not_found("no such repository"),
            RepoError::Oxy(oxy_core::repo::RepoError::Msg(m)) => ApiError(StatusCode::NOT_FOUND, m),
            other => ApiError(StatusCode::INTERNAL_SERVER_ERROR, other.to_string()),
        }
    }
}

impl From<sqlx::Error> for ApiError {
    fn from(e: sqlx::Error) -> ApiError {
        ApiError(StatusCode::INTERNAL_SERVER_ERROR, e.to_string())
    }
}

pub(crate) fn not_found(what: &str) -> ApiError {
    ApiError(StatusCode::NOT_FOUND, what.into())
}

pub(crate) fn forbidden(what: &str) -> ApiError {
    ApiError(StatusCode::FORBIDDEN, what.into())
}

/// Who calls: the account behind a bearer token, with the token's scopes.
pub struct Caller {
    pub account: Option<Account>,
    pub scopes: Vec<String>,
    pub site: bool,
}

impl Caller {
    fn has(&self, scope: &str) -> bool {
        self.site
            || self.scopes.iter().any(|s| {
                s == scope
                    || (scope == "repo:read" && (s == "repo:write" || s == "repo:admin"))
                    || (scope == "repo:write" && s == "repo:admin")
            })
    }

    fn require(&self, scope: &str) -> Result<&Account, ApiError> {
        if !self.has(scope) {
            return Err(forbidden(&format!("this token lacks the {scope} scope")));
        }
        self.account.as_ref().ok_or_else(|| ApiError(StatusCode::UNAUTHORIZED, "a personal access token is required".into()))
    }
}

pub async fn caller(app: &Shared, headers: &HeaderMap) -> Result<Caller, ApiError> {
    let Some(t) = oxy_server::bearer_token(headers) else { return Ok(Caller { account: None, scopes: vec![], site: false }) };
    if app.config.auth.push_tokens.iter().any(|x| auth::mac_equal(x, t)) {
        let admin = db::accounts::accounts(&app.db).await?.into_iter().find(|a| a.is_admin);
        return Ok(Caller { account: admin, scopes: vec!["repo:admin".into(), "user:read".into(), "checks:write".into()], site: true });
    }
    let token = db::accounts::token_by_hash(&app.db, &auth::token_hash(t)).await?;
    match token {
        Some(tok) if !tok.expired(db::now_ms()) => {
            let account = db::accounts::account_by_id(&app.db, tok.account_id).await?.filter(|a| !a.banned);
            db::accounts::touch_token(&app.db, tok.id).await.ok();
            Ok(Caller { account, scopes: tok.scope_list().iter().map(|s| s.to_string()).collect(), site: false })
        }
        _ => Err(ApiError(StatusCode::UNAUTHORIZED, "unknown or expired token".into())),
    }
}

fn repository(app: &Shared, r: &db::repos::RepoRow) -> Repository {
    Repository {
        owner: r.owner.clone(),
        name: r.name.clone(),
        description: r.description.clone(),
        default_bookmark: r.default_bookmark.clone(),
        visibility: r.visibility(),
        created_ms: r.created_ms,
        updated_ms: r.updated_ms,
        clone_url: format!("{}/{}/{}", app.config.base_url(), r.owner, r.name),
    }
}

/// A repository the caller may reach with `access`, else 404.
async fn reach(
    app: &Shared,
    c: &Caller,
    owner: &str,
    name: &str,
    access: Access,
) -> Result<(RepoName, db::repos::RepoRow, Role), ApiError> {
    let repo = RepoName::new(owner, name).ok_or_else(|| not_found("no such repository"))?;
    let row = db::repos::get(&app.db, owner, name).await?.ok_or_else(|| not_found("no such repository"))?;
    let role = auth::roles::role_for(&app.db, c.account.as_ref(), &row).await?;
    if !auth::roles::allows(role, access) {
        return Err(not_found("no such repository"));
    }
    Ok((repo, row, role.unwrap_or(Role::Read)))
}

fn summary(c: &view::ChangeView) -> ChangeSummary {
    ChangeSummary {
        hash: c.hash.clone(),
        message: if c.body.is_empty() { c.title.clone() } else { format!("{}\n\n{}", c.title, c.body) },
        author: Author {
            name: c.author.name.clone(),
            email: c.author.email.clone(),
            key: c.author.key.clone(),
            account: c.author.account.clone(),
            note: Author::note_for(&c.author.key, &c.author.account),
        },
        when_ms: c.when_ms,
        deps: c.deps.clone(),
        head: c.head,
        signature: match &c.signature {
            view::SigView::Unsigned => Signature::Unsigned,
            view::SigView::Valid { key, sealed, revoked, .. } => Signature::Valid { key: key.clone(), sealed: *sealed, revoked: *revoked },
            view::SigView::Invalid(why) => Signature::Invalid { reason: why.clone() },
        },
    }
}

// ---------------------------------------------------------------- accounts

async fn me(State(app): State<Shared>, headers: HeaderMap) -> Result<Json<User>, ApiError> {
    let c = caller(&app, &headers).await?;
    let a = c.require("user:read")?;
    Ok(Json(user_of(&app, a).await?))
}

#[derive(Deserialize)]
struct InboxQuery {
    #[serde(default)]
    limit: Option<i64>,
}

/// The caller's inbox; reading and clearing it needs `user:read`, since
/// it touches nothing but the caller's own notifications.
async fn notifications(
    State(app): State<Shared>,
    headers: HeaderMap,
    Query(q): Query<InboxQuery>,
) -> Result<Json<hub_api::Inbox>, ApiError> {
    let c = caller(&app, &headers).await?;
    let a = c.require("user:read")?;
    let limit = q.limit.unwrap_or(50).clamp(1, 200);
    let base = app.config.base_url().trim_end_matches('/').to_string();
    let items = db::notify::inbox(&app.db, a.id, limit)
        .await?
        .into_iter()
        .map(|n| hub_api::Notification {
            id: n.id,
            at_ms: n.at_ms,
            kind: n.kind,
            title: n.title,
            url: if n.url.starts_with('/') { format!("{base}{}", n.url) } else { n.url },
            actor: n.actor,
            read: n.read,
        })
        .collect();
    Ok(Json(hub_api::Inbox { unread: db::notify::unread(&app.db, a.id).await?, items }))
}

async fn notification_read(State(app): State<Shared>, headers: HeaderMap, Path(id): Path<i64>) -> Result<StatusCode, ApiError> {
    let c = caller(&app, &headers).await?;
    let a = c.require("user:read")?;
    db::notify::mark_read(&app.db, a.id, Some(id)).await?;
    Ok(StatusCode::NO_CONTENT)
}

async fn notifications_read_all(State(app): State<Shared>, headers: HeaderMap) -> Result<StatusCode, ApiError> {
    let c = caller(&app, &headers).await?;
    let a = c.require("user:read")?;
    db::notify::mark_read(&app.db, a.id, None).await?;
    Ok(StatusCode::NO_CONTENT)
}

async fn user_of(app: &Shared, a: &Account) -> Result<User, ApiError> {
    let keys = db::accounts::identities_of(&app.db, a.id).await?.into_iter().map(|i| i.key).collect();
    Ok(User { username: a.username.clone(), display_name: a.display_name.clone(), is_admin: a.is_admin, keys, created_ms: a.created_ms })
}

async fn user(State(app): State<Shared>, Path(name): Path<String>) -> Result<Json<User>, ApiError> {
    let a = db::accounts::account_by_name(&app.db, &name).await?.ok_or_else(|| not_found("no such account"))?;
    Ok(Json(user_of(&app, &a).await?))
}

async fn org(State(app): State<Shared>, Path(name): Path<String>) -> Result<Json<Organisation>, ApiError> {
    let o = db::accounts::org_by_name(&app.db, &name).await?.ok_or_else(|| not_found("no such organisation"))?;
    let members = db::accounts::org_members(&app.db, o.id).await?.into_iter().map(|(a, _)| a.username).collect();
    Ok(Json(Organisation { name: o.name, display_name: o.display_name, description: o.description, members }))
}

#[derive(Deserialize)]
struct SearchQuery {
    q: String,
}

async fn search(
    State(app): State<Shared>,
    headers: HeaderMap,
    Query(q): Query<SearchQuery>,
) -> Result<Json<Vec<serde_json::Value>>, ApiError> {
    let c = caller(&app, &headers).await?;
    let mut out = Vec::new();
    for h in db::notify::search(&app.db, &q.q, None, 50).await? {
        let Some(row) = db::repos::get_by_id(&app.db, h.repo_id).await? else { continue };
        let role = auth::roles::role_for(&app.db, c.account.as_ref(), &row).await?;
        if !auth::roles::allows(role, Access::Read) {
            continue;
        }
        out.push(
            serde_json::json!({ "kind": h.kind, "repository": row.slug(), "number": h.number, "title": h.title, "snippet": h.snippet }),
        );
    }
    Ok(Json(out))
}

// ------------------------------------------------------------ repositories

async fn list_repos(State(app): State<Shared>, headers: HeaderMap) -> Result<Json<Vec<Repository>>, ApiError> {
    let c = caller(&app, &headers).await?;
    let mut out = Vec::new();
    for r in db::repos::list(&app.db).await? {
        let role = auth::roles::role_for(&app.db, c.account.as_ref(), &r).await?;
        if auth::roles::allows(role, Access::Read) {
            out.push(repository(&app, &r));
        }
    }
    Ok(Json(out))
}

async fn create_repo(
    State(app): State<Shared>,
    headers: HeaderMap,
    Json(body): Json<NewRepository>,
) -> Result<(StatusCode, Json<Repository>), ApiError> {
    let c = caller(&app, &headers).await?;
    let me = c.require("repo:admin")?;
    let name = RepoName::new(&body.owner, &body.name).ok_or_else(|| ApiError(StatusCode::BAD_REQUEST, "invalid owner or name".into()))?;
    if !auth::roles::may_create_under(&app.db, me, &name.owner).await? {
        return Err(forbidden("you cannot create repositories under that owner"));
    }
    if db::repos::get(&app.db, &name.owner, &name.name).await?.is_some() || app.repos.exists(&name) {
        return Err(ApiError(StatusCode::CONFLICT, "that repository exists".into()));
    }
    app.repos.create(&name, None)?;
    let row = db::repos::create(&app.db, &name.owner, &name.name, &body.description, body.visibility).await?;
    db::accounts::audit(&app.db, Some(me), "repo.created", &name.to_string(), "api").await.ok();
    Ok((StatusCode::CREATED, Json(repository(&app, &row))))
}

async fn get_repo(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name)): Path<(String, String)>,
) -> Result<Json<Repository>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (_, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    Ok(Json(repository(&app, &row)))
}

async fn bookmarks(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name)): Path<(String, String)>,
) -> Result<Json<Vec<Bookmark>>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (repo, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let default = row.default_bookmark.clone();
    let list = app.repos.read(&repo, move |r, cache| view::bookmarks(r, cache, &default)).await?;
    Ok(Json(list.into_iter().map(|b| Bookmark { name: b.name, heads: b.heads, changes: b.changes, default: b.default }).collect()))
}

async fn tags(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name)): Path<(String, String)>,
) -> Result<Json<Vec<Tag>>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (repo, _, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let list = app.repos.read(&repo, |r, _| view::tags(r)).await?;
    Ok(Json(list.into_iter().map(|t| Tag { name: t.name, heads: t.heads, message: t.message, signer: t.signer }).collect()))
}

#[derive(Deserialize)]
struct HistoryQuery {
    path: Option<String>,
    offset: Option<usize>,
    limit: Option<usize>,
}

async fn history(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, r)): Path<(String, String, String)>,
    Query(q): Query<HistoryQuery>,
) -> Result<Json<History>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (repo, _, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let (offset, limit) = (q.offset.unwrap_or(0), q.limit.unwrap_or(50).min(500));
    let h = app
        .repos
        .read(&repo, move |repo, cache| {
            let target = view::resolve(repo, cache, &r)?;
            view::history(repo, cache, target, q.path.as_deref(), offset, limit)
        })
        .await?;
    let mut entries = h.entries;
    crate::web::attribute(&app, &mut entries.iter_mut().collect::<Vec<_>>()).await;
    Ok(Json(History {
        reference: h.target.label,
        heads: h.target.heads.iter().map(|x| x.to_hex()).collect(),
        total: h.total,
        offset: h.offset,
        changes: entries.iter().map(summary).collect(),
    }))
}

async fn change(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, hash)): Path<(String, String, String)>,
) -> Result<Json<ChangeDetail>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (repo, _, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let d = app
        .repos
        .read(&repo, move |repo, cache| {
            let h = view::resolve_change(repo, cache, &hash)?;
            view::change(repo, cache, &h)
        })
        .await?;
    let mut v = d.view;
    crate::web::attribute(&app, &mut [&mut v]).await;
    let files = crate::web::history::render_files(&d.files, &d.bases)
        .into_iter()
        .map(|f| FileChange { path: f.path, kind: f.kind, from: f.from, added: f.added, removed: f.removed })
        .collect();
    Ok(Json(ChangeDetail {
        body: v.body.clone(),
        change: summary(&v),
        dependents: d.dependents.iter().map(|x| x.hash.clone()).collect(),
        in_bookmarks: d.in_bookmarks,
        in_tags: d.in_tags,
        files,
    }))
}

fn entry(e: &view::Entry) -> TreeEntry {
    TreeEntry {
        name: e.name.clone(),
        path: e.path.clone(),
        kind: match e.kind {
            view::EntryKind::Dir => "dir",
            view::EntryKind::File => "file",
            view::EntryKind::Symlink => "symlink",
            view::EntryKind::Subrepo => "subrepo",
        }
        .into(),
        exec: e.exec,
        size: e.size,
        conflicted: e.conflicted,
    }
}

async fn tree_root(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, r)): Path<(String, String, String)>,
) -> Result<Json<Vec<TreeEntry>>, ApiError> {
    tree(State(app), headers, Path((owner, name, r, String::new()))).await
}

async fn tree(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, r, path)): Path<(String, String, String, String)>,
) -> Result<Json<Vec<TreeEntry>>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (repo, _, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let t = app
        .repos
        .read(&repo, move |repo, cache| {
            let target = view::resolve(repo, cache, &r)?;
            view::tree(repo, cache, target, &path)
        })
        .await?;
    Ok(Json(t.entries.iter().map(entry).collect()))
}

async fn file(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, r, path)): Path<(String, String, String, String)>,
) -> Result<Response, ApiError> {
    let c = caller(&app, &headers).await?;
    let (repo, _, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let limit = app.config.limits.render_limit.0;
    let f = app
        .repos
        .read(&repo, move |repo, cache| {
            let target = view::resolve(repo, cache, &r)?;
            view::file(repo, cache, target, &path, limit)
        })
        .await?;
    Ok(crate::web::raw(f.bytes, &f.name, false))
}

async fn blame(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, r, path)): Path<(String, String, String, String)>,
) -> Result<Json<Vec<BlameLine>>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (repo, _, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let limit = app.config.limits.render_limit.0;
    let b = app
        .repos
        .read(&repo, move |repo, cache| {
            let target = view::resolve(repo, cache, &r)?;
            view::blame(repo, cache, target, &path, limit)
        })
        .await?;
    Ok(Json(
        b.lines
            .into_iter()
            .map(|l| BlameLine {
                line: l.line,
                change: l.hash.to_hex(),
                index: l.index,
                author: l.author,
                when_ms: l.when_ms,
                text: String::from_utf8_lossy(&l.text).into_owned(),
            })
            .collect(),
    ))
}

async fn conflicts(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name)): Path<(String, String)>,
) -> Result<Json<Vec<Conflict>>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (repo, _, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let list = app.repos.read(&repo, view::conflicts).await?;
    Ok(Json(
        list.into_iter()
            .map(|c| Conflict {
                bookmark: c.bookmark,
                path: c.path,
                kind: c.kind,
                contributors: c.contributors.iter().map(|x| x.hash.clone()).collect(),
            })
            .collect(),
    ))
}

async fn trust(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name)): Path<(String, String)>,
) -> Result<Json<Trust>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (repo, _, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let key = app.hub_key.key;
    let t = app.repos.read(&repo, move |r, cache| view::trust(r, cache, &key)).await?;
    Ok(Json(Trust {
        policy: t.policy.map(|p| Policy {
            serial: p.serial,
            expires_ms: p.expires_ms,
            roots: p.roots.iter().map(|k| k.key.clone()).collect(),
            root_threshold: p.root_threshold,
            rules: p
                .rules
                .iter()
                .map(|r| Rule {
                    pattern: r.pattern.clone(),
                    keys: r.keys.iter().map(|k| k.key.clone()).collect(),
                    threshold: r.threshold,
                    require: r.require.clone(),
                    allow_conflicts: r.allow_conflicts,
                })
                .collect(),
        }),
        signed: t.verification.signed,
        sealed: t.verification.sealed,
        unsigned: t.verification.unsigned,
        invalid: t.verification.invalid.iter().map(|(h, _)| h.clone()).collect(),
        hub_key: t.hub_key,
    }))
}

async fn pushes(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name)): Path<(String, String)>,
) -> Result<Json<Vec<Push>>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (_, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let rows = db::repos::pushes(&app.db, row.id, 200).await?;
    Ok(Json(
        rows.into_iter()
            .map(|p| Push {
                at_ms: p.at_ms,
                pusher: p.pusher,
                reference: p.reference,
                ok: p.ok,
                reason: p.reason,
                old_state: p.old_state,
                new_state: p.new_state,
                heads: p.heads,
                changes: p.changes,
            })
            .collect(),
    ))
}

// --------------------------------------------------------------- proposals

async fn proposals(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name)): Path<(String, String)>,
) -> Result<Json<Vec<Proposal>>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (repo, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let mut out = Vec::new();
    for p in db::proposals::list(&app.db, row.id, &["open", "draft"]).await? {
        let loaded = crate::web::proposals::load(&app, &repo, p).await?;
        let v = crate::web::proposals::verdict(&app, &loaded, row.id).await?;
        out.push(crate::web::proposals::to_api(&app, &owner, &name, &loaded, &v, None).await);
    }
    Ok(Json(out))
}

async fn proposal(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, number)): Path<(String, String, i64)>,
) -> Result<Json<Proposal>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (repo, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let p = db::proposals::get(&app.db, row.id, number).await?.ok_or_else(|| not_found("no such proposal"))?;
    let source_url = match p.source_repo_id {
        Some(id) => db::repos::get_by_id(&app.db, id).await?.map(|r| format!("{}/{}", app.config.base_url(), r.slug())),
        None => None,
    };
    let loaded = crate::web::proposals::load(&app, &repo, p).await?;
    let v = crate::web::proposals::verdict(&app, &loaded, row.id).await?;
    Ok(Json(crate::web::proposals::to_api(&app, &owner, &name, &loaded, &v, source_url).await))
}

/// The files a proposal changes (hub spec §12.1).
async fn proposal_files(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, number)): Path<(String, String, i64)>,
) -> Result<Json<Vec<hub_api::ProposalFile>>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (repo, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let p = db::proposals::get(&app.db, row.id, number).await?.ok_or_else(|| not_found("no such proposal"))?;
    let loaded = crate::web::proposals::load(&app, &repo, p).await?;
    Ok(Json(
        loaded
            .files
            .iter()
            .map(|f| hub_api::ProposalFile {
                path: f.path.clone(),
                from: f.from.clone(),
                kind: f.kind.clone(),
                added: f.added,
                removed: f.removed,
            })
            .collect(),
    ))
}

/// One file's bytes on a side of a proposal: `base` is the target's
/// state, `head` the projected state. 404 when the file does not exist
/// on that side.
async fn proposal_content(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, number, side, path)): Path<(String, String, i64, String, String)>,
) -> Result<Response, ApiError> {
    let c = caller(&app, &headers).await?;
    let (repo, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let p = db::proposals::get(&app.db, row.id, number).await?.ok_or_else(|| not_found("no such proposal"))?;
    let loaded = crate::web::proposals::load(&app, &repo, p).await?;
    let heads = match side.as_str() {
        "base" => loaded.target_heads,
        "head" => loaded.heads,
        _ => return Err(ApiError(StatusCode::BAD_REQUEST, "the side is base or head".into())),
    };
    let limit = app.config.limits.render_limit.0;
    let target = view::RefTarget { label: side, kind: view::RefKind::Change, heads };
    let f = app.repos.read(&repo, move |repo, cache| view::file(repo, cache, target, &path, limit)).await?;
    Ok(crate::web::raw(f.bytes, &f.name, false))
}

async fn create_proposal(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name)): Path<(String, String)>,
    Json(body): Json<NewProposal>,
) -> Result<(StatusCode, Json<Proposal>), ApiError> {
    let c = caller(&app, &headers).await?;
    let me = c.require("proposals:write").or_else(|_| c.require("repo:write"))?.clone();
    let (repo, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let created =
        crate::web::proposals::open_proposal(&app, &repo, &row, &me, &body.title, &body.body, &body.target, &body.source, body.draft)
            .await
            .map_err(|e| ApiError(StatusCode::BAD_REQUEST, e))?;
    let loaded = crate::web::proposals::load(&app, &repo, created).await?;
    let v = crate::web::proposals::verdict(&app, &loaded, row.id).await?;
    Ok((StatusCode::CREATED, Json(crate::web::proposals::to_api(&app, &owner, &name, &loaded, &v, None).await)))
}

fn comment_of(c: &db::proposals::CommentRow) -> Comment {
    Comment {
        id: c.id,
        author: c.author.clone(),
        body: c.body.clone(),
        created_ms: c.created_ms,
        path: if c.path.is_empty() { None } else { Some(c.path.clone()) },
        anchor: if c.anchor_change.is_empty() {
            None
        } else {
            Some(Atom { change: c.anchor_change.clone(), index: c.anchor_index as u32 })
        },
        resolved: c.resolved,
    }
}

async fn proposal_comments(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, number)): Path<(String, String, i64)>,
) -> Result<Json<Vec<Comment>>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (_, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let p = db::proposals::get(&app.db, row.id, number).await?.ok_or_else(|| not_found("no such proposal"))?;
    Ok(Json(db::proposals::comments(&app.db, p.id).await?.iter().map(comment_of).collect()))
}

async fn proposal_comment(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, number)): Path<(String, String, i64)>,
    Json(body): Json<NewComment>,
) -> Result<(StatusCode, Json<Comment>), ApiError> {
    let c = caller(&app, &headers).await?;
    let me = c.require("proposals:write").or_else(|_| c.require("repo:write"))?.clone();
    let (_, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let p = db::proposals::get(&app.db, row.id, number).await?.ok_or_else(|| not_found("no such proposal"))?;
    if body.body.trim().is_empty() {
        return Err(ApiError(StatusCode::BAD_REQUEST, "an empty comment says nothing".into()));
    }
    let (repo, _) = (RepoName::new(&owner, &name).ok_or_else(|| not_found("no such repository"))?, ());
    let anchor = match (body.path.as_deref().map(|x| x.trim_matches('/')), body.line) {
        (Some(path), Some(line)) if !path.is_empty() => {
            let loaded = crate::web::proposals::load(&app, &repo, p.clone()).await?;
            let (heads, file) = (loaded.heads.clone(), path.to_string());
            let atom = app
                .repos
                .read(&repo, move |r, cache| {
                    let projected = cache.load(r, &heads)?;
                    Ok(crate::repos::proposals::atom_at(&projected, &file, line).map(|(h, i)| (h.to_hex(), i)))
                })
                .await?
                .ok_or_else(|| ApiError(StatusCode::BAD_REQUEST, format!("{path}:{line} is not a line of the projected state")))?;
            Some((path.to_string(), atom))
        }
        _ => None,
    };
    let row_c = db::proposals::add_comment(
        &app.db,
        p.id,
        Some(me.id),
        &me.username,
        body.body.trim(),
        anchor.as_ref().map(|(path, _)| path.as_str()).unwrap_or(""),
        anchor.as_ref().map(|(_, (h, i))| (h.as_str(), *i as i64)),
    )
    .await?;
    crate::notify::deliver(
        &app,
        crate::notify::Event {
            kind: "proposal.comment",
            title: format!("{owner}/{name}#{number}: {}", p.title),
            url: format!("/{owner}/{name}/proposal/{number}"),
            actor: &me,
            repo_id: row.id,
            thread: Some(("proposal", p.id)),
            mention_text: &body.body,
            direct: p.author_id.into_iter().collect(),
        },
    )
    .await;
    crate::hooks::emit(
        &app,
        &row,
        "comment.proposal",
        &me.username,
        serde_json::json!({ "number": number, "comment": comment_of(&row_c) }),
    )
    .await;
    Ok((StatusCode::CREATED, Json(comment_of(&row_c))))
}

async fn proposal_reviews(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, number)): Path<(String, String, i64)>,
) -> Result<Json<Vec<Review>>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (repo, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let p = db::proposals::get(&app.db, row.id, number).await?.ok_or_else(|| not_found("no such proposal"))?;
    let loaded = crate::web::proposals::load(&app, &repo, p).await?;
    let v = crate::web::proposals::verdict(&app, &loaded, row.id).await?;
    Ok(Json(
        v.reviews
            .into_iter()
            .map(|r| Review {
                id: r.row.id,
                author: r.row.author,
                verdict: r.row.verdict,
                body: r.row.body,
                sealed: r.sealed,
                created_ms: r.row.created_ms,
            })
            .collect(),
    ))
}

async fn proposal_review(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, number)): Path<(String, String, i64)>,
    Json(body): Json<NewReview>,
) -> Result<(StatusCode, Json<Review>), ApiError> {
    let c = caller(&app, &headers).await?;
    let me = c.require("proposals:write").or_else(|_| c.require("repo:write"))?.clone();
    let (_, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let p = db::proposals::get(&app.db, row.id, number).await?.ok_or_else(|| not_found("no such proposal"))?;
    if !matches!(body.verdict.as_str(), "comment" | "changes" | "approve") {
        return Err(ApiError(StatusCode::BAD_REQUEST, "verdict is comment, changes or approve".into()));
    }
    if body.verdict == "approve" && Some(me.id) == p.author_id {
        return Err(forbidden("you cannot approve your own proposal"));
    }
    let r = db::proposals::add_review(&app.db, p.id, me.id, &me.username, &body.verdict, body.body.trim()).await?;
    db::proposals::add_event(&app.db, p.id, &me.username, &format!("review.{}", body.verdict), "").await.ok();
    crate::hooks::emit(&app, &row, "review", &me.username, serde_json::json!({ "number": number, "verdict": body.verdict })).await;
    Ok((
        StatusCode::CREATED,
        Json(Review { id: r.id, author: r.author, verdict: r.verdict, body: r.body, sealed: false, created_ms: r.created_ms }),
    ))
}

async fn proposal_checks(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, number)): Path<(String, String, i64)>,
) -> Result<Json<Vec<Check>>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (repo, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let p = db::proposals::get(&app.db, row.id, number).await?.ok_or_else(|| not_found("no such proposal"))?;
    let loaded = crate::web::proposals::load(&app, &repo, p).await?;
    Ok(Json(db::hooks::checks_for_state(&app.db, row.id, &loaded.state).await?.iter().map(check_of).collect()))
}

// ------------------------------------------------------------------ issues

async fn issue_of(app: &Shared, row: &db::repos::RepoRow, i: &db::issues::IssueRow) -> Result<Issue, ApiError> {
    let labels = db::issues::issue_labels(&app.db, i.id)
        .await?
        .into_iter()
        .map(|l| Label { name: l.name, colour: l.colour, description: l.description })
        .collect();
    let assignees = db::issues::assignees(&app.db, i.id).await?;
    let milestone = match i.milestone_id {
        Some(id) => db::issues::milestone(&app.db, id).await?.map(|m| m.title),
        None => None,
    };
    let comments: i64 = sqlx::query_scalar("SELECT COUNT(*) FROM issue_comments WHERE issue_id = ?").bind(i.id).fetch_one(&app.db).await?;
    Ok(Issue {
        number: i.number,
        title: i.title.clone(),
        body: i.body.clone(),
        author: i.author.clone(),
        state: i.state.clone(),
        reason: i.reason.clone(),
        labels,
        assignees,
        milestone,
        comments,
        locked: i.locked,
        pinned: i.pinned,
        created_ms: i.created_ms,
        updated_ms: i.updated_ms,
        closed_ms: i.closed_ms,
        url: format!("{}/{}/issue/{}", app.config.base_url(), row.slug(), i.number),
    })
}

#[derive(Deserialize)]
struct IssuesQuery {
    state: Option<String>,
}

async fn issues(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name)): Path<(String, String)>,
    Query(q): Query<IssuesQuery>,
) -> Result<Json<Vec<Issue>>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (_, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let state = q.state.unwrap_or_else(|| "open".into());
    let mut out = Vec::new();
    for i in db::issues::list(&app.db, row.id).await? {
        if state == "all" || i.state == state {
            out.push(issue_of(&app, &row, &i).await?);
        }
    }
    Ok(Json(out))
}

async fn create_issue(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name)): Path<(String, String)>,
    Json(body): Json<NewIssue>,
) -> Result<(StatusCode, Json<Issue>), ApiError> {
    let c = caller(&app, &headers).await?;
    let me = c.require("issues:write").or_else(|_| c.require("repo:write"))?.clone();
    let (_, row, role) = reach(&app, &c, &owner, &name, Access::Read).await?;
    if body.title.trim().is_empty() {
        return Err(ApiError(StatusCode::BAD_REQUEST, "an issue needs a title".into()));
    }
    let triage = !body.labels.is_empty() || !body.assignees.is_empty() || body.milestone.is_some();
    if triage && role < Role::Triage {
        return Err(forbidden("setting labels, assignees or a milestone needs triage access"));
    }
    // Check the names before anything is created.
    resolve_triage(&app, row.id, Some(&body.labels), Some(&body.assignees), body.milestone.as_deref()).await?;
    let i = db::issues::create(
        &app.db,
        db::issues::NewIssue {
            repo_id: row.id,
            title: body.title.trim(),
            body: body.body.trim(),
            author_id: Some(me.id),
            author: &me.username,
        },
    )
    .await?;
    db::issues::add_event(&app.db, i.id, &me.username, "opened", "").await.ok();
    if triage {
        let t = resolve_triage(&app, row.id, Some(&body.labels), Some(&body.assignees), body.milestone.as_deref()).await?;
        apply_triage(&app, &i, &me, t).await?;
    }
    let i = db::issues::get(&app.db, row.id, i.number).await?.unwrap_or(i);
    crate::web::issues::reindex(&app, row.id, &i).await;
    let api = issue_of(&app, &row, &i).await?;
    crate::notify::deliver(
        &app,
        crate::notify::Event {
            kind: "issue.opened",
            title: format!("{owner}/{name}#{}: {}", i.number, i.title),
            url: format!("/{owner}/{name}/issue/{}", i.number),
            actor: &me,
            repo_id: row.id,
            thread: Some(("issue", i.id)),
            mention_text: &body.body,
            direct: vec![],
        },
    )
    .await;
    crate::hooks::emit(&app, &row, "issue.opened", &me.username, serde_json::json!({ "issue": api })).await;
    Ok((StatusCode::CREATED, Json(api)))
}

async fn issue(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, number)): Path<(String, String, i64)>,
) -> Result<Json<Issue>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (_, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let i = db::issues::get(&app.db, row.id, number).await?.ok_or_else(|| not_found("no such issue"))?;
    Ok(Json(issue_of(&app, &row, &i).await?))
}

async fn issue_state(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, number)): Path<(String, String, i64)>,
    Json(body): Json<IssueStateChange>,
) -> Result<Json<Issue>, ApiError> {
    let c = caller(&app, &headers).await?;
    let me = c.require("issues:write").or_else(|_| c.require("repo:write"))?.clone();
    let (_, row, role) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let i = db::issues::get(&app.db, row.id, number).await?.ok_or_else(|| not_found("no such issue"))?;
    if role < Role::Triage && Some(me.id) != i.author_id {
        return Err(forbidden("only the author or triage may change the state"));
    }
    let (state, reason) = match body.state.as_str() {
        "closed" => ("closed", if body.reason == "not_planned" { "not_planned" } else { "completed" }),
        "open" => ("open", ""),
        _ => return Err(ApiError(StatusCode::BAD_REQUEST, "state is open or closed".into())),
    };
    db::issues::set_state(&app.db, i.id, state, reason).await?;
    db::issues::add_event(&app.db, i.id, &me.username, if state == "closed" { "closed" } else { "reopened" }, "").await.ok();
    let fresh = db::issues::get(&app.db, row.id, number).await?.unwrap_or(i);
    let api = issue_of(&app, &row, &fresh).await?;
    crate::hooks::emit(
        &app,
        &row,
        if state == "closed" { "issue.closed" } else { "issue.reopened" },
        &me.username,
        serde_json::json!({ "issue": api }),
    )
    .await;
    Ok(Json(api))
}

async fn issue_comments(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, number)): Path<(String, String, i64)>,
) -> Result<Json<Vec<Comment>>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (_, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let i = db::issues::get(&app.db, row.id, number).await?.ok_or_else(|| not_found("no such issue"))?;
    Ok(Json(
        db::issues::comments(&app.db, i.id)
            .await?
            .into_iter()
            .map(|c| Comment {
                id: c.id,
                author: c.author,
                body: c.body,
                created_ms: c.created_ms,
                path: None,
                anchor: None,
                resolved: false,
            })
            .collect(),
    ))
}

async fn issue_comment(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, number)): Path<(String, String, i64)>,
    Json(body): Json<NewComment>,
) -> Result<(StatusCode, Json<Comment>), ApiError> {
    let c = caller(&app, &headers).await?;
    let me = c.require("issues:write").or_else(|_| c.require("repo:write"))?.clone();
    let (_, row, role) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let i = db::issues::get(&app.db, row.id, number).await?.ok_or_else(|| not_found("no such issue"))?;
    if i.locked && role < Role::Triage {
        return Err(forbidden("this issue is locked"));
    }
    if body.body.trim().is_empty() {
        return Err(ApiError(StatusCode::BAD_REQUEST, "an empty comment says nothing".into()));
    }
    let cm = db::issues::add_comment(&app.db, i.id, Some(me.id), &me.username, body.body.trim()).await?;
    crate::web::issues::reindex(&app, row.id, &i).await;
    crate::notify::deliver(
        &app,
        crate::notify::Event {
            kind: "issue.comment",
            title: format!("{owner}/{name}#{number}: {}", i.title),
            url: format!("/{owner}/{name}/issue/{number}"),
            actor: &me,
            repo_id: row.id,
            thread: Some(("issue", i.id)),
            mention_text: &body.body,
            direct: i.author_id.into_iter().collect(),
        },
    )
    .await;
    let api = Comment { id: cm.id, author: cm.author, body: cm.body, created_ms: cm.created_ms, path: None, anchor: None, resolved: false };
    crate::hooks::emit(&app, &row, "comment.issue", &me.username, serde_json::json!({ "number": number, "comment": api })).await;
    Ok((StatusCode::CREATED, Json(api)))
}

/// Labels, assignees and milestone named in a request, looked up.
struct Triage {
    labels: Option<Vec<db::issues::Label>>,
    assignees: Option<Vec<Account>>,
    /// `Some(None)` clears the milestone.
    milestone: Option<Option<db::issues::Milestone>>,
}

async fn resolve_triage(
    app: &Shared,
    repo_id: i64,
    labels: Option<&[String]>,
    assignees: Option<&[String]>,
    milestone: Option<&str>,
) -> Result<Triage, ApiError> {
    let bad = |m: String| ApiError(StatusCode::BAD_REQUEST, m);
    let labels = match labels {
        Some(names) => {
            let mut out = Vec::new();
            for n in names {
                out.push(
                    db::issues::label_by_name(&app.db, repo_id, n.trim())
                        .await?
                        .ok_or_else(|| bad(format!("no label {n:?}; create it first")))?,
                );
            }
            Some(out)
        }
        None => None,
    };
    let assignees = match assignees {
        Some(names) => {
            let mut out = Vec::new();
            for n in names {
                out.push(db::accounts::account_by_name(&app.db, n.trim()).await?.ok_or_else(|| bad(format!("no account {n:?}")))?);
            }
            Some(out)
        }
        None => None,
    };
    let milestone = match milestone.map(str::trim) {
        None => None,
        Some("") => Some(None),
        Some(title) => Some(Some(
            db::issues::milestones(&app.db, repo_id)
                .await?
                .into_iter()
                .find(|m| m.title == title)
                .ok_or_else(|| bad(format!("no milestone {title:?}")))?,
        )),
    };
    Ok(Triage { labels, assignees, milestone })
}

/// Make an issue's labels, assignees and milestone what `t` says, with
/// timeline events for what changed.
async fn apply_triage(app: &Shared, i: &db::issues::IssueRow, me: &Account, t: Triage) -> Result<(), ApiError> {
    if let Some(want) = t.labels {
        let have = db::issues::issue_labels(&app.db, i.id).await?;
        for l in &have {
            if !want.iter().any(|w| w.id == l.id) {
                db::issues::set_issue_label(&app.db, i.id, l.id, false).await?;
            }
        }
        for w in &want {
            if !have.iter().any(|l| l.id == w.id) {
                db::issues::set_issue_label(&app.db, i.id, w.id, true).await?;
            }
        }
        let names: Vec<&str> = want.iter().map(|l| l.name.as_str()).collect();
        db::issues::add_event(&app.db, i.id, &me.username, "set labels", &names.join(", ")).await.ok();
    }
    if let Some(want) = t.assignees {
        let have = db::issues::assignees(&app.db, i.id).await?;
        for name in &have {
            if !want.iter().any(|a| &a.username == name) {
                if let Some(a) = db::accounts::account_by_name(&app.db, name).await? {
                    db::issues::set_assignee(&app.db, i.id, a.id, false).await?;
                    db::issues::add_event(&app.db, i.id, &me.username, "unassigned", name).await.ok();
                }
            }
        }
        for a in &want {
            if !have.contains(&a.username) {
                db::issues::set_assignee(&app.db, i.id, a.id, true).await?;
                db::issues::add_event(&app.db, i.id, &me.username, "assigned", &a.username).await.ok();
            }
        }
    }
    if let Some(m) = t.milestone {
        db::issues::set_milestone(&app.db, i.id, m.as_ref().map(|m| m.id)).await?;
        db::issues::add_event(&app.db, i.id, &me.username, "set milestone", m.as_ref().map(|m| m.title.as_str()).unwrap_or("")).await.ok();
    }
    Ok(())
}

/// `PATCH /repos/{o}/{n}/issues/{number}`.
async fn issue_edit(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, number)): Path<(String, String, i64)>,
    Json(body): Json<IssueEdit>,
) -> Result<Json<Issue>, ApiError> {
    let c = caller(&app, &headers).await?;
    let me = c.require("issues:write").or_else(|_| c.require("repo:write"))?.clone();
    let (_, row, role) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let i = db::issues::get(&app.db, row.id, number).await?.ok_or_else(|| not_found("no such issue"))?;
    let text = body.title.is_some() || body.body.is_some();
    let triage = body.labels.is_some() || body.assignees.is_some() || body.milestone.is_some();
    if text && role < Role::Triage && Some(me.id) != i.author_id {
        return Err(forbidden("only the author or triage may edit the title and body"));
    }
    if triage && role < Role::Triage {
        return Err(forbidden("setting labels, assignees or a milestone needs triage access"));
    }
    if i.locked && role < Role::Triage {
        return Err(forbidden("this issue is locked"));
    }
    let t = resolve_triage(&app, row.id, body.labels.as_deref(), body.assignees.as_deref(), body.milestone.as_deref()).await?;
    if text {
        let title = body.title.as_deref().map(str::trim).unwrap_or(&i.title);
        if title.is_empty() {
            return Err(ApiError(StatusCode::BAD_REQUEST, "an issue needs a title".into()));
        }
        db::issues::edit(&app.db, i.id, title, body.body.as_deref().unwrap_or(&i.body)).await?;
        db::issues::add_event(&app.db, i.id, &me.username, "edited", "").await.ok();
    }
    apply_triage(&app, &i, &me, t).await?;
    db::issues::touch(&app.db, i.id).await.ok();
    let fresh = db::issues::get(&app.db, row.id, number).await?.unwrap_or(i);
    crate::web::issues::reindex(&app, row.id, &fresh).await;
    let api = issue_of(&app, &row, &fresh).await?;
    crate::hooks::emit(&app, &row, "issue.edited", &me.username, serde_json::json!({ "issue": api })).await;
    Ok(Json(api))
}

/// `POST /repos/{o}/{n}/labels` (triage).
async fn create_label(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name)): Path<(String, String)>,
    Json(body): Json<NewLabel>,
) -> Result<(StatusCode, Json<Label>), ApiError> {
    let c = caller(&app, &headers).await?;
    c.require("issues:write").or_else(|_| c.require("repo:write"))?;
    let (_, row, role) = reach(&app, &c, &owner, &name, Access::Read).await?;
    if role < Role::Triage {
        return Err(forbidden("labels need triage access"));
    }
    let label = body.name.trim();
    if label.is_empty() || label.len() > 50 {
        return Err(ApiError(StatusCode::BAD_REQUEST, "a label has a name of 1 to 50 characters".into()));
    }
    let colour = match body.colour.as_deref() {
        Some(c) if c.len() == 7 && c.starts_with('#') && c[1..].chars().all(|x| x.is_ascii_hexdigit()) => c.to_string(),
        Some(c) => return Err(ApiError(StatusCode::BAD_REQUEST, format!("colour {c:?} is not #rrggbb"))),
        None => "#5aa8ff".to_string(),
    };
    let l = db::issues::upsert_label(&app.db, row.id, label, &colour, body.description.trim()).await?;
    Ok((StatusCode::CREATED, Json(Label { name: l.name, colour: l.colour, description: l.description })))
}

/// `DELETE /repos/{o}/{n}/labels/{label}` (triage).
async fn delete_label(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, label)): Path<(String, String, String)>,
) -> Result<StatusCode, ApiError> {
    let c = caller(&app, &headers).await?;
    c.require("issues:write").or_else(|_| c.require("repo:write"))?;
    let (_, row, role) = reach(&app, &c, &owner, &name, Access::Read).await?;
    if role < Role::Triage {
        return Err(forbidden("labels need triage access"));
    }
    let l = db::issues::label_by_name(&app.db, row.id, &label).await?.ok_or_else(|| not_found("no such label"))?;
    db::issues::delete_label(&app.db, l.id).await?;
    Ok(StatusCode::NO_CONTENT)
}

async fn labels(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name)): Path<(String, String)>,
) -> Result<Json<Vec<Label>>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (_, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    Ok(Json(
        db::issues::labels(&app.db, row.id)
            .await?
            .into_iter()
            .map(|l| Label { name: l.name, colour: l.colour, description: l.description })
            .collect(),
    ))
}

async fn milestones(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name)): Path<(String, String)>,
) -> Result<Json<Vec<Milestone>>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (_, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let mut out = Vec::new();
    for m in db::issues::milestones(&app.db, row.id).await? {
        let (open, closed) = db::issues::milestone_counts(&app.db, m.id).await?;
        out.push(Milestone { title: m.title, description: m.description, due_ms: m.due_ms, state: m.state, open, closed });
    }
    Ok(Json(out))
}

// --------------------------------------------------------- hooks, checks

fn hook_of(h: &db::hooks::Hook) -> Hook {
    Hook { id: h.id, url: h.url.clone(), events: h.events.clone(), active: h.active, created_ms: h.created_ms }
}

async fn hooks(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name)): Path<(String, String)>,
) -> Result<Json<Vec<Hook>>, ApiError> {
    let c = caller(&app, &headers).await?;
    c.require("hooks:admin").or_else(|_| c.require("repo:admin"))?;
    let (_, row, _) = reach(&app, &c, &owner, &name, Access::Admin).await?;
    Ok(Json(db::hooks::hooks_for_repo(&app.db, row.id).await?.iter().map(hook_of).collect()))
}

async fn create_hook(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name)): Path<(String, String)>,
    Json(body): Json<NewHook>,
) -> Result<(StatusCode, Json<Hook>), ApiError> {
    let c = caller(&app, &headers).await?;
    let me = c.require("hooks:admin").or_else(|_| c.require("repo:admin"))?.clone();
    let (_, row, _) = reach(&app, &c, &owner, &name, Access::Admin).await?;
    if !(body.url.starts_with("http://") || body.url.starts_with("https://")) {
        return Err(ApiError(StatusCode::BAD_REQUEST, "the URL must be http or https".into()));
    }
    let h = db::hooks::create_hook(&app.db, Some(row.id), None, &body.url, &body.secret, &body.events).await?;
    db::accounts::audit(&app.db, Some(&me), "hook.created", &row.slug(), &body.url).await.ok();
    Ok((StatusCode::CREATED, Json(hook_of(&h))))
}

async fn delete_hook(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, id)): Path<(String, String, i64)>,
) -> Result<StatusCode, ApiError> {
    let c = caller(&app, &headers).await?;
    c.require("hooks:admin").or_else(|_| c.require("repo:admin"))?;
    let (_, row, _) = reach(&app, &c, &owner, &name, Access::Admin).await?;
    if db::hooks::hook(&app.db, id).await?.is_some_and(|h| h.repo_id == Some(row.id)) {
        db::hooks::delete_hook(&app.db, id).await?;
    }
    Ok(StatusCode::NO_CONTENT)
}

pub fn check_of(c: &db::hooks::Check) -> Check {
    Check {
        state: c.state.clone(),
        name: c.name.clone(),
        status: CheckStatus::parse(&c.status).unwrap_or(CheckStatus::Queued),
        summary: c.summary.clone(),
        url: c.url.clone(),
        reporter: c.reporter.clone(),
        seal: if c.seal.is_empty() { None } else { Some(c.seal.clone()) },
        started_ms: c.started_ms,
        finished_ms: c.finished_ms,
    }
}

/// `GET /repos/{o}/{n}/checks/required`.
async fn required_checks(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name)): Path<(String, String)>,
) -> Result<Json<RequiredChecks>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (_, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    Ok(Json(RequiredChecks { names: db::hooks::required_checks(&app.db, row.id).await? }))
}

/// `PUT /repos/{o}/{n}/checks/required` (repository admin): the whole list.
async fn set_required_checks(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name)): Path<(String, String)>,
    Json(body): Json<RequiredChecks>,
) -> Result<Json<RequiredChecks>, ApiError> {
    let c = caller(&app, &headers).await?;
    c.require("repo:admin")?;
    let (_, row, _) = reach(&app, &c, &owner, &name, Access::Admin).await?;
    let mut names: Vec<String> = body.names.iter().map(|n| n.trim().to_string()).filter(|n| !n.is_empty()).collect();
    names.sort();
    names.dedup();
    if names.len() > 32 || names.iter().any(|n| n.len() > 100 || n.contains(',')) {
        return Err(ApiError(StatusCode::BAD_REQUEST, "at most 32 check names, each under 100 characters and without commas".into()));
    }
    db::hooks::set_required_checks(&app.db, row.id, &names).await?;
    db::accounts::audit(&app.db, c.account.as_ref(), "repo.required_checks", &format!("{owner}/{name}"), &names.join(", ")).await.ok();
    Ok(Json(RequiredChecks { names }))
}

fn flow_run_of(app: &Shared, row: &db::repos::RepoRow, r: &db::flow::Run, jobs: Vec<db::flow::Job>) -> FlowRun {
    FlowRun {
        number: r.number,
        bookmark: r.bookmark.clone(),
        state: r.state.clone(),
        heads: r.head_list().into_iter().map(String::from).collect(),
        status: r.status.clone(),
        trigger: r.trigger.clone(),
        actor: r.actor.clone(),
        pipeline_hash: r.pipeline_hash.clone(),
        error: r.error.clone(),
        created_ms: r.created_ms,
        finished_ms: r.finished_ms,
        url: format!("{}/{}/{}/flow/{}", app.config.base_url(), row.owner, row.name, r.number),
        jobs: jobs
            .into_iter()
            .map(|j| FlowJob {
                depends_on: j.depends_on(),
                name: j.name,
                status: j.status,
                runner: j.runner,
                exit_code: j.exit_code,
                error: j.error,
                started_ms: j.started_ms,
                finished_ms: j.finished_ms,
                log_lines: j.log_count,
            })
            .collect(),
    }
}

#[derive(Deserialize)]
struct RunsPage {
    /// Runs numbered below this one (the next page).
    before: Option<i64>,
    limit: Option<i64>,
}

/// `GET /repos/{o}/{n}/flow/runs`: newest first, `?before=N&limit=` (max 100).
async fn flow_runs(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name)): Path<(String, String)>,
    Query(q): Query<RunsPage>,
) -> Result<Json<Vec<FlowRun>>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (_, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let limit = q.limit.unwrap_or(30).clamp(1, 100);
    let runs = db::flow::runs_by_number(&app.db, row.id, limit, q.before).await?;
    Ok(Json(runs.iter().map(|r| flow_run_of(&app, &row, r, vec![])).collect()))
}

/// `GET /repos/{o}/{n}/flow/runs/{number}`: a run with its jobs.
async fn flow_run(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, number)): Path<(String, String, i64)>,
) -> Result<Json<FlowRun>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (_, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let run = db::flow::run(&app.db, row.id, number).await?.ok_or_else(|| ApiError(StatusCode::NOT_FOUND, "no such run".into()))?;
    let jobs = db::flow::jobs(&app.db, run.id).await?;
    Ok(Json(flow_run_of(&app, &row, &run, jobs)))
}

#[derive(Deserialize)]
struct LogPage {
    /// Lines after this `seq`.
    #[serde(default)]
    after: i64,
    limit: Option<i64>,
}

/// `GET /repos/{o}/{n}/flow/runs/{number}/jobs/{job}/log`: `?after=seq&limit=` (max 5000).
async fn flow_job_log(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, number, job)): Path<(String, String, i64, String)>,
    Query(q): Query<LogPage>,
) -> Result<Json<Vec<FlowLogLine>>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (_, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let run = db::flow::run(&app.db, row.id, number).await?.ok_or_else(|| ApiError(StatusCode::NOT_FOUND, "no such run".into()))?;
    let j = db::flow::jobs(&app.db, run.id)
        .await?
        .into_iter()
        .find(|j| j.name == job)
        .ok_or_else(|| ApiError(StatusCode::NOT_FOUND, "no such job".into()))?;
    let lines = db::flow::log(&app.db, j.id, q.after, q.limit.unwrap_or(1000).clamp(1, 5000)).await?;
    Ok(Json(lines.into_iter().map(|l| FlowLogLine { seq: l.seq, t: l.t, stream: l.stream, text: l.text }).collect()))
}

#[derive(Deserialize)]
struct StartRun {
    /// Default: the repository's default bookmark.
    #[serde(default)]
    bookmark: Option<String>,
}

fn started(app: &Shared, row: &db::repos::RepoRow, number: i64) -> (StatusCode, Json<serde_json::Value>) {
    let url = format!("{}/{}/{}/flow/{number}", app.config.base_url(), row.owner, row.name);
    (StatusCode::CREATED, Json(serde_json::json!({ "number": number, "url": url })))
}

/// `POST /repos/{o}/{n}/flow/runs` (repo:write): run a bookmark's current
/// state without moving it (hub spec §13.2).
async fn start_flow_run(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name)): Path<(String, String)>,
    Json(body): Json<StartRun>,
) -> Result<(StatusCode, Json<serde_json::Value>), ApiError> {
    let c = caller(&app, &headers).await?;
    let me = c.require("repo:write")?.clone();
    let (_, row, _) = reach(&app, &c, &owner, &name, Access::Write).await?;
    let bookmark = body.bookmark.unwrap_or_else(|| row.default_bookmark.clone());
    let n = crate::flow::run_bookmark(&app, &row, &bookmark, &me.username).await.map_err(|m| ApiError(StatusCode::CONFLICT, m))?;
    db::accounts::audit(&app.db, Some(&me), "flow.run", &format!("{owner}/{name}"), &format!("#{n} {bookmark}")).await.ok();
    Ok(started(&app, &row, n))
}

/// `POST /repos/{o}/{n}/flow/runs/{number}/rerun` (repo:write).
async fn rerun_flow_run(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, number)): Path<(String, String, i64)>,
) -> Result<(StatusCode, Json<serde_json::Value>), ApiError> {
    let c = caller(&app, &headers).await?;
    let me = c.require("repo:write")?.clone();
    let (_, row, _) = reach(&app, &c, &owner, &name, Access::Write).await?;
    let run = db::flow::run(&app.db, row.id, number).await?.ok_or_else(|| ApiError(StatusCode::NOT_FOUND, "no such run".into()))?;
    let n = crate::flow::rerun(&app, &row, &run, &me.username).await.map_err(|m| ApiError(StatusCode::CONFLICT, m))?;
    db::accounts::audit(&app.db, Some(&me), "flow.rerun", &format!("{owner}/{name}"), &format!("#{n} of #{number}")).await.ok();
    Ok(started(&app, &row, n))
}

/// `POST /repos/{o}/{n}/checks`: any `checks:write` (or write) token may
/// report; the state hash names what was checked.
async fn post_check(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name)): Path<(String, String)>,
    Json(body): Json<NewCheck>,
) -> Result<(StatusCode, Json<Check>), ApiError> {
    let c = caller(&app, &headers).await?;
    let me = c.require("checks:write").or_else(|_| c.require("repo:write"))?.clone();
    let (_, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    if body.state.len() != 64 || !body.state.chars().all(|ch| ch.is_ascii_hexdigit()) {
        return Err(ApiError(StatusCode::BAD_REQUEST, "state is a 64-character hex state hash".into()));
    }
    if body.name.trim().is_empty() || body.name.len() > 100 {
        return Err(ApiError(StatusCode::BAD_REQUEST, "a check has a short name".into()));
    }
    let ch = db::hooks::upsert_check(
        &app.db,
        row.id,
        &body.state,
        body.name.trim(),
        body.status.as_str(),
        &body.summary,
        &body.url,
        Some((me.id, &me.username)),
        body.seal.as_deref().unwrap_or(""),
    )
    .await?;
    let api = check_of(&ch);
    app.events.proposal(row.id, ProposalEvent { number: 0, kind: "check".into(), check: Some(api.clone()) });
    crate::hooks::emit(&app, &row, "check", &me.username, serde_json::json!({ "check": api })).await;
    Ok((StatusCode::CREATED, Json(api)))
}

async fn checks_for_state(
    State(app): State<Shared>,
    headers: HeaderMap,
    Path((owner, name, state)): Path<(String, String, String)>,
) -> Result<Json<Vec<Check>>, ApiError> {
    let c = caller(&app, &headers).await?;
    let (repo, row, _) = reach(&app, &c, &owner, &name, Access::Read).await?;
    let state = state_key(&app, &repo, &state).await?;
    Ok(Json(db::hooks::checks_for_state(&app.db, row.id, &state).await?.iter().map(check_of).collect()))
}

/// The state hash checks are keyed by, from what a client has: a state
/// hash, its heads (full change hashes joined with `+`, or the one head of
/// a single-head state, which is what `oxy log` shows), or a bookmark.
async fn state_key(app: &Shared, repo: &RepoName, s: &str) -> Result<String, ApiError> {
    use oxy_core::hash::{hash_object, ChangeHash, ObjectType};
    let hexes: Vec<&str> = s.split('+').collect();
    let all_hashes = hexes.iter().all(|h| h.len() == 64 && h.bytes().all(|b| b.is_ascii_hexdigit()));
    if all_hashes {
        let row = db::repos::get(&app.db, &repo.owner, &repo.name).await?.ok_or_else(|| not_found("no such repository"))?;
        if hexes.len() == 1 && !db::hooks::checks_for_state(&app.db, row.id, s).await?.is_empty() {
            return Ok(s.to_string());
        }
        let heads: Vec<ChangeHash> = hexes.iter().filter_map(|h| ChangeHash::from_hex(h)).collect();
        return Ok(hash_object(ObjectType::State, &oxy_core::objects::StateObject::new(heads).encode()).to_hex());
    }
    let b = s.to_string();
    let found = app.repos.read(repo, move |r, _| Ok(r.view()?.bookmarks.get(&b).copied())).await?;
    found.map(|st| st.to_hex()).ok_or_else(|| ApiError(StatusCode::NOT_FOUND, format!("{s:?} is not a state hash, heads or a bookmark")))
}