//! 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;

pub fn router() -> Router<Shared> {

    Router::new()

        .route("/user", get(me))

        .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))

        .route("/repos/{owner}/{name}/issues/{number}/comments", get(issue_comments).post(issue_comment))

        .route("/repos/{owner}/{name}/labels", get(labels))

        .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}/checks/{state}", get(checks_for_state))

}

pub struct ApiError(StatusCode, 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())

    }

}

fn not_found(what: &str) -> ApiError {

    ApiError(StatusCode::NOT_FOUND, what.into())

}

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(),

        },

        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?))

}

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)>,