//! Creating repositories and their settings pages (hub spec §6.3).

use super::settings::{csrf, require};
use super::{filters, lookup_role, Error, Page, RepoShell, Shell};
use crate::auth::{roles, Access, Role, Viewer};
use crate::db::{self, accounts};
use crate::repos::RepoName;
use crate::Shared;
use askama::Template;
use axum::extract::{Form, Path, State};
use axum::response::{IntoResponse, Redirect, Response};
use hub_api::Visibility;
use serde::Deserialize;

#[derive(Template)]
#[template(path = "repo_new.html")]
pub struct NewRepoPage {
    shell: Shell,
    owners: Vec<String>,
    error: Option<String>,
}

pub(crate) async fn owners_for(app: &Shared, me: &accounts::Account) -> Vec<String> {
    let mut owners = vec![me.username.clone()];
    if let Ok(orgs) = accounts::orgs_of(&app.db, me.id).await {
        owners.extend(orgs.into_iter().map(|(o, _)| o.name));
    }
    owners
}

pub async fn new_form(State(app): State<Shared>, viewer: Viewer) -> Result<Page<NewRepoPage>, Error> {
    let shell = Shell::new(&app, "/new", &viewer);
    let me = require(&viewer, &shell)?;
    let owners = owners_for(&app, &me.account).await;
    Ok(Page(NewRepoPage { shell, owners, error: None }))
}

#[derive(Deserialize)]
pub struct NewRepoForm {
    #[serde(rename = "_csrf")]
    csrf_token: String,
    owner: String,
    name: String,
    #[serde(default)]
    description: String,
    #[serde(default = "default_visibility")]
    visibility: String,
}

fn default_visibility() -> String {
    "public".into()
}

pub async fn create(State(app): State<Shared>, viewer: Viewer, Form(f): Form<NewRepoForm>) -> Result<Response, Error> {
    let shell = Shell::new(&app, "/new", &viewer);
    let me = require(&viewer, &shell)?;
    csrf(&viewer, &f.csrf_token, &shell)?;
    let owners = owners_for(&app, &me.account).await;
    let fail = |msg: &str| Page(NewRepoPage { shell: shell.clone(), owners: owners.clone(), error: Some(msg.into()) }).into_response();
    let Some(name) = RepoName::new(f.owner.trim(), f.name.trim()) else {
        return Ok(fail("A repository name is letters, digits, dots, dashes and underscores."));
    };
    if !roles::may_create_under(&app.db, &me.account, &name.owner).await.map_err(|e| Error::from_db(shell.clone(), e))? {
        return Ok(fail("You cannot create repositories under that owner."));
    }
    let Some(visibility) = Visibility::parse(&f.visibility) else { return Ok(fail("Visibility is public, internal or private.")) };
    if db::repos::get(&app.db, &name.owner, &name.name).await.map_err(|e| Error::from_db(shell.clone(), e))?.is_some()
        || app.repos.exists(&name)
    {
        return Ok(fail("That repository exists."));
    }
    app.repos.create(&name, None).map_err(|e| Error::from_repo(shell.clone(), e))?;
    db::repos::create(&app.db, &name.owner, &name.name, f.description.trim(), visibility)
        .await
        .map_err(|e| Error::from_db(shell.clone(), e))?;
    accounts::audit(&app.db, Some(&me.account), "repo.created", &name.to_string(), visibility.as_str()).await.ok();
    Ok(Redirect::to(&name.url()).into_response())
}

#[derive(Template)]
#[template(path = "repo_settings.html")]
pub struct RepoSettingsPage {
    shell: Shell,
    repo: RepoShell,
    row: db::repos::RepoRow,
    collaborators: Vec<accounts::Collaborator>,
    teams: Vec<accounts::Team>,
    role: Role,
    requirements: db::proposals::Requirements,
    hooks: Vec<super::webhooks::HookRow>,
    required_checks: String,
    /// Whether hub.toml alone would run Flow here, and whether it runs.
    flow_default: bool,
    flow_enabled: bool,
    site_admin: bool,
    notice: Option<String>,
    error: Option<String>,
    /// Runners that may take this repository's jobs: (runner, what it
    /// serves, whether it is this repository's own).
    runners: Vec<(db::runners::Runner, String, bool)>,
    /// A registration token just made, shown once.
    runner_token: Option<String>,
}

async fn settings_page(
    app: &Shared,
    shell: Shell,
    row: db::repos::RepoRow,
    role: Role,
    notice: Option<String>,
    error: Option<String>,
) -> Result<Page<RepoSettingsPage>, Error> {
    let collaborators = accounts::collaborators(&app.db, row.id).await.map_err(|e| Error::from_db(shell.clone(), e))?;
    let teams = match accounts::org_by_name(&app.db, &row.owner).await.map_err(|e| Error::from_db(shell.clone(), e))? {
        Some(org) => accounts::teams(&app.db, org.id).await.map_err(|e| Error::from_db(shell.clone(), e))?,
        None => vec![],
    };
    let repo = RepoShell::new(app, &row, "settings").with_role(role);
    let requirements = db::proposals::requirements(&app.db, row.id).await.map_err(|e| Error::from_db(shell.clone(), e))?;
    let hooks = db::hooks::hooks_for_repo(&app.db, row.id).await.map_err(|e| Error::from_db(shell.clone(), e))?;
    let hooks = super::webhooks::rows(app, hooks).await.map_err(|e| Error::from_db(shell.clone(), e))?;
    let required_checks = db::hooks::required_checks(&app.db, row.id).await.map_err(|e| Error::from_db(shell.clone(), e))?.join(", ");
    let flow_default = app.config.flow.allows(&row.owner, &row.name);
    let flow_enabled = crate::flow::enabled(app, &row);
    let site_admin = shell.is_admin;
    let runners = db::runners::serving(&app.db, &row.owner, row.id)
        .await
        .map_err(|e| Error::from_db(shell.clone(), e))?
        .into_iter()
        .map(|r| {
            let own = r.scope_repo_id == Some(row.id);
            let serves = if own {
                "this repository".to_string()
            } else if r.scope_owner.is_empty() {
                "the whole site".to_string()
            } else {
                format!("{}'s repositories", r.scope_owner)
            };
            (r, serves, own)
        })
        .collect();
    Ok(Page(RepoSettingsPage {
        runners,
        runner_token: None,
        shell,
        repo,
        row,
        collaborators,
        teams,
        role,
        requirements,
        hooks,
        required_checks,
        flow_default,
        flow_enabled,
        site_admin,
        notice,
        error,
    }))
}

pub async fn settings(
    State(app): State<Shared>,
    viewer: Viewer,
    Path((owner, name)): Path<(String, String)>,
) -> Result<Page<RepoSettingsPage>, Error> {
    let shell = Shell::new(&app, &format!("/{owner}/{name}/settings"), &viewer);
    let (_, row, role) = lookup_role(&app, &shell, &viewer, &owner, &name, Access::Maintain).await?;
    settings_page(&app, shell, row, role, None, None).await
}

#[derive(Deserialize)]
pub struct GeneralForm {
    #[serde(rename = "_csrf")]
    csrf_token: String,
    description: String,
    default_bookmark: String,
    visibility: String,
    #[serde(default)]
    topics: String,
}

pub async fn update(
    State(app): State<Shared>,
    viewer: Viewer,
    Path((owner, name)): Path<(String, String)>,
    Form(f): Form<GeneralForm>,
) -> Result<Page<RepoSettingsPage>, Error> {
    let shell = Shell::new(&app, &format!("/{owner}/{name}/settings"), &viewer);
    let (_, row, role) = lookup_role(&app, &shell, &viewer, &owner, &name, Access::Maintain).await?;
    csrf(&viewer, &f.csrf_token, &shell)?;
    let e = |e| Error::from_db(shell.clone(), e);
    let topics = match db::repos::parse_topics(&f.topics) {
        Ok(t) => t,
        Err(msg) => return settings_page(&app, shell, row, role, None, Some(msg)).await,
    };
    db::repos::set_description(&app.db, row.id, f.description.trim()).await.map_err(e)?;
    db::repos::set_topics(&app.db, row.id, &topics).await.map_err(e)?;
    if crate::repos::names::valid_segment(f.default_bookmark.trim()) {
        db::repos::set_default_bookmark(&app.db, row.id, f.default_bookmark.trim()).await.map_err(e)?;
    }
    if role >= Role::Admin {
        if let Some(v) = Visibility::parse(&f.visibility) {
            db::repos::set_visibility(&app.db, row.id, v).await.map_err(e)?;
        }
    }
    accounts::audit(&app.db, viewer.account(), "repo.updated", &format!("{owner}/{name}"), "").await.ok();
    let row = db::repos::get_by_id(&app.db, row.id).await.map_err(e)?.unwrap_or(row);
    settings_page(&app, shell, row, role, Some("Saved.".into()), None).await
}

#[derive(Deserialize)]
pub struct CollaboratorForm {
    #[serde(rename = "_csrf")]
    csrf_token: String,
    #[serde(default)]
    username: String,
    #[serde(default)]
    team: String,
    #[serde(default)]
    role: String,
    #[serde(default)]
    remove: Option<String>,
}

pub async fn collaborator(
    State(app): State<Shared>,
    viewer: Viewer,
    Path((owner, name)): Path<(String, String)>,
    Form(f): Form<CollaboratorForm>,
) -> Result<Page<RepoSettingsPage>, Error> {
    let shell = Shell::new(&app, &format!("/{owner}/{name}/settings"), &viewer);
    let (_, row, role) = lookup_role(&app, &shell, &viewer, &owner, &name, Access::Admin).await?;
    csrf(&viewer, &f.csrf_token, &shell)?;
    let e = |e| Error::from_db(shell.clone(), e);
    let (account_id, team_id, label) = if !f.username.trim().is_empty() {
        match accounts::account_by_name(&app.db, f.username.trim()).await.map_err(e)? {
            Some(a) => (Some(a.id), None, a.username),
            None => return settings_page(&app, shell, row, role, None, Some("No such account.".into())).await,
        }
    } else if !f.team.trim().is_empty() {
        let org = accounts::org_by_name(&app.db, &row.owner).await.map_err(e)?;
        let team = match org {
            Some(o) => accounts::team_by_name(&app.db, o.id, f.team.trim()).await.map_err(e)?,
            None => None,
        };
        match team {
            Some(t) => (None, Some(t.id), format!("team {}", t.name)),
            None => return settings_page(&app, shell, row, role, None, Some("No such team in this organisation.".into())).await,
        }
    } else {
        return settings_page(&app, shell, row, role, None, Some("Name an account or a team.".into())).await;
    };
    if f.remove.is_some() {
        accounts::remove_collaborator(&app.db, row.id, account_id, team_id).await.map_err(e)?;
        accounts::audit(&app.db, viewer.account(), "repo.collaborator.removed", &format!("{owner}/{name}"), &label).await.ok();
        return settings_page(&app, shell, row, role, Some(format!("Removed {label}.")), None).await;
    }
    let Some(new_role) = Role::parse(&f.role) else {
        return settings_page(&app, shell, row, role, None, Some("Pick a role.".into())).await;
    };
    accounts::set_collaborator(&app.db, row.id, account_id, team_id, new_role.as_str()).await.map_err(e)?;
    accounts::audit(
        &app.db,
        viewer.account(),
        "repo.collaborator.set",
        &format!("{owner}/{name}"),
        &format!("{label} {}", new_role.as_str()),
    )
    .await
    .ok();
    settings_page(&app, shell, row, role, Some(format!("{label} now has {} access.", new_role.as_str())), None).await
}

#[derive(Deserialize)]
pub struct DeleteForm {
    #[serde(rename = "_csrf")]
    csrf_token: String,
    confirm: String,
}

pub async fn delete(
    State(app): State<Shared>,
    viewer: Viewer,
    Path((owner, name)): Path<(String, String)>,
    Form(f): Form<DeleteForm>,
) -> Result<Response, Error> {
    let shell = Shell::new(&app, &format!("/{owner}/{name}/settings"), &viewer);
    let (repo, row, role) = lookup_role(&app, &shell, &viewer, &owner, &name, Access::Admin).await?;
    csrf(&viewer, &f.csrf_token, &shell)?;
    if f.confirm.trim() != repo.to_string() {
        return Ok(settings_page(&app, shell, row, role, None, Some("Type the repository's full name to delete it.".into()))
            .await?
            .into_response());
    }
    let _guard = app.repos.write_guard(&repo).await;
    app.repos.trash(&repo).map_err(|e| Error::from_repo(shell.clone(), e))?;
    db::repos::delete(&app.db, row.id).await.map_err(|e| Error::from_db(shell.clone(), e))?;
    accounts::audit(&app.db, viewer.account(), "repo.deleted", &repo.to_string(), "moved to trash").await.ok();
    Ok(Redirect::to(&format!("/{owner}")).into_response())
}

#[derive(Deserialize)]
pub struct RequirementsForm {
    #[serde(rename = "_csrf")]
    csrf_token: String,
    #[serde(default)]
    required_approvals: i64,
    #[serde(default)]
    require_owners: Option<String>,
    #[serde(default)]
    allow_conflicts: Option<String>,
}

pub async fn requirements(
    State(app): State<Shared>,
    viewer: Viewer,
    Path((owner, name)): Path<(String, String)>,
    Form(f): Form<RequirementsForm>,
) -> Result<Page<RepoSettingsPage>, Error> {
    let shell = Shell::new(&app, &format!("/{owner}/{name}/settings"), &viewer);
    let (_, row, role) = lookup_role(&app, &shell, &viewer, &owner, &name, Access::Maintain).await?;
    csrf(&viewer, &f.csrf_token, &shell)?;
    let r = db::proposals::Requirements {
        required_approvals: f.required_approvals.max(0),
        require_owners: f.require_owners.is_some(),
        allow_conflicts: f.allow_conflicts.is_some(),
    };
    db::proposals::set_requirements(&app.db, row.id, r).await.map_err(|e| Error::from_db(shell.clone(), e))?;
    accounts::audit(
        &app.db,
        viewer.account(),
        "repo.requirements",
        &format!("{owner}/{name}"),
        &format!("{} approvals, owners {}, conflicts {}", r.required_approvals, r.require_owners, r.allow_conflicts),
    )
    .await
    .ok();
    settings_page(&app, shell, row, role, Some("Landing requirements saved.".into()), None).await
}

pub async fn hooks(
    State(app): State<Shared>,
    viewer: Viewer,
    Path((owner, name)): Path<(String, String)>,
    Form(f): Form<super::webhooks::HookForm>,
) -> Result<Page<RepoSettingsPage>, Error> {
    let shell = Shell::new(&app, &format!("/{owner}/{name}/settings"), &viewer);
    let (_, row, role) = lookup_role(&app, &shell, &viewer, &owner, &name, Access::Admin).await?;
    csrf(&viewer, &f.csrf_token, &shell)?;
    let scope = super::webhooks::Scope::Repo { id: row.id, slug: format!("{owner}/{name}") };
    match super::webhooks::apply(&app, &viewer, &scope, f).await.map_err(|e| Error::from_db(shell.clone(), e))? {
        Ok(notice) => settings_page(&app, shell, row, role, Some(notice), None).await,
        Err(error) => settings_page(&app, shell, row, role, None, Some(error)).await,
    }
}

pub async fn deliveries(
    State(app): State<Shared>,
    viewer: Viewer,
    Path((owner, name, id)): Path<(String, String, i64)>,
) -> Result<Page<super::webhooks::DeliveriesPage>, Error> {
    let shell = Shell::new(&app, &format!("/{owner}/{name}/settings/hooks/{id}/deliveries"), &viewer);
    let (_, row, role) = lookup_role(&app, &shell, &viewer, &owner, &name, Access::Admin).await?;
    let scope = super::webhooks::Scope::Repo { id: row.id, slug: format!("{owner}/{name}") };
    super::webhooks::deliveries_page(&app, shell, &scope, Some(RepoShell::new(&app, &row, "settings").with_role(role)), id).await
}

pub async fn redeliver(
    State(app): State<Shared>,
    viewer: Viewer,
    Path((owner, name, id, delivery)): Path<(String, String, i64, i64)>,
    Form(f): Form<super::session::CsrfForm>,
) -> Result<Page<super::webhooks::DeliveriesPage>, Error> {
    let shell = Shell::new(&app, &format!("/{owner}/{name}/settings/hooks/{id}/deliveries"), &viewer);
    let (_, row, role) = lookup_role(&app, &shell, &viewer, &owner, &name, Access::Admin).await?;
    csrf(&viewer, &f.csrf, &shell)?;
    let scope = super::webhooks::Scope::Repo { id: row.id, slug: format!("{owner}/{name}") };
    super::webhooks::redeliver(&app, &scope, id, delivery).await.map_err(|e| Error::from_db(shell.clone(), e))?;
    super::webhooks::deliveries_page(&app, shell, &scope, Some(RepoShell::new(&app, &row, "settings").with_role(role)), id).await
}

#[derive(Deserialize)]
pub struct ChecksForm {
    #[serde(rename = "_csrf")]
    csrf_token: String,
    #[serde(default)]
    required_checks: String,
}

pub async fn required_checks(
    State(app): State<Shared>,
    viewer: Viewer,
    Path((owner, name)): Path<(String, String)>,
    Form(f): Form<ChecksForm>,
) -> Result<Page<RepoSettingsPage>, Error> {
    let shell = Shell::new(&app, &format!("/{owner}/{name}/settings"), &viewer);
    let (_, row, role) = lookup_role(&app, &shell, &viewer, &owner, &name, Access::Maintain).await?;
    csrf(&viewer, &f.csrf_token, &shell)?;
    let names: Vec<String> = f.required_checks.split(',').map(str::trim).filter(|s| !s.is_empty()).map(String::from).collect();
    db::hooks::set_required_checks(&app.db, row.id, &names).await.map_err(|e| Error::from_db(shell.clone(), e))?;
    settings_page(&app, shell, row, role, Some("Required checks saved.".into()), None).await
}

#[derive(Deserialize)]
pub struct MirrorForm {
    #[serde(rename = "_csrf")]
    csrf_token: String,
    #[serde(default)]
    enabled: Option<String>,
}

#[derive(Deserialize)]
pub struct FlowForm {
    #[serde(rename = "_csrf")]
    csrf_token: String,
    /// `on`, `off`, or `default`.
    flow: String,
}

/// Turn OxygenFlow on or off for one repository. Runs use the site's
/// runners, so only site administrators decide.
pub async fn flow(
    State(app): State<Shared>,
    viewer: Viewer,
    Path((owner, name)): Path<(String, String)>,
    Form(f): Form<FlowForm>,
) -> Result<Page<RepoSettingsPage>, Error> {
    let shell = Shell::new(&app, &format!("/{owner}/{name}/settings"), &viewer);
    let (_, row, role) = lookup_role(&app, &shell, &viewer, &owner, &name, Access::Maintain).await?;
    csrf(&viewer, &f.csrf_token, &shell)?;
    if !viewer.is_admin() {
        return settings_page(&app, shell, row, role, None, Some("Only site administrators turn OxygenFlow on or off.".into())).await;
    }
    let setting = match f.flow.as_str() {
        "on" => "on",
        "off" => "off",
        "default" => "",
        _ => return settings_page(&app, shell, row, role, None, Some("Pick on, off or the site default.".into())).await,
    };
    db::repos::set_flow(&app.db, row.id, setting).await.map_err(|e| Error::from_db(shell.clone(), e))?;
    let label = if setting.is_empty() { "default" } else { setting };
    accounts::audit(&app.db, viewer.account(), "repo.flow", &format!("{owner}/{name}"), label).await.ok();
    let row = db::repos::get_by_id(&app.db, row.id).await.map_err(|e| Error::from_db(shell.clone(), e))?.unwrap_or(row);
    let notice = if crate::flow::enabled(&app, &row) {
        "OxygenFlow is on: pushes with a .flow/pipeline.kdl start runs."
    } else {
        "OxygenFlow is off for this repository."
    };
    settings_page(&app, shell, row, role, Some(notice.into()), None).await
}

pub async fn mirror(
    State(app): State<Shared>,
    viewer: Viewer,
    Path((owner, name)): Path<(String, String)>,
    Form(f): Form<MirrorForm>,
) -> Result<Page<RepoSettingsPage>, Error> {
    let shell = Shell::new(&app, &format!("/{owner}/{name}/settings"), &viewer);
    let (_, row, role) = lookup_role(&app, &shell, &viewer, &owner, &name, Access::Maintain).await?;
    csrf(&viewer, &f.csrf_token, &shell)?;
    db::repos::set_git_mirror(&app.db, row.id, f.enabled.is_some()).await.map_err(|e| Error::from_db(shell.clone(), e))?;
    let row = db::repos::get_by_id(&app.db, row.id).await.map_err(|e| Error::from_db(shell.clone(), e))?.unwrap_or(row);
    if row.git_mirror {
        crate::mirror::refresh(&app, &row).await;
    }
    accounts::audit(&app.db, viewer.account(), "repo.mirror", &format!("{owner}/{name}"), if row.git_mirror { "on" } else { "off" })
        .await
        .ok();
    let row = db::repos::get_by_id(&app.db, row.id).await.map_err(|e| Error::from_db(shell.clone(), e))?.unwrap_or(row);
    let notice = if row.git_mirror { "The Git mirror is on and up to date." } else { "The Git mirror is off." };
    settings_page(&app, shell, row, role, Some(notice.into()), None).await
}

/// `POST /{owner}/{name}/settings/runners/token`: a one-time registration
/// token for a runner that serves this repository only (oxygenhub#41).
pub async fn runner_token(
    State(app): State<Shared>,
    viewer: Viewer,
    Path((owner, name)): Path<(String, String)>,
    Form(f): Form<super::session::CsrfForm>,
) -> Result<Page<RepoSettingsPage>, Error> {
    let shell = Shell::new(&app, &format!("/{owner}/{name}/settings"), &viewer);
    let (_, row, role) = lookup_role(&app, &shell, &viewer, &owner, &name, Access::Admin).await?;
    csrf(&viewer, &f.csrf, &shell)?;
    let me = viewer.account().map(|a| a.username.clone()).unwrap_or_default();
    let token = format!("flowreg_{}", crate::auth::random_hex(24));
    let scope = db::runners::Scope { owner: row.owner.clone(), repo_id: Some(row.id) };
    db::runners::add_registration(&app.db, &blake3::hash(token.as_bytes()).to_hex(), &me, &scope)
        .await
        .map_err(|e| Error::from_db(shell.clone(), e))?;
    accounts::audit(&app.db, viewer.account(), "flow.runner.token", &row.slug(), "registration token for this repository").await.ok();
    let mut page = settings_page(&app, shell, row, role, Some("Copy the token now; it is not shown again.".into()), None).await?;
    page.0.runner_token = Some(token);
    Ok(page)
}

/// `POST /{owner}/{name}/settings/runners/{id}/remove`: remove one of this
/// repository's own runners, when it is running nothing.
pub async fn runner_remove(
    State(app): State<Shared>,
    viewer: Viewer,
    Path((owner, name, id)): Path<(String, String, i64)>,
    Form(f): Form<super::session::CsrfForm>,
) -> Result<Page<RepoSettingsPage>, Error> {
    let shell = Shell::new(&app, &format!("/{owner}/{name}/settings"), &viewer);
    let (_, row, role) = lookup_role(&app, &shell, &viewer, &owner, &name, Access::Admin).await?;
    csrf(&viewer, &f.csrf, &shell)?;
    let e = |e| Error::from_db(shell.clone(), e);
    let Some(r) = db::runners::get(&app.db, id).await.map_err(e)?.filter(|r| r.scope_repo_id == Some(row.id)) else {
        return Err(Error::not_found(shell));
    };
    if db::runners::running(&app.db).await.map_err(e)?.iter().any(|(rid, n)| *rid == id && *n > 0) {
        return settings_page(&app, shell, row, role, None, Some(format!("{} is running jobs: wait for them to finish.", r.name))).await;
    }
    db::runners::remove(&app.db, id).await.map_err(e)?;
    accounts::audit(&app.db, viewer.account(), "flow.runner.removed", &r.name, &row.slug()).await.ok();
    settings_page(&app, shell, row, role, Some(format!("{} removed: its credential no longer works.", r.name)), None).await
}