//! Webhooks of a repository or an organisation (hub spec §12.2): the
//! settings form, deliveries and redelivery, shared by both scopes.

use super::{filters, Error, Page, RepoShell, Shell};
use crate::auth::Viewer;
use crate::db::{self, accounts};
use crate::Shared;
use askama::Template;
use serde::Deserialize;

/// Whose webhooks.
pub enum Scope {
    Repo { id: i64, slug: String },
    Org { id: i64, name: String },
}

impl Scope {
    fn owns(&self, h: &db::hooks::Hook) -> bool {
        match self {
            Scope::Repo { id, .. } => h.repo_id == Some(*id),
            Scope::Org { id, .. } => h.org_id == Some(*id),
        }
    }

    /// Where the settings page is.
    pub fn settings_url(&self) -> String {
        match self {
            Scope::Repo { slug, .. } => format!("/{slug}/settings"),
            Scope::Org { name, .. } => format!("/orgs/{name}/settings"),
        }
    }

    /// Where its webhooks are listed: a repository's own settings page
    /// (#278), an organisation's section.
    pub fn webhooks_url(&self) -> String {
        match self {
            Scope::Repo { slug, .. } => format!("/{slug}/settings/webhooks"),
            Scope::Org { name, .. } => format!("/orgs/{name}/settings#webhooks"),
        }
    }

    fn label(&self) -> &str {
        match self {
            Scope::Repo { slug, .. } => slug,
            Scope::Org { name, .. } => name,
        }
    }
}

#[derive(Deserialize)]
pub struct HookForm {
    #[serde(rename = "_csrf")]
    pub csrf_token: String,
    #[serde(default)]
    url: String,
    #[serde(default)]
    secret: String,
    #[serde(default = "star")]
    events: String,
    #[serde(default)]
    id: Option<i64>,
    #[serde(default)]
    action: String,
    /// `oxygenhub`, `discord` or `slack`; guessed from the URL when absent.
    #[serde(default)]
    format: String,
    /// For `update`: whether the hook stays active.
    #[serde(default)]
    active: Option<String>,
}

/// A hook as the settings table shows it: the URL masked, and how its
/// newest delivery went.
pub struct HookRow {
    pub hook: db::hooks::Hook,
    pub masked: String,
    pub last: Option<db::hooks::Delivery>,
}

impl HookRow {
    /// `✔ 204` or `✘ 400: why`, for the table.
    pub fn last_result(&self) -> Option<(bool, String)> {
        let d = self.last.as_ref()?;
        let ok = d.delivered_ms.is_some();
        let status = d.status.map(|s| s.to_string()).unwrap_or_else(|| "no answer".into());
        let why: String = d.response.chars().take(80).collect();
        Some((ok, if ok || why.is_empty() { status } else { format!("{status}: {why}") }))
    }
}

pub async fn rows(app: &Shared, hooks: Vec<db::hooks::Hook>) -> sqlx::Result<Vec<HookRow>> {
    let mut out = Vec::with_capacity(hooks.len());
    for hook in hooks {
        let last = db::hooks::last_attempt(&app.db, hook.id).await?;
        out.push(HookRow { masked: db::hooks::masked_url(&hook.url), last, hook });
    }
    Ok(out)
}

fn url_ok(url: &str) -> bool {
    (url.starts_with("http://") || url.starts_with("https://")) && url.len() <= 2000 && !url.contains(char::is_whitespace)
}

fn star() -> String {
    "*".into()
}

/// Apply the webhook form: `Ok(notice)` or `Err(message for the user)`.
pub async fn apply(app: &Shared, viewer: &Viewer, scope: &Scope, f: HookForm) -> sqlx::Result<Result<String, String>> {
    let owned = |h: Option<db::hooks::Hook>| h.filter(|h| scope.owns(h));
    Ok(Ok(match (f.action.as_str(), f.id) {
        ("delete", Some(id)) => {
            if owned(db::hooks::hook(&app.db, id).await?).is_some() {
                db::hooks::delete_hook(&app.db, id).await?;
                accounts::audit(&app.db, viewer.account(), "hook.deleted", scope.label(), "").await.ok();
            }
            "Webhook deleted.".to_string()
        }
        ("toggle", Some(id)) => {
            if let Some(h) = owned(db::hooks::hook(&app.db, id).await?) {
                db::hooks::set_hook_active(&app.db, id, !h.active).await?;
            }
            "Webhook updated.".to_string()
        }
        ("ping", Some(id)) => {
            if let Some(h) = owned(db::hooks::hook(&app.db, id).await?) {
                let delivery = crate::auth::random_hex(16);
                let env = hub_api::WebhookEnvelope {
                    event: "ping".into(),
                    delivery: delivery.clone(),
                    repository: None,
                    actor: viewer.account().map(|a| a.username.clone()).unwrap_or_default(),
                    at_ms: db::now_ms(),
                    data: serde_json::json!({ "zen": "changes commute" }),
                };
                db::hooks::queue_delivery(&app.db, h.id, &delivery, "ping", &serde_json::to_string(&env).unwrap_or_default()).await?;
                app.bus.delivery_waiting();
            }
            "Ping queued.".to_string()
        }
        ("update", Some(id)) => {
            let Some(h) = owned(db::hooks::hook(&app.db, id).await?) else { return Ok(Err("No such webhook.".into())) };
            let url = f.url.trim();
            if !url.is_empty() && !url_ok(url) {
                return Ok(Err("A webhook URL starts with http:// or https://.".into()));
            }
            let format = if db::hooks::FORMATS.contains(&f.format.as_str()) { f.format.as_str() } else { h.format.as_str() };
            let events = if f.events.trim().is_empty() { "*" } else { f.events.trim() };
            let secret = f.secret.trim();
            db::hooks::update_hook(
                &app.db,
                id,
                (!url.is_empty()).then_some(url),
                (!secret.is_empty()).then_some(secret),
                events,
                format,
                f.active.is_some(),
            )
            .await?;
            accounts::audit(
                &app.db,
                viewer.account(),
                "hook.updated",
                scope.label(),
                &db::hooks::masked_url(if url.is_empty() { &h.url } else { url }),
            )
            .await
            .ok();
            "Webhook saved.".to_string()
        }
        _ => {
            let url = f.url.trim();
            if !url_ok(url) {
                return Ok(Err("A webhook URL starts with http:// or https://.".into()));
            }
            let (repo_id, org_id) = match scope {
                Scope::Repo { id, .. } => (Some(*id), None),
                Scope::Org { id, .. } => (None, Some(*id)),
            };
            let h = db::hooks::create_hook(&app.db, repo_id, org_id, url, f.secret.trim(), f.events.trim()).await?;
            if db::hooks::FORMATS.contains(&f.format.as_str()) && f.format != h.format {
                db::hooks::set_hook_format(&app.db, h.id, &f.format).await?;
            }
            // Never the full URL in the log: it can hold a token.
            accounts::audit(&app.db, viewer.account(), "hook.created", scope.label(), &db::hooks::masked_url(url)).await.ok();
            "Webhook added.".to_string()
        }
    }))
}

#[derive(Template)]
#[template(path = "deliveries.html")]
pub struct DeliveriesPage {
    shell: Shell,
    /// The repository's tabs, for a repository's webhook.
    repo: Option<RepoShell>,
    hook: db::hooks::Hook,
    rows: Vec<db::hooks::Delivery>,
    settings_url: String,
    /// The page listing the webhooks, to go back to.
    back_url: String,
}

pub async fn deliveries_page(
    app: &Shared,
    shell: Shell,
    scope: &Scope,
    repo: Option<RepoShell>,
    id: i64,
) -> Result<Page<DeliveriesPage>, Error> {
    let hook = db::hooks::hook(&app.db, id)
        .await
        .map_err(|e| Error::from_db(shell.clone(), e))?
        .filter(|h| scope.owns(h))
        .ok_or_else(|| Error::not_found(shell.clone()))?;
    let rows = db::hooks::deliveries_for_hook(&app.db, id, 100).await.map_err(|e| Error::from_db(shell.clone(), e))?;
    Ok(Page(DeliveriesPage { shell, repo, hook, rows, settings_url: scope.settings_url(), back_url: scope.webhooks_url() }))
}

pub async fn redeliver(app: &Shared, scope: &Scope, id: i64, delivery: i64) -> sqlx::Result<()> {
    let mine = db::hooks::hook(&app.db, id).await?.is_some_and(|h| scope.owns(&h));
    if mine && db::hooks::delivery(&app.db, delivery).await?.is_some_and(|d| d.hook_id == id) {
        db::hooks::redeliver(&app.db, delivery).await?;
        app.bus.delivery_waiting();
    }
    Ok(())
}