//! OxygenFlow runners (hub spec §13.2): who may claim jobs, what they are,
//! whether they are taking work, and what they have run.

use super::{now_ms, Pool};
use sqlx::FromRow;

#[derive(Clone, Debug, FromRow)]
pub struct Runner {
    pub id: i64,
    pub name: String,
    pub token_hash: String,
    pub source: String,
    pub key: String,
    pub key_name: String,
    pub arch: String,
    pub os: String,
    pub version: String,
    pub labels: String,
    pub max_jobs: i64,
    pub memory_mib: Option<i64>,
    pub cpus: Option<i64>,
    pub state: String,
    pub created_ms: i64,
    pub created_by: String,
    pub last_seen_ms: Option<i64>,
    /// The owner whose repositories it serves; empty for the whole site.
    pub scope_owner: String,
    /// The one repository it serves, when it serves one.
    pub scope_repo_id: Option<i64>,
}

/// Which repositories' jobs a runner may take (oxygenhub#41).
#[derive(Clone, Debug, Default, PartialEq, Eq)]
pub struct Scope {
    /// Empty: any owner.
    pub owner: String,
    /// `None`: any of the owner's repositories.
    pub repo_id: Option<i64>,
}

impl Scope {
    pub fn is_site(&self) -> bool {
        self.owner.is_empty() && self.repo_id.is_none()
    }
}

/// A runner that has not polled for this long is shown offline.
pub const ONLINE_MS: i64 = 90_000;

impl Runner {
    pub fn online(&self) -> bool {
        self.last_seen_ms.is_some_and(|t| now_ms() - t < ONLINE_MS)
    }

    /// `online`, `offline`, `draining` or `disabled`.
    pub fn status(&self) -> &'static str {
        match self.state.as_str() {
            "disabled" => "disabled",
            "draining" => "draining",
            _ if self.online() => "online",
            _ => "offline",
        }
    }

    pub fn label_list(&self) -> Vec<&str> {
        self.labels.split(',').filter(|l| !l.is_empty()).collect()
    }

    pub fn scope(&self) -> Scope {
        Scope { owner: self.scope_owner.clone(), repo_id: self.scope_repo_id }
    }
}

pub async fn by_token(pool: &Pool, token_hash: &str) -> sqlx::Result<Option<Runner>> {
    sqlx::query_as("SELECT * FROM flow_runners WHERE token_hash = ?").bind(token_hash).fetch_optional(pool).await
}

pub async fn get(pool: &Pool, id: i64) -> sqlx::Result<Option<Runner>> {
    sqlx::query_as("SELECT * FROM flow_runners WHERE id = ?").bind(id).fetch_optional(pool).await
}

pub async fn list(pool: &Pool) -> sqlx::Result<Vec<Runner>> {
    sqlx::query_as("SELECT * FROM flow_runners ORDER BY name, id").fetch_all(pool).await
}

/// The row of a runner configured with a hub.toml token, made on first sight.
pub async fn configured(pool: &Pool, token_hash: &str, name: &str) -> sqlx::Result<Runner> {
    sqlx::query("INSERT OR IGNORE INTO flow_runners (name, token_hash, source, created_ms) VALUES (?, ?, 'config', ?)")
        .bind(name)
        .bind(token_hash)
        .bind(now_ms())
        .execute(pool)
        .await?;
    Ok(by_token(pool, token_hash).await?.expect("just made"))
}

/// What a claim says about the runner, and that it was seen now. A
/// configured runner takes the name it claims with.
pub async fn seen(pool: &Pool, id: i64, name: Option<&str>, info: Option<&flow_core::api::RunnerInfo>) -> sqlx::Result<()> {
    let now = now_ms();
    match info {
        Some(i) => {
            sqlx::query(
                "UPDATE flow_runners SET arch = ?, os = ?, version = ?, labels = ?, max_jobs = ?, memory_mib = ?, cpus = ?, last_seen_ms = ? WHERE id = ?",
            )
            .bind(&i.arch)
            .bind(&i.os)
            .bind(&i.version)
            .bind(i.labels.join(","))
            .bind(i.max_jobs as i64)
            .bind(i.memory_mib.map(i64::from))
            .bind(i.cpus.map(i64::from))
            .bind(now)
            .bind(id)
            .execute(pool)
            .await?;
        }
        None => {
            sqlx::query("UPDATE flow_runners SET last_seen_ms = ? WHERE id = ?").bind(now).bind(id).execute(pool).await?;
        }
    }
    if let Some(n) = name {
        sqlx::query("UPDATE flow_runners SET name = ? WHERE id = ? AND source = 'config'").bind(n).bind(id).execute(pool).await?;
    }
    Ok(())
}

pub async fn set_state(pool: &Pool, id: i64, state: &str) -> sqlx::Result<()> {
    sqlx::query("UPDATE flow_runners SET state = ? WHERE id = ?").bind(state).bind(id).execute(pool).await?;
    Ok(())
}

/// Forget a runner: its credential stops working. Its jobs keep its name.
pub async fn remove(pool: &Pool, id: i64) -> sqlx::Result<()> {
    sqlx::query("DELETE FROM flow_runners WHERE id = ?").bind(id).execute(pool).await?;
    Ok(())
}

/// The key a runner signs receipts with: the one bound, or `key` (named
/// `name`) when none is yet.
pub async fn bind_key(pool: &Pool, id: i64, key: &str, name: &str) -> sqlx::Result<String> {
    sqlx::query("UPDATE flow_runners SET key = ?, key_name = ? WHERE id = ? AND key = ''")
        .bind(key)
        .bind(name)
        .bind(id)
        .execute(pool)
        .await?;
    sqlx::query_scalar("SELECT key FROM flow_runners WHERE id = ?").bind(id).fetch_one(pool).await
}

/// Keys that runners of this hub sign with.
pub async fn keys(pool: &Pool) -> sqlx::Result<Vec<String>> {
    sqlx::query_scalar("SELECT key FROM flow_runners WHERE key != ''").fetch_all(pool).await
}

/// A one-time registration token, valid for a day, for a runner of `scope`.
pub async fn add_registration(pool: &Pool, token_hash: &str, by: &str, scope: &Scope) -> sqlx::Result<()> {
    let now = now_ms();
    sqlx::query(
        "INSERT INTO flow_runner_registrations (token_hash, created_by, created_ms, expires_ms, scope_owner, scope_repo_id) VALUES (?, ?, ?, ?, ?, ?)",
    )
    .bind(token_hash)
    .bind(by)
    .bind(now)
    .bind(now + 24 * 3_600_000)
    .bind(&scope.owner)
    .bind(scope.repo_id)
    .execute(pool)
    .await?;
    Ok(())
}

/// The runners that may take a repository's jobs: the site's, its owner's
/// and its own (oxygenhub#41).
pub async fn serving(pool: &Pool, owner: &str, repo_id: i64) -> sqlx::Result<Vec<Runner>> {
    sqlx::query_as(
        "SELECT * FROM flow_runners WHERE (scope_owner = '' AND scope_repo_id IS NULL) \
         OR (scope_owner = ? AND scope_repo_id IS NULL) OR scope_repo_id = ? ORDER BY name",
    )
    .bind(owner)
    .bind(repo_id)
    .fetch_all(pool)
    .await
}

/// The runners that serve an owner: the site's, and those scoped to the
/// owner or one of its repositories.
pub async fn serving_owner(pool: &Pool, owner: &str) -> sqlx::Result<Vec<Runner>> {
    sqlx::query_as("SELECT * FROM flow_runners WHERE (scope_owner = '' AND scope_repo_id IS NULL) OR scope_owner = ? ORDER BY name")
        .bind(owner)
        .fetch_all(pool)
        .await
}

/// Change the repositories a runner serves.
pub async fn set_scope(pool: &Pool, id: i64, scope: &Scope) -> sqlx::Result<()> {
    sqlx::query("UPDATE flow_runners SET scope_owner = ?, scope_repo_id = ? WHERE id = ?")
        .bind(&scope.owner)
        .bind(scope.repo_id)
        .bind(id)
        .execute(pool)
        .await?;
    Ok(())
}

/// Registration tokens not used yet and not expired: (created by, created, expires).
pub async fn pending_registrations(pool: &Pool) -> sqlx::Result<Vec<(String, i64, i64)>> {
    sqlx::query_as("SELECT created_by, created_ms, expires_ms FROM flow_runner_registrations WHERE used_ms IS NULL AND expires_ms > ? ORDER BY created_ms DESC")
        .bind(now_ms())
        .fetch_all(pool)
        .await
}

/// Use registration token `token_hash` to register a runner: `None` when
/// the token is unknown, used or expired.
#[allow(clippy::too_many_arguments)]
pub async fn register(
    pool: &Pool,
    registration: &str,
    name: &str,
    token_hash: &str,
    key: &str,
    key_name: &str,
    by_default: &str,
) -> sqlx::Result<Option<Runner>> {
    let mut tx = super::begin_write(pool).await?;
    let now = now_ms();
    let found: Option<(String, String, Option<i64>)> = sqlx::query_as(
        "SELECT created_by, scope_owner, scope_repo_id FROM flow_runner_registrations WHERE token_hash = ? AND used_ms IS NULL AND expires_ms > ?",
    )
    .bind(registration)
    .bind(now)
    .fetch_optional(&mut *tx)
    .await?;
    let Some((who, scope_owner, scope_repo_id)) = found else { return Ok(None) };
    let id: i64 = sqlx::query_scalar(
        "INSERT INTO flow_runners (name, token_hash, source, key, key_name, created_ms, created_by, scope_owner, scope_repo_id) VALUES (?, ?, 'registered', ?, ?, ?, ?, ?, ?) RETURNING id",
    )
    .bind(name)
    .bind(token_hash)
    .bind(key)
    .bind(key_name)
    .bind(now)
    .bind(if who.is_empty() { by_default } else { &who })
    .bind(scope_owner)
    .bind(scope_repo_id)
    .fetch_one(&mut *tx)
    .await?;
    sqlx::query("UPDATE flow_runner_registrations SET used_ms = ?, runner_id = ? WHERE token_hash = ?")
        .bind(now)
        .bind(id)
        .bind(registration)
        .execute(&mut *tx)
        .await?;
    tx.commit().await?;
    get(pool, id).await
}

/// A job a runner ran, for its history.
#[derive(Clone, Debug, FromRow)]
pub struct RunnerJob {
    pub owner: String,
    pub repo: String,
    pub run_number: i64,
    pub job: String,
    pub status: String,
    pub started_ms: Option<i64>,
    pub finished_ms: Option<i64>,
    pub receipt_attest: String,
}

/// Jobs runner `id` ran or is running, newest first.
pub async fn history(pool: &Pool, id: i64, limit: i64, before: Option<i64>) -> sqlx::Result<Vec<RunnerJob>> {
    sqlx::query_as(
        "SELECT p.owner AS owner, p.name AS repo, r.number AS run_number, j.name AS job, j.status AS status, j.started_ms AS started_ms, \
         j.finished_ms AS finished_ms, j.receipt_attest AS receipt_attest \
         FROM flow_jobs j JOIN flow_runs r ON r.id = j.run_id JOIN repositories p ON p.id = r.repo_id \
         WHERE j.runner_id = ? AND (? IS NULL OR j.started_ms < ?) ORDER BY j.started_ms DESC LIMIT ?",
    )
    .bind(id)
    .bind(before)
    .bind(before)
    .bind(limit)
    .fetch_all(pool)
    .await
}

/// (jobs run, passed, busy milliseconds) of runner `id`.
pub async fn totals(pool: &Pool, id: i64) -> sqlx::Result<(i64, i64, i64)> {
    sqlx::query_as(
        "SELECT COUNT(*), COALESCE(SUM(status = 'passed'), 0), COALESCE(SUM(finished_ms - started_ms), 0) \
         FROM flow_jobs WHERE runner_id = ? AND finished_ms IS NOT NULL",
    )
    .bind(id)
    .fetch_one(pool)
    .await
}

/// Jobs running on each runner now, by runner id.
pub async fn running(pool: &Pool) -> sqlx::Result<Vec<(i64, i64)>> {
    sqlx::query_as("SELECT runner_id, COUNT(*) FROM flow_jobs WHERE status = 'running' AND runner_id IS NOT NULL GROUP BY runner_id")
        .fetch_all(pool)
        .await
}

pub async fn set_job_runner(pool: &Pool, job_id: i64, runner_id: i64) -> sqlx::Result<()> {
    sqlx::query("UPDATE flow_jobs SET runner_id = ? WHERE id = ?").bind(runner_id).bind(job_id).execute(pool).await?;
    Ok(())
}