pub mod bugzilla;
pub mod gitea;
pub mod github;
pub mod github_repo;
pub mod github_search;
pub mod hg;

use async_trait::async_trait;
use chrono::{DateTime, Utc};
use moments_core::{EventReader, EventWriter, PollerState, PollerStateStore, StoreError};
use chrono::NaiveDate;
use moments_entities::{DailyCount, Event, EventQuery, ProjectSummary, Source, SourceSummary};
use sqlx::Row;
use sqlx::postgres::{PgPool, PgPoolOptions};
use std::str::FromStr;

pub static MIGRATOR: sqlx::migrate::Migrator = sqlx::migrate!("./migrations");

#[derive(Clone)]
pub struct PgStore {
    pool: PgPool,
}

impl PgStore {
    pub async fn connect(database_url: &str) -> Result<Self, sqlx::Error> {
        let pool = PgPoolOptions::new()
            .max_connections(8)
            .connect(database_url)
            .await?;
        Ok(Self { pool })
    }

    pub async fn migrate(&self) -> Result<(), sqlx::migrate::MigrateError> {
        MIGRATOR.run(&self.pool).await
    }
}

fn map_err<E: std::fmt::Display>(e: E) -> StoreError {
    StoreError::Database(e.to_string())
}

#[async_trait]
impl EventReader for PgStore {
    async fn list_events(&self, query: &EventQuery) -> Result<Vec<Event>, StoreError> {
        let sources: Option<Vec<String>> = query
            .sources
            .as_ref()
            .map(|s| s.iter().map(|x| x.as_str().to_string()).collect());

        let rows = sqlx::query(
            r#"
            SELECT id, source, action, occurred_at, public, payload
            FROM events
            WHERE ($1::timestamptz IS NULL OR occurred_at >= $1)
              AND ($2::timestamptz IS NULL OR occurred_at <  $2)
              AND ($3::text[]      IS NULL OR source = ANY($3))
              AND ($4::bool        OR public = true)
              AND ($6::text IS NULL OR (CASE source
                    WHEN 'github' THEN COALESCE(
                        payload->'repo'->>'name',
                        payload->'repository'->>'full_name',
                        payload->>'_repo'
                    )
                    WHEN 'gitea' THEN COALESCE(
                        payload->'repo'->>'full_name',
                        payload->'repo'->>'name'
                    )
                    WHEN 'hg'       THEN payload->>'_repo'
                    WHEN 'bugzilla' THEN payload->>'product'
                    ELSE NULL
                  END) = $6)
            ORDER BY occurred_at DESC
            LIMIT $5
            "#,
        )
        .bind(query.from)
        .bind(query.to)
        .bind(sources.as_deref())
        .bind(query.include_private)
        .bind(query.limit as i64)
        .bind(query.repo.as_deref())
        .fetch_all(&self.pool)
        .await
        .map_err(map_err)?;

        rows.into_iter()
            .map(|r| {
                let source_str: String = r.try_get("source").map_err(map_err)?;
                Ok(Event {
                    id: r.try_get("id").map_err(map_err)?,
                    source: Source::from_str(&source_str).map_err(map_err)?,
                    action: r.try_get("action").map_err(map_err)?,
                    occurred_at: r.try_get("occurred_at").map_err(map_err)?,
                    public: r.try_get("public").map_err(map_err)?,
                    payload: r.try_get("payload").map_err(map_err)?,
                })
            })
            .collect()
    }

    async fn source_summaries(&self, include_private: bool) -> Result<Vec<SourceSummary>, StoreError> {
        let rows = sqlx::query(
            r#"
            SELECT source,
                   COUNT(*)         AS count,
                   MIN(occurred_at) AS earliest,
                   MAX(occurred_at) AS latest
            FROM events
            WHERE $1::bool OR public = true
            GROUP BY source
            ORDER BY source
            "#,
        )
        .bind(include_private)
        .fetch_all(&self.pool)
        .await
        .map_err(map_err)?;

        rows.into_iter()
            .map(|r| {
                let source_str: String = r.try_get("source").map_err(map_err)?;
                let earliest: Option<DateTime<Utc>> = r.try_get("earliest").map_err(map_err)?;
                let latest: Option<DateTime<Utc>> = r.try_get("latest").map_err(map_err)?;
                let count: i64 = r.try_get("count").map_err(map_err)?;
                Ok(SourceSummary {
                    source: Source::from_str(&source_str).map_err(map_err)?,
                    count,
                    earliest,
                    latest,
                })
            })
            .collect()
    }

    async fn list_projects(&self) -> Result<Vec<ProjectSummary>, StoreError> {
        let rows = sqlx::query(
            r#"
            SELECT source, repo, host,
                   SUM(commits)::bigint  AS commit_count,
                   SUM(issues)::bigint   AS issue_count,
                   SUM(prs)::bigint      AS pr_count,
                   MIN(occurred_at)       AS first_activity,
                   MAX(occurred_at)       AS last_activity
            FROM (
                SELECT source, occurred_at,
                    CASE source
                        WHEN 'github' THEN COALESCE(
                            payload->'repo'->>'name',
                            payload->'repository'->>'full_name',
                            payload->>'_repo'
                        )
                        WHEN 'gitea' THEN COALESCE(
                            payload->'repo'->>'full_name',
                            payload->'repo'->>'name'
                        )
                        WHEN 'hg'       THEN payload->>'_repo'
                        WHEN 'bugzilla' THEN payload->>'product'
                        ELSE NULL
                    END AS repo,
                    CASE source
                        WHEN 'github'   THEN 'github.com'
                        WHEN 'gitea'    THEN COALESCE(payload->>'_host', 'git.lair.cafe')
                        WHEN 'hg'       THEN COALESCE(payload->>'_host', 'hg-edge.mozilla.org')
                        WHEN 'bugzilla' THEN 'bugzilla.mozilla.org'
                        ELSE 'unknown'
                    END AS host,
                    CASE WHEN action IN ('Commit', 'PushEvent', 'commit_repo') THEN 1 ELSE 0 END AS commits,
                    CASE WHEN action IN ('Issue', 'IssuesEvent') THEN 1 ELSE 0 END AS issues,
                    CASE WHEN action IN ('PullRequest', 'PullRequestEvent') THEN 1 ELSE 0 END AS prs
                FROM events
                WHERE public = true
            ) sub
            WHERE repo IS NOT NULL AND repo != ''
            GROUP BY source, repo, host
            ORDER BY MAX(occurred_at) DESC
            "#,
        )
        .fetch_all(&self.pool)
        .await
        .map_err(map_err)?;

        rows.into_iter()
            .map(|r| {
                let source_str: String = r.try_get("source").map_err(map_err)?;
                Ok(ProjectSummary {
                    source: Source::from_str(&source_str).map_err(map_err)?,
                    repo: r.try_get("repo").map_err(map_err)?,
                    host: r.try_get("host").map_err(map_err)?,
                    commit_count: r.try_get::<i64, _>("commit_count").map_err(map_err).unwrap_or(0),
                    issue_count: r.try_get::<i64, _>("issue_count").map_err(map_err).unwrap_or(0),
                    pr_count: r.try_get::<i64, _>("pr_count").map_err(map_err).unwrap_or(0),
                    first_activity: r.try_get("first_activity").map_err(map_err)?,
                    last_activity: r.try_get("last_activity").map_err(map_err)?,
                })
            })
            .collect()
    }

    async fn daily_counts(&self, from: NaiveDate, to: NaiveDate) -> Result<Vec<DailyCount>, StoreError> {
        let rows = sqlx::query(
            r#"
            SELECT d::date AS date,
                   COUNT(e.id)::bigint AS count
            FROM generate_series($1::date, $2::date, '1 day') d
            LEFT JOIN events e
              ON e.occurred_at >= d AND e.occurred_at < d + interval '1 day'
              AND e.public = true
            GROUP BY d::date
            ORDER BY d::date
            "#,
        )
        .bind(from)
        .bind(to)
        .fetch_all(&self.pool)
        .await
        .map_err(map_err)?;

        rows.into_iter()
            .map(|r| {
                Ok(DailyCount {
                    date: r.try_get("date").map_err(map_err)?,
                    count: r.try_get("count").map_err(map_err)?,
                })
            })
            .collect()
    }
}

#[async_trait]
impl PollerStateStore for PgStore {
    async fn load(&self, source: &str) -> Result<Option<PollerState>, StoreError> {
        let row = sqlx::query(
            r#"
            SELECT source, etag, last_modified, last_fetched
            FROM poller_state
            WHERE source = $1
            "#,
        )
        .bind(source)
        .fetch_optional(&self.pool)
        .await
        .map_err(map_err)?;

        Ok(match row {
            None => None,
            Some(r) => Some(PollerState {
                source: r.try_get("source").map_err(map_err)?,
                etag: r.try_get("etag").map_err(map_err)?,
                last_modified: r.try_get("last_modified").map_err(map_err)?,
                last_fetched: r.try_get("last_fetched").map_err(map_err)?,
            }),
        })
    }

    async fn save(
        &self,
        source: &str,
        etag: Option<&str>,
        last_modified: Option<DateTime<Utc>>,
    ) -> Result<(), StoreError> {
        sqlx::query(
            r#"
            INSERT INTO poller_state (source, etag, last_modified, last_fetched)
            VALUES ($1, $2, $3, now())
            ON CONFLICT (source) DO UPDATE
            SET etag          = EXCLUDED.etag,
                last_modified = EXCLUDED.last_modified,
                last_fetched  = EXCLUDED.last_fetched
            "#,
        )
        .bind(source)
        .bind(etag)
        .bind(last_modified)
        .execute(&self.pool)
        .await
        .map_err(map_err)?;
        Ok(())
    }

    async fn touch(&self, source: &str) -> Result<(), StoreError> {
        sqlx::query(
            r#"
            INSERT INTO poller_state (source, last_fetched)
            VALUES ($1, now())
            ON CONFLICT (source) DO UPDATE
            SET last_fetched = EXCLUDED.last_fetched
            "#,
        )
        .bind(source)
        .execute(&self.pool)
        .await
        .map_err(map_err)?;
        Ok(())
    }
}

#[async_trait]
impl EventWriter for PgStore {
    async fn upsert_events(&self, events: &[Event]) -> Result<usize, StoreError> {
        if events.is_empty() {
            return Ok(0);
        }

        let mut tx = self.pool.begin().await.map_err(map_err)?;
        let mut inserted = 0;
        for ev in events {
            let n = sqlx::query(
                r#"
                INSERT INTO events (id, source, action, occurred_at, public, payload)
                VALUES ($1, $2, $3, $4, $5, $6)
                ON CONFLICT (id) DO UPDATE
                SET source      = EXCLUDED.source,
                    action      = EXCLUDED.action,
                    occurred_at = EXCLUDED.occurred_at,
                    public      = EXCLUDED.public,
                    payload     = EXCLUDED.payload
                "#,
            )
            .bind(&ev.id)
            .bind(ev.source.as_str())
            .bind(&ev.action)
            .bind(ev.occurred_at)
            .bind(ev.public)
            .bind(&ev.payload)
            .execute(&mut *tx)
            .await
            .map_err(map_err)?
            .rows_affected();
            inserted += n as usize;
        }
        tx.commit().await.map_err(map_err)?;
        Ok(inserted)
    }
}