use crate::admin::{station::Station, team::Team};
use axum::Router;
use serde::{Deserialize, Serialize};
use sqlx::{FromRow, Row, SqlitePool};
use std::sync::Arc;

mod web;

#[derive(FromRow, Debug, Serialize, Deserialize)]
pub(crate) struct Route {
    pub(crate) id: i64,
    pub(crate) name: String,
}

impl Route {
    pub(crate) async fn all(db: &SqlitePool) -> Vec<Self> {
        sqlx::query_as::<_, Self>("SELECT id, name FROM route;")
            .fetch_all(db)
            .await
            .unwrap()
    }

    pub async fn find_by_id(db: &SqlitePool, id: i64) -> Option<Self> {
        sqlx::query_as!(Self, "SELECT id, name FROM route WHERE id = ?", id)
            .fetch_one(db)
            .await
            .ok()
    }

    async fn create(db: &SqlitePool, name: &str) -> Result<(), String> {
        sqlx::query!("INSERT INTO route(name) VALUES (?)", name)
            .execute(db)
            .await
            .map_err(|e| e.to_string())?;
        Ok(())
    }

    async fn update_name(&self, db: &SqlitePool, name: &str) {
        sqlx::query!("UPDATE route SET name = ? WHERE id = ?", name, self.id)
            .execute(db)
            .await
            .unwrap();
    }

    async fn add_station(&self, db: &SqlitePool, station: &Station) -> Result<(), String> {
        sqlx::query!(
            r#"
        INSERT INTO route_station (route_id, station_id, pos)
        VALUES (?, ?, (
            SELECT COALESCE(MAX(pos), 0) + 2 
            FROM route_station 
            WHERE route_id = ?
        ))
        "#,
            self.id,
            station.id,
            self.id
        )
        .execute(db)
        .await
        .map_err(|e| e.to_string())?;

        Ok(())
    }

    async fn delete_station(&self, db: &SqlitePool, station: &Station) -> bool {
        let result = sqlx::query!(
            "DELETE FROM route_station WHERE route_id = ? AND station_id = ?",
            self.id,
            station.id
        )
        .execute(db)
        .await
        .unwrap();

        result.rows_affected() > 0
    }

    async fn move_station_higher(&self, db: &SqlitePool, station: &Station) -> bool {
        let result = sqlx::query!(
            "UPDATE route_station SET pos = pos-3 WHERE route_id = ? AND station_id = ?",
            self.id,
            station.id
        )
        .execute(db)
        .await
        .unwrap();

        if result.rows_affected() == 0 {
            return false;
        }

        sqlx::query(
            &format!(
            "
-- Step 1: Create a temporary table with new rank values
CREATE TEMP TABLE IF NOT EXISTS temp_pos AS
SELECT
  route_id,
  station_id,
  ROW_NUMBER() OVER (ORDER BY pos ASC) AS new_rank
FROM
  route_station WHERE route_id = {};

-- Step 2: Update the original table
UPDATE route_station 
SET pos = (SELECT 2*new_rank FROM temp_pos WHERE temp_pos.route_id = route_station.route_id AND temp_pos.station_id = route_station.station_id) WHERE route_id = {};

-- Step 3: Drop the temporary table (no longer needed)
DROP TABLE temp_pos;",
            self.id,
            self.id,
        ))
        .execute(db)
        .await
        .unwrap();

        true
    }

    async fn delete(&self, db: &SqlitePool) -> Result<(), String> {
        sqlx::query!("DELETE FROM route WHERE id = ?", self.id)
            .execute(db)
            .await
            .map_err(|e| e.to_string())?;
        Ok(())
    }

    pub(crate) async fn stations(&self, db: &SqlitePool) -> Vec<Station> {
        sqlx::query_as::<_, Station>(
            "
            SELECT s.id, s.name, s.notes, s.amount_people, s.last_login, s.pw, s.lat, s.lng
            FROM station s
            JOIN route_station rs ON s.id = rs.station_id
            WHERE rs.route_id = ?
            ORDER BY rs.pos
            ",
        )
        .bind(self.id)
        .fetch_all(db)
        .await
        .unwrap()
    }

    async fn stations_not_in_route(&self, db: &SqlitePool) -> Vec<Station> {
        sqlx::query_as::<_, Station>(
            "
            SELECT id, name, notes, amount_people, last_login, pw, lat, lng
            FROM station
            WHERE id NOT IN (
                SELECT station_id
                FROM route_station
                WHERE route_id = ?
            )
            ORDER BY name
            ",
        )
        .bind(self.id)
        .fetch_all(db)
        .await
        .unwrap()
    }

    pub(crate) async fn teams(&self, db: &SqlitePool) -> Vec<Team> {
        Team::all_with_route(db, self).await
    }

    pub(crate) async fn get_next_first_station(&self, db: &SqlitePool) -> Option<Station> {
        let Ok(row) = sqlx::query(&format!(
            "
            SELECT 
                s.id AS next_first_station_id,
                COUNT(g.id) AS team_count
            FROM station s
            JOIN route_station rs ON s.id = rs.station_id
            LEFT JOIN 'team' g ON s.id = g.first_station_id
            WHERE rs.route_id = {}
            GROUP BY s.id
            ORDER BY team_count ASC, s.id ASC
           LIMIT 1",
            self.id
        ))
        .fetch_one(db)
        .await
        else {
            return None; // No station for route exists
        };
        let next_first_station_id = row.get::<i64, _>("next_first_station_id");

        Some(
            Station::find_by_id(db, next_first_station_id)
                .await
                .expect("db constraints"),
        )
    }
}

pub(super) fn routes() -> Router<Arc<SqlitePool>> {
    web::routes()
}