use sqlx::FromRow;
use sqlx::PgPool;
use sqlx::types::chrono::{DateTime, Utc};
use chrono::serde::{ts_seconds, ts_seconds_option};
use serde::{Serialize, Deserialize};

pub trait TableName {
  const TABLE_NAME: &'static str;
}
macro_rules! impl_table_name {
  ($ty:ident, $tname:expr) => {
    impl TableName for $ty {
      const TABLE_NAME: &'static str = $tname;
    }
  }
}

#[derive(FromRow, Serialize, Deserialize)]
pub struct League {
  pub id: i32,
  pub name: String,
  #[serde(with = "ts_seconds")]
  pub start_date: DateTime<Utc>,
  #[serde(with = "ts_seconds_option")]
  pub end_date: Option<DateTime<Utc>>,
}
#[derive(FromRow, Serialize, Deserialize)]
pub struct NewLeague {
  pub name: String,
  #[serde(with = "ts_seconds")]
  pub start_date: DateTime<Utc>,
  #[serde(with = "ts_seconds_option")]
  pub end_date: Option<DateTime<Utc>>,
}

#[derive(FromRow, Serialize, Deserialize)]
pub struct Division {
  pub id: i32,
  pub name: String,
  pub league: i32,
}

#[derive(FromRow, Serialize, Deserialize)]
pub struct NewDivision {
  pub id: i32,
  pub name: String,
  pub league: i32,
}

#[derive(FromRow, Serialize, Deserialize)]
pub struct Team {
  pub id: i32,
  pub name: String,
  pub division: i32,
}

#[derive(FromRow, Serialize, Deserialize)]
pub struct NewTeam {
  pub name: String,
  pub division: i32,
}

#[derive(FromRow, Serialize, Deserialize)]
pub struct Player {
  pub id: i32,
  pub name: String,
  pub weight_kg: Option<i32>,
  pub height_cm: Option<i32>,
}

#[derive(FromRow, Deserialize, Serialize)]
pub struct NewPlayer {
  pub name: String,
  pub weight_kg: Option<i32>,
  pub height_cm: Option<i32>,
}

#[derive(FromRow, Deserialize, Serialize)]
pub struct Shot {
  pub id: i32,
  pub shooter_team: i32,
  pub goalie: i32,
  pub assistant: Option<i32>,
  pub game: i32,
  pub period: i32,
  pub period_time: i32,
  pub video_timestamp: Option<i32>,
}

#[derive(FromRow, Deserialize, Serialize)]
pub struct TeamPlayer {
  pub id: i32,
  pub team: i32,
  pub player: i32,
  pub position: i32,
}

#[derive(FromRow, Deserialize, Serialize, Debug)]
pub struct Notification {
  pub scorer_name: String,
  pub scorer_number: i32,
  pub position: String,
  pub scorer_team_name: String,
  pub period_name: String,
  pub period_time_left: i32,
}

#[derive(FromRow, Deserialize, Serialize, Debug)]
pub struct PlayerStats {
  pub player_name: String,
  pub goals: i64,
  pub assists: i64,
  pub points: i64,
}

async fn get_player_stats_overview(pool: PgPool) -> Result<Vec<PlayerStats>, sqlx::Error> {
  let query = r#"
SELECT
  (
    SELECT COUNT(id)
    FROM shots
    WHERE shooter=players.id
      AND goal=true
  ) AS goals,
  (
    SELECT COUNT(id)
    FROM shots
    WHERE assistant=players.id
      AND goal=true
  ) AS assists,
  (
    SELECT COUNT(id)
    FROM shots
    WHERE assistant=players.id
       OR shooter=players.id
  ) AS points,
  players.name AS player_name
FROM players
ORDER BY
  points DESC,
  players.name;
"#;
  let result = sqlx::query_as::<_, PlayerStats>(query)
    .fetch_all(&pool)
    .await;
  result
}

impl_table_name!(TeamPlayer, "team_players");
impl_table_name!(Player, "players");
impl_table_name!(League, "leagues");
impl_table_name!(Division, "divisions");
impl_table_name!(Team, "teams");
impl_table_name!(Shot, "shots");

#[cfg(test)]
mod tests {
  use std::env;
  use crate::model::{
    TeamPlayer,
    Player,
    League,
    Division,
    Team,
    Shot,
    TableName,
    Notification,
    get_player_stats_overview,
  };

  #[test]
  fn check_player_overall_stats() {
    tokio_test::block_on(async move {
      let pool = db_connect().await;
      let players_stats = get_player_stats_overview(pool).await.unwrap();
      for player_stats in players_stats {
        println!("{player_stats:?}");
      }
    })
  }

  #[test]
  fn check_notification_query() {
    tokio_test::block_on(async move {
      let pool = db_connect().await;
      let query = r#"
SELECT
  teams.name AS scorer_team_name,
  players.name AS scorer_name,
  positions.name AS position,
  team_players.player_number AS scorer_number,
  shots.period_time AS period_time_left,
  periods.name AS period_name
FROM
  shots
JOIN teams ON teams.id=shots.shooter_team
JOIN players ON players.id=shots.shooter
JOIN team_players ON team_players.player=players.id AND team_players.team=teams.id
JOIN periods ON periods.id=shots.period
JOIN positions ON positions.id=team_players.position;
"#;
      let result = sqlx::query_as::<_, Notification>(query)
        .fetch_one(&pool)
        .await
        .unwrap();
      let minutes = result.period_time_left / 60;
      let seconds = result.period_time_left % 60;
      println!("{0} {1} player #{3} {2} has scored! Time of the goal: {4}:{5} in the {6}",
        result.scorer_team_name,
        result.position,
        result.scorer_name,
        result.scorer_number,
        minutes,
        seconds,
        result.period_name
      );
    });
  }

  /// A simple function to connect to the database.
  async fn db_connect() -> sqlx::PgPool {
    let db_url = env::var("DATABASE_URL").expect("DATABASE_URL environment variable must be set to run tests.");
    sqlx::postgres::PgPoolOptions::new()
      .max_connections(1)
      .connect(&db_url)
      .await
      .expect("Active database connection must be made")
  }

  /// This macro generates a test that will `SELECT` all records for a table.
  /// Then, it checks that
  /// 1. The table rows gets deserialized correctly.
  /// 2. There is at least one row.
  macro_rules! generate_select_test {
    ($ret_type:ident, $func_name:ident) => {
      #[test]
      fn $func_name() {
        tokio_test::block_on(async move {
          let pool = db_connect().await;
          let results = sqlx::query_as::<_, $ret_type>(
            &format!(
              "SELECT * FROM {};",
              <$ret_type as TableName>::TABLE_NAME
            )
          )
          .fetch_all(&pool)
          .await
          .unwrap();
          // check that there is at least one result item
          assert!(results.len() > 0, "There must be at least one result in the table.");
        });
      }
    }
  }
  generate_select_test!(TeamPlayer, select_team_player);
  generate_select_test!(Player, select_player);
  generate_select_test!(League, select_league);
  generate_select_test!(Division, select_division);
  generate_select_test!(Team, select_team);
  generate_select_test!(Shot, select_shot);
}