use std::time::Duration;

use log::{debug, trace};
use spacetimedb::{
    ReducerContext, ScheduleAt::Interval, Table as _, rand::seq::SliceRandom, reducer,
};

use crate::tables::{
    DbTile, DbWall, GameTimer, Lobby, PlayerClock, PlayerHand, bot, game_timer, lobby as _, player,
    player_clock, player_hand, tile as _, wall,
};
use jong_types::{GameState, PlayerOrBot, TurnState};

mod hand;
mod lobby;

#[reducer]
pub fn advance_game(ctx: &ReducerContext, mut game_timer: GameTimer) -> Result<(), String> {
    advance_game_private(ctx, game_timer)
}

#[reducer]
pub fn advance_game_private(ctx: &ReducerContext, mut game_timer: GameTimer) -> Result<(), String> {
    // checks every second (or more? when users make moves) on whether to advance the game's various states
    // TODO this, or allow player/debug to call this?

    if let Some(mut lobby) = ctx.db.lobby().id().find(game_timer.lobby_id) {
        trace!("running schedule for lobby {}", lobby.id);
        match lobby.game_state {
            GameState::Setup => {
                // TODO reduce interval beforehand so we don't wait a second?
                // TODO keep a count to clear stale lobbies
                trace!("shuffle wall");
                let tiles = {
                    let mut rng = ctx.rng();
                    let mut wall: Vec<_> = jong_types::tiles::tiles()
                        .into_iter()
                        .map(|tile| ctx.db.tile().insert(DbTile { id: 0, tile }))
                        .collect();
                    wall.shuffle(&mut rng);
                    wall
                };
                ctx.db.wall().insert(DbWall {
                    // id: 0,
                    lobby_id: lobby.id,
                    tiles,
                });
                lobby.game_state = GameState::Deal;
            }
            GameState::Deal => {
                // TODO reduce interval beforehand so this can animate?
                // TODO change loop to be per interval somehow?
                trace!("deal hands");
                let mut wall = ctx.db.wall().lobby_id().find(lobby.id).unwrap();
                for pob in &lobby.players {
                    let mut tiles = wall.tiles.split_off(wall.tiles.len() - 13);
                    wall = ctx.db.wall().lobby_id().update(wall);
                    tiles.sort_by_key(|t| t.tile);
                    match pob {
                        PlayerOrBot::Player { id }
                            if let Some(p) = ctx.db.player().id().find(id) =>
                        {
                            ctx.db.player_hand().insert(PlayerHand {
                                id: 0,
                                player_id: p.id,
                                turn_state: jong_types::TurnState::None,
                                pond: vec![],
                                hand: tiles,
                                working_tile: None,
                            });
                            ctx.db.player_clock().insert(PlayerClock {
                                id: 0,
                                player_id: p.id,
                                renewable: 5,
                                total: 30,
                            });
                        }
                        PlayerOrBot::Bot { id } if let Some(mut b) = ctx.db.bot().id().find(id) => {
                            b.hand = tiles;
                            ctx.db.bot().id().update(b);
                        }
                        _ => Err("couldn't find player or bot".to_string())?,
                    }
                }
                lobby.game_state = jong_types::states::GameState::Play;
                trace!("dealt hands");
            }
            GameState::Play => {
                trace!("in play");
                let curr_player = lobby.players.get(lobby.current_idx as usize).unwrap();
                match curr_player {
                    PlayerOrBot::Player { id: player_id } => {
                        trace!("current player is {player_id}");
                        let mut clock = ctx.db.player_clock().player_id().find(player_id).unwrap();
                        let mut hand = ctx.db.player_hand().player_id().find(player_id).unwrap();
                        match hand.turn_state {
                            TurnState::None => {
                                trace!("draw a tile");
                                if let Some(mut wall) = ctx.db.wall().lobby_id().find(lobby.id)
                                    && let Some(tile) = wall.tiles.pop()
                                {
                                    hand.working_tile = Some(tile);
                                    hand.turn_state = TurnState::Tsumo;
                                    ctx.db.wall().lobby_id().update(wall);
                                    ctx.db.player_hand().id().update(hand);
                                } else {
                                    // TODO out of tiles
                                    todo!()
                                }
                            }
                            TurnState::Tsumo => {
                                trace!("wait for discard");
                                if clock.tick() {
                                    ctx.db.player_clock().id().update(clock);
                                } else {
                                    // TODO auto-discard
                                }
                            }
                            TurnState::Menzen => {}
                            TurnState::RiichiKan => {}
                            TurnState::RonChiiPonKan => {}
                            TurnState::End => {}
                        }
                    }
                    PlayerOrBot::Bot { id: bot_id } => {
                        debug!("current bot is {bot_id}");
                        let bot = ctx.db.bot().id().find(bot_id).unwrap();
                        match bot.turn_state {
                            // TurnState::None => todo!(),
                            // TurnState::Tsumo => todo!(),
                            // TurnState::Menzen => todo!(),
                            // TurnState::RiichiKan => todo!(),
                            // TurnState::RonChiiPonKan => todo!(),
                            // TurnState::End => todo!(),
                            _ => {}
                        }
                        lobby.next_player();
                    }
                }
            }
            GameState::Exit => {
                ctx.db.game_timer().id().delete(game_timer.id);
                ctx.db.lobby().id().delete(lobby.id);
                // TODO reset all player lobbies, delete bots, etc?
                // is there a way to do this automatically, or rely on elsewhere's checks clearing the state?
                return Ok(());
            }

            // TODO handle stale lobbies
            // TODO should this delete the timer?
            _ => Err(format!("lobby {} in impossible state", lobby.id))?,
        }

        // ctx.db.game_timer().id().update(game_timer);
        ctx.db.lobby().id().update(lobby);
    } else {
        ctx.db.game_timer().id().delete(game_timer.id);
        Err(format!(
            "ran schedule {} for empty lobby {}",
            game_timer.id, game_timer.lobby_id
        ))?;
    }

    Ok(())
}

impl PlayerClock {
    fn tick(&mut self) -> bool {
        if self.renewable > 0 {
            self.renewable -= 1;
            true
        } else if self.total > 0 {
            self.total -= 1;
            true
        } else {
            false
        }
    }

    fn renew(&mut self) {
        self.renewable = 5;
    }
}

impl Lobby {
    fn next_player(&mut self) {
        if self.current_idx + 1 >= 4 {
            self.current_idx = 0
        } else {
            self.current_idx += 1;
        }
    }
}