use rand::prelude::SliceRandom;
use rand::rngs::SmallRng;
use rand::SeedableRng;
use serde::{Deserialize, Serialize};
use tsify::Tsify;
use crate::board::{Board, Coordinates, Letter};
use crate::constants::{standard_tile_pool, TRAY_LENGTH};
use crate::dictionary::{Dictionary, DictionaryImpl};
use crate::player_interaction::ai::Difficulty;
use crate::player_interaction::Tray;

pub enum Player {
    Human(String),
    AI{
        name: String,
        difficulty: Difficulty,
    }
}

impl Player {

    pub fn get_name(&self) -> &str {
        match &self {
            Player::Human(name) => {name}
            Player::AI { name, .. } => {name}
        }
    }
}

pub struct PlayerState {
    pub player: Player,
    pub score: u32,
    pub tray: Tray
}

#[derive(Deserialize, Tsify, Copy, Clone)]
#[tsify(from_wasm_abi)]
pub struct PlayedTile {
    index: usize,
    character: Option<char>,
}

#[derive(Debug, Serialize, Deserialize, Tsify)]
#[tsify(from_wasm_abi)]
pub struct WordResult {
    word: String,
    score: u32,
}

pub struct PlayerStates(pub Vec<PlayerState>);
impl PlayerStates {
    pub fn get_player_state(&self, name: &str) -> Option<&PlayerState> {
        self.0.iter()
            .filter(|state| state.player.get_name().eq(name))
            .nth(0)

    }

    pub fn get_player_state_mut(&mut self, name: &str) -> Option<&mut PlayerState> {
        self.0.iter_mut()
            .filter(|state| state.player.get_name().eq(name))
            .nth(0)

    }

    pub fn get_tray(&self, name: &str) -> Option<&Tray> {
        let player = self.get_player_state(name)?;

        Some(&player.tray)

    }

    pub fn get_tray_mut(&mut self, name: &str) -> Option<&mut Tray> {
        let player = self.get_player_state_mut(name)?;

        Some(&mut player.tray)

    }
}

pub struct Game{
    pub tile_pool: Vec<Letter>,
    rng: SmallRng,
    board: Board,
    pub player_states: PlayerStates,
    dictionary: DictionaryImpl,
}

// Problem - I want to provide a UI to the player
// Ideally they would get some kind of 'tray' object with methods to use and run
// However I want the main game state to live in Rust, not in JS.
// Does this mean I provide Rc<RefCell<Tray>>?

// Other option - what if I just have one Game object that exposes all methods.
// At no point do they get a Tray reference that auto-updates, they need to handle that
// I just provide read-only JSON of everything, and they call the methods for updates
// This will later work out well when I build it out as an API for multiplayer.

impl Game {
    pub fn new(seed: u64, dictionary_text: &str, mut player_names: Vec<String>) -> Self {
        let mut rng = SmallRng::seed_from_u64(seed);

        let mut letters = standard_tile_pool(Some(&mut rng));

        player_names.shuffle(&mut rng);
        let player_states: Vec<PlayerState> = player_names.iter()
            .map(|name| {
                let mut tray = Tray::new(TRAY_LENGTH);
                tray.fill(&mut letters);
                PlayerState {
                    player: Player::Human(name.clone()),
                    score: 0,
                    tray,
                }
            })
            .collect();

        Game {
            tile_pool: letters,
            rng,
            board: Board::new(),
            player_states: PlayerStates(player_states),
            dictionary: DictionaryImpl::create_from_str(dictionary_text)
        }
    }



    pub fn get_board(&self) -> &Board {&self.board}

    pub fn set_board(&mut self, new_board: Board) {
        self.board = new_board;
    }

    pub fn fill_trays(&mut self){
        for state in self.player_states.0.iter_mut() {
            let tray = &mut state.tray;
            tray.fill(&mut self.tile_pool);
        }
    }

    pub fn get_dictionary(&self) -> &DictionaryImpl {
        &self.dictionary
    }

    pub fn receive_play(&mut self, player: &str, tray_tile_locations: Vec<Option<PlayedTile>>, commit_move: bool) -> Result<Vec<WordResult>, String> {

        let mut board_instance = self.get_board().clone();
        let mut tray = self.player_states.get_tray(player).unwrap().clone();

        let mut played_letters: Vec<(Letter, Coordinates)> = Vec::new();
        for (i, played_tile) in tray_tile_locations.iter().enumerate() {
            if played_tile.is_some() {
                let played_tile = played_tile.unwrap();
                let mut letter: Letter = tray.letters.get(i).unwrap().unwrap();
                *tray.letters.get_mut(i).unwrap() = None;

                let coord = Coordinates::new_from_index(played_tile.index);
                if letter.is_blank {
                    match played_tile.character {
                        None => {
                            panic!("You can't play a blank character without providing a letter value")
                        }
                        Some(x) => {
                            // TODO - I should check that the character is a valid letter
                            letter.text = x;
                        }
                    }
                }
                played_letters.push((letter, coord));

            }
        }

        board_instance.receive_play(played_letters)?;


        let x = board_instance.calculate_scores(self.get_dictionary())?;

        let words: Vec<WordResult> = x.0.iter()
            .map(|(word, score)| {
                WordResult {
                    word: word.to_string(),
                    score: *score
                }

            })
            .collect();

        if commit_move {
            let mut player_state = self.player_states.get_player_state_mut(player).unwrap();
            player_state.score += x.1;
            player_state.tray = tray;

            board_instance.fix_tiles();
            self.set_board(board_instance);
            self.fill_trays()
        }

        Ok(words)
    }

    pub fn exchange_tiles(&mut self, player: &str, tray_tile_locations: Vec<bool>) -> Result<Tray, String> {
        let tray = match self.player_states.get_tray_mut(player) {
            None => {return Err(format!("Player {} not found", player))}
            Some(x) => {x}
        };

        if tray.letters.len() != tray_tile_locations.len() {
            return Err("Incoming tray and existing tray have different lengths".to_string());
        }

        let tile_pool = &mut self.tile_pool;

        for (i, played_tile) in tray_tile_locations.iter().enumerate() {
            if *played_tile {
                let letter = tray.letters.get_mut(i).unwrap();
                if letter.is_some() {
                    tile_pool.push(letter.unwrap().clone());
                    *letter = None;
                }
            }
        }

        tile_pool.shuffle(&mut self.rng);
        tray.fill(&mut self.tile_pool);

        Ok(tray.clone())

    }

}