use std::{collections::HashMap, net::SocketAddr};

use async_trait::async_trait;

use crate::*;

#[derive(Clone)]
pub struct RoundRobin {
    pub players: HashMap<u32, SocketAddr>,
    pub top_half: Vec<u32>,
    pub bottom_half: Vec<u32>,
    pub is_completed: bool,
}

impl RoundRobin {
    async fn create_matches(&self, clients: &Clients, matches: &Matches) {
        let clients_guard = clients.read().await;
        for (i, id) in self.top_half.iter().enumerate() {
            let player1_addr = self.players.get(id).unwrap();
            let player2_addr = self.players.get(self.bottom_half.get(i).unwrap());

            if player2_addr.is_none() {
                continue;
            }
            let player2_addr = player2_addr.unwrap();

            let match_id: u32 = gen_match_id(matches).await;
            let new_match = Arc::new(RwLock::new(Match::new(
                match_id,
                *player1_addr,
                *player2_addr,
            )));

            let match_guard = new_match.read().await;
            let mut player1 = clients_guard.get(player1_addr).unwrap().write().await;

            player1.current_match = Some(match_id);
            player1.ready = false;

            if match_guard.player1 == *player1_addr {
                player1.color = Color::Red;
                let _ = send(&player1.connection, "GAME:START:1");
            } else {
                player1.color = Color::Yellow;
                let _ = send(&player1.connection, "GAME:START:0");
            }

            drop(player1);

            let mut player2 = clients_guard.get(player2_addr).unwrap().write().await;

            player2.current_match = Some(match_id);
            player2.ready = false;

            if match_guard.player1 == *player2_addr {
                player2.color = Color::Red;
                let _ = send(&player2.connection, "GAME:START:1");
            } else {
                player2.color = Color::Yellow;
                let _ = send(&player2.connection, "GAME:START:0");
            }

            drop(player2);

            matches.write().await.insert(match_id, new_match.clone());
        }
    }
}

#[async_trait]
impl Tournament for RoundRobin {
    fn new(ready_players: &[SocketAddr]) -> RoundRobin {
        let mut result = RoundRobin {
            players: HashMap::new(),
            top_half: Vec::new(),
            bottom_half: Vec::new(),
            is_completed: false,
        };

        let size = ready_players.len();

        for (id, player) in ready_players.iter().enumerate() {
            result.players.insert(id as u32, *player);
        }

        for i in 0..size / 2 {
            result.top_half.push(i as u32);
        }

        for i in size / 2..size {
            result.bottom_half.push(i as u32);
        }

        result
    }

    async fn next(&mut self, clients: &Clients, matches: &Matches, observers: &Observers) {
        if self.is_completed {
            return;
        }

        if self.top_half.len() <= 1 || self.bottom_half.is_empty() {
            self.is_completed = true;
            return;
        }

        let last_from_top = self.top_half.pop().unwrap();
        let first_from_bottom = self.bottom_half.remove(0);

        self.top_half.insert(1, first_from_bottom);
        self.bottom_half.push(last_from_top);

        let expected_bottom_start = self.top_half.len() as u32;
        if self.top_half[1] == 1 && self.bottom_half[0] == expected_bottom_start {
            self.is_completed = true;
        }

        if self.is_completed() {
            // Send scores
            let clients_guard = clients.read().await;
            let mut player_scores: Vec<(String, u32)> = Vec::new();
            for (_, player_addr) in self.players.iter() {
                let mut player = clients_guard.get(player_addr).unwrap().write().await;
                let _ = send(&player.connection.clone(), "TOURNAMENT:END");
                player_scores.push((player.username.clone(), player.score));
                player.score = 0;
                player.round_robin_id = 0;
            }

            player_scores.sort_by(|a, b| b.1.cmp(&a.1));

            let mut message = "TOURNAMENT:END:".to_string();
            for (player, score) in player_scores.iter() {
                message.push_str(&format!("{},{}|", player, score))
            }
            message.pop();

            broadcast_message_all_observers(observers, &message).await;
        } else {
            // Create next matches
            self.create_matches(clients, matches).await;
        }
    }

    async fn start(&mut self, clients: &Clients, matches: &Matches) {
        self.create_matches(clients, matches).await;
    }

    async fn cancel(&mut self, clients: &Clients, matches: &Matches, observers: &Observers) {
        for (_, addr) in self.players.iter() {
            let clients_guard = clients.read().await;

            let client = clients_guard.get(addr);
            if client.is_none() {
                continue;
            }
            let client = client.unwrap().read().await;
            let client_connection = client.connection.clone();
            let client_ready = client.ready;

            let match_id = client.current_match;
            if match_id.is_none() {
                continue;
            }
            let match_id = match_id.unwrap();

            drop(client);
            drop(clients_guard);

            terminate_match(match_id, matches, clients, observers, false).await;

            if !client_ready {
                let _ = send(&client_connection, "TOURNAMENT:END");
            }
        }
    }

    fn is_completed(&self) -> bool {
        self.is_completed
    }
}