use uuid::Uuid;
use rand::prelude::*;

// Db Commons
use serde_cbor::{from_slice, to_vec};
use postgres::transaction::Transaction;
use failure::Error;
use failure::err_msg;

use account::Account;
use rpc::{GameStateParams, GameSkillParams, GamePveParams, GamePvpParams, GameTargetParams, GameJoinParams};
use cryp::{Cryp, cryp_get};
use skill::{Skill, Cast};

#[derive(Debug,Clone,Serialize,Deserialize)]
pub struct Team {
    id: Uuid,
    cryps: Vec<Cryp>,
}

impl Team {
    pub fn new(account: Uuid) -> Team {
        return Team {
            id: account,
            cryps: vec![],
        };
    }

    fn skills_required(&self) -> usize {
        let required = self.cryps.iter().filter(|c| c.available_skills().len() > 0).collect::<Vec<&Cryp>>().len();
        println!("{:?} requires {:?} skills this turn", self.id, required);
        return required;
    }

    pub fn set_cryps(&mut self, cryps: Vec<Cryp>) -> &mut Team {
        self.cryps = cryps;
        self
    }

    pub fn cryp_by_id(&mut self, id: Uuid) -> Option<&mut Cryp> {
        self.cryps.iter_mut().find(|c| c.id == id)
    }
}

#[derive(Debug,Clone,Copy,PartialEq,Serialize,Deserialize)]
pub enum Phase {
    Start,
    Skill,
    Target,
    Damage,
    Finish,
}

#[derive(Debug,Clone,Serialize,Deserialize)]
pub struct Game {
    pub id: Uuid,
    pub team_size: usize,
    pub team_num: usize,
    pub teams: Vec<Team>,
    pub is_pve: bool,
    pub phase: Phase,
    pub skills: Vec<Cast>,
    pub resolutions: Vec<Cast>,
    pub log: Vec<String>,
}

impl Game {
    fn new() -> Game {
        return Game {
            id: Uuid::new_v4(),
            team_size: 0,
            team_num: 0,
            teams: vec![],
            is_pve: true,
            phase: Phase::Start,
            skills: vec![],
            resolutions: vec![],
            log: vec![],
        };
    }

    fn set_team_num(&mut self, size: usize) -> &mut Game {
        self.team_num = size;
        self
    }

    fn set_team_size(&mut self, size: usize) -> &mut Game {
        self.team_size = size;
        self
    }

    fn set_pve(&mut self, pve: bool) -> &mut Game {
        self.is_pve = pve;
        self
    }

    // check team not already in
    fn add_team(&mut self, team: Team) -> Result<&mut Game, Error> {
        if self.teams.len() == self.team_num {
            return Err(err_msg("maximum number of teams"));
        }
        self.teams.push(team);

        Ok(self)
    }

    // handle missing team properly
    fn team_by_id(&mut self, id: Uuid) -> &mut Team {
        match self.teams.iter_mut().find(|t| t.id == id) {
            Some(t) => t,
            None => panic!("id not in game {:?}", id),
        }
    }

    fn cryp_by_id(&mut self, id: Uuid) -> Option<&mut Cryp> {
        match self.teams.iter_mut().find(|t| t.cryps.iter().any(|c| c.id == id)) {
            Some(team) => {
                return team.cryps.iter_mut().find(|c| c.id == id);
            },
            None => panic!("cryp not in game"),
        };
    }

    fn update_cryp(&mut self, cryp: &mut Cryp) -> &mut Game {
        match self.teams.iter_mut().find(|t| t.cryps.iter().any(|c| c.id == cryp.id)) {
            Some(team) => {
                let index = team.cryps.iter().position(|t| t.id == cryp.id).unwrap();
                team.cryps.remove(index);
                team.cryps.push(cryp.clone());
            },
            None => panic!("cryp not in game"),
        };

        self
    }

    fn can_start(&self) -> bool {
        self.teams.len() == self.team_num
    }

    fn start(&mut self) -> &mut Game {
        self.skill_phase_start();
        self
    }

    fn skill_phase_start(&mut self) -> &mut Game {
        if ![Phase::Start, Phase::Damage].contains(&self.phase) {
            panic!("game not in damage or start phase");
        }

        self.phase = Phase::Skill;

        self.skills.clear();

        if self.is_pve {
            self.pve_add_skills();
        }

        self
    }

    fn pve_add_skills(&mut self) -> &mut Game {
        {
            let mob_team_id = Uuid::nil();
            let mobs = self.team_by_id(mob_team_id).clone();

            // TODO attack multiple players based on some criteria
            let player_team_id = self.teams.iter().find(|t| t.id != mob_team_id).unwrap().id;
            for mob in &mobs.cryps {
                // doesn't matter if the cryp can't cast
                self.add_skill(mob_team_id, mob.id, player_team_id, Skill::Attack).ok();
            }
        }

        self
    }

    // skills can target any team, but we have to check if the caller is the owner of the cryp
    // and that the cryp has the skill they are trying to add
    fn add_skill(&mut self, team_id: Uuid, source_cryp_id: Uuid, target_team_id: Uuid, skill: Skill) -> Result<Uuid, Error> {
        if self.phase != Phase::Skill {
            return Err(err_msg("game not in skill phase"));
        }

        {
            let cryp = match self.cryp_by_id(source_cryp_id) {
                Some(c) => c,
                None => return Err(err_msg("cryp not in team")),
            };

            // check the cryp has the skill
            if !cryp.knows(skill) {
                return Err(err_msg("cryp does not have that skill"));
            }

            if cryp.skill_on_cd(skill).is_some() {
               return Err(err_msg("abiltity on cooldown"));
            }

            if !cryp.skill_can_cast(skill) {
               return Err(err_msg("cryp cannot cast spell"));
            }
        }


        // replace cryp skill
        if let Some(s) = self.skills.iter_mut().position(|s| s.source_cryp_id == source_cryp_id) {
            self.skills.remove(s);
        }

        let skill = Cast::new(source_cryp_id, team_id, target_team_id, skill);
        self.skills.push(skill);

        return Ok(skill.id);
    }

    fn skill_phase_finished(&self) -> bool {
        self.teams.iter()
            // for every team
            .all(|t| self.skills.iter()
                // the number of skills they have cast
                .filter(|s| s.target_team_id == t.id)
                .collect::<Vec<&Cast>>()
                // should equal the number required this turn
                .len() == t.skills_required()
            )
    }

    // move all skills into their target team's targets list
    fn target_phase_start(&mut self) -> &mut Game {
        if self.phase != Phase::Skill {
            panic!("game not in skill phase");
        }

        self.phase = Phase::Target;

        if self.is_pve {
            self.pve_add_targets();
        }

        // all cryps are stunned or otherwise inactive
        if self.target_phase_finished() {
            self.damage_phase_start();
        }

        self
    }

    fn pve_add_targets(&mut self) -> &mut Game {
        {
            let mob_team_id = Uuid::nil();
            let mobs = self.team_by_id(mob_team_id).clone();
            // TODO attack multiple players based on some criteria
            for incoming_skill_id in self.skills.clone().iter().filter(|s| s.target_team_id == mob_team_id).map(|s| s.id) {
                self.add_target(mob_team_id, mobs.cryps[0].id, incoming_skill_id).unwrap();
            }
        }

        self
    }

    // targets can only be added by the owner of the team
    fn add_target(&mut self, team_id: Uuid, cryp_id: Uuid, cast_id: Uuid) -> Result<&mut Cast, Error> {
        {
            // whose team is this?
            let team = self.team_by_id(team_id);

            // is the target in the team?
            match team.cryp_by_id(cryp_id) {
                Some(c) => c,
                None => return Err(err_msg("cryp not in team")),
            };
        }

        // set the target
        let cast = match self.skills.iter_mut().find(|s| s.id == cast_id) {
            Some(c) => c,
            None => return Err(err_msg("cast_id not found")),
        };

        Ok(cast.set_target(cryp_id))
    }

    fn target_phase_finished(&self) -> bool {
        self.skills.iter().all(|s| s.target_cryp_id.is_some())
    }

    // requires no input
    // just do it
    fn damage_phase_start(&mut self) -> &mut Game {
        if self.phase != Phase::Target {
            panic!("game not in target phase");
        }

        self.phase = Phase::Damage;

        self.resolve_skills();

        if self.is_finished() {
            return self.finish()
        }

        self.skill_phase_start();

        self
    }

    fn resolve_skills(&mut self) -> &mut Game {
        if self.phase != Phase::Damage {
            panic!("game not in damage phase");
        }

        for skill in self.skills.clone().iter_mut() {
            let mut source = self.cryp_by_id(skill.source_cryp_id).unwrap().clone();
            let mut target = self.cryp_by_id(skill.target_cryp_id.unwrap()).unwrap().clone();
            let resolution = skill.resolve(&mut source, &mut target);

            self.update_cryp(&mut source);
            self.update_cryp(&mut target);
        }

        // now damage has all been assigned
        // handle cooldowns
        self.progress_cooldowns();

        self
    }

    fn progress_cooldowns(&mut self) -> &mut Game {
        for skill in self.skills.clone().iter() {
            // copy the creep cause we will replace it
            let mut cryp = self.cryp_by_id(skill.source_cryp_id).unwrap().clone();

            if skill.used_cooldown() {
                cryp.skill_set_cd(skill.skill);
                self.update_cryp(&mut cryp);
                continue;
            }

            cryp.decrease_cooldowns();

            println!("{:?}", cryp);

            self.update_cryp(&mut cryp);
        }

        self
    }


    fn is_finished(&self) -> bool {
        self.teams.iter().any(|t| t.cryps.iter().all(|c| c.is_ko()))
    }

    fn finish(&mut self) -> &mut Game {
        self.phase = Phase::Finish;

        self.skills.clear();

        self
    }
}

pub fn game_skill(params: GameSkillParams, tx: &mut Transaction, account: &Account) -> Result<Game, Error> {
    let query = "
        SELECT *
        FROM games
        WHERE id = $1
    ";

    let result = tx
        .query(query, &[&params.game_id])?;

    let returned = match result.iter().next() {
        Some(row) => row,
        None => return Err(err_msg("game not found")),
    };

    // tells from_slice to cast into a cryp
    let game_bytes: Vec<u8> = returned.get("data");
    let mut game = from_slice::<Game>(&game_bytes)?;

    game.add_skill(account.id, params.cryp_id, params.target_team_id, params.skill)?;

    if game.skill_phase_finished() {
        game.target_phase_start();
    }

    game_update(&game, tx)?;

    Ok(game)
}

pub fn game_target(params: GameTargetParams, tx: &mut Transaction, account: &Account) -> Result<Game, Error> {
    let query = "
        SELECT *
        FROM games
        WHERE id = $1
    ";

    let result = tx
        .query(query, &[&params.game_id])?;

    let returned = match result.iter().next() {
        Some(row) => row,
        None => return Err(err_msg("game not found")),
    };

    // tells from_slice to cast into a cryp
    let game_bytes: Vec<u8> = returned.get("data");
    let mut game = from_slice::<Game>(&game_bytes)?;

    game.add_target(account.id, params.cryp_id, params.skill_id)?;

    if game.target_phase_finished() {
        game.damage_phase_start();
    }

    game_update(&game, tx)?;

    Ok(game)
}

pub fn game_new(game: &Game, tx: &mut Transaction) -> Result<(), Error> {
    let game_bytes = to_vec(&game)?;

    let query = "
        INSERT INTO games (id, data)
        VALUES ($1, $2)
        RETURNING id;
    ";

    let result = tx
        .query(query, &[&game.id, &game_bytes])?;

    result.iter().next().ok_or(format_err!("no game written"))?;

    println!("{:?} wrote game", game.id);

    return Ok(());
}

pub fn game_state(params: GameStateParams, tx: &mut Transaction, _account: &Account) -> Result<Game, Error> {
    return game_get(tx, params.id)
}

pub fn game_get(tx: &mut Transaction, id: Uuid) -> Result<Game, Error> {
    let query = "
        SELECT *
        FROM games
        WHERE id = $1
    ";

    let result = tx
        .query(query, &[&id])?;

    let returned = match result.iter().next() {
        Some(row) => row,
        None => return Err(err_msg("game not found")),
    };

    // tells from_slice to cast into a cryp
    let game_bytes: Vec<u8> = returned.get("data");
    let game = from_slice::<Game>(&game_bytes)?;

    return Ok(game);
}

/// write a row for every cryp in a team when added to a battle
pub fn players_write(team: &Team, game_id: Uuid, tx: &mut Transaction) -> Result<(), Error> {
    // pve
    if !team.id.is_nil() {
        for cryp in &team.cryps {
            let id = Uuid::new_v4();

            let query = "
                INSERT INTO players (id, game, cryp, account)
                VALUES ($1, $2, $3, $4)
                RETURNING id, account;
            ";

            let result = tx
                .query(query, &[&id, &game_id, &cryp.id, &team.id])?;

            let _returned = result.iter().next().expect("no row written");

            println!("wrote player entry game:{:?} cryp:{:?} account:{:?}", game_id, cryp.id, team.id);
        }
    }

    return Ok(());
}

pub fn game_update(game: &Game, tx: &mut Transaction) -> Result<(), Error> {
    let game_bytes = to_vec(&game)?;

    let query = "
        UPDATE games
        SET data = $1
        WHERE id = $2
        RETURNING id, data;
    ";

    let result = tx
        .query(query, &[&game_bytes, &game.id])?;

    result.iter().next().ok_or(format_err!("game {:?} could not be written", game))?;

    println!("{:?} wrote game", game.id);

    return Ok(());
}

fn generate_mob(plr: &Cryp) -> Cryp {
    let mut rng = thread_rng();

    // rng panics on min == max
    let mob_lvl: u8 = match plr.lvl {
      1 => 1,
      _ => rng.gen_range(1, plr.lvl)
    };

    return Cryp::new()
        .named(&"bamboo basher".to_string())
        .level(mob_lvl)
        .create();

}

pub fn game_pve(params: GamePveParams, tx: &mut Transaction, account: &Account) -> Result<Game, Error> {
    let query = "
        SELECT *
        FROM cryps
        WHERE id = $1
        AND account = $2;
    ";

    let result = tx
        .query(query, &[&params.id, &account.id])?;

    let returned = match result.iter().next() {
        Some(row) => row,
        None => return Err(err_msg("cryp not found")),
    };

    // tells from_slice to cast into a cryp
    let cryp_bytes: Vec<u8> = returned.get("data");
    let plr: Cryp = from_slice::<Cryp>(&cryp_bytes)?;

    // TEMP
    if plr.hp.value == 0 {
      return Err(err_msg("cryp is ko"));
        // plr.rez();
    }

    let mob = generate_mob(&plr);

    let mut game = Game::new();

    let game_id = game.id;

    game
        .set_team_num(2)
        .set_team_size(1);

    let mut plr_team = Team::new(account.id);
    plr_team
        .set_cryps(vec![plr]);

    let mut mob_team = Team::new(Uuid::nil());
    mob_team
        .set_cryps(vec![mob]);

    game
        .add_team(plr_team)?
        .add_team(mob_team)?;

    game.start();

    // persist
    game_new(&game, tx)?;
    players_write(&game.team_by_id(account.id), game_id, tx)?;

    Ok(game)
}

pub fn game_pvp(params: GamePvpParams, tx: &mut Transaction, account: &Account) -> Result<Game, Error> {
    let cryps = params.cryp_ids
        .iter()
        .map(|id| cryp_get(tx, *id, account.id))
        .collect::<Result<Vec<Cryp>, Error>>()?;

    // create the game
    let mut game = Game::new();
    let game_id = game.id;

    game
        .set_pve(false)
        .set_team_num(2)
        .set_team_size(1);

    // create the initiators team
    let mut team = Team::new(account.id);
    team.set_cryps(cryps);

    game.add_team(team)?;

    // persist
    game_new(&game, tx)?;
    players_write(&game.team_by_id(account.id), game_id, tx)?;

    Ok(game)
}

pub fn game_join(params: GameJoinParams, tx: &mut Transaction, account: &Account) -> Result<Game, Error> {
    let mut game = game_get(tx, params.game_id)?;
    let game_id = game.id;

    let cryps = params.cryp_ids
        .iter()
        .map(|id| cryp_get(tx, *id, account.id))
        .collect::<Result<Vec<Cryp>, Error>>()?;

    let mut team = Team::new(account.id);
    team.set_cryps(cryps);

    game.add_team(team)?;

    if game.can_start() {
        game.start();
    }

    game_update(&game, tx)?;
    players_write(&game.team_by_id(account.id), game_id, tx)?;

    Ok(game)
}


#[cfg(test)]
mod tests {
    use game::*;
    use cryp::*;

    fn create_test_game() -> Game {
        let x = Cryp::new()
            .named(&"pronounced \"creeep\"".to_string())
            .level(8)
            .learn(Skill::TestStun)
            .learn(Skill::TestTouch)
            .learn(Skill::Block)
            .create();

        let y = Cryp::new()
            .named(&"lemongrass tea".to_string())
            .level(8)
            .learn(Skill::TestStun)
            .learn(Skill::TestTouch)
            .learn(Skill::Block)
            .create();

        let mut game = Game::new();

        game
            .set_team_num(2)
            .set_team_size(1)
            .set_pve(false);

        let x_team_id = Uuid::new_v4();
        let mut x_team = Team::new(x_team_id);
        x_team
            .set_cryps(vec![x]);

        let y_team_id = Uuid::new_v4();
        let mut y_team = Team::new(y_team_id);
        y_team
            .set_cryps(vec![y]);

        game
            .add_team(x_team).unwrap()
            .add_team(y_team).unwrap();

        assert!(game.can_start());

        game.start();

        return game;
    }

    #[test]
    fn phase_test() {
        let mut game = create_test_game();

        let x_team = game.teams[0].clone();
        let y_team = game.teams[1].clone();

        let x_cryp = x_team.cryps[0].clone();
        let y_cryp = y_team.cryps[0].clone();

        let x_attack_id = game.add_skill(x_team.id, x_cryp.id, y_team.id, Skill::Attack).unwrap();
        let y_attack_id = game.add_skill(y_team.id, y_cryp.id, x_team.id, Skill::Attack).unwrap();

        assert!(game.skill_phase_finished());

        game.target_phase_start();

        game.add_target(x_team.id, x_cryp.id, y_attack_id).unwrap();
        game.add_target(y_team.id, y_cryp.id, x_attack_id).unwrap();

        assert!(game.target_phase_finished());

        game.damage_phase_start();

        assert!([Phase::Skill, Phase::Finish].contains(&game.phase));

        return;
    }

    #[test]
    fn stun_test() {
        let mut game = create_test_game();

        let x_team = game.teams[0].clone();
        let y_team = game.teams[1].clone();

        let x_cryp = x_team.cryps[0].clone();
        let y_cryp = y_team.cryps[0].clone();

        let x_stun_id = game.add_skill(x_team.id, x_cryp.id, y_team.id, Skill::TestStun).unwrap();
        let y_attack_id = game.add_skill(y_team.id, y_cryp.id, x_team.id, Skill::TestTouch).unwrap();

        assert!(game.skill_phase_finished());
        game.target_phase_start();

        game.add_target(x_team.id, x_cryp.id, y_attack_id).unwrap();
        game.add_target(y_team.id, y_cryp.id, x_stun_id).unwrap();

        assert!(game.target_phase_finished());
        game.damage_phase_start();

        // should auto progress back to skill phase
        assert!(game.phase == Phase::Skill);

        println!("{:#?}", game);
        assert!(game.team_by_id(y_team.id).cryps[0].is_stunned());
        assert!(game.team_by_id(y_team.id).skills_required() == 0);
    }

    #[test]
    fn cooldown_test() {
        let mut game = create_test_game();

        let x_team = game.teams[0].clone();
        let y_team = game.teams[1].clone();

        let x_cryp = x_team.cryps[0].clone();
        let y_cryp = y_team.cryps[0].clone();

        let x_stun_id = game.add_skill(x_team.id, x_cryp.id, y_team.id, Skill::TestTouch).unwrap();
        let y_attack_id = game.add_skill(y_team.id, y_cryp.id, x_team.id, Skill::TestTouch).unwrap();

        game.target_phase_start();
        game.add_target(x_team.id, x_cryp.id, y_attack_id).unwrap();
        game.add_target(y_team.id, y_cryp.id, x_stun_id).unwrap();

        game.damage_phase_start();

        // should auto progress back to skill phase
        assert!(game.phase == Phase::Skill);

        // after 1 turn block should be off cooldown
        assert!(game.team_by_id(y_team.id).cryps[0].skill_on_cd(Skill::Block).is_none());

        // second round
        // now we block and it should go back on cd
        let x_block_id = game.add_skill(x_team.id, x_cryp.id, y_team.id, Skill::Block).unwrap();
        let y_block_id = game.add_skill(y_team.id, y_cryp.id, x_team.id, Skill::Block).unwrap();

        game.target_phase_start();
        game.add_target(x_team.id, x_cryp.id, y_block_id).unwrap();
        game.add_target(y_team.id, y_cryp.id, x_block_id).unwrap();
        game.damage_phase_start();

        assert!(game.team_by_id(y_team.id).cryps[0].skill_on_cd(Skill::Block).is_some());
        println!("{:#?}", game);
    }
}