use uuid::Uuid;
use rand::prelude::*;
use serde_cbor::{from_slice, to_vec};

use postgres::transaction::Transaction;

use failure::Error;
use failure::err_msg;

use account::Account;
use rpc::{CrypSpawnParams, CrypLearnParams, CrypForgetParams, CrypUnspecParams};
use skill::{Skill, Cooldown, Effect, Cast, Category, Immunity, Disable, ResolutionResult};
use spec::{Spec, SpecLevel};
use game::{Log};

#[derive(Debug,Clone,Copy,PartialEq,Serialize,Deserialize)]
pub struct CrypSkill {
    pub skill: Skill,
    pub self_targeting: bool,
    pub cd: Cooldown,
}

impl CrypSkill {
    pub fn new(skill: Skill) -> CrypSkill {
        CrypSkill {
            skill,
            self_targeting: skill.self_targeting(),
            cd: skill.base_cd(),
        }
    }
}

#[derive(Debug,Clone,PartialEq,Serialize,Deserialize)]
pub struct CrypEffect {
    pub effect: Effect,
    pub duration: u8,
    pub tick: Option<Cast>,
}

#[derive(Debug,Clone,Copy,PartialEq,Serialize,Deserialize)]
pub enum Stat {
    Str,
    Agi,
    Int,
    Hp,
    Speed,
    Stamina,
    PhysicalDamage,
    PhysicalDamageTaken,
    SpellDamage,
    SpellDamageTaken,
    Healing,
    HealingTaken,
    Armour,
    SpellShield,
    Evasion,
}

#[derive(Debug,Clone,Copy,PartialEq,Serialize,Deserialize)]
pub struct CrypStat {
    base: u64,
    value: u64,
    pub stat: Stat,
}

impl CrypStat {
    pub fn set(&mut self, v: u64, specs: &CrypSpecs) -> &mut CrypStat {
        self.base = v;
        self.recalculate(specs)
    }

    pub fn recalculate(&mut self, specs: &CrypSpecs) -> &mut CrypStat {
        let specs = specs.affects(self.stat);
        // applied with fold because it can be zeroed or multiplied
        // but still needs access to the base amount
        let value = specs.iter().fold(self.base, |acc, s| s.apply(acc, self.base));
        self.value = value;

        self
    }

    pub fn reduce(&mut self, amt: u64) -> &mut CrypStat {
        self.value = self.value.saturating_sub(amt);
        self
    }

    pub fn increase(&mut self, amt: u64) -> &mut CrypStat {
        self.value = self.value.saturating_add(amt);
        self
    }

    pub fn force(&mut self, v: u64) -> &mut CrypStat {
        self.base = v;
        self.value = v;

        self
    }
}


#[derive(Debug,Clone,Serialize,Deserialize)]
pub struct CrypSpecs {
    common: Vec<Spec>,
    uncommon: Vec<Spec>,
    rare: Vec<Spec>,
}

impl CrypSpecs {
    fn new() -> CrypSpecs {
        CrypSpecs {
            common: vec![],
            uncommon: vec![],
            rare: vec![],
        }
    }

    fn affects(&self, stat: Stat) -> Vec<Spec> {
        [&self.common, &self.uncommon, &self.rare]
            .iter()
            .flat_map(|specs| specs.iter().filter(|s| s.affects == stat))
            .map(|s| *s)
            .collect::<Vec<Spec>>()
    }
}

#[derive(Debug,Clone,Serialize,Deserialize)]
pub struct CrypRecover {
    pub id: Uuid,
    pub account: Uuid,
    pub xp: u64,
    pub lvl: u8,
    pub name: String,
}

#[derive(Debug,Clone,Serialize,Deserialize)]
pub struct Cryp {
    pub id: Uuid,
    pub account: Uuid,
    pub phys_dmg: CrypStat,
    pub spell_dmg: CrypStat,
    pub speed: CrypStat,
    pub stamina: CrypStat,
    pub hp: CrypStat,
    pub armour: CrypStat,
    pub spell_shield: CrypStat,
    pub evasion: CrypStat,
    pub xp: u64,
    pub lvl: u8,
    pub skills: Vec<CrypSkill>,
    pub effects: Vec<CrypEffect>,
    pub specs: CrypSpecs,
    pub name: String,
    pub ko_logged: bool,
}

fn check_lvl(lvl: u8) -> u8 {
    if lvl > 64 { return 64; }
    return lvl;
}

impl Cryp {
    pub fn new() -> Cryp {
        let id = Uuid::new_v4();
        return Cryp {
            id,
            account: id,
            phys_dmg: CrypStat { base: 0, value: 0, stat: Stat::PhysicalDamage },
            spell_dmg: CrypStat { base: 0, value: 0, stat: Stat::SpellDamage },
            speed: CrypStat { base: 0, value: 0, stat: Stat::Speed },
            stamina: CrypStat { base: 0, value: 0, stat: Stat::Stamina },
            hp: CrypStat { base: 0, value: 0, stat: Stat::Hp },
            armour: CrypStat { base: 0, value: 0, stat: Stat::Armour },
            spell_shield: CrypStat { base: 0, value: 0, stat: Stat::SpellShield },
            evasion: CrypStat { base: 0, value: 0, stat: Stat::Evasion },
            lvl: 0,
            xp: 0,
            skills: vec![],
            effects: vec![],
            specs: CrypSpecs::new(),
            name: String::new(),
            ko_logged: false,
        };
    }

    pub fn named(mut self, name: &String) -> Cryp {
        self.name = name.clone();
        self
    }

    pub fn set_account(mut self, account: Uuid) -> Cryp {
        self.account = account;
        self
    }

    pub fn level(mut self, lvl: u8) -> Cryp {
        self.lvl = check_lvl(lvl);
        self
    }

    pub fn learn(mut self, s: Skill) -> Cryp {
        self.skills.push(CrypSkill::new(s));
        self
    }

    pub fn forget(mut self, skill: Skill) -> Result<Cryp, Error> {
        match self.skills.iter().position(|s| s.skill == skill) {
            Some(i) => {
                self.skills.remove(i);
                return Ok(self);
            },
            None => Err(format_err!("{:?} does not know {:?}", self.name, skill)),
        }
    }

    // pub fn add_xp(mut self) -> Cryp {
    //     self.xp = self.xp.saturating_add(1);
    //     if self.xp.is_power_of_two() {
    //         return self.level_up();
    //     }
    //     self
    // }

    // pub fn level_up(mut self) -> Cryp {
    //     self.lvl = self.lvl.saturating_add(1);
    //     self.create()
    // }

    pub fn roll_stat(&mut self, stat: Stat) -> &mut Cryp {
        let mut rng = thread_rng();

        let stam_min = 512u64.saturating_mul(self.lvl.into());
        let stam_max = 1024u64.saturating_mul(self.lvl.into());

        let stat_min = 128u64.saturating_mul(self.lvl.into());
        let stat_max = 256u64.saturating_mul(self.lvl.into());

        let evasion_min = 1u64;
        let evasion_max = 5;

        match stat {
            Stat::PhysicalDamage => self.phys_dmg.set(rng.gen_range(stat_min, stat_max), &self.specs),
            Stat::SpellDamage => self.spell_dmg.set(rng.gen_range(stat_min, stat_max), &self.specs),
            Stat::Speed => self.speed.set(rng.gen_range(stat_min, stat_max), &self.specs),
            Stat::Stamina => {
                self.stamina.set(rng.gen_range(stam_min, stam_max), &self.specs);
                self.hp.set(self.stamina.base, &self.specs)
            },
            Stat::SpellShield => self.spell_shield.set(rng.gen_range(stat_min, stat_max), &self.specs),
            Stat::Armour => self.armour.set(rng.gen_range(stat_min, stat_max), &self.specs),
            Stat::Evasion => self.evasion.set(rng.gen_range(evasion_min, evasion_max), &self.specs),
            _ => panic!("{:?} not a rollable stat", stat),
        };

        self
    }

    pub fn create(mut self) -> Cryp {
        let xp = match self.lvl == 64 {
            true => u64::max_value(),
            false => 2_u64.pow(self.lvl.into()),
        };

        self.xp = xp;

        self.roll_stat(Stat::PhysicalDamage);
        self.roll_stat(Stat::SpellDamage);
        self.roll_stat(Stat::Speed);
        self.roll_stat(Stat::Stamina);

        self
    }

    pub fn spec_add(&mut self, spec: Spec) -> Result<&mut Cryp, Error> {
        let max_common = 20;
        let max_uncommon = 10;
        let max_rare = 5;

        match spec.level {
            SpecLevel::Common => {
                if self.specs.common.len() >= max_common {
                    return Err(format_err!("cryp at maximum common specalisations ({:})", max_common))
                }

                self.specs.common.push(spec);
            },
            SpecLevel::Uncommon => {
                if self.specs.uncommon.len() >= max_uncommon {
                    return Err(format_err!("cryp at maximum uncommon specalisations ({:})", max_uncommon))
                }

                self.specs.uncommon.push(spec);
            },
            SpecLevel::Rare => {
                if self.specs.rare.len() >= max_rare {
                    return Err(format_err!("cryp at maximum rare specalisations ({:})", max_rare))
                }

                if self.specs.rare.iter().find(|s| s.spec == spec.spec).is_some() {
                    return Err(format_err!("duplicate rare specialisation {:?}", spec.spec));
                }

                self.specs.rare.push(spec);
            },
        };

        return Ok(self.recalculate_stats());
    }

    pub fn spec_remove(mut self, spec: Spec) -> Result<Cryp, Error> {
        let find_spec = |spec_v: &Vec<Spec>| spec_v.iter().position(|s| s.spec == spec.spec);

        match spec.level {
            SpecLevel::Common => match find_spec(&self.specs.common) {
                Some(p) => self.specs.common.remove(p),
                None => return Err(err_msg("spec not found")),
            },
            SpecLevel::Uncommon => match find_spec(&self.specs.uncommon) {
                Some(p) => self.specs.uncommon.remove(p),
                None => return Err(err_msg("spec not found")),
            },
            SpecLevel::Rare => match find_spec(&self.specs.rare) {
                Some(p) => self.specs.rare.remove(p),
                None => return Err(err_msg("spec not found")),
            },
        };

        Ok(self)
    }


    fn recalculate_stats(&mut self) -> &mut Cryp {
        self.stamina.recalculate(&self.specs);
        self.hp.recalculate(&self.specs);
        self.phys_dmg.recalculate(&self.specs);
        self.spell_dmg.recalculate(&self.specs);
        self.evasion.recalculate(&self.specs);
        self.armour.recalculate(&self.specs);
        self.spell_shield.recalculate(&self.specs);
        self.speed.recalculate(&self.specs);

        self
    }

    pub fn is_ko(&self) -> bool {
        self.hp.value == 0
    }

    pub fn immune(&self, skill: Skill) -> Immunity {
        if self.is_ko() {
           return Immunity { immune: true, effects: vec![Effect::Ko]};
        }

        let immunities = self.effects.iter()
            .filter(|e| e.effect.immune(skill))
            .map(|e| e.effect)
            .collect::<Vec<Effect>>();

        if immunities.len() > 0 {
            return Immunity { immune: true, effects: immunities};
        }

        return Immunity { immune: false, effects: vec![]};
    }

    pub fn disabled(&self, skill: Skill) -> Disable {
        if self.is_ko() && !skill.ko_castable() {
           return Disable { disabled: true, effects: vec![Effect::Ko]};
        }

        let disables = self.effects.iter()
            .filter(|e| e.effect.disables_skill(skill))
            .map(|e| e.effect)
            .collect::<Vec<Effect>>();

        if disables.len() > 0 {
            return Disable { disabled: true, effects: disables};
        }

        return Disable { disabled: false, effects: vec![]};
    }


    pub fn is_stunned(&self) -> bool {
        self.effects.iter().any(|s| s.effect == Effect::Stun)
    }

    pub fn available_skills(&self) -> Vec<&CrypSkill> {
        self.skills.iter()
            .filter(|s| s.cd.is_none())
            .filter(|s| !self.disabled(s.skill).disabled)
            .collect()
    }

    pub fn mob_select_skill(&self) -> Option<Skill> {
        let available = self.available_skills();

        if available.len() == 0 {
            return None;
        }

        let highest_cd = available.iter()
            .filter(|s| s.skill.base_cd().is_some())
            .max_by_key(|s| s.skill.base_cd().unwrap());

        return match highest_cd {
            Some(s) => Some(s.skill),
            None => Some(available[0].skill),
        };
    }

    pub fn knows(&self, skill: Skill) -> bool {
        self.skills.iter().any(|s| s.skill == skill)
    }

    pub fn skill_on_cd(&self, skill: Skill) -> Option<&CrypSkill> {
        self.skills.iter().find(|s| s.skill == skill && s.cd.is_some())
    }

    pub fn skill_set_cd(&mut self, skill: Skill) -> &mut Cryp {
        let i = self.skills.iter().position(|s| s.skill == skill).unwrap();
        self.skills.remove(i);
        self.skills.push(CrypSkill::new(skill));

        self
    }

    pub fn reduce_cooldowns(&mut self) -> &mut Cryp {
        for skill in self.skills.iter_mut() {
            // if used cooldown
            if skill.skill.base_cd().is_some() {
                // what is the current cd
                if let Some(current_cd) = skill.cd {

                    // if it's 1 set it to none
                    if current_cd == 1 {
                        skill.cd = None;
                        continue;
                    }

                    // otherwise decrement it
                    skill.cd = Some(current_cd.saturating_sub(1));
                }

            }
        }

        self
    }

    pub fn reduce_effect_durations(&mut self, _log: &mut Log) -> &mut Cryp {
        self.effects = self.effects.clone().into_iter().filter_map(|mut effect| {
            effect.duration = effect.duration.saturating_sub(1);

            if effect.duration == 0 {
                return None;
            }

            // println!("reduced effect {:?}", effect);
            return Some(effect);
        }).collect::<Vec<CrypEffect>>();

        self
    }

    // pub fn rez(&mut self) -> &mut Cryp {
    //     self.hp.set(self.stamina.base);
    //     self
    // }

    // Stats
    pub fn phys_dmg(&self) -> u64 {
        let phys_dmg_mods = self.effects.iter()
            .filter(|e| e.effect.modifications().contains(&Stat::PhysicalDamage))
            .map(|cryp_effect| cryp_effect.effect)
            .collect::<Vec<Effect>>();

        let modified_phys_dmg = phys_dmg_mods.iter().fold(self.phys_dmg.value, |acc, m| m.apply(acc));
        return modified_phys_dmg;
    }

    pub fn spell_dmg(&self) -> u64 {
        let spell_dmg_mods = self.effects.iter()
            .filter(|e| e.effect.modifications().contains(&Stat::SpellDamage))
            .map(|cryp_effect| cryp_effect.effect)
            .collect::<Vec<Effect>>();

        let modified_spell_dmg = spell_dmg_mods.iter().fold(self.spell_dmg.value, |acc, m| m.apply(acc));
        return modified_spell_dmg;
    }

    pub fn skill_speed(&self, s: Skill) -> u64 {
        self.speed().saturating_mul(s.speed() as u64)
    }

    pub fn speed(&self) -> u64 {
        let speed_mods = self.effects.iter()
            .filter(|e| e.effect.modifications().contains(&Stat::Speed))
            .map(|cryp_effect| cryp_effect.effect)
            .collect::<Vec<Effect>>();

        let modified_speed = speed_mods.iter().fold(self.speed.value, |acc, m| m.apply(acc));
        return modified_speed;
    }

    pub fn hp(&self) -> u64 {
        self.hp.value
    }

    pub fn stamina(&self) -> u64 {
        self.stamina.value
    }

    pub fn heal(&mut self, skill: Skill, amount: u64) -> ResolutionResult {
        let immunity = self.immune(skill);
        let immune = immunity.immune;

        if immune {
            ResolutionResult::Healing {
                amount: 0,
                overhealing: 0,
                category: Category::PhysHeal,
                immunity: immunity.clone(),
            };
        }

        let healing_mods = self.effects.iter()
            .filter(|e| e.effect.modifications().contains(&Stat::HealingTaken))
            .map(|cryp_effect| cryp_effect.effect)
            .collect::<Vec<Effect>>();

        // println!("{:?}", healing_mods);

        let modified_healing = healing_mods.iter().fold(amount, |acc, m| m.apply(acc));

        let current_hp = self.hp();
        let new_hp = *[
            self.hp().saturating_add(modified_healing),
            self.stamina()
        ].iter().min().unwrap();

        let healing = new_hp - current_hp;
        let overhealing = amount - healing;

        self.hp.increase(healing);

        return ResolutionResult::Healing {
            amount: healing,
            overhealing,
            category: Category::PhysHeal,
            immunity,
        };
    }

    pub fn deal_phys_dmg(&mut self, skill: Skill, amount: u64) -> ResolutionResult {
        let immunity = self.immune(skill);
        let immune = immunity.immune;

        if immune {
            return ResolutionResult::Damage {
                amount: 0,
                mitigation: 0,
                category: Category::PhysDmg,
                immunity,
            };
        }

        let phys_dmg_mods = self.effects.iter()
            .filter(|e| e.effect.modifications().contains(&Stat::PhysicalDamageTaken))
            .map(|cryp_effect| cryp_effect.effect)
            .collect::<Vec<Effect>>();

        // println!("{:?}", phys_dmg_mods);

        let modified_dmg = phys_dmg_mods.iter().fold(amount, |acc, m| m.apply(acc));

        // calculate amount of damage armour will not absorb
        // eg 50 armour 25 dmg  ->  0 remainder     25 mitigation
        //    50 armour 100 dmg ->  50 remainder    50 mitigation
        //    50 armour 5 dmg   ->  0 remainder     5  mitigation
        let remainder = modified_dmg.saturating_sub(self.armour.value);
        let mitigation = modified_dmg.saturating_sub(remainder);

        // reduce armour by mitigation amount
        self.armour.reduce(mitigation);

        // deal remainder to hp
        self.hp.reduce(remainder);

        return ResolutionResult::Damage {
            amount: remainder,
            mitigation,
            category: Category::PhysDmg,
            immunity,
        };
    }

    pub fn deal_spell_dmg(&mut self, skill: Skill, amount: u64) -> ResolutionResult {
        let immunity = self.immune(skill);
        let immune = immunity.immune;

        if immune {
            return ResolutionResult::Damage {
                amount: 0,
                mitigation: 0,
                category: Category::SpellDmg,
                immunity,
            };
        }

        let spell_dmg_mods = self.effects.iter()
            .filter(|e| e.effect.modifications().contains(&Stat::SpellDamageTaken))
            .map(|cryp_effect| cryp_effect.effect)
            .collect::<Vec<Effect>>();

        // println!("{:?}", spell_dmg_mods);

        let modified_dmg = spell_dmg_mods.iter().fold(amount, |acc, m| m.apply(acc));
        let remainder = modified_dmg.saturating_sub(self.armour.value);
        let mitigation = modified_dmg.saturating_sub(remainder);

        self.armour.reduce(mitigation);
        self.hp.reduce(remainder);

        return ResolutionResult::Damage {
            amount: remainder,
            mitigation,
            category: Category::SpellDmg,
            immunity,
        };
    }

    pub fn add_effect(&mut self, skill: Skill, effect: CrypEffect) -> ResolutionResult {
        let immunity = self.immune(skill);
        let immune = immunity.immune;

        // todo modified durations cause of buffs
        let result = ResolutionResult::Effect {
            effect: effect.effect,
            duration: effect.effect.duration(),
            immunity,
        };

        if !immune {
            // println!("{:?} {:?} adding effect", self.name, effect.effect);
            self.effects.push(effect);
        }

        return result;
    }

    pub fn evade(&self, skill: Skill) -> Option<ResolutionResult> {
        if self.evasion.value == 0 {
            return None;
        }

        let mut rng = thread_rng();
        let hp_pct = (self.hp.value * 100) / self.stamina.value;
        let evasion_rating = (self.evasion.value * hp_pct) / 100;
        let roll = rng.gen_range(0, 100);
        println!("{:} < {:?}", roll, evasion_rating);

        match roll < evasion_rating {
            true => Some(ResolutionResult::Evasion {
                skill,
                evasion_rating: evasion_rating,
            }),
            false => None,
        }
    }
}

pub fn cryp_get(tx: &mut Transaction, id: Uuid, account_id: Uuid) -> Result<Cryp, Error> {
    let query = "
        SELECT data
        FROM cryps
        WHERE id = $1
        AND account = $2;
    ";

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

    let result = result.iter().next().ok_or(format_err!("cryp {:} not found", id))?;
    let cryp_bytes: Vec<u8> = result.get(0);
    let cryp = from_slice::<Cryp>(&cryp_bytes)?;

    return Ok(cryp);
}

pub fn cryp_spawn(params: CrypSpawnParams, tx: &mut Transaction, account: &Account) -> Result<Cryp, Error> {
    let cryp = Cryp::new()
        .named(&params.name)
        .learn(Skill::Attack)
        .level(1)
        .set_account(account.id)
        .create();

    let cryp_bytes = to_vec(&cryp)?;

    let query = "
        INSERT INTO cryps (id, account, data)
        VALUES ($1, $2, $3)
        RETURNING id, account;
    ";

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

    let _returned = result.iter().next().ok_or(err_msg("no row returned"))?;

    // println!("{:?} spawned cryp {:}", account.id, cryp.id);

    return Ok(cryp);
}

pub fn cryp_learn(params: CrypLearnParams, tx: &mut Transaction, account: &Account) -> Result<Cryp, Error> {
    let mut cryp = cryp_get(tx, params.id, account.id)?;

    // done here because i teach them a tonne of skills for tests
    let max_skills = 4;
    if cryp.skills.len() >= max_skills {
        return Err(format_err!("cryp at max skills ({:?})", max_skills));
    }

    cryp = cryp.learn(params.skill);
    return cryp_write(cryp, tx);
}

pub fn cryp_forget(params: CrypForgetParams, tx: &mut Transaction, account: &Account) -> Result<Cryp, Error> {
    let mut cryp = cryp_get(tx, params.id, account.id)?;
    cryp = cryp.forget(params.skill)?;
    return cryp_write(cryp, tx);
}

pub fn cryp_unspec(params: CrypUnspecParams, tx: &mut Transaction, account: &Account) -> Result<Cryp, Error> {
    let mut cryp = cryp_get(tx, params.id, account.id)?;
    cryp = cryp.spec_remove(params.spec)?;
    return cryp_write(cryp, tx);
}

pub fn cryp_write(cryp: Cryp, tx: &mut Transaction) -> Result<Cryp, Error> {
    let cryp_bytes = to_vec(&cryp)?;

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

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

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

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

    return Ok(cryp);
}

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

  #[test]
  fn create_cryp_test() {
        let max_level = Cryp::new()
            .named(&"hatchling".to_string())
            .level(64)
            // .learn(Skill::Stoney)
            .create();

        assert_eq!(max_level.lvl, 64);
        return;
    }
}