// TOOD: `pub(super) for most of these?`
use std::io::{Read};
use std::collections::HashMap;

use byteorder::{LittleEndian, ReadBytesExt};
use thiserror::Error;

use crate::ship::monster::MonsterType;
use crate::ship::room::Episode;

use crate::ship::map::*;

use rand::{Rng, SeedableRng};
use serde::{Serialize, Deserialize};
use crate::ship::drops::{load_rare_monster_file};

#[derive(Debug, Copy, Clone)]
pub struct RawMapEnemy {
    id: u32,
    _unknown1: u16,
    pub children: u16,
    _map_area: u16,
    _unknown4: u16,
    _section: u16,
    _wave_idd: u16,
    _wave_id: u32,
    _x: f32,
    _y: f32,
    _z: f32,
    _xrot: u32,
    _yrot: u32,
    _zrot: u32,
    _field1: u32,
    field2: u32,
    _field3: u32,
    _field4: u32,
    _field5: u32,
    skin: u32,
    _field6: u32
}

impl RawMapEnemy {
    pub fn from_byte_stream<R: Read>(cursor: &mut R) -> Result<RawMapEnemy, std::io::Error> {
        Ok(RawMapEnemy {
            id: cursor.read_u32::<LittleEndian>()?, // TODO: is this really u32? shiny monsters are referred to by u16 in the client
            _unknown1: cursor.read_u16::<LittleEndian>()?,
            children: cursor.read_u16::<LittleEndian>()?,
            _map_area: cursor.read_u16::<LittleEndian>()?,
            _unknown4: cursor.read_u16::<LittleEndian>()?,
            _section: cursor.read_u16::<LittleEndian>()?,
            _wave_idd: cursor.read_u16::<LittleEndian>()?,
            _wave_id: cursor.read_u32::<LittleEndian>()?,
            _x: cursor.read_f32::<LittleEndian>()?,
            _y: cursor.read_f32::<LittleEndian>()?,
            _z: cursor.read_f32::<LittleEndian>()?,
            _xrot: cursor.read_u32::<LittleEndian>()?,
            _yrot: cursor.read_u32::<LittleEndian>()?,
            _zrot: cursor.read_u32::<LittleEndian>()?,
            _field1: cursor.read_u32::<LittleEndian>()?,
            field2: cursor.read_u32::<LittleEndian>()?,
            _field3: cursor.read_u32::<LittleEndian>()?,
            _field4: cursor.read_u32::<LittleEndian>()?,
            _field5: cursor.read_u32::<LittleEndian>()?,
            skin: cursor.read_u32::<LittleEndian>()?,
            _field6: cursor.read_u32::<LittleEndian>()?,
        })
    }
}


#[derive(Error, Debug)]
#[error("")]
pub enum MapEnemyError {
    UnknownEnemyId(u32),
    MapAreaError(#[from] MapAreaError),
}

// making this `pub type` doesn't allow `impl`s to be defined?
#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct RareMonsterAppearTable {
    pub appear_rate: HashMap<MonsterType, f32>,
}

impl RareMonsterAppearTable {
    pub fn new(episode: Episode) -> RareMonsterAppearTable {
        let cfg: HashMap<String, f32> = load_rare_monster_file(episode);

        let appear_rates: HashMap<MonsterType, f32> = cfg
            .into_iter()
            .map(|(monster, rate)| {
                let monster: MonsterType = monster.parse().unwrap(); // TODO: don't unwrap!
                let appear_rate = rate;
                (monster, appear_rate)
            })
            .collect();

        RareMonsterAppearTable {
            appear_rate: appear_rates,
        }
    }

    pub fn roll_appearance(&self, monster: &MonsterType) -> bool {
        if rand_chacha::ChaChaRng::from_entropy().gen::<f32>() < *self.appear_rate.get(monster).unwrap_or(&0.0f32) {
            return true
        }
        false
    }
}


#[derive(Debug, Copy, Clone)]
pub struct MapEnemy {
    pub monster: MonsterType,
    pub map_area: MapArea,
    _hp: u32,
    // TODO: other stats from battleparam
    pub player_hit: [bool; 4],
    pub dropped_item: bool,
    pub gave_exp: bool,
    pub shiny: bool,
}

impl MapEnemy {
    pub fn from_raw(enemy: RawMapEnemy, episode: &Episode, map_area: &MapArea /*, battleparam */) -> Result<MapEnemy, MapEnemyError> {
        // TODO: rare enemies ep1-4, tower lilys, event rappies, ult variants?
        // TODO: check what "skin" actually does. some unexpected enemies have many (panarms, slimes, lilys)
        let monster = match map_area {
            MapArea::Forest1 | MapArea::Forest2 | MapArea::Dragon | 
            MapArea::Caves1  | MapArea::Caves2  | MapArea::Caves3 | MapArea::DeRolLe | 
            MapArea::Mines1  | MapArea::Mines2  | MapArea::VolOpt | 
            MapArea::Ruins1  | MapArea::Ruins2  | MapArea::Ruins3 | MapArea::DarkFalz => {
                match (enemy, episode) {
                    (RawMapEnemy {id: 64, skin: 0, ..}, _) => MonsterType::Hildebear,
                    (RawMapEnemy {id: 64, skin: 1, ..}, _) => MonsterType::Hildeblue,
                    (RawMapEnemy {id: 65, skin: 0, ..}, _) => MonsterType::RagRappy,
                    (RawMapEnemy {id: 65, skin: 1, ..}, _) => MonsterType::AlRappy,
                    (RawMapEnemy {id: 66, ..}, _) => MonsterType::Monest,
                    (RawMapEnemy {id: 67, field2: 0, ..}, _) => MonsterType::SavageWolf,
                    (RawMapEnemy {id: 67, ..}, _) => MonsterType::BarbarousWolf,
                    (RawMapEnemy {id: 68, skin: 0, ..}, _) => MonsterType::Booma,
                    (RawMapEnemy {id: 68, skin: 1, ..}, _) => MonsterType::Gobooma,
                    (RawMapEnemy {id: 68, skin: 2, ..}, _) => MonsterType::Gigobooma,
                    (RawMapEnemy {id: 96, ..}, _) => MonsterType::GrassAssassin,
                    (RawMapEnemy {id: 97, ..}, _) => MonsterType::PoisonLily,
                    // (RawMapEnemy {id: 97, skin: 0, ..}, _) => MonsterType::PoisonLily,
                    // (RawMapEnemy {id: 97, skin: 1, ..}, _) => MonsterType::NarLily,
                    (RawMapEnemy {id: 98, ..}, _) => MonsterType::NanoDragon,
                    (RawMapEnemy {id: 99, skin: 0, ..}, _) => MonsterType::EvilShark,
                    (RawMapEnemy {id: 99, skin: 1, ..}, _) => MonsterType::PalShark,
                    (RawMapEnemy {id: 99, skin: 2, ..}, _) => MonsterType::GuilShark,
                    (RawMapEnemy {id: 100, ..}, _) => MonsterType::PofuillySlime,
                    // (RawMapEnemy {id: 100, skin: 0, ..}, _) => MonsterType::PofuillySlime,
                    // (RawMapEnemy {id: 100, skin: 1, ..}, _) => MonsterType::PouillySlime,
                    // (RawMapEnemy {id: 100, skin: 2, ..}, _) => MonsterType::PofuillySlime,
                    (RawMapEnemy {id: 101, ..}, _) => MonsterType::PanArms,
                    (RawMapEnemy {id: 128, skin: 0, ..}, _) => MonsterType::Dubchic,
                    (RawMapEnemy {id: 128, skin: 1, ..}, _) => MonsterType::Gillchic,
                    (RawMapEnemy {id: 129, ..}, _) => MonsterType::Garanz,
                    (RawMapEnemy {id: 130, field2: 0, ..}, _) => MonsterType::SinowBeat,
                    (RawMapEnemy {id: 130, ..}, _) => MonsterType::SinowGold,
                    (RawMapEnemy {id: 131, ..}, _) => MonsterType::Canadine,
                    (RawMapEnemy {id: 132, ..}, _) => MonsterType::Canane,
                    (RawMapEnemy {id: 133, ..}, _) => MonsterType::Dubwitch,
                    (RawMapEnemy {id: 160, ..}, _) => MonsterType::Delsaber,
                    (RawMapEnemy {id: 161, ..}, _) => MonsterType::ChaosSorcerer,
                    (RawMapEnemy {id: 162, ..}, _) => MonsterType::DarkGunner,
                    (RawMapEnemy {id: 163, ..}, _) => MonsterType::DeathGunner,
                    (RawMapEnemy {id: 164, ..}, _) => MonsterType::ChaosBringer,
                    (RawMapEnemy {id: 165, ..}, _) => MonsterType::DarkBelra,
                    (RawMapEnemy {id: 166, skin: 0, ..}, _) => MonsterType::Dimenian,
                    (RawMapEnemy {id: 166, skin: 1, ..}, _) => MonsterType::LaDimenian,
                    (RawMapEnemy {id: 166, skin: 2, ..}, _) => MonsterType::SoDimenian,
                    (RawMapEnemy {id: 167, ..}, _) => MonsterType::Bulclaw,
                    (RawMapEnemy {id: 168, ..}, _) => MonsterType::Claw,
                    (RawMapEnemy {id: 192, ..}, Episode::One) => MonsterType::Dragon,
                    (RawMapEnemy {id: 193, ..}, _) => MonsterType::DeRolLe,
                    (RawMapEnemy {id: 194, ..}, _) => MonsterType::VolOptPartA,
                    (RawMapEnemy {id: 197, ..}, _) => MonsterType::VolOpt,
                    (RawMapEnemy {id: 200, ..}, _) => MonsterType::DarkFalz,
                    _ => return Err(MapEnemyError::UnknownEnemyId(enemy.id))
                }
            },

            MapArea::VrTempleAlpha | MapArea::VrTempleBeta | MapArea::BarbaRay | 
            MapArea::VrSpaceshipAlpha | MapArea::VrSpaceshipBeta | MapArea::GolDragon | 
            MapArea::JungleAreaNorth | MapArea::JungleAreaEast | MapArea::Mountain | MapArea::Seaside | MapArea::SeasideNight | MapArea::Cca | MapArea::GalGryphon |
            MapArea::SeabedUpper | MapArea::SeabedLower | MapArea::OlgaFlow => {
                match (enemy, episode) {
                    (RawMapEnemy {id: 64, skin: 0, ..}, _) => MonsterType::Hildebear,
                    (RawMapEnemy {id: 64, skin: 1, ..}, _) => MonsterType::Hildeblue,
                    (RawMapEnemy {id: 65, skin: 0, ..}, _) => MonsterType::RagRappy,
                    (RawMapEnemy {id: 65, skin: 1, ..}, _) => MonsterType::EventRappy,
                    (RawMapEnemy {id: 66, ..}, _) => MonsterType::Monest,
                    (RawMapEnemy {id: 67, field2: 0, ..}, _) => MonsterType::SavageWolf,
                    (RawMapEnemy {id: 67, ..}, _) => MonsterType::BarbarousWolf,
                    (RawMapEnemy {id: 96, ..}, _) => MonsterType::GrassAssassin,
                    (RawMapEnemy {id: 97, skin: 0, ..}, _) => MonsterType::PoisonLily,
                    (RawMapEnemy {id: 97, skin: 1, ..}, _) => MonsterType::NarLily,
                    (RawMapEnemy {id: 101, ..}, _) => MonsterType::PanArms,
                    (RawMapEnemy {id: 128, skin: 0, ..}, _) => MonsterType::Dubchic,
                    (RawMapEnemy {id: 128, skin: 1, ..}, _) => MonsterType::Gillchic,
                    (RawMapEnemy {id: 129, ..}, _) => MonsterType::Garanz,
                    (RawMapEnemy {id: 133, ..}, _) => MonsterType::Dubwitch,
                    (RawMapEnemy {id: 160, ..}, _) => MonsterType::Delsaber,
                    (RawMapEnemy {id: 161, ..}, _) => MonsterType::ChaosSorcerer,
                    (RawMapEnemy {id: 165, ..}, _) => MonsterType::DarkBelra,
                    (RawMapEnemy {id: 166, skin: 0, ..}, _) => MonsterType::Dimenian,
                    (RawMapEnemy {id: 166, skin: 1, ..}, _) => MonsterType::LaDimenian,
                    (RawMapEnemy {id: 166, skin: 2, ..}, _) => MonsterType::SoDimenian,
                    (RawMapEnemy {id: 192, ..}, Episode::Two) => MonsterType::GalGryphon,
                    (RawMapEnemy {id: 202, ..}, _) => MonsterType::OlgaFlow,
                    (RawMapEnemy {id: 203, ..}, _) => MonsterType::BarbaRay,
                    (RawMapEnemy {id: 204, ..}, _) => MonsterType::GolDragon,
                    (RawMapEnemy {id: 212, skin: 0, ..}, _) => MonsterType::SinowBerill,
                    (RawMapEnemy {id: 212, skin: 1, ..}, _) => MonsterType::SinowSpigell,
                    (RawMapEnemy {id: 213, skin: 0, ..}, _) => MonsterType::Merillia,
                    (RawMapEnemy {id: 213, skin: 1, ..}, _) => MonsterType::Meriltas,
                    (RawMapEnemy {id: 214, skin: 0, ..}, _) => MonsterType::Mericarol,
                    (RawMapEnemy {id: 214, skin: 1, ..}, _) => MonsterType::Merikle,
                    (RawMapEnemy {id: 214, skin: 2, ..}, _) => MonsterType::Mericus,
                    (RawMapEnemy {id: 215, skin: 0, ..}, _) => MonsterType::UlGibbon,
                    (RawMapEnemy {id: 215, skin: 1, ..}, _) => MonsterType::ZolGibbon,
                    (RawMapEnemy {id: 216, ..}, _) => MonsterType::Gibbles,
                    (RawMapEnemy {id: 217, ..}, _) => MonsterType::Gee,
                    (RawMapEnemy {id: 218, ..}, _) => MonsterType::GiGue,
                    (RawMapEnemy {id: 219, ..}, _) => MonsterType::Deldepth,
                    (RawMapEnemy {id: 220, ..}, _) => MonsterType::Delbiter,
                    (RawMapEnemy {id: 221, skin: 0, ..}, _) => MonsterType::Dolmolm,
                    (RawMapEnemy {id: 221, skin: 1, ..}, _) => MonsterType::Dolmdarl,
                    (RawMapEnemy {id: 222, ..}, _) => MonsterType::Morfos,
                    (RawMapEnemy {id: 223, ..}, _) => MonsterType::Recobox,
                    (RawMapEnemy {id: 224, skin: 0, ..}, _) => MonsterType::SinowZoa,
                    (RawMapEnemy {id: 224, skin: 1, ..}, _) => MonsterType::SinowZele,
                    (RawMapEnemy {id: 224, ..}, _) => MonsterType::Epsilon,
                    (RawMapEnemy {id: 225, ..}, _) => MonsterType::IllGill,
                    _ => return Err(MapEnemyError::UnknownEnemyId(enemy.id))
                }
            },

            MapArea::Tower => {
                match (enemy, episode) {
                    (RawMapEnemy {id: 97, ..}, _) => MonsterType::DelLily,
                    (RawMapEnemy {id: 214, skin: 0, ..}, _) => MonsterType::Mericarol,
                    (RawMapEnemy {id: 214, skin: 1, ..}, _) => MonsterType::Merikle,
                    (RawMapEnemy {id: 214, skin: 2, ..}, _) => MonsterType::Mericus,
                    (RawMapEnemy {id: 216, ..}, _) => MonsterType::Gibbles,
                    (RawMapEnemy {id: 218, ..}, _) => MonsterType::GiGue,
                    (RawMapEnemy {id: 220, ..}, _) => MonsterType::Delbiter,
                    (RawMapEnemy {id: 223, ..}, _) => MonsterType::Recobox,
                    (RawMapEnemy {id: 224, ..}, _) => MonsterType::Epsilon,
                    (RawMapEnemy {id: 225, ..}, _) => MonsterType::IllGill,
                    _ => return Err(MapEnemyError::UnknownEnemyId(enemy.id))
                }
            },

            MapArea::CraterEast | MapArea::CraterWest | MapArea::CraterSouth | MapArea::CraterNorth | MapArea::CraterInterior => {
                match (enemy, episode) {
                    (RawMapEnemy {id: 65, skin: 0, ..}, Episode::Four) => MonsterType::SandRappyCrater,
                    (RawMapEnemy {id: 65, skin: 1, ..}, Episode::Four) => MonsterType::DelRappyCrater,
                    (RawMapEnemy {id: 272, ..}, _) => MonsterType::Astark,
                    (RawMapEnemy {id: 273, field2: 0, ..}, _) => MonsterType::SatelliteLizardCrater,
                    (RawMapEnemy {id: 273, ..}, _) => MonsterType::YowieCrater,
                    (RawMapEnemy {id: 276, skin: 0, ..}, _) => MonsterType::ZuCrater,
                    (RawMapEnemy {id: 276, skin: 1, ..}, _) => MonsterType::PazuzuCrater,
                    (RawMapEnemy {id: 277, skin: 0, ..}, _) => MonsterType::Boota,
                    (RawMapEnemy {id: 277, skin: 1, ..}, _) => MonsterType::ZeBoota,
                    (RawMapEnemy {id: 277, skin: 2, ..}, _) => MonsterType::BaBoota,
                    (RawMapEnemy {id: 278, skin: 0, ..}, _) => MonsterType::Dorphon,
                    (RawMapEnemy {id: 278, skin: 1, ..}, _) => MonsterType::DorphonEclair,
                    _ => return Err(MapEnemyError::UnknownEnemyId(enemy.id))
                }
            },
            MapArea::SubDesert1 | MapArea::SubDesert2 | MapArea::SubDesert3 | MapArea::SaintMillion => {
                match (enemy, episode) {
                    (RawMapEnemy {id: 65, skin: 0, ..}, Episode::Four) => MonsterType::SandRappyDesert,
                    (RawMapEnemy {id: 65, skin: 1, ..}, Episode::Four) => MonsterType::DelRappyDesert,
                    (RawMapEnemy {id: 273, field2: 0, ..}, _) => MonsterType::SatelliteLizardDesert,
                    (RawMapEnemy {id: 273, ..}, _) => MonsterType::YowieDesert,
                    (RawMapEnemy {id: 274, skin: 0, ..}, _) => MonsterType::MerissaA,
                    (RawMapEnemy {id: 274, skin: 1, ..}, _) => MonsterType::MerissaAA,
                    (RawMapEnemy {id: 275, ..}, _) => MonsterType::Girtablulu,
                    (RawMapEnemy {id: 276, skin: 0, ..}, _) => MonsterType::ZuDesert,
                    (RawMapEnemy {id: 276, skin: 1, ..}, _) => MonsterType::PazuzuDesert,
                    (RawMapEnemy {id: 279, skin: 0, ..}, _) => MonsterType::Goran,
                    (RawMapEnemy {id: 279, skin: 1, ..}, _) => MonsterType::PyroGoran,
                    (RawMapEnemy {id: 279, skin: 2, ..}, _) => MonsterType::GoranDetonator,
                    (RawMapEnemy {id: 281, skin: 0, ..}, _) => MonsterType::SaintMillion,
                    (RawMapEnemy {id: 281, skin: 1, ..}, _) => MonsterType::Shambertin, // TODO: don't guess the skin
                    (RawMapEnemy {id: 281, skin: 2, ..}, _) => MonsterType::Kondrieu, // TODO: don't guess the skin
                    _ => return Err(MapEnemyError::UnknownEnemyId(enemy.id))
                }
            },
            _ => return Err(MapEnemyError::UnknownEnemyId(enemy.id))
        };

        Ok(MapEnemy {
            monster,
            map_area: *map_area,
            _hp: 0,
            dropped_item: false,
            gave_exp: false,
            player_hit: [false; 4],
            shiny: false,
        })
    }

    pub fn new(monster: MonsterType, map_area: MapArea) -> MapEnemy {
        MapEnemy {
            monster,
            map_area,
            _hp: 0,
            dropped_item: false,
            gave_exp: false,
            player_hit: [false; 4],
            shiny: false,
        }
    }

    pub fn set_shiny(self) -> MapEnemy {
        MapEnemy {
            shiny: true,
            ..self
        }
    }

    pub fn has_rare_appearance(self) -> bool {
        matches!(self.monster,
            MonsterType::RagRappy | MonsterType::Hildebear |
            MonsterType::PoisonLily | MonsterType::PofuillySlime |
            MonsterType::SandRappyCrater | MonsterType::ZuCrater | MonsterType::Dorphon |
            MonsterType::SandRappyDesert | MonsterType::ZuDesert | MonsterType::MerissaA |
            MonsterType::SaintMillion | MonsterType::Shambertin
        )
    }
    
    /*
    TODO: distinguish between a `random` rare monster and a `set/guaranteed` rare monster? (does any acceptable quest even have this?)
    guaranteed rare monsters don't count towards the limit
    */
    pub fn set_rare_appearance(self) -> MapEnemy {
        match (self.monster, self.map_area.to_episode()) {
            (MonsterType::RagRappy, Episode::One) => {MapEnemy {monster: MonsterType::AlRappy, shiny:true, ..self}},
            (MonsterType::RagRappy, Episode::Two) => {MapEnemy {monster: MonsterType::EventRappy, shiny:true, ..self}},
            (MonsterType::Hildebear, _) => {MapEnemy {monster: MonsterType::Hildeblue, shiny:true, ..self}},
            (MonsterType::PoisonLily, _) => {MapEnemy {monster: MonsterType::NarLily, shiny:true, ..self}},
            (MonsterType::PofuillySlime, _) => {MapEnemy {monster: MonsterType::PouillySlime, shiny:true, ..self}},
            (MonsterType::SandRappyCrater, _) => {MapEnemy {monster: MonsterType::DelRappyCrater, shiny:true, ..self}},
            (MonsterType::ZuCrater, _) => {MapEnemy {monster: MonsterType::PazuzuCrater, shiny:true, ..self}},
            (MonsterType::Dorphon, _) => {MapEnemy {monster: MonsterType::DorphonEclair, shiny:true, ..self}},
            (MonsterType::SandRappyDesert, _) => {MapEnemy {monster: MonsterType::DelRappyDesert, shiny:true, ..self}},
            (MonsterType::ZuDesert, _) => {MapEnemy {monster: MonsterType::PazuzuDesert, shiny:true, ..self}},
            (MonsterType::MerissaA, _) => {MapEnemy {monster: MonsterType::MerissaAA, shiny:true, ..self}},
            (MonsterType::SaintMillion, _) => {MapEnemy {monster: MonsterType::Kondrieu, shiny:true, ..self}},
            (MonsterType::Shambertin, _) => {MapEnemy {monster: MonsterType::Kondrieu, shiny:true, ..self}},
            _ => {self},
        }
    }
    
    // in theory this should only be called on monsters we know can have rare types
    pub fn roll_appearance_for_mission(self, rare_monster_table: &RareMonsterAppearTable) -> MapEnemy {
        if rare_monster_table.roll_appearance(&self.monster) {
            return self.set_rare_appearance()
        }
        self
    }
}