// TOOD: `pub(super) for most of these?`

use std::path::PathBuf;
use std::io::{Read};
use std::fs::File;

use thiserror::Error;


//use crate::ship::ship::ShipEvent;
use crate::area::MapArea;
use crate::Holiday;
use crate::enemy::{MapEnemy, RawMapEnemy, RareMonsterAppearTable};
use crate::monster::MonsterType;
use crate::variant::{MapVariant, MapVariantMode};
use crate::object::{MapObject, RawMapObject};
use crate::room::{Episode, RoomMode, PlayerMode};

pub fn objects_from_stream(cursor: &mut impl Read, episode: &Episode, map_area: &MapArea) -> Vec<Option<MapObject>> {
    let mut object_data = Vec::new();

    while let Ok(raw_object) = RawMapObject::from_byte_stream(cursor) {
        let object = MapObject::from_raw(raw_object, *episode, map_area);
        object_data.push(object.ok());
    }
    object_data
}

fn objects_from_map_data(path: PathBuf, episode: &Episode, map_area: &MapArea) -> Vec<Option<MapObject>> {
    let mut cursor = File::open(path).unwrap();
    objects_from_stream(&mut cursor, episode, map_area)
}

fn parse_enemy(episode: &Episode, map_area: &MapArea, raw_enemy: RawMapEnemy) -> Vec<Option<MapEnemy>> {
    let enemy = MapEnemy::from_raw(raw_enemy, episode, map_area);

    enemy
        .map_or(vec![None], |monster| {
            let mut monsters = vec![Some(monster)];

            match monster.monster {
                MonsterType::Monest => {
                    for _ in 0..30 {
                        monsters.push(Some(MapEnemy::new(MonsterType::Mothmant, monster.map_area)));
                    }
                },
                MonsterType::PanArms => {
                    monsters.push(Some(MapEnemy::new(MonsterType::Hidoom, monster.map_area)));
                    monsters.push(Some(MapEnemy::new(MonsterType::Migium, monster.map_area)));
                },
                MonsterType::PofuillySlime => {
                    for _ in 0..5 {
                        monsters.push(Some(MapEnemy::new(MonsterType::PofuillySlime, monster.map_area)));
                    }
                },
                MonsterType::PouillySlime => {
                    for _ in 0..5 {
                        monsters.push(Some(MapEnemy::new(MonsterType::PofuillySlime, monster.map_area)));
                    }
                },
                MonsterType::SinowBeat => {
                    for _ in 0..4 {
                        monsters.push(Some(MapEnemy::new(MonsterType::SinowBeat, monster.map_area)));
                    }
                },
                MonsterType::SinowGold => {
                    for _ in 0..4 {
                        monsters.push(Some(MapEnemy::new(MonsterType::SinowGold, monster.map_area)));
                    }
                },
                MonsterType::Canane => {
                    for _ in 0..8 {
                        monsters.push(Some(MapEnemy::new(MonsterType::RingCanadine, monster.map_area)));
                    }
                },
                MonsterType::ChaosSorcerer => {
                    monsters.push(Some(MapEnemy::new(MonsterType::BeeR, monster.map_area)));
                    monsters.push(Some(MapEnemy::new(MonsterType::BeeL, monster.map_area)));
                },
                MonsterType::Bulclaw => {
                    for _ in 0..4 {
                        monsters.push(Some(MapEnemy::new(MonsterType::Claw, monster.map_area)));
                    }
                },
                MonsterType::DeRolLe => {
                    for _ in 0..10 {
                        monsters.push(Some(MapEnemy::new(MonsterType::DeRolLeBody, monster.map_area)));
                    }
                    for _ in 0..9 {
                        monsters.push(Some(MapEnemy::new(MonsterType::DeRolLeMine, monster.map_area)));
                    }
                },
                MonsterType::VolOptPartA => {
                    for _ in 0..6 {
                        monsters.push(Some(MapEnemy::new(MonsterType::VolOptPillar, monster.map_area)));
                    }
                    for _ in 0..24 {
                        monsters.push(Some(MapEnemy::new(MonsterType::VolOptMonitor, monster.map_area)));
                    }
                    for _ in 0..2 {
                        monsters.push(Some(MapEnemy::new(MonsterType::VolOptUnused, monster.map_area)));
                    }
                    monsters.push(Some(MapEnemy::new(MonsterType::VolOptAmp, monster.map_area)));
                    monsters.push(Some(MapEnemy::new(MonsterType::VolOptCore, monster.map_area)));
                    monsters.push(Some(MapEnemy::new(MonsterType::VolOptUnused, monster.map_area)));
                },
                // TOOD: this cares about difficulty (theres an ult-specific darvant?)
                MonsterType::DarkFalz => {
                    for _ in 0..509 {
                        monsters.push(Some(MapEnemy::new(MonsterType::Darvant, monster.map_area)));
                    }
                    monsters.push(Some(MapEnemy::new(MonsterType::DarkFalz3, monster.map_area)));
                    monsters.push(Some(MapEnemy::new(MonsterType::DarkFalz2, monster.map_area)));
                    monsters.push(Some(MapEnemy::new(MonsterType::DarkFalz1, monster.map_area)));
                },
                MonsterType::OlgaFlow => {
                    for _ in 0..512 {
                        monsters.push(Some(MapEnemy::new(MonsterType::OlgaFlow, monster.map_area)));
                    }
                },
                MonsterType::BarbaRay => {
                    for _ in 0..47 {
                        monsters.push(Some(MapEnemy::new(MonsterType::PigRay, monster.map_area)));
                    }
                },
                MonsterType::GolDragon => {
                    for _ in 0..5 {
                        monsters.push(Some(MapEnemy::new(MonsterType::GolDragon, monster.map_area)));
                    }
                },
                MonsterType::SinowBerill => {
                    for _ in 0..4 {
                        monsters.push(Some(MapEnemy::new(MonsterType::SinowBerill, monster.map_area))); // unused clones
                    }
                },
                MonsterType::SinowSpigell => {
                    for _ in 0..4 {
                        monsters.push(Some(MapEnemy::new(MonsterType::SinowSpigell, monster.map_area))); // unused clones
                    }
                },
                MonsterType::Recobox => { // + recons
                    for _ in 0..raw_enemy.children {
                        monsters.push(Some(MapEnemy::new(MonsterType::Recon, monster.map_area)));
                    }
                },
                MonsterType::Epsilon => {
                    for _ in 0..4 {
                        monsters.push(Some(MapEnemy::new(MonsterType::Epsiguard, monster.map_area)));
                    }
                },
                _ => {
                    for _ in 0..raw_enemy.children {
                        monsters.push(Some(MapEnemy::new(monster.monster, monster.map_area)));
                    }
                }
            }
            monsters
        })
}


pub fn enemy_data_from_stream(cursor: &mut impl Read, map_area: &MapArea, episode: &Episode) -> Vec<Option<MapEnemy>> {
    let mut enemy_data = Vec::new();
    while let Ok(enemy) = RawMapEnemy::from_byte_stream(cursor) {
        enemy_data.append(&mut parse_enemy(episode, map_area, enemy));
    }
    enemy_data
}

fn enemy_data_from_map_data(map_variant: &MapVariant, episode: &Episode) -> Vec<Option<MapEnemy>> {
    let path = map_variant.dat_file();
    let mut cursor = File::open(path).unwrap();
    enemy_data_from_stream(&mut cursor, &map_variant.map, episode)
}


pub fn default_map_variants(episode: Episode, player_mode: PlayerMode) -> Vec<MapVariant> {
    match (episode, player_mode) {
        (Episode::One, PlayerMode::Multi) => {
            vec![MapVariant::new(MapArea::Pioneer2Ep1, MapVariantMode::Online),
                 MapVariant::new(MapArea::Forest1, MapVariantMode::Online),
                 MapVariant::new(MapArea::Forest2, MapVariantMode::Online),
                 MapVariant::new(MapArea::Caves1, MapVariantMode::Online),
                 MapVariant::new(MapArea::Caves2, MapVariantMode::Online),
                 MapVariant::new(MapArea::Caves3, MapVariantMode::Online),
                 MapVariant::new(MapArea::Mines1, MapVariantMode::Online),
                 MapVariant::new(MapArea::Mines2, MapVariantMode::Online),
                 MapVariant::new(MapArea::Ruins1, MapVariantMode::Online),
                 MapVariant::new(MapArea::Ruins2, MapVariantMode::Online),
                 MapVariant::new(MapArea::Ruins3, MapVariantMode::Online),
                 MapVariant::new(MapArea::Dragon, MapVariantMode::Online),
                 MapVariant::new(MapArea::DeRolLe, MapVariantMode::Online),
                 MapVariant::new(MapArea::VolOpt, MapVariantMode::Online),
                 MapVariant::new(MapArea::DarkFalz, MapVariantMode::Online),
            ]
        },
        (Episode::One, PlayerMode::Single) => {
            vec![MapVariant::new(MapArea::Pioneer2Ep1, MapVariantMode::Offline),
                 MapVariant::new(MapArea::Forest1, MapVariantMode::Offline),
                 MapVariant::new(MapArea::Forest2, MapVariantMode::Offline),
                 MapVariant::new(MapArea::Caves1, MapVariantMode::Offline),
                 MapVariant::new(MapArea::Caves2, MapVariantMode::Offline),
                 MapVariant::new(MapArea::Caves3, MapVariantMode::Offline),
                 MapVariant::new(MapArea::Mines1, MapVariantMode::Offline),
                 MapVariant::new(MapArea::Mines2, MapVariantMode::Offline),
                 MapVariant::new(MapArea::Ruins1, MapVariantMode::Offline),
                 MapVariant::new(MapArea::Ruins2, MapVariantMode::Offline),
                 MapVariant::new(MapArea::Ruins3, MapVariantMode::Offline),
                 MapVariant::new(MapArea::Dragon, MapVariantMode::Offline),
                 MapVariant::new(MapArea::DeRolLe, MapVariantMode::Offline),
                 MapVariant::new(MapArea::VolOpt, MapVariantMode::Offline),
                 MapVariant::new(MapArea::DarkFalz, MapVariantMode::Offline),
            ]
        },
        (Episode::Two, PlayerMode::Multi) => {
            vec![MapVariant::new(MapArea::Pioneer2Ep2, MapVariantMode::Online),
                 MapVariant::new(MapArea::VrTempleAlpha, MapVariantMode::Online),
                 MapVariant::new(MapArea::VrTempleBeta, MapVariantMode::Online),
                 MapVariant::new(MapArea::VrSpaceshipAlpha, MapVariantMode::Online),
                 MapVariant::new(MapArea::VrSpaceshipBeta, MapVariantMode::Online),
                 MapVariant::new(MapArea::Cca, MapVariantMode::Online),
                 MapVariant::new(MapArea::JungleAreaNorth, MapVariantMode::Online),
                 MapVariant::new(MapArea::JungleAreaEast, MapVariantMode::Online),
                 MapVariant::new(MapArea::Mountain, MapVariantMode::Online),
                 MapVariant::new(MapArea::Seaside, MapVariantMode::Online),
                 MapVariant::new(MapArea::SeabedUpper, MapVariantMode::Online),
                 MapVariant::new(MapArea::SeabedLower, MapVariantMode::Online),
                 MapVariant::new(MapArea::GalGryphon, MapVariantMode::Online),
                 MapVariant::new(MapArea::OlgaFlow, MapVariantMode::Online),
                 MapVariant::new(MapArea::BarbaRay, MapVariantMode::Online),
                 MapVariant::new(MapArea::GolDragon, MapVariantMode::Online),
            ]
        },
        (Episode::Two, PlayerMode::Single) => {
            vec![MapVariant::new(MapArea::Pioneer2Ep2, MapVariantMode::Offline),
                 MapVariant::new(MapArea::VrTempleAlpha, MapVariantMode::Offline),
                 MapVariant::new(MapArea::VrTempleBeta, MapVariantMode::Offline),
                 MapVariant::new(MapArea::VrSpaceshipAlpha, MapVariantMode::Offline),
                 MapVariant::new(MapArea::VrSpaceshipBeta, MapVariantMode::Offline),
                 MapVariant::new(MapArea::Cca, MapVariantMode::Offline),
                 MapVariant::new(MapArea::JungleAreaNorth, MapVariantMode::Offline),
                 MapVariant::new(MapArea::JungleAreaEast, MapVariantMode::Offline),
                 MapVariant::new(MapArea::Mountain, MapVariantMode::Offline),
                 MapVariant::new(MapArea::Seaside, MapVariantMode::Offline),
                 MapVariant::new(MapArea::SeabedUpper, MapVariantMode::Offline),
                 MapVariant::new(MapArea::SeabedLower, MapVariantMode::Offline),
                 MapVariant::new(MapArea::GalGryphon, MapVariantMode::Offline),
                 MapVariant::new(MapArea::OlgaFlow, MapVariantMode::Offline),
                 MapVariant::new(MapArea::BarbaRay, MapVariantMode::Offline),
                 MapVariant::new(MapArea::GolDragon, MapVariantMode::Offline),
            ]
        },
        (Episode::Four, PlayerMode::Multi) => {
            vec![MapVariant::new(MapArea::Pioneer2Ep4, MapVariantMode::Online),
                 MapVariant::new(MapArea::CraterEast, MapVariantMode::Online),
                 MapVariant::new(MapArea::CraterWest, MapVariantMode::Online),
                 MapVariant::new(MapArea::CraterSouth, MapVariantMode::Online),
                 MapVariant::new(MapArea::CraterNorth, MapVariantMode::Online),
                 MapVariant::new(MapArea::CraterInterior, MapVariantMode::Online),
                 MapVariant::new(MapArea::SubDesert1, MapVariantMode::Online),
                 MapVariant::new(MapArea::SubDesert2, MapVariantMode::Online),
                 MapVariant::new(MapArea::SubDesert3, MapVariantMode::Online),
                 MapVariant::new(MapArea::SaintMillion, MapVariantMode::Online),
            ]
        },
        (Episode::Four, PlayerMode::Single) => {
            vec![MapVariant::new(MapArea::Pioneer2Ep4, MapVariantMode::Offline),
                 MapVariant::new(MapArea::CraterEast, MapVariantMode::Offline),
                 MapVariant::new(MapArea::CraterWest, MapVariantMode::Offline),
                 MapVariant::new(MapArea::CraterSouth, MapVariantMode::Offline),
                 MapVariant::new(MapArea::CraterNorth, MapVariantMode::Offline),
                 MapVariant::new(MapArea::CraterInterior, MapVariantMode::Offline),
                 MapVariant::new(MapArea::SubDesert1, MapVariantMode::Offline),
                 MapVariant::new(MapArea::SubDesert2, MapVariantMode::Offline),
                 MapVariant::new(MapArea::SubDesert3, MapVariantMode::Offline),
                 MapVariant::new(MapArea::SaintMillion, MapVariantMode::Offline),
            ]
        },
    }
}

#[derive(Error, Debug)]
#[error("")]
pub enum MapsError {
    InvalidMonsterId(usize),
    InvalidObjectId(usize),
}

#[derive(Debug)]
pub struct Maps {
    map_variants: Vec<MapVariant>,
    enemy_data: Vec<Option<MapEnemy>>,
    object_data: Vec<Option<MapObject>>,
}

impl Maps {
    pub fn new(map_variants: Vec<MapVariant>, enemy_data: Vec<Option<MapEnemy>>, object_data: Vec<Option<MapObject>>) -> Maps {
        Maps {
            map_variants,
            enemy_data,
            object_data,
        }
    }

    pub fn enemy_by_id(&self, id: usize) -> Result<MapEnemy, MapsError> {
        self.enemy_data[id].ok_or(MapsError::InvalidMonsterId(id))
    }

    pub fn object_by_id(&self, id: usize) -> Result<MapObject, MapsError> {
        self.object_data[id].ok_or(MapsError::InvalidObjectId(id))
    }

    pub fn map_headers(&self) -> [u32; 0x20] {
        self.map_variants.iter()
            .enumerate()
            .fold([0; 0x20], |mut header, (i, map_variant)| {
                let [major, minor] = map_variant.pkt_header();

                header[i*2] = major as u32;
                header[i*2 + 1] = minor as u32;
                header
            })
    }

    pub fn set_quest_data(&mut self,
                          enemies: Vec<Option<MapEnemy>>,
                          objects: Vec<Option<MapObject>>,
                          rare_monster_table: &RareMonsterAppearTable,
                          event: Holiday)
    {
        self.enemy_data = enemies
            .into_iter()
            .map(|enemy| enemy.map(|enemy| rare_monster_table.apply(enemy, event)))
            .collect();
        self.object_data = objects;
    }

    pub fn get_rare_monster_list(&self) -> Vec<u16> {
        let mut rare_monsters = vec![0xFFFF; 16];
        let shiny: Vec<(usize, &Option<MapEnemy>)> = self.enemy_data.iter()
            .enumerate()
            .filter(|(_,m)| {
                match m {
                    Some(m) => {
                        m.shiny
                    },
                    None => false,
                }
            })
            .collect();
        for monster in &shiny {
            if let Some(j) = rare_monsters.iter().position(|&x| x == 0xFFFF) {
                rare_monsters[j] = monster.0 as u16;
            } else {
                break
            }
        }
        rare_monsters
    }
}

pub fn generate_free_roam_maps(room_mode: RoomMode, event: Holiday) -> Maps {
    let rare_monster_table = RareMonsterAppearTable::new(room_mode.episode());
    let map_variants = default_map_variants(room_mode.episode(), room_mode.player_mode());
    Maps {
        enemy_data: map_variants.iter()
            .flat_map(|map_variant| {
                enemy_data_from_map_data(map_variant, &room_mode.episode())
            })
            .map(|enemy| enemy.map(|enemy| rare_monster_table.apply(enemy, event)))
            .collect(),
        object_data: map_variants.iter()
            .flat_map(|map_variant| {
                objects_from_map_data(map_variant.obj_file().into(), &room_mode.episode(), &map_variant.map)
            }).collect(),
        map_variants,
    }
}