use std::collections::HashMap;

use rltk::{FontCharType, RandomNumberGenerator, RGB};
use specs::prelude::*;
use specs::saveload::{MarkedBuilder, SimpleMarker};

use crate::random_table::RandomTable;
use crate::rect::Rect;
use crate::{
    AreaOfEffect, BlocksTile, CombatStats, Confusion, Consumable, DefenseBonus, EntryTrigger,
    EquipmentSlot, Equippable, Hidden, HungerClock, HungerState, InflictsDamage, Item, MagicMapper,
    Map, MeleePowerBonus, Monster, Name, Player, Position, ProvidesFood, ProvidesHealing, Ranged,
    Renderable, SerializeMe, SingleActivation, TileType, Viewshed, MAP_WIDTH, MAX_MONSTER,
};

pub fn player(ecs: &mut World, player_x: i32, player_y: i32) -> Entity {
    ecs.create_entity()
        .with(Position {
            x: player_x,
            y: player_y,
        })
        .with(Renderable {
            glyph: rltk::to_cp437('@'),
            fg: RGB::named(rltk::YELLOW),
            bg: RGB::named(rltk::BLACK),
            render_order: 0,
        })
        .with(Player {})
        .with(Viewshed {
            visible_tiles: Vec::new(),
            range: 8,
            dirty: true,
        })
        .with(Name {
            name: "Player".to_string(),
        })
        .with(CombatStats {
            max_hp: 30,
            hp: 30,
            defense: 2,
            power: 5,
        })
        .with(HungerClock {
            duration: 20,
            state: HungerState::WellFed,
        })
        .marked::<SimpleMarker<SerializeMe>>()
        .build()
}

fn orc(ecs: &mut World, x: i32, y: i32) {
    monster(ecs, x, y, rltk::to_cp437('o'), "Orc")
}

fn goblin(ecs: &mut World, x: i32, y: i32) {
    monster(ecs, x, y, rltk::to_cp437('g'), "Goblin")
}

fn monster<S: ToString>(ecs: &mut World, x: i32, y: i32, glyph: FontCharType, name: S) {
    ecs.create_entity()
        .with(Position { x, y })
        .with(Renderable {
            glyph,
            fg: RGB::named(rltk::RED),
            bg: RGB::named(rltk::BLACK),
            render_order: 1,
        })
        .with(Viewshed {
            visible_tiles: Vec::new(),
            range: 8,
            dirty: true,
        })
        .with(Monster {})
        .with(Name {
            name: name.to_string(),
        })
        .with(BlocksTile {})
        .with(CombatStats {
            max_hp: 16,
            hp: 16,
            defense: 1,
            power: 4,
        })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

#[allow(clippy::map_entry)]
pub fn spawn_room(ecs: &mut World, room: &Rect, map_depth: i32) {
    let mut possible_targets: Vec<usize> = Vec::new();

    {
        let map = ecs.fetch::<Map>();
        for y in room.y1 + 1..room.y2 {
            for x in room.x1 + 1..room.x2 {
                let idx = map.xy_idx(x, y);
                if map.tiles[idx] == TileType::Floor {
                    possible_targets.push(idx)
                }
            }
        }
    }

    spawn_region(ecs, &possible_targets, map_depth);
}

pub(crate) fn spawn_region(ecs: &mut World, area: &[usize], map_depth: i32) {
    if let Some(spawn_points) = calculate_spawn_points(ecs, area, map_depth) {
        spawn_entities(ecs, spawn_points)
    }
}

fn spawn_entities(ecs: &mut World, spawn_points: HashMap<usize, String>) {
    for spawn in spawn_points.iter() {
        spawn_entity(ecs, &spawn);
    }
}

fn calculate_spawn_points(ecs: &mut World, area: &[usize], map_depth: i32) -> Option<HashMap<usize, String>> {
    let mut spawn_points: HashMap<usize, String> = HashMap::new();
    let spawn_table = room_table(map_depth);
    let mut areas: Vec<usize> = Vec::from(area);
    let mut rng = ecs.write_resource::<RandomNumberGenerator>();

    let num_spawns = i32::min(areas.len() as i32, rng.roll_dice(1, MAX_MONSTER + 3));
    if num_spawns == 0 { return None; }

    for _i in 0..num_spawns {
        let array_idx = if areas.len() == 1 { 0usize } else { (rng.roll_dice(1, areas.len() as i32 - 1) as usize) };
        let map_idx = areas[array_idx];
        spawn_points.insert(map_idx, spawn_table.roll(&mut rng));
        areas.remove(array_idx);
    }

    Some(spawn_points)
}

fn spawn_entity(ecs: &mut World, spawn: &(&usize, &String)) {
    let x = (*spawn.0 % MAP_WIDTH) as i32;
    let y = (*spawn.0 / MAP_WIDTH) as i32;

    match spawn.1.as_ref() {
        "Goblin" => goblin(ecs, x, y),
        "Orc" => orc(ecs, x, y),
        "Health Potion" => health_potion(ecs, x, y),
        "Fireball Scroll" => fireball_scroll(ecs, x, y),
        "Confusion Scroll" => confusion_scroll(ecs, x, y),
        "Magic Missile Scroll" => magic_missile_scroll(ecs, x, y),
        "Dagger" => dagger(ecs, x, y),
        "Longsword" => longsword(ecs, x, y),
        "Shield" => shield(ecs, x, y),
        "Tower Shield" => tower_shield(ecs, x, y),
        "Helmet" => helmet(ecs, x, y),
        "Breastplate" => breastplate(ecs, x, y),
        "Leggings" => leggings(ecs, x, y),
        "Sabatons" => sabatons(ecs, x, y),
        "Rations" => rations(ecs, x, y),
        "Magic Mapping Scroll" => magic_mapper_scroll(ecs, x, y),
        "Bear Trap" => bear_trap(ecs, x, y),
        _ => {}
    }
}

pub fn health_potion(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position { x, y })
        .with(Renderable {
            glyph: rltk::to_cp437('i'),
            fg: RGB::named(rltk::MAGENTA),
            bg: RGB::named(rltk::BLACK),
            render_order: 2,
        })
        .with(Name {
            name: "Health Potion".to_string(),
        })
        .with(Item {})
        .with(Consumable {})
        .with(ProvidesHealing { heal_amount: 8 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

pub fn magic_missile_scroll(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position { x, y })
        .with(Renderable {
            glyph: rltk::to_cp437(')'),
            fg: RGB::named(rltk::CYAN),
            bg: RGB::named(rltk::BLACK),
            render_order: 2,
        })
        .with(Name {
            name: "Magic Missile Scroll".to_string(),
        })
        .with(Item {})
        .with(Consumable {})
        .with(Ranged { range: 6 })
        .with(InflictsDamage { damage: 20 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

pub fn fireball_scroll(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position { x, y })
        .with(Renderable {
            glyph: rltk::to_cp437(')'),
            fg: RGB::named(rltk::ORANGE),
            bg: RGB::named(rltk::BLACK),
            render_order: 2,
        })
        .with(Name {
            name: "Fireball Scroll".to_string(),
        })
        .with(Item {})
        .with(Consumable {})
        .with(Ranged { range: 6 })
        .with(InflictsDamage { damage: 20 })
        .with(AreaOfEffect { radius: 3 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

pub fn confusion_scroll(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position { x, y })
        .with(Renderable {
            glyph: rltk::to_cp437(')'),
            fg: RGB::named(rltk::PINK),
            bg: RGB::named(rltk::BLACK),
            render_order: 2,
        })
        .with(Name {
            name: "Confusion Scroll".to_string(),
        })
        .with(Item {})
        .with(Consumable {})
        .with(Ranged { range: 6 })
        .with(Confusion { turns: 4 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

pub fn room_table(map_depth: i32) -> RandomTable {
    RandomTable::new()
        .add("Goblin", 10)
        .add("Orc", 1 + map_depth)
        .add("Health Potion", 7)
        .add("Fireball Scroll", 2 + map_depth)
        .add("Confusion Scroll", 2 + map_depth)
        .add("Magic Missile Scroll", 4)
        .add("Dagger", 3)
        .add("Longsword", map_depth - 1)
        .add("Shield", 3)
        .add("Tower Shield", map_depth - 1)
        .add("Helmet", map_depth - 2)
        .add("Breastplate", map_depth - 3)
        .add("Leggings", map_depth - 4)
        .add("Sabatons", map_depth - 4)
        .add("Rations", 10)
        .add("Magic Mapping Scroll", 2)
        .add("Bear Trap", 2)
}

fn dagger(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position { x, y })
        .with(Renderable {
            glyph: rltk::to_cp437('/'),
            render_order: 2,
            fg: RGB::named(rltk::CYAN),
            bg: RGB::named(rltk::BLACK),
        })
        .with(Item {})
        .with(Name {
            name: "Dagger".to_string(),
        })
        .with(Equippable {
            slot: EquipmentSlot::Melee,
        })
        .with(MeleePowerBonus { power: 2 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn longsword(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position { x, y })
        .with(Renderable {
            glyph: rltk::to_cp437('/'),
            render_order: 2,
            fg: RGB::named(rltk::CYAN),
            bg: RGB::named(rltk::BLACK),
        })
        .with(Item {})
        .with(Name {
            name: "Longsword".to_string(),
        })
        .with(Equippable {
            slot: EquipmentSlot::Melee,
        })
        .with(MeleePowerBonus { power: 4 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn shield(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position { x, y })
        .with(Renderable {
            glyph: rltk::to_cp437('('),
            render_order: 2,
            fg: RGB::named(rltk::CYAN),
            bg: RGB::named(rltk::BLACK),
        })
        .with(Item {})
        .with(Name {
            name: "Shield".to_string(),
        })
        .with(Equippable {
            slot: EquipmentSlot::Shield,
        })
        .with(DefenseBonus { defense: 1 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn tower_shield(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position { x, y })
        .with(Renderable {
            glyph: rltk::to_cp437('('),
            render_order: 2,
            fg: RGB::named(rltk::CYAN),
            bg: RGB::named(rltk::BLACK),
        })
        .with(Item {})
        .with(Name {
            name: "Tower Shield".to_string(),
        })
        .with(Equippable {
            slot: EquipmentSlot::Shield,
        })
        .with(DefenseBonus { defense: 3 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn helmet(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position { x, y })
        .with(Renderable {
            glyph: rltk::to_cp437('^'),
            render_order: 2,
            fg: RGB::named(rltk::CYAN),
            bg: RGB::named(rltk::BLACK),
        })
        .with(Item {})
        .with(Name {
            name: "Helmet".to_string(),
        })
        .with(Equippable {
            slot: EquipmentSlot::Head,
        })
        .with(DefenseBonus { defense: 1 })
        .with(MeleePowerBonus { power: 1 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn breastplate(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position { x, y })
        .with(Renderable {
            glyph: rltk::to_cp437('x'),
            render_order: 2,
            fg: RGB::named(rltk::CYAN),
            bg: RGB::named(rltk::BLACK),
        })
        .with(Item {})
        .with(Name {
            name: "Breastplate".to_string(),
        })
        .with(Equippable {
            slot: EquipmentSlot::Chest,
        })
        .with(DefenseBonus { defense: 2 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn leggings(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position { x, y })
        .with(Renderable {
            glyph: rltk::to_cp437('"'),
            render_order: 2,
            fg: RGB::named(rltk::CYAN),
            bg: RGB::named(rltk::BLACK),
        })
        .with(Item {})
        .with(Name {
            name: "Leggings".to_string(),
        })
        .with(Equippable {
            slot: EquipmentSlot::Legs,
        })
        .with(DefenseBonus { defense: 1 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn sabatons(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position { x, y })
        .with(Renderable {
            glyph: rltk::to_cp437(','),
            render_order: 2,
            fg: RGB::named(rltk::CYAN),
            bg: RGB::named(rltk::BLACK),
        })
        .with(Item {})
        .with(Name {
            name: "Sabatons".to_string(),
        })
        .with(Equippable {
            slot: EquipmentSlot::Feet,
        })
        .with(DefenseBonus { defense: 1 })
        .with(MeleePowerBonus { power: 1 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn rations(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position { x, y })
        .with(Renderable {
            glyph: rltk::to_cp437('%'),
            render_order: 2,
            fg: RGB::named(rltk::GREEN),
            bg: RGB::named(rltk::BLACK),
        })
        .with(Item {})
        .with(Name {
            name: "Rations".to_string(),
        })
        .with(Consumable {})
        .with(ProvidesFood {})
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn magic_mapper_scroll(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position { x, y })
        .with(Renderable {
            glyph: rltk::to_cp437(')'),
            render_order: 2,
            fg: RGB::named(rltk::CYAN3),
            bg: RGB::named(rltk::BLACK),
        })
        .with(Item {})
        .with(Name {
            name: "Scroll to Magic Mapping".to_string(),
        })
        .with(Consumable {})
        .with(MagicMapper {})
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn bear_trap(ecs: &mut World, x: i32, y: i32) {
    ecs.create_entity()
        .with(Position { x, y })
        .with(Renderable {
            glyph: rltk::to_cp437('^'),
            render_order: 2,
            fg: RGB::named(rltk::RED),
            bg: RGB::named(rltk::BLACK),
        })
        .with(Name {
            name: "Bear Trap".to_string(),
        })
        .with(Hidden {})
        .with(EntryTrigger {})
        .with(InflictsDamage { damage: 6 })
        .with(SingleActivation {})
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}