use std::collections::HashMap;

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

use crate::components::*;
use crate::map::MAP_WIDTH;
use crate::random_table::RandomTable;
use crate::{Map, Rect, TileType};

/// Spawns the player and returns their entity object
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::default())
        .with(Name::from("Player"))
        .with(CombatStats {
            max_hp: 30,
            hp: 30,
            defense: 2,
            power: 5,
        })
        .with(HungerClock {
            state: HungerState::WellFed,
            duration: 20,
        })
        .marked::<SimpleMarker<SerializeMe>>()
        .build()
}

const MAX_MONSTERS: i32 = 4;

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("Shield", 3)
        .add("Longsword", map_depth - 1)
        .add("Tower Shield", map_depth - 1)
        .add("Rations", 10)
        .add("Magic Mapping Scroll", 2)
        .add("Bear Trap", 2)
}

/// fills a room with stuff!
#[allow(clippy::map_entry)]
pub fn spawn_room(
    map: &Map,
    rng: &mut RandomNumberGenerator,
    room: &Rect,
    map_depth: i32,
    spawn_list: &mut Vec<(usize, String)>,
) {
    let mut possible_targets: Vec<usize> = Vec::new();

    // Borrow scope - to keep access to the map separated
    {
        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(map, rng, &possible_targets, map_depth, spawn_list);
}

pub fn spawn_region(
    map: &Map,
    rng: &mut RandomNumberGenerator,
    area: &[usize],
    map_depth: i32,
    spawn_list: &mut Vec<(usize, String)>,
) {
    let spawn_table = room_table(map_depth);
    let mut spawn_points: HashMap<usize, String> = HashMap::new();
    let mut areas: Vec<usize> = Vec::from(area);

    // Scope to keep the borrow checker happy
    {
        let num_spawns = i32::min(
            areas.len() as i32,
            rng.roll_dice(1, MAX_MONSTERS + 3) + (map_depth - 1) - 3,
        );
        if num_spawns == 0 {
            return;
        }

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

    // Actually spawn the monsters
    for spawn in spawn_points.iter() {
        spawn_list.push((*spawn.0, spawn.1.to_string()));
    }
}

/// Spawns a named entity (name in tuple.1) at the location in (tuple.0)
pub 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),
        "Shield" => shield(ecs, x, y),
        "Longsword" => longsword(ecs, x, y),
        "Tower Shield" => tower_shield(ecs, x, y),
        "Rations" => rations(ecs, x, y),
        "Magic Mapping Scroll" => magic_mapping_scroll(ecs, x, y),
        "Bear Trap" => bear_trap(ecs, x, y),
        _ => {}
    }
}

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: rltk::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::default())
        .with(Monster {})
        .with(Name::from(name))
        .with(BlocksTile {})
        .with(CombatStats {
            max_hp: 16,
            hp: 16,
            defense: 1,
            power: 4,
        })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

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

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::from("Magic Missile Scroll"))
        .with(Item {})
        .with(Consumable {})
        .with(Ranged { range: 6 })
        .with(InflictsDamage { damage: 20 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

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::from("Fireball Scroll"))
        .with(Item {})
        .with(Consumable {})
        .with(Ranged { range: 6 })
        .with(InflictsDamage { damage: 20 })
        .with(AreaOfEffect { radius: 3 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

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::from("Confusion Scroll"))
        .with(Item {})
        .with(Consumable {})
        .with(Ranged { range: 6 })
        .with(Confusion { turns: 4 })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn dagger(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::from("Dagger"))
        .with(Item {})
        .with(Equippable {
            slot: EquipmentSlot::Melee,
        })
        .with(MeleePowerBonus { power: 2 })
        .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('('),
            fg: RGB::named(rltk::CYAN),
            bg: RGB::named(rltk::BLACK),
            render_order: 2,
        })
        .with(Name::from("Shield"))
        .with(Item {})
        .with(Equippable {
            slot: EquipmentSlot::Shield,
        })
        .with(DefenseBonus { defense: 1 })
        .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('/'),
            fg: RGB::named(rltk::CYAN),
            bg: RGB::named(rltk::BLACK),
            render_order: 2,
        })
        .with(Name::from("Longsword"))
        .with(Item {})
        .with(Equippable {
            slot: EquipmentSlot::Melee,
        })
        .with(MeleePowerBonus { power: 4 })
        .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('('),
            fg: RGB::named(rltk::CYAN),
            bg: RGB::named(rltk::BLACK),
            render_order: 2,
        })
        .with(Name::from("Tower Shield"))
        .with(Item {})
        .with(Equippable {
            slot: EquipmentSlot::Shield,
        })
        .with(DefenseBonus { defense: 3 })
        .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('%'),
            fg: RGB::named(rltk::GREEN),
            bg: RGB::named(rltk::BLACK),
            render_order: 2,
        })
        .with(Name::from("Rations"))
        .with(Item {})
        .with(ProvidesFood {})
        .with(Consumable {})
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}

fn magic_mapping_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::CYAN3),
            bg: RGB::named(rltk::BLACK),
            render_order: 2,
        })
        .with(Name::from("Scroll of Magic Mapping"))
        .with(Item {})
        .with(MagicMapper {})
        .with(Consumable {})
        .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('^'),
            fg: RGB::named(rltk::RED),
            bg: RGB::named(rltk::BLACK),
            render_order: 2,
        })
        .with(Name::from("Bear Trap"))
        .with(Hidden {})
        .with(EntryTrigger {})
        .with(InflictsDamage { damage: 6 })
        .with(SingleActivation {})
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
}