use ::rltk::{Point, RandomNumberGenerator};
use ::specs::prelude::*;
use rltk::RGB;

use crate::components::{
    Attributes, Equipped, InBackpack, LootTable, Name, Player, Pools, Position, SufferDamage,
};
use crate::game_log::GameLog;
use crate::gamesystem::{mana_at_level, player_hp_at_level};
use crate::particle_system::ParticleBuilder;
use crate::raws::{self, SpawnType, RAWS};
use crate::{spatial, Map, RunState};

pub struct DamageSystem {}

impl<'a> System<'a> for DamageSystem {
    #[allow(clippy::type_complexity)]
    type SystemData = (
        WriteStorage<'a, Pools>,
        WriteStorage<'a, SufferDamage>,
        ReadStorage<'a, Position>,
        WriteExpect<'a, Map>,
        Entities<'a>,
        ReadExpect<'a, Entity>,
        ReadStorage<'a, Attributes>,
        WriteExpect<'a, GameLog>,
        WriteExpect<'a, ParticleBuilder>,
        ReadExpect<'a, Point>,
    );

    fn run(&mut self, data: Self::SystemData) {
        let (
            mut stats,
            mut damage,
            positions,
            mut map,
            entities,
            player,
            attributes,
            mut log,
            mut particles,
            player_pos,
        ) = data;
        let mut xp_gain = 0;
        let mut gold_gain = 0.0_f32;

        for (entity, mut stats, damage) in (&entities, &mut stats, &damage).join() {
            gold_gain += stats.gold;
            for dmg in damage.amount.iter() {
                if !stats.god_mode {
                    stats.hit_points.current -= dmg.0;
                }

                if let Some(pos) = positions.get(entity) {
                    let idx = map.xy_idx(pos.x, pos.y);
                    map.bloodstains.insert(idx);
                    spatial::remove_entity(entity, idx);
                }

                if stats.hit_points.current < 1 && dmg.1 {
                    xp_gain += stats.level * 100;
                }
            }
        }

        if xp_gain != 0 || gold_gain != 0.0 {
            let mut player_stats = stats.get_mut(*player).unwrap();
            let player_attributes = attributes.get(*player).unwrap();

            player_stats.xp += xp_gain;
            player_stats.gold += gold_gain;

            if player_stats.xp >= player_stats.level * 1000 {
                // We've gone up a level!
                player_stats.level += 1;
                log.append(format!(
                    "Congratulations, you are now level {}",
                    player_stats.level
                ));
                player_stats.hit_points.max = player_hp_at_level(
                    player_attributes.fitness.base + player_attributes.fitness.modifiers,
                    player_stats.level,
                );
                player_stats.hit_points.current = player_stats.hit_points.max;
                player_stats.mana.max = mana_at_level(
                    player_attributes.intelligence.base + player_attributes.intelligence.modifiers,
                    player_stats.level,
                );
                player_stats.mana.current = player_stats.mana.max;

                for i in 0..10 {
                    if player_pos.y - i > 1 {
                        particles.request(
                            player_pos.x,
                            player_pos.y - 1,
                            RGB::named(rltk::GOLD),
                            RGB::named(rltk::BLACK),
                            rltk::to_cp437('░'),
                            400.0,
                        );
                    }
                }
            }
        }

        damage.clear();
    }
}

pub fn delete_the_dead(ecs: &mut World) {
    let mut dead: Vec<Entity> = Vec::new();

    // Scope for the sake of the borrow checker
    {
        let combat_stats = ecs.read_storage::<Pools>();
        let players = ecs.read_storage::<Player>();
        let names = ecs.read_storage::<Name>();
        let entities = ecs.entities();
        let mut log = ecs.write_resource::<GameLog>();

        for (entity, stats) in (&entities, &combat_stats).join() {
            if stats.hit_points.current < 1 {
                match players.get(entity) {
                    None => {
                        if let Some(victim_name) = names.get(entity) {
                            log.append(format!("{} is dead", &victim_name.name));
                        }

                        dead.push(entity)
                    }
                    Some(_) => {
                        let mut runstate = ecs.write_resource::<RunState>();
                        *runstate = RunState::GameOver;
                    }
                }
            }
        }
    }

    // Drop everything held by dead people
    let mut to_spawn: Vec<(String, Position)> = Vec::new();
    {
        // To avoid hold of borrowed entires, use a scope
        let mut to_drop: Vec<(Entity, Position)> = Vec::new();
        let entities = ecs.entities();
        let mut equipped = ecs.write_storage::<Equipped>();
        let mut carried = ecs.write_storage::<InBackpack>();
        let mut positions = ecs.write_storage::<Position>();
        let loot_tables = ecs.read_storage::<LootTable>();
        let mut rng = ecs.write_resource::<RandomNumberGenerator>();

        for victim in dead.iter() {
            let pos = positions.get(*victim);
            for (entity, equipped) in (&entities, &equipped).join() {
                if equipped.owner == *victim {
                    // Drop their stuff
                    if let Some(pos) = pos {
                        to_drop.push((entity, *pos));
                    }
                }
            }
            for (entity, backpack) in (&entities, &carried).join() {
                if backpack.owner == *victim {
                    // Drop their stuff
                    if let Some(pos) = pos {
                        to_drop.push((entity, *pos));
                    }
                }
            }

            if let Some(table) = loot_tables.get(*victim) {
                let drop_finder =
                    raws::get_item_drop(&crate::raws::RAWS.lock().unwrap(), &mut rng, &table.table);
                if let Some(tag) = drop_finder {
                    if let Some(pos) = pos {
                        to_spawn.push((tag, *pos));
                    }
                }
            }
        }

        for drop in to_drop.iter() {
            equipped.remove(drop.0);
            carried.remove(drop.0);
            positions
                .insert(drop.0, drop.1)
                .expect("Unable to insert position");
        }
    }

    {
        for drop in to_spawn.iter() {
            raws::spawn_named_item(
                &RAWS.lock().unwrap(),
                ecs,
                &drop.0,
                SpawnType::AtPosition {
                    x: drop.1.x,
                    y: drop.1.y,
                },
            );
        }
    }

    for victim in dead {
        ecs.delete_entity(victim)
            .expect("Unable to delete the dead");
    }
}