use specs::prelude::*;

use crate::components::{CombatStats, Name, SufferDamage, WantsToMelee};
use crate::gamelog::GameLog;
use crate::particle_system::ParticleBuilder;
use crate::{DefenseBonus, Equipped, HungerClock, HungerState, MeleePowerBonus, Position};

pub struct MeleeCombatSystem {}

impl<'a> System<'a> for MeleeCombatSystem {
    #[allow(clippy::complexity)]
    type SystemData = (
        Entities<'a>,
        WriteExpect<'a, GameLog>,
        WriteStorage<'a, WantsToMelee>,
        ReadStorage<'a, Name>,
        ReadStorage<'a, CombatStats>,
        WriteStorage<'a, SufferDamage>,
        ReadStorage<'a, MeleePowerBonus>,
        ReadStorage<'a, DefenseBonus>,
        ReadStorage<'a, Equipped>,
        WriteExpect<'a, ParticleBuilder>,
        ReadStorage<'a, Position>,
        ReadStorage<'a, HungerClock>,
    );

    fn run(&mut self, data: Self::SystemData) {
        let (
            entities,
            mut log,
            mut wants_melee,
            names,
            combat_stats,
            mut inflict_damage,
            melee_bonus,
            defense_bonus,
            equipped,
            mut particle_builder,
            positions,
            hunger_clock,
        ) = data;

        for (entity, wants_melee, name, stats) in
            (&entities, &wants_melee, &names, &combat_stats).join()
        {
            if stats.hp <= 0 {
                continue;
            }

            let mut offensive_bonus = 0;
            for (_item_entity, power_bonus, equipped_by) in
                (&entities, &melee_bonus, &equipped).join()
            {
                if equipped_by.owner == entity {
                    offensive_bonus += power_bonus.power;
                }
            }

            if let Some(hc) = hunger_clock.get(entity) {
                if hc.state == HungerState::WellFed {
                    offensive_bonus += 1;
                }
            }

            let target_stats = combat_stats.get(wants_melee.target).unwrap();
            if target_stats.hp > 0 {
                let target_name = names.get(wants_melee.target).unwrap();

                let mut defensive_bonus = 0;
                for (_item_entity, defense_bonus, equipped_by) in
                    (&entities, &defense_bonus, &equipped).join()
                {
                    if equipped_by.owner == wants_melee.target {
                        defensive_bonus += defense_bonus.defense;
                    }
                }

                if let Some(pos) = positions.get(wants_melee.target) {
                    particle_builder.request(
                        pos.x,
                        pos.y,
                        rltk::RGB::named(rltk::ORANGE),
                        rltk::RGB::named(rltk::BLACK),
                        rltk::to_cp437('‼'),
                        200.0,
                    );
                }

                let damage = i32::max(
                    0,
                    (stats.power + offensive_bonus) - (target_stats.defense + defensive_bonus),
                );

                if damage == 0 {
                    log.entries.push(format!(
                        "{} is unable to hurt {}",
                        &name.name, &target_name.name
                    ));
                } else {
                    log.entries.push(format!(
                        "{} hits {}, for {} hp.",
                        &name.name, &target_name.name, damage
                    ));
                    SufferDamage::new_damage(&mut inflict_damage, wants_melee.target, damage)
                }
            }
        }

        wants_melee.clear();
    }
}