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

mod components;
pub use components::*;

mod map;
pub use map::*;

mod player;
pub use player::*;

mod rect;
pub use rect::Rect;

mod visibility_system;
pub use visibility_system::*;

mod monster_ai_system;
pub use monster_ai_system::*;

mod map_indexing_system;
pub use map_indexing_system::*;

mod melee_combat_system;
pub use melee_combat_system::*;

mod damage_system;
pub use damage_system::*;

mod gui;
pub use gui::*;

mod gamelog;
pub use gamelog::*;

pub struct State {
    pub ecs: World
}

impl State {
    fn run_systems(&mut self) {
        let mut vis = VisibilitySystem {};
        vis.run_now(&self.ecs);
        let mut mob = MonsterAI {};
        mob.run_now(&self.ecs);
        let mut mapindex = MapIndexingSystem{};
        mapindex.run_now(&self.ecs);
        let mut melee_combat_system = MeleeCombatSystem{};
        melee_combat_system.run_now(&self.ecs);
        let mut damage_system = DamageSystem{};
        damage_system.run_now(&self.ecs);
        self.ecs.maintain();
    }
}

impl GameState for State {
    fn tick(&mut self, ctx: &mut Rltk) {
        ctx.cls();
        let mut newrunstate;
        {
            let runstate = self.ecs.fetch::<RunState>();
            newrunstate = *runstate;
        }

        match newrunstate {
            RunState::PreRun => {
                self.run_systems();
                newrunstate = RunState::AwaitingInput;
            }
            RunState::AwaitingInput => {
                newrunstate = player_input(self, ctx);
            }
            RunState::PlayerTurn => {
                self.run_systems();
                newrunstate = RunState::MonsterTurn;
            }
            RunState::MonsterTurn => {
                self.run_systems();
                newrunstate = RunState::AwaitingInput;
            }
        }

        {
            let mut runwriter = self.ecs.write_resource::<RunState>();
            *runwriter = newrunstate;
        }

        damage_system::delete_the_dead(&mut self.ecs);
        draw_map(&self.ecs, ctx);

        let positions = self.ecs.read_storage::<Position>();
        let renderables = self.ecs.read_storage::<Renderable>();
        let map = self.ecs.fetch::<Map>();

        for (pos, render) in (&positions, &renderables).join() {
            let idx = map.xy_idx(pos.x, pos.y);
            if map.visible_tiles[idx] {
                ctx.set(pos.x, pos.y, render.fg, render.bg, render.glyph)
            }
        }
        gui::draw_ui(&self.ecs, ctx);
    }
}

fn main() -> rltk::BError {
    use rltk::RltkBuilder;
    let mut context = RltkBuilder::simple80x50()
        .with_title("Rougelike Tutorial")
        .build()?;
    context.with_post_scanlines(true);
    let mut gs = State {
        ecs: World::new()
    };
    gs.ecs.register::<Position>();
    gs.ecs.register::<Renderable>();
    gs.ecs.register::<Player>();
    gs.ecs.register::<Viewshed>();
    gs.ecs.register::<Monster>();
    gs.ecs.register::<Name>();
    gs.ecs.register::<BlocksTile>();
    gs.ecs.register::<CombatStats>();
    gs.ecs.register::<WantsToMelee>();
    gs.ecs.register::<SufferDamage>();
    

    let map = Map::new_map_rooms_and_corridors();
    let (player_x, player_y) = map.rooms[0].center();

    gs.ecs.insert(Point::new(player_x, player_y));
    let player_entity = gs.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),
        })
        .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, defence: 2, power: 5})
        .build();

    gs.ecs.insert(player_entity);
    let mut rng = rltk::RandomNumberGenerator::new();
    for (i, room) in map.rooms.iter().skip(1).enumerate() {
        let (x, y) = room.center();

        let glyph: rltk::FontCharType;
        let name: String;
        let roll = rng.roll_dice(1, 2);
        match roll {
            1 => {
                glyph = rltk::to_cp437('g');
                name = "Goblin".to_string()
            }
            _ => {
                glyph = rltk::to_cp437('o');
                name = "Orc".to_string()
            }
        }

        gs.ecs
            .create_entity()
            .with(Position { x, y })
            .with(Renderable {
                glyph: glyph,
                fg: RGB::named(rltk::RED),
                bg: RGB::named(rltk::BLACK),
            })
            .with(Viewshed {
                visible_tiles: Vec::new(),
                range: 8,
                dirty: true,
            })
            .with(Monster {})
            .with(Name {
                name: format!("{} #{}", &name, i),
            })
            .with(BlocksTile{})
            .with(CombatStats{max_hp: 16, hp: 16, defence: 1, power: 4})
            .build();
    }
    gs.ecs.insert(map);
    gs.ecs.insert(RunState::PreRun);
    gs.ecs.insert(gamelog::GameLog{ entries : vec!["Welcome to my rougelike".to_string()]});

    // Main loop runner
    rltk::main_loop(context, gs)
}