extern crate serde;
extern crate rltk;
use rltk::{Console, GameState, Rltk, Point};
extern crate specs;
use specs::prelude::*;
use specs::saveload::{SimpleMarker, SimpleMarkerAllocator};
#[macro_use]
extern crate specs_derive;
mod components;
pub use components::*;
mod map;
pub use map::*;
mod player;
use player::*;
mod rect;
pub use rect::Rect;
mod visibility_system;
use visibility_system::VisibilitySystem;
mod monster_ai_system;
use monster_ai_system::MonsterAI;
mod map_indexing_system;
use map_indexing_system::MapIndexingSystem;
mod melee_combat_system;
use melee_combat_system::MeleeCombatSystem;
mod damage_system;
use damage_system::DamageSystem;
mod gui;
mod gamelog;
mod spawner;
mod inventory_system;
use inventory_system::{ ItemCollectionSystem, ItemUseSystem, ItemDropSystem };
mod saveload_system;

#[derive(PartialEq, Copy, Clone)]
pub enum RunState { AwaitingInput, 
    PreRun, 
    PlayerTurn, 
    MonsterTurn, 
    ShowInventory, 
    ShowDropItem, 
    ShowTargeting { range : i32, item : Entity},
    MainMenu { menu_selection : gui::MainMenuSelection },
    SaveGame
}

pub struct State {
    pub ecs: World,
    pub systems: Dispatcher<'static, 'static>
}

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

        ctx.cls();        

        match newrunstate {
            RunState::MainMenu{..} => {}
            _ => {
                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>();

                    let mut data = (&positions, &renderables).join().collect::<Vec<_>>();
                    data.sort_by(|&a, &b| b.1.render_order.cmp(&a.1.render_order) );
                    for (pos, render) in data.iter() {
                        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);
                } 
            }
        }
        
        match newrunstate {
            RunState::PreRun => {
                self.systems.dispatch(&self.ecs);
                self.ecs.maintain();
                newrunstate = RunState::AwaitingInput;
            }
            RunState::AwaitingInput => {
                newrunstate = player_input(self, ctx);
            }
            RunState::PlayerTurn => {
                self.systems.dispatch(&self.ecs);
                self.ecs.maintain();
                newrunstate = RunState::MonsterTurn;
            }
            RunState::MonsterTurn => {
                self.systems.dispatch(&self.ecs);
                self.ecs.maintain();
                newrunstate = RunState::AwaitingInput;
            }
            RunState::ShowInventory => {
                let result = gui::show_inventory(self, ctx);
                match result.0 {
                    gui::ItemMenuResult::Cancel => newrunstate = RunState::AwaitingInput,
                    gui::ItemMenuResult::NoResponse => {}
                    gui::ItemMenuResult::Selected => {
                        let item_entity = result.1.unwrap();
                        let is_ranged = self.ecs.read_storage::<Ranged>();
                        let is_item_ranged = is_ranged.get(item_entity);
                        if let Some(is_item_ranged) = is_item_ranged {
                            newrunstate = RunState::ShowTargeting{ range: is_item_ranged.range, item: item_entity };
                        } else {
                            let mut intent = self.ecs.write_storage::<WantsToUseItem>();
                            intent.insert(*self.ecs.fetch::<Entity>(), WantsToUseItem{ item: item_entity, target: None }).expect("Unable to insert intent");
                            newrunstate = RunState::PlayerTurn;
                        }
                    }
                }
            }
            RunState::ShowDropItem => {
                let result = gui::drop_item_menu(self, ctx);
                match result.0 {
                    gui::ItemMenuResult::Cancel => newrunstate = RunState::AwaitingInput,
                    gui::ItemMenuResult::NoResponse => {}
                    gui::ItemMenuResult::Selected => {
                        let item_entity = result.1.unwrap();
                        let mut intent = self.ecs.write_storage::<WantsToDropItem>();
                        intent.insert(*self.ecs.fetch::<Entity>(), WantsToDropItem{ item: item_entity }).expect("Unable to insert intent");
                        newrunstate = RunState::PlayerTurn;
                    }
                }
            }
            RunState::ShowTargeting{range, item} => {
                let result = gui::ranged_target(self, ctx, range);
                match result.0 {
                    gui::ItemMenuResult::Cancel => newrunstate = RunState::AwaitingInput,
                    gui::ItemMenuResult::NoResponse => {}
                    gui::ItemMenuResult::Selected => {
                        let mut intent = self.ecs.write_storage::<WantsToUseItem>();
                        intent.insert(*self.ecs.fetch::<Entity>(), WantsToUseItem{ item, target: result.1 }).expect("Unable to insert intent");
                        newrunstate = RunState::PlayerTurn;
                    }
                }
            }
            RunState::MainMenu{ .. } => {
                let result = gui::main_menu(self, ctx);
                match result {
                    gui::MainMenuResult::NoSelection{ selected } => newrunstate = RunState::MainMenu{ menu_selection: selected },
                    gui::MainMenuResult::Selected{ selected } => {
                        match selected {
                            gui::MainMenuSelection::NewGame => newrunstate = RunState::PreRun,
                            gui::MainMenuSelection::LoadGame => newrunstate = RunState::PreRun,
                            gui::MainMenuSelection::Quit => { ::std::process::exit(0); }
                        }
                    }
                }
            }
            RunState::SaveGame => {
                saveload_system::save_game(&mut self.ecs);

                //let data = serde_json::to_string(&*self.ecs.fetch::<Map>()).unwrap();
                //let mut f = File::create("./savemap.json").expect("Unable to create file");
                //f.write_all(data.as_bytes()).expect("Unable to write data");

                newrunstate = RunState::MainMenu{ menu_selection : gui::MainMenuSelection::LoadGame };
            }
        }

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

fn main() {
    let mut context = Rltk::init_simple8x8(80, 50, "Hello Rust World", "../resources");
    context.with_post_scanlines(true);
    let mut gs = State {
        ecs: World::new(),
        systems : DispatcherBuilder::new()
            .with(MapIndexingSystem{}, "map_indexing_system", &[])
            .with(VisibilitySystem{}, "visibility_system", &[])
            .with(MonsterAI{}, "monster_ai", &["visibility_system", "map_indexing_system"])
            .with(MeleeCombatSystem{}, "melee_combat", &["monster_ai"])
            .with(DamageSystem{}, "damage", &["melee_combat"])
            .with(ItemCollectionSystem{}, "pickup", &["melee_combat"])
            .with(ItemUseSystem{}, "potions", &["melee_combat"])
            .with(ItemDropSystem{}, "drop_items", &["melee_combat"])
            .build(),
    };
    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>();
    gs.ecs.register::<Item>();
    gs.ecs.register::<ProvidesHealing>();
    gs.ecs.register::<InflictsDamage>();
    gs.ecs.register::<AreaOfEffect>();
    gs.ecs.register::<Consumable>();
    gs.ecs.register::<Ranged>();
    gs.ecs.register::<InBackpack>();
    gs.ecs.register::<WantsToPickupItem>();
    gs.ecs.register::<WantsToUseItem>();
    gs.ecs.register::<WantsToDropItem>();
    gs.ecs.register::<Confusion>();
    gs.ecs.register::<SimpleMarker<SerializeMe>>();

    gs.ecs.insert(SimpleMarkerAllocator::<SerializeMe>::new());

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

    let player_entity = spawner::player(&mut gs.ecs, player_x, player_y);

    gs.ecs.insert(rltk::RandomNumberGenerator::new());
    for room in map.rooms.iter().skip(1) {
        spawner::spawn_room(&mut gs.ecs, room);
    }

    gs.ecs.insert(map);
    gs.ecs.insert(Point::new(player_x, player_y));
    gs.ecs.insert(player_entity);
    gs.ecs.insert(RunState::MainMenu{ menu_selection: gui::MainMenuSelection::NewGame });
    gs.ecs.insert(gamelog::GameLog{ entries : vec!["Welcome to Rusty Roguelike".to_string()] });

    rltk::main_loop(context, gs);
}