use std::rc::Rc;

use dungeon::{
	Dungeon, UpdateResult, entity::Item, map::Tile, player::PLAYER_INVENTORY_SIZE_USIZE,
	player_input::PlayerInput, pos::Direction,
};
use graphics::{Key, Window};

use crate::music::Music;

mod music;

macro_rules! play_sound {
	($self:expr, $sound:expr) => {
		$self.window.audio().schedule(
			Rc::clone(&$sound.track),
			$sound.priority,
			$sound.looping,
		);
	};
}

/// The `Error` type used within this crate
pub type Error = Box<dyn std::error::Error>;

/// The `Result` type used witin this crate
pub type Result<T> = std::result::Result<T, crate::Error>;

pub struct Game {
	window: Window,
	dungeon: Dungeon,
	music: Music,
	// to ensure the most recently-pressed direction key is used:
	current_dir: Option<(Direction, Key)>,
}

impl Game {
	pub fn new(window: Window, seed: Option<u64>) -> Result<Self> {
		let music = Music::load()?;
		let dungeon = match seed {
			Some(s) => Dungeon::new(s),
			None => Dungeon::random(),
		};
		let game = Self {
			window,
			dungeon,
			music,
			current_dir: None,
		};
		Ok(game)
	}

	fn player_dir(&mut self) -> Option<Direction> {
		const MOVE_KEYS: [(Direction, [Key; 2]); 4] = [
			(Direction::North, [Key::Up, Key::W]),
			(Direction::West, [Key::Left, Key::A]),
			(Direction::South, [Key::Down, Key::S]),
			(Direction::East, [Key::Right, Key::D]),
		];

		// if a key was just pressed, use it for the new direction to move in
		for (dir, keys) in MOVE_KEYS {
			for key in keys {
				if self.window.is_key_pressed(key) {
					self.current_dir = Some((dir, key));
					return Some(dir);
				}
			}
		}
		// otherwise, use existing direction, so long as the key is still down
		match self.current_dir {
			Some((dir, key)) if self.window.is_key_down(key) => return Some(dir),
			_ => self.current_dir = None,
		}
		// otherwise, use any key that is already down
		for (dir, keys) in MOVE_KEYS {
			for key in keys {
				if self.window.is_key_down(key) {
					self.current_dir = Some((dir, key));
					return Some(dir);
				}
			}
		}
		// otherwise, no direction key is pressed, so return None
		None
	}

	fn get_player_input(&mut self) -> PlayerInput {
		let direction = self.player_dir();
		let interact = self.window.is_key_pressed(Key::Return);
		let use_item = self.window.is_key_pressed(Key::E);
		let attack = self.window.is_key_pressed(Key::F);
		let drop = self.window.is_key_pressed(Key::Q);
		let inv_slot = (0..PLAYER_INVENTORY_SIZE_USIZE)
			.find(|n| self.window.is_key_pressed(Key::Number(n + 1)));
		PlayerInput {
			direction,
			interact,
			use_item,
			attack,
			drop,
			inv_slot,
		}
	}

	pub fn run(&mut self) {
		play_sound!(self, &self.music.background);

		// Main game loop
		while self.window.is_open() {
			// Handle debug keys
			if self.window.is_key_pressed(Key::F3) {
				self.window.toggle_debug();
			}
			if self.window.is_key_pressed(Key::F4) {
				*self.dungeon.floor.get_mut(self.dungeon.player.entity.pos) =
					Tile::Chest(Some(Item::Bomb));
			}

			// Update game state
			let inputs = self.get_player_input();
			let result = self
				.dungeon
				.update(inputs, self.window.delta_time().as_secs_f32());
			match result {
				UpdateResult::Default(action) => {
					// items
					if action.bomb {
						play_sound!(self, &self.music.use_bomb);
					} else if action.potion {
						play_sound!(self, &self.music.use_potion);
					} else if action.drop_item {
						play_sound!(self, &self.music.drop_item);
					} else if action.pickup_item {
						play_sound!(self, &self.music.pickup_item);
					}

					// actions
					if action.attack {
						play_sound!(self, &self.music.attack);
					} else if action.walk {
						// TODO: do we want walking sounds? (were a ghost)
					}
				}
				UpdateResult::NextFloor => {
					play_sound!(self, &self.music.discover);
				}
				UpdateResult::MessageUpdated(changed) => {
					if changed {
						play_sound!(self, &self.music.speak);
					}
				}
				UpdateResult::GameOver => {
					self.window.audio().clear();
					play_sound!(self, &self.music.game_over);
				}
				UpdateResult::Nothing => {}
			}

			// Draw a single frame
			self.window.draw_frame(&self.dungeon);

			// Update audio
			self.window.audio().update();
		}
	}
}