module;

#include <cassert>
#include <memory>
#include <optional>
#include <vector>

export module game.game;

import core.drawing.sprite;
import core.drawing.tile_map;
import core.drawing.tile_set;
import core.engine;
import core.render_server;
import wrappers.sdl;
import wrappers.sdl_image;

export namespace game
{
    class Game
    {
        // Whether this class is currently instantiated (to prevent multiple instances)
        static bool instantiated_;

        // Reference to the engine
        core::Engine& engine_;

        // Sprites for testing
        core::Sprite player_sprite_;
        std::vector<core::Sprite> sprites_;

        // Tile set and tile map (TODO: tile set should be moved to resource manager in engine)
        core::TileSet tile_set_;
        core::TileMap tile_map_;

        // Private constructor
        explicit Game(core::Engine& engine)
            : engine_(engine),
              player_sprite_{
                  core::Sprite::create_from_texture(
                      engine_.get_render_server(),
                      "assets/sprites/neocat_64.png",
                      std::nullopt,
                      sdl::FPoint{0, 0},
                      sdl::FPoint{-32, -32}
                  )
              },
              tile_set_{
                  core::TileSet::create_from_texture(
                      engine_.get_render_server(),
                      "assets/tilesets/terrain.png",
                      32,
                      {
                          // Tile 0: No tile
                          {0, 0},
                          // Tile 1: Actual first tile in the texture
                          {0, 0},
                          {1, 0},
                          {2, 0},
                          {3, 0},
                      }
                  )
              },
              tile_map_(0, 32, 16, 12, {50, 50})
        {
            // Initialize tile map with example data
            for (auto x = 0; x < 10; x++) {
                for (auto y = 0; y < 10; y++) {
                    const auto tile_index = 2 + (x + y) % 2;
                    tile_map_.set_tile(x, y, tile_index);
                }
            }
        }

        public:
            Game() = delete;

            // No copy or move operations because we have a reference to the engine
            Game(const Game&) = delete;
            Game& operator=(const Game&) = delete;
            Game(Game&&) = delete;
            Game& operator=(Game&&) = delete;

            ~Game()
            {
                instantiated_ = false;
            }

            static std::unique_ptr<Game> create(core::Engine& engine)
            {
                // Prevent the class from being instantiated multiple times
                assert(!instantiated_);
                return std::unique_ptr<Game>{
                    new Game(engine)
                };
            }

            // Handles an SDL event. Returns true if the event has been handled.
            bool handle_event(const sdl::Event* event)
            {
                if (event->type == sdl::EventType::MouseMotion) {
                    player_sprite_.set_position({event->motion.x, event->motion.y});
                    return true;
                }

                if (event->type == sdl::EventType::MouseButtonUp) {
                    sprites_.push_back(
                        core::Sprite::create_from_texture(
                            engine_.get_render_server(),
                            "assets/sprites/neofox_64.png",
                            std::nullopt,
                            sdl::FPoint{event->motion.x, event->motion.y},
                            sdl::FPoint{-32, -32}
                        )
                    );
                    return true;
                }

                return false;
            }

            void update()
            {
            }

            void render() const
            {
                const auto& render_server = engine_.get_render_server();
                render_server.start_frame();

                // Render tilemap
                tile_map_.draw(render_server, tile_set_);

                // Render sprites
                for (const core::Sprite& sprite : sprites_) {
                    sprite.draw(render_server);
                }
                player_sprite_.draw(render_server);

                render_server.finish_frame();
            }

            void shutdown()
            {
            }
    };

    bool Game::instantiated_ = false;
}