/*
 * Copyright (C) 2023  Christopher J. Howard
 *
 * This file is part of Antkeeper source code.
 *
 * Antkeeper source code is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Antkeeper source code is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Antkeeper source code.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef ANTKEEPER_GAME_HPP
#define ANTKEEPER_GAME_HPP

#include "game/ecoregion.hpp"
#include "game/states/game-state.hpp"
#include <AL/al.h>
#include <AL/alc.h>
#include <engine/animation/tween.hpp>
#include <engine/app/input-manager.hpp>
#include <engine/app/window-manager.hpp>
#include <engine/entity/id.hpp>
#include <engine/entity/registry.hpp>
#include <engine/event/subscription.hpp>
#include <engine/gl/framebuffer.hpp>
#include <engine/gl/texture.hpp>
#include <engine/i18n/string-map.hpp>
#include <engine/input/action-map.hpp>
#include <engine/input/action.hpp>
#include <engine/input/mapper.hpp>
#include <engine/math/moving-average.hpp>
#include <engine/render/anti-aliasing-method.hpp>
#include <engine/render/material-variable.hpp>
#include <engine/render/material.hpp>
#include <engine/type/bitmap-font.hpp>
#include <engine/type/typeface.hpp>
#include <engine/utility/dict.hpp>
#include <engine/math/vector.hpp>
#include <engine/utility/state-machine.hpp>
#include <engine/utility/frame-scheduler.hpp>
#include <engine/scene/text.hpp>
#include <engine/scene/directional-light.hpp>
#include <engine/scene/rectangle-light.hpp>
#include <engine/scene/spot-light.hpp>
#include <engine/scene/camera.hpp>
#include <engine/scene/billboard.hpp>
#include <engine/scene/collection.hpp>
#include <engine/scene/text.hpp>
#include <engine/math/angles.hpp>
#include <entt/entt.hpp>
#include <filesystem>
#include <memory>
#include <optional>
#include <queue>
#include <string>
#include <unordered_map>
#include <random>
#include <vector>

// Forward declarations
class animator;
class resource_manager;
class screen_transition;
class timeline;

template <typename T> class animation;

namespace debug
{
	class cli;
}

namespace render
{
	class bloom_pass;
	class compositor;
	class final_pass;
	class resample_pass;
	class material_pass;
	class renderer;
	class simple_render_pass;
	class sky_pass;
}


// Forward declarations of system types.
class astronomy_system;
class atmosphere_system;
class behavior_system;
class blackbody_system;
class camera_system;
class collision_system;
class constraint_system;
class locomotion_system;
class animation_system;
class nest_system;
class orbit_system;
class render_system;
class spatial_system;
class steering_system;
class reproductive_system;
class metabolic_system;
class metamorphosis_system;
class physics_system;
class subterrain_system;
class terrain_system;
class ik_system;

struct control_profile;


class game
{
public:
	/**
	 * Boots up the game.
	 *
	 * @param argc Command line argument count.
	 * @param argv Command line argument vector.
	 */
	game(int argc, const char* const* argv);
	
	/**
	 * Boots down the game.
	 */
	~game();
	
	/**
	 * Executes the game.
	 */
	void execute();
	
	// Command-line options
	std::optional<bool> option_continue;
	std::optional<std::string> option_data;
	std::optional<bool> option_fullscreen;
	std::optional<bool> option_new_game;
	std::optional<bool> option_quick_start;
	std::optional<bool> option_reset;
	std::optional<bool> option_v_sync;
	std::optional<bool> option_windowed;
	
	// Resource management and paths
	std::unique_ptr<resource_manager> resource_manager;
	std::filesystem::path data_package_path;
	std::filesystem::path mods_path;
	std::filesystem::path local_config_path;
	std::filesystem::path shared_config_path;
	std::filesystem::path saves_path;
	std::filesystem::path screenshots_path;
	std::filesystem::path controls_path;
	
	// Persistent settings
	std::shared_ptr<dict<hash::fnv1a32_t>> settings;
	
	// Window management and window event handling
	std::unique_ptr<app::window_manager> window_manager;
	std::shared_ptr<app::window> window;
	bool closed;
	std::shared_ptr<::event::subscription> window_closed_subscription;
	std::shared_ptr<::event::subscription> window_resized_subscription;
	
	// Input management and input event handling
	std::unique_ptr<app::input_manager> input_manager;
	std::shared_ptr<::event::subscription> application_quit_subscription;
	std::shared_ptr<::event::subscription> gamepad_axis_moved_subscription;
	std::shared_ptr<::event::subscription> gamepad_button_pressed_subscription;
	std::shared_ptr<::event::subscription> mouse_button_pressed_subscription;
	std::shared_ptr<::event::subscription> mouse_moved_subscription;
	std::shared_ptr<::event::subscription> mouse_scrolled_subscription;
	bool gamepad_active;
	
	// Localization and internationalization
	std::string language_tag;
	std::shared_ptr<i18n::string_map> string_map;
	
	// Fonts
	std::unordered_map<hash::fnv1a32_t, std::shared_ptr<type::typeface>> typefaces;
	type::bitmap_font debug_font;
	type::bitmap_font menu_font;
	type::bitmap_font title_font;
	std::shared_ptr<render::material> debug_font_material;
	std::shared_ptr<render::material> menu_font_material;
	std::shared_ptr<render::material> title_font_material;
	
	// Action maps, actions, and action event handling
	std::string control_profile_filename;
	std::shared_ptr<::control_profile> control_profile;
	
	std::unordered_map<hash::fnv1a32_t, input::action> actions;
	
	input::action_map window_action_map;
	input::action fullscreen_action;
	input::action screenshot_action;
	
	input::action_map menu_action_map;
	input::action menu_up_action;
	input::action menu_down_action;
	input::action menu_left_action;
	input::action menu_right_action;
	input::action menu_select_action;
	input::action menu_back_action;
	input::action menu_modifier_action;
	
	input::action_map movement_action_map;
	input::mapper input_mapper;

	input::action move_forward_action;
	input::action move_back_action;
	input::action move_left_action;
	input::action move_right_action;
	input::action move_up_action;
	input::action move_down_action;
	input::action move_fast_action;
	input::action move_slow_action;
	input::action pause_action;
	
	input::action_map camera_action_map;
	input::action camera_mouse_pick_action;
	input::action camera_mouse_look_action;
	input::action camera_mouse_drag_action;
	input::action camera_mouse_zoom_action;
	input::action camera_zoom_in_action;
	input::action camera_zoom_out_action;
	input::action camera_orbit_left_action;
	input::action camera_orbit_right_action;
	input::action camera_orbit_up_action;
	input::action camera_orbit_down_action;
	input::action camera_look_ahead_action;
	input::action camera_preset_1_action;
	input::action camera_preset_2_action;
	input::action camera_preset_3_action;
	input::action camera_preset_4_action;
	input::action camera_preset_5_action;
	input::action camera_preset_6_action;
	input::action camera_preset_7_action;
	input::action camera_preset_8_action;
	input::action camera_preset_9_action;
	input::action camera_preset_10_action;
	input::action camera_save_preset_action;
	
	input::action_map ant_action_map;
	input::action ant_move_forward_action;
	input::action ant_move_back_action;
	input::action ant_move_left_action;
	input::action ant_move_right_action;
	input::action ant_move_fast_action;
	input::action ant_move_slow_action;
	input::action ant_interact_action;
	input::action ant_oviposit_action;
	
	input::action_map debug_action_map;
	input::action toggle_debug_ui_action;
	input::action adjust_exposure_action;
	input::action adjust_time_action;
	
	std::vector<std::shared_ptr<::event::subscription>> event_subscriptions;
	
	std::vector<std::shared_ptr<::event::subscription>> menu_action_subscriptions;
	std::vector<std::shared_ptr<::event::subscription>> menu_mouse_subscriptions;
	std::vector<std::shared_ptr<::event::subscription>> movement_action_subscriptions;
	
	// Mouse settings
	double mouse_radians_per_pixel{math::radians(0.1)};
	double mouse_pan_sensitivity{1.0};
	double mouse_tilt_sensitivity{1.0};
	bool mouse_invert_pan{false};
	bool mouse_invert_tilt{false};
	double mouse_pan_factor{1.0};
	double mouse_tilt_factor{1.0};
	bool toggle_mouse_look{false};
	bool toggle_mouse_grip{false};
	bool toggle_mouse_zoom{false};
	float zoom_steps{6.0};
	
	// Gamepad settings
	double gamepad_radians_per_second{math::radians(180.0)};
	double gamepad_pan_sensitivity{1.0};
	double gamepad_tilt_sensitivity{1.0};
	bool gamepad_invert_pan{false};
	bool gamepad_invert_tilt{false};
	double gamepad_pan_factor{1.0};
	double gamepad_tilt_factor{1.0};
	
	// Debugging
	bool debug_ui_visible{false};
	std::unique_ptr<scene::text> frame_time_text;
	std::unique_ptr<debug::cli> cli;
	
	// Hierarchichal state machine
	hsm::state_machine<game_state> state_machine;
	std::function<void()> resume_callback;
	
	// Queue for scheduling "next frame" function calls
	std::queue<std::function<void()>> function_queue;
	
	// Framebuffers
	std::shared_ptr<gl::texture_2d> hdr_color_texture;
	std::shared_ptr<gl::texture_2d> hdr_depth_texture;
	std::shared_ptr<gl::framebuffer> hdr_framebuffer;
	std::shared_ptr<gl::texture_2d> ldr_color_texture_a;
	std::shared_ptr<gl::framebuffer> ldr_framebuffer_a;
	std::shared_ptr<gl::texture_2d> ldr_color_texture_b;
	std::shared_ptr<gl::framebuffer> ldr_framebuffer_b;
	std::shared_ptr<gl::texture_2d> shadow_map_depth_texture;
	std::shared_ptr<gl::framebuffer> shadow_map_framebuffer;
	
	// Rendering
	math::ivec2 render_resolution;
	float render_scale;
	int shadow_map_resolution;
	std::unique_ptr<render::material_pass> ui_material_pass;
	std::unique_ptr<render::compositor> ui_compositor;
	std::unique_ptr<render::bloom_pass> bloom_pass;
	std::unique_ptr<render::final_pass> common_final_pass;
	std::unique_ptr<render::resample_pass> resample_pass;
	std::unique_ptr<render::material_pass> underground_material_pass;
	std::unique_ptr<render::compositor> underground_compositor;
	std::unique_ptr<render::sky_pass> sky_pass;
	std::unique_ptr<render::material_pass> surface_material_pass;
	std::unique_ptr<render::compositor> surface_compositor;
	std::unique_ptr<render::renderer> renderer;
	
	// UI
	std::unique_ptr<scene::collection> ui_scene;
	std::unique_ptr<scene::camera> ui_camera;
	std::unique_ptr<scene::billboard> menu_bg_billboard;
	std::shared_ptr<render::material> menu_bg_material;
	std::unique_ptr<animation<float>> menu_fade_animation;
	std::unique_ptr<animation<float>> menu_bg_fade_in_animation;
	std::unique_ptr<animation<float>> menu_bg_fade_out_animation;
	
	float font_scale;
	bool dyslexia_font;
	float debug_font_size_pt;
	float menu_font_size_pt;
	float title_font_size_pt;
	
	std::vector<std::function<void()>> menu_select_callbacks;
	std::vector<std::function<void()>> menu_left_callbacks;
	std::vector<std::function<void()>> menu_right_callbacks;
	std::function<void()> menu_back_callback;
	std::vector<std::tuple<scene::text*, scene::text*>> menu_item_texts;
	std::unordered_map<hash::fnv1a32_t, int> menu_item_indices;
	int* menu_item_index;
	
	// Scene
	std::unique_ptr<scene::collection> surface_scene;
	std::shared_ptr<scene::camera> surface_camera;
	std::unique_ptr<scene::directional_light> sun_light;
	std::unique_ptr<scene::directional_light> moon_light;
	std::unique_ptr<scene::collection> underground_scene;
	std::shared_ptr<scene::camera> underground_camera;
	std::unique_ptr<scene::directional_light> underground_directional_light;
	std::unique_ptr<scene::rectangle_light> underground_rectangle_light;
	scene::collection* active_scene;
	
	// Animation
	std::unique_ptr<timeline> timeline;
	std::unique_ptr<animator> animator;
	std::unique_ptr<animation<float>> radial_transition_in;
	std::unique_ptr<animation<float>> radial_transition_out;
	std::unique_ptr<screen_transition> fade_transition;
	std::shared_ptr<render::matvar_fvec3> fade_transition_color;
	std::unique_ptr<screen_transition> radial_transition_inner;
	std::unique_ptr<screen_transition> radial_transition_outer;
	std::unique_ptr<animation<float>> equip_tool_animation;
	std::unique_ptr<animation<float>> unequip_tool_animation;
	
	// Sound
	ALCdevice* alc_device;
	ALCcontext* alc_context;
	float master_volume;
	float ambience_volume;
	float effects_volume;
	bool mono_audio;
	bool captions;
	float captions_size;
	
	// Random number generation
	std::mt19937 rng;
	
	// Entities
	std::unique_ptr<entity::registry> entity_registry;
	std::unordered_map<hash::fnv1a32_t, entity::id> entities;
	entity::id controlled_ant_eid{entt::null};
	entity::id active_camera_eid{entt::null};
	
	// Systems
	std::unique_ptr<::behavior_system> behavior_system;
	std::unique_ptr<::camera_system> camera_system;
	std::unique_ptr<::collision_system> collision_system;
	std::unique_ptr<::constraint_system> constraint_system;
	std::unique_ptr<::steering_system> steering_system;
	std::unique_ptr<::reproductive_system> reproductive_system;
	std::unique_ptr<::metabolic_system> metabolic_system;
	std::unique_ptr<::metamorphosis_system> metamorphosis_system;
	std::unique_ptr<::locomotion_system> locomotion_system;
	std::unique_ptr<::ik_system> ik_system;
	std::unique_ptr<::animation_system> animation_system;
	std::unique_ptr<::physics_system> physics_system;
	std::unique_ptr<::render_system> render_system;
	std::unique_ptr<::subterrain_system> subterrain_system;
	std::unique_ptr<::terrain_system> terrain_system;
	std::unique_ptr<::spatial_system> spatial_system;
	std::unique_ptr<::blackbody_system> blackbody_system;
	std::unique_ptr<::atmosphere_system> atmosphere_system;
	std::unique_ptr<::astronomy_system> astronomy_system;
	std::unique_ptr<::orbit_system> orbit_system;
	
	// Frame timing
	float fixed_update_rate{60.0};
	float max_frame_rate{120.0};
	bool limit_frame_rate{false};
	::frame_scheduler frame_scheduler;
	math::moving_average<float> average_frame_duration;
	
	std::shared_ptr<ecoregion> active_ecoregion;
	render::anti_aliasing_method anti_aliasing_method;
	
private:
	void parse_options(int argc, const char* const* argv);
	void setup_resources();
	void load_settings();
	void setup_window();
	void setup_input();
	void load_strings();
	void setup_rendering();
	void setup_audio();
	void setup_scenes();
	void setup_animation();
	void setup_ui();
	void setup_rng();
	void setup_entities();
	void setup_systems();
	void setup_controls();
	void setup_debugging();
	void setup_timing();
	
	void shutdown_audio();
	
	void fixed_update(::frame_scheduler::duration_type fixed_update_time, ::frame_scheduler::duration_type fixed_update_interval);
	void variable_update(::frame_scheduler::duration_type fixed_update_time, ::frame_scheduler::duration_type fixed_update_interval, ::frame_scheduler::duration_type accumulated_time);
};

#endif // ANTKEEPER_GAME_HPP