/**
 * spacexplore.c -- прототип игры управления звездолетом
 *
 * Copyright (c) 2019, Nikita Semenov <ndsemeno@petrsu.ru>
 *
 * This code is licensed under a MIT-style license.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <SDL.h>
#include <SDL_ttf.h>

 /* Скорости корабля */
#define VXD 6
#define VYD 6

typedef struct _gamescreen { // экран
	SDL_Surface* sprite;
} gamescreen;

typedef struct _gamebackground { // фон
	SDL_Surface* sprite;
} gamebackground;

typedef struct _spaceship { // корабль
	SDL_Surface* sprite;
	int x;
	int y;
	int vx;
	int vy;
} spaceship;

typedef struct _obstacle { // астероиды
	int vx[8];
	int vy[8];
	int x[8];
	int y[8];
	int if_exist[8];
	int n_existing;
} obstacle;

typedef struct _gameresources { // ресурсы
	SDL_Surface* asteroid;
	SDL_Surface* bitcoin;
	int x;
	int y;
	int if_exist;
	int bitcoin_count;
	int flag;
} gameresources;


typedef struct _game { // состояние игры
	gamescreen* screen;
	spaceship* ship;
	gameresources* resources;
	gamebackground* background;
	obstacle* obstacles;
	TTF_Font* font;
	int timer;
} game;

game* init();

void run(game* g);

void draw(game* g);

void show_counter(game* g, const int counter, const int mode);

void show_mission_status(game* g);

void spawn_asteroids(game* g);


int main()
{
	game* g = init(); // инициализируем игру

	run(g); // запускаем цикл обработки

	return 0;
}


game* init()
{
	/* Создаем структуру представления состояния игры */
	game* g;
	g = (game*)malloc(sizeof(game));
	if (g == NULL) {
		fprintf(stderr, "Not enough memory!");
		exit(EXIT_FAILURE);
	}

	/* Инициализируем библиотеку SDL, используем только видеоподсистему */
	if (SDL_Init(SDL_INIT_VIDEO) < 0) {
		fprintf(stderr, "Couldn't initialize SDL: %s\n", SDL_GetError());
		exit(EXIT_FAILURE);
	}

	/* Регистрируем обработчик завершения программы */
	atexit(SDL_Quit);

	/* Инициализируем библиотеку SDL_ttf и загружаем шрифт */
	TTF_Init();
	g->font = TTF_OpenFont("AbrilFatface-Regular.ttf", 44);

	/* Выделяем память для структуры представления экрана */
	g->screen = (gamescreen*)malloc(sizeof(gamescreen));
	if (g->screen == NULL) {
		fprintf(stderr, "Not enough memory!");
		exit(EXIT_FAILURE);
	}

	/* Инициализируем видеорежим */
	g->screen->sprite = SDL_SetVideoMode(1024, 768, 0, SDL_HWSURFACE | SDL_DOUBLEBUF);
	if (g->screen->sprite == NULL) {
		fprintf(stderr, "Couldn't set video mode: %s\n", SDL_GetError());
		exit(EXIT_FAILURE);
	}

	/* Инициализируем фон*/
	g->background = (gamebackground*)malloc(sizeof(gamebackground));
	if (g->background == NULL) {
		fprintf(stderr, "Not enough memory!");
		exit(EXIT_FAILURE);
	}
	g->background->sprite = SDL_LoadBMP("kosmos.bmp");
	if (g->background->sprite == NULL) {
		fprintf(stderr, "Couldn't load a bitmap: %s\n", SDL_GetError());
		exit(EXIT_FAILURE);
	}

	/* Инициализируем ресурсы */
	g->resources = (gameresources*)malloc(sizeof(gameresources));
	if (g->resources == NULL) {
		fprintf(stderr, "Not enough memory!");
		exit(EXIT_FAILURE);
	}
	g->resources->bitcoin = SDL_LoadBMP("bitcoin.bmp");
	if (g->resources->bitcoin == NULL) {
		fprintf(stderr, "Couldn't load a bitmap: %s\n", SDL_GetError());
		exit(EXIT_FAILURE);
	}
	g->resources->asteroid = SDL_LoadBMP("asteroid.bmp");
	if (g->resources->asteroid == NULL) {
		fprintf(stderr, "Couldn't load a bitmap: %s\n", SDL_GetError());
		exit(EXIT_FAILURE);
	}

	/* Инициализируем астероиды */
	g->obstacles = (obstacle*)malloc(sizeof(obstacle));
	if (g->obstacles == NULL) {
		fprintf(stderr, "Not enough memory!");
		exit(EXIT_FAILURE);
	}

	/* Выделяем память для структуры представления корабля */
	g->ship = (spaceship*)malloc(sizeof(spaceship));
	if (g->ship == NULL) {
		fprintf(stderr, "Not enough memory!");
		exit(EXIT_FAILURE);
	}
	g->ship->sprite = SDL_LoadBMP("ship.bmp");
	if (g->ship->sprite == NULL) {
		fprintf(stderr, "Couldn't load a bitmap: %s\n", SDL_GetError());
		exit(EXIT_FAILURE);
	}

	/* Задаем начальное положение кораблю */
	g->ship->x = g->screen->sprite->w / 2 - g->ship->sprite->w / 2;
	g->ship->y = g->screen->sprite->h - g->ship->sprite->h;

	/* Задание начальных значений для счетчиков и флагов */
	g->resources->bitcoin_count = -1;
	g->resources->if_exist = 0;
	g->resources->flag = 0;
	g->timer = 0;

	/* Устанавливаем заголовок окна */
	SDL_WM_SetCaption("Space explore", NULL);

	return g;
}


void run(game* g)
{
	int done = 0; // Флажок выхода
	unsigned int start_time = SDL_GetTicks();
	/* Продолжаем выполнение, пока не поднят флажок */
	while (!done) {
		/* Структура описания события */
		SDL_Event event;

		/* Извлекаем и обрабатываем все доступные события */
		while (SDL_PollEvent(&event)) {
			switch (event.type) {
				/* Если клавишу нажали */
			case SDL_KEYDOWN:
				switch (event.key.keysym.sym) {
				case SDLK_LEFT:
					g->ship->vx += -VXD;
					break;
				case SDLK_RIGHT:
					g->ship->vx += VXD;
					break;

				case SDLK_UP:
					g->ship->vy += -VYD;
					break;
				case SDLK_DOWN:
					g->ship->vy += VYD;
					break;
				case SDLK_ESCAPE:
					done = 1;
					break;
				}
				break;
				/* Если клавишу отпустили */
			case SDL_KEYUP:
				switch (event.key.keysym.sym) {
				case SDLK_LEFT:
					g->ship->vx += VXD;
					break;
				case SDLK_RIGHT:
					g->ship->vx += -VXD;
					break;
				case SDLK_UP:
					g->ship->vy += VYD;
					break;
				case SDLK_DOWN:
					g->ship->vy += -VYD;
					break;
				default:
					break;
				}
				break;
				/* Если закрыли окно */
			case SDL_QUIT:
				done = 1;
				break;
			default:
				break;
			}
		}
		/* Верхняя граница корабля */
		if (g->ship->x + g->ship->vx >= 0 && g->ship->x + g->ship->vx <= g->screen->sprite->w - g->ship->sprite->w)
			g->ship->x += g->ship->vx;
		/* Нижняя граница корабля */
		if (g->ship->y + g->ship->vy >= g->screen->sprite->h / 3 && g->ship->y + g->ship->vy <= g->screen->sprite->h)
			g->ship->y += g->ship->vy;
		/* Проверка взятия ресурса */
		if (g->resources->if_exist == 1)
			if (g->ship->x <= g->resources->x + g->resources->bitcoin->w && g->ship->x + g->ship->sprite->w >= g->resources->x)
				if (g->ship->y <= g->resources->y + g->resources->bitcoin->h && g->ship->y + g->ship->sprite->h >= g->resources->y)
					g->resources->if_exist = 0;

		/* Получаем значение времени прошедшего с начала игры */
		unsigned int current_time = SDL_GetTicks();
		g->timer = (current_time - start_time) / 1000;

		if (g->timer <= 60) {
			draw(g);
		}
		else {
			show_mission_status(g);
			SDL_Delay(2500);
			done = 1;
		}
		SDL_Delay(10);
	}
}


void draw(game* g)
{
	/* Прямоугольники, определяющие зону отображения */
	SDL_Rect src, dest;

	/* Отображаем фон */
	src.x = 0;
	src.y = 0;
	src.w = g->background->sprite->w;
	src.h = g->background->sprite->h;

	dest.x = 0;
	dest.y = 0;
	dest.w = g->background->sprite->w;
	dest.h = g->background->sprite->h;

	SDL_BlitSurface(g->background->sprite, &src, g->screen->sprite, &dest);

	/* Отображаем счетчики */
	show_counter(g, g->resources->bitcoin_count, 1);
	show_counter(g, g->timer, 2);

	/* Отображаем корабль */
	src.x = 0;
	src.y = 0;
	src.w = g->ship->sprite->w;
	src.h = g->ship->sprite->h;

	dest.x = g->ship->x;
	dest.y = g->ship->y;
	dest.w = g->ship->sprite->w;
	dest.h = g->ship->sprite->h;

	SDL_SetColorKey(g->ship->sprite, SDL_SRCCOLORKEY, 0x000000); // Удаляем черные пиксели
	SDL_BlitSurface(g->ship->sprite, &src, g->screen->sprite, &dest);

	/* Отображение ресурса */
	if (g->resources->if_exist == 0) {
		srand(time(NULL));
		while (g->resources->flag == 0) {
			g->resources->x = rand() % (g->screen->sprite->w - g->resources->bitcoin->w);
			g->resources->y = rand() % (g->screen->sprite->h * 2 / 3 - g->resources->bitcoin->h) + g->screen->sprite->h / 3;

			if (g->ship->x <= g->resources->x + g->resources->bitcoin->w && g->ship->x + g->ship->sprite->w >= g->resources->x) {
				if (g->ship->y <= g->resources->y + g->resources->bitcoin->h && g->ship->y + g->ship->sprite->h >= g->resources->y) {
					;
				}
				else {
					g->resources->flag = 1;
				}
			}
		}
		g->resources->flag = 0;
		g->resources->if_exist = 1;
		g->resources->bitcoin_count++;
	}

	src.x = 0;
	src.y = 0;
	src.w = g->resources->bitcoin->w;
	src.h = g->resources->bitcoin->h;

	dest.x = g->resources->x;
	dest.y = g->resources->y;
	dest.w = g->resources->bitcoin->w;
	dest.h = g->resources->bitcoin->h;

	SDL_SetColorKey(g->resources->bitcoin, SDL_SRCCOLORKEY, 0x000000);
	SDL_BlitSurface(g->resources->bitcoin, &src, g->screen->sprite, &dest);

	spawn_asteroids(g);

	/* Отрисовываем обновленный экран */
	SDL_Flip(g->screen->sprite);
}

void show_counter(game* g, const int counter, const int mode)
{
	char text[5] = "";

	/* Переводим int счетчик в char */
	if (sprintf(text, "%d", counter) == 0) {
		;
	}
	SDL_Surface* fontSurface;
	SDL_Color fColor = { 0xff, 0x00, 0x00, 0xff };
	SDL_Color bColor = { 0x00, 0x00, 0x00, 0xff };
	fontSurface = TTF_RenderUTF8_Shaded(g->font, text, fColor, bColor);

	int w, h;
	TTF_SizeUTF8(g->font, text, &w, &h);

	SDL_Rect fontRect;
	if (mode == 1) {
		fontRect.x = 0;
	} else {
		fontRect.x = g->screen->sprite->w - w;
	}
	fontRect.y = 0;
	SDL_SetColorKey(fontSurface, SDL_SRCCOLORKEY, 0x000000);
	SDL_BlitSurface(fontSurface, NULL, g->screen->sprite, &fontRect);
}

void show_mission_status(game* g)
{
	char text[] = "Mission complete!";

	SDL_Surface* status;
	SDL_Color fColor = { 0x00, 0xff, 0x00, 0xff };
	SDL_Color bColor = { 0x00, 0x00, 0x00, 0xff };
	status = TTF_RenderUTF8_Shaded(g->font, text, fColor, bColor);

	int w, h;
	TTF_SizeUTF8(g->font, text, &w, &h);

	SDL_Rect statusRect;
	statusRect.x = g->screen->sprite->w / 2 - w / 2;
	statusRect.y = g->screen->sprite->h / 2 - h / 2;
	SDL_SetColorKey(status, SDL_SRCCOLORKEY, 0x000000);
	SDL_BlitSurface(status, NULL, g->screen->sprite, &statusRect);
	SDL_Flip(g->screen->sprite);
}

void spawn_asteroids(game* g)
{
	SDL_Rect src, dest;

	for (int i = 0; i < 8; i++) {
		/* Проверка на существование астероида в плоскости
		 * и последующее задание ему случайной координаты x
		 */
		if (g->obstacles->if_exist[i] == 0) {
			srand(time(NULL));
			g->obstacles->if_exist[i] = 1;
			g->obstacles->x[i] = rand() % (g->screen->sprite->w - g->resources->asteroid->w);
			g->obstacles->y[i] = 0 - g->resources->asteroid->h;
			g->obstacles->vx[i] = rand() % (12) - 6;
			g->obstacles->vy[i] = rand() % (3);
		}
		else {
			/* Обработка ситуации выхода астероида за границы */
			if (g->obstacles->y[i] > g->screen->sprite->h || g->obstacles->x[i] < 0 - g->resources->asteroid->w
				|| g->obstacles->x[i] > g->screen->sprite->w) {
				g->obstacles->if_exist[i] = 0;
			}
			else {
				g->obstacles->x[i] += g->obstacles->vx[i];
				g->obstacles->y[i] += g->obstacles->yx[i];
			}

			src.x = 0;
			src.y = 0;
			src.w = g->resources->asteroid->w;
			src.h = g->resources->asteroid->h;

			dest.x = g->obstacles->x[i];
			dest.y = g->obstacles->y[i];
			dest.w = g->resources->asteroid->w;
			dest.h = g->resources->asteroid->h;

			SDL_SetColorKey(g->resources->asteroid, SDL_SRCCOLORKEY, 0x000000);
			SDL_BlitSurface(g->resources->asteroid, &src, g->screen->sprite, &dest);
		}
	}
}