#include <stdio.h>
#include <stdint.h>
#include <allegro5/allegro.h>
#include <allegro5/allegro_image.h>
#include <allegro5/allegro_primitives.h>

#include "aoi.h"

/**********
 * macros *
 **********/

#define aoi_log(...) do {\
	fprintf(stderr,"[%s:%i] ",__FILE__,__LINE__);\
	fprintf(stderr,__VA_ARGS__);\
	fputc('\n',stderr);\
} while (0)

#define aoi_error(...) do {\
	aoi_log(__VA_ARGS__);\
	exit(1);\
} while (0)

#define aoi_assert(x) if (!(x)) aoi_error("assertion failed '%s'", #x)

/*********
 * state *
 *********/

ALLEGRO_DISPLAY* display = NULL;
ALLEGRO_BITMAP* sheet = NULL;

/*******************
 * input functions *
 *******************/

//bitmask for input (current frame and previous frame)
uint16_t buttons = 0, buttonsprev = 0;

int aoi_btn(uint8_t btn) {
	return !!(buttons & (1 << btn));
}

typedef struct {
	int kb_keycode;
	int js_button;
} aoi_input_keymap_t;

struct {
	uint8_t n; //how many input buttons defined, max 16 (16 bit bitmask)
	ALLEGRO_JOYSTICK* js; //joystick
	aoi_input_keymap_t keymaps[16]; //keymaps for each input button
} aoi_input_config;


//init input config variable
void aoi_input_init(int n, ALLEGRO_JOYSTICK* js, aoi_input_keymap_t* keymaps) {
	for (int i = 0; i < n; i++) {
		aoi_input_config.keymaps[i] = keymaps[i];
	}
	aoi_input_config.n = n;
	aoi_input_config.js = js;
}


//parse input config string and init input config
void aoi_input_load(char* cfg) {
	/*cfg of the format:
		(@joystick name;)kKEY_CODE,jJOYSTICK_BUTTON;...;
	*/
	char js_name[200];
	int js_name_idx = 0;
	char c;
	aoi_input_keymap_t keymaps[16];
	uint8_t keymap = 0;

	while ((c = *cfg++)) {
		switch (c) {
			case '@': {
				while (((c = *cfg++) != ';') && c)
					js_name[js_name_idx++] = c;
				js_name[js_name_idx] = 0;
			} break;
			case 'k':
			case 'j': {
				char t = c;
				int n = -1;
				char s[10];
				int i = 0;
				c = *cfg++;
				while (c && c != ';' && c != ',') {
					s[i++] = c;
					c = *cfg++;
				}
				//aoi_log("END %c", c);
				sscanf(s, "%d", &n);
				if (t	== 'k')
					keymaps[keymap].kb_keycode = n;
				else
					keymaps[keymap].js_button = n;
				if (c == ';' || !c) keymap++;
			} break;
		}
	}

	int max = al_get_num_joysticks();
	ALLEGRO_JOYSTICK* js = NULL;
	for (int i = 0; i < max; i++) {
		js = al_get_joystick(i);
		if (js) {
			const char* name = al_get_joystick_name(js);
			if (strcmp(name,js_name) == 0) {
				aoi_log("loaded joystick '%s' (index %i)", name, i);
				break;
			}
			al_release_joystick(js);
			js = NULL;
		}
	}

	aoi_input_init(keymap, js, keymaps);
}

void aoi_input_update() {
	buttonsprev = buttons;
	buttons = 0;
	
	ALLEGRO_JOYSTICK_STATE jst;
	if (aoi_input_config.js) al_get_joystick_state(aoi_input_config.js, &jst);
	
	ALLEGRO_KEYBOARD_STATE kst;
	al_get_keyboard_state(&kst);

	for (int i = 0; i < aoi_input_config.n; i++) {
		aoi_input_keymap_t map = aoi_input_config.keymaps[i];
		if (al_key_down(&kst, map.kb_keycode) || (aoi_input_config.js && jst.button[i]))
			buttons |= 1 << i;
	}
}

/**********************
 * graphics functions *
 **********************/

void aoi_cls(aoi_color_t color) {
	al_clear_to_color((ALLEGRO_COLOR) color);
}

const int TW_ = AOI_TILE_WIDTH;
const int TH_ = AOI_TILE_HEIGHT;

//draw sprite from spritesheet
void aoi_spr(uint8_t spr, int x, int y, uint8_t flip) {
	al_draw_bitmap_region(sheet, TW_*(spr&0xF), TH_*(spr>>4), TW_, TH_, x, y, flip);
}

//same but with extra options
void aoi_sprEX(uint8_t spr, int x, int y, uint8_t flip, float scale, float rot, int w, int h) {
	al_draw_tinted_scaled_rotated_bitmap_region(
		sheet,
		TW_*(spr&0xF),
		TH_*(spr>>4),
		TW_*w,
		TH_*h,
		al_map_rgb(255,255,255),
		0,
		0,
		x,
		y,
		scale,
		scale,
		rot,
		flip
	);
}

void aoi_line(int x0, int y0, int x1, int y1, aoi_color_t color) {
	al_draw_line(x0, y0, x1, y1, (ALLEGRO_COLOR) color, -1);
}

void aoi_rect(int x, int y, int w, int h, uint8_t filled, aoi_color_t color) {
	if (filled)
		al_draw_filled_rectangle(x, y, x+w, y+h, (ALLEGRO_COLOR) color);
	else
		al_draw_rectangle(x, y, x+w, y+h, (ALLEGRO_COLOR) color, -1);
}

/*****************
 * map functions *
 *****************/

typedef struct {
	uint8_t width, height; //dimensions in tiles
	uint8_t* data;
} aoi_map_t;

aoi_map_t* map = NULL;

#define mget(x,y) (map->data[x+y*map->width])
uint8_t aoi_mget(uint8_t x, uint8_t y) {
	return (map && x < map->width && y < map->height && x > 0 && y > 0) ? mget(x,y) : 0;
}

#define mset(x,y,t) (map->data[x+y*map->width] = t)
void aoi_mset(uint8_t x, uint8_t y, uint8_t tile) {
	if (map && x < map->width && y < map->height && x >= 0 && y >= 0)
		mset(x, y, tile);
}

//draws map
void aoi_map(int x, int y) {
	uint16_t siz = map->width*map->height;
	for (int i = 0; i <= siz; i++)
		aoi_spr(map->data[i], TW_*(i%map->width) + x, TH_*((int)i/map->height) + y, 0);
}

/*********************
 * loading functions *
 *********************/

int aoi_load_spritesheet(char* path) {
	return (sheet = al_load_bitmap(path)) != NULL;
}

int aoi_load_map(char* path) {
	ALLEGRO_FILE* f = al_fopen(path, "r");
	if (!f) return 0;

	//read once to get dimensions
	int rows = 0, columns = 1;
	int c = 0;
	while ((c = al_fgetc(f)) != EOF) {
		if (!rows && c == ',') columns++;
		else if (c == '\n') rows++;
	}
	//aoi_log("%ix%i", columns, rows);
	map = malloc(sizeof(aoi_map_t));
	map->width = columns, map->height = rows;
	map->data = malloc(map->width*map->height);
	
	//read again to get data
	al_fseek(f, 0, ALLEGRO_SEEK_SET);
	int n = 0;
	char s[6];
	int s_idx = 0;
	int i = 0;
	while ((c = al_fgetc(f)) != EOF) {
		if (c == ',') {
			s[s_idx] = 0;
			s_idx = 0;
			sscanf(s, "%d", &n);
			map->data[i++] = (n < 0 ? 0 : n);
			n = 0;
		} else if (c == '\n');
		else if (s_idx < sizeof(s))
			s[s_idx++] = c;
	}

	al_fclose(f);
	return 1;
}

void aoi_destroy_maps() {
	free(map->data);
	free(map);
}

/*****************
 * main function *
 *****************/

int aoi_loop(void);

int main(int argc, char** argv) {
	aoi_log("starting up");
	al_init();
	al_init_image_addon();
	al_install_keyboard();
	al_install_joystick();
	
	aoi_assert(display = al_create_display(AOI_INTERNAL_WIDTH, AOI_INTERNAL_HEIGHT));
	aoi_assert(aoi_load_spritesheet(AOI_SPRITESHEET_PATH));

	//TODO load from run-time/compile-time(for defaults) config file
	aoi_input_load("@mayflash limited MAYFLASH GameCube Controller Adapter;k26,j0;");

	aoi_load_map("map.csv");

	int running = 1;
	unsigned int frames = 0;
	double init_time = al_get_time();

	while (running) {
		double t0 = al_get_time();

		aoi_input_update();

		running = !aoi_loop();
		al_flip_display();

		double delta = al_get_time() - t0;
		if (delta < 1/AOI_FPS) {
			al_rest(1/AOI_FPS-delta);
		} //else aoi_log("lag frame (%u)", frames);
		
		frames++;
	}

	double t = al_get_time();
	aoi_log("%i frames in %f seconds: avg = %fFPS", frames, init_time, frames/(t-init_time));
	aoi_log("quitting");
	
	al_destroy_display(display);
	al_destroy_bitmap(sheet);

	aoi_destroy_maps();

	return 0;
}