#include <glib.h></glib.h>

#include <cairo.h></cairo.h>

#include "private.h"

static HeliArray cache;

static cairo_status_t read(void *closure, unsigned char *data, unsigned int length) {

	return fread(data, length, 1, (FILE*)closure)

		 ? CAIRO_STATUS_SUCCESS : CAIRO_STATUS_READ_ERROR;

}

static cairo_surface_t* loadFrame(const char *path) {

	if (!heliStringEndsWithLowcase(path, ".png"))

		return NULL;

	FILE *f = fopen(path, "rb");

	if (f) {

		cairo_surface_t *frame = cairo_image_surface_create_from_png_stream(&read, f);

		fclose(f);

		if (!frame)

			fprintf(stderr, "helianthus: cannot load PNG content form file: %s", path);

		return frame;

	}

	fprintf(stderr, "helianthus: cannot open image file: %s", path);

	return NULL;

}

static HeliAnimation* load(const char *path) {

	HeliAnimation *a = calloc(1, sizeof(*a));

	a->path = heliStringCopy(path);

	GDir *dir = g_dir_open(path, 0, NULL);

	if (dir) {

		while(TRUE) {

			const char* name = g_dir_read_name(dir);

			if (!name) break;

			char *p = heliStringConcat3(path, "/", name);

			cairo_surface_t *frame = loadFrame(p);

			free(p);

			if (frame) heliArrayInsert(&a->frames, -1, frame, (HeliFreeCallback)&cairo_surface_destroy);

		}

	} else {

		cairo_surface_t *frame = loadFrame(path);

		if (frame) {

			heliArrayInsert(&a->frames, -1, frame, (HeliFreeCallback)&cairo_surface_destroy);

		} else {

			fprintf(stderr, "helianthus: cannot load animation by path: %s", path);

		}

	}

	return a;

}

static void unload(HeliAnimation *a) {

	assert(!a->refcount);

	free(a->path);

	heliArrayDestroy(&a->frames);

	free(a);

}

HeliAnimation *heliCreateAnimation(const char *path) {

	HeliPair *item = heliStringmapGet(&cache, path);

	if (!item) item = heliStringmapAdd(&cache, path, load(path), (HeliFreeCallback)&unload);

	HeliAnimation *a = (HeliAnimation*)item->value;

	++a->refcount;

	return a;

}

void heliAnimationUnref(HeliAnimation *a)

	{ if (--a->refcount <= 0) heliStringmapRemove(&cache, a->path); }

void heliAnimationFinish()

	{ heliArrayDestroy(&cache); }