#include <ruby.h>
#include <FreeImage.h>

static VALUE rb_mFI;
//static VALUE rb_eFI;
static VALUE Class_Image;
static VALUE Class_RFIError;

__attribute__((constructor))
static void __rfi_module_init() {
	FreeImage_Initialise(FALSE);
}

__attribute__((destructor))
static void __rfi_module_uninit() {
	FreeImage_DeInitialise();
}

static VALUE rb_rfi_version(VALUE self)
{
	return rb_ary_new3(3, INT2NUM(FREEIMAGE_MAJOR_VERSION),
		INT2NUM(FREEIMAGE_MINOR_VERSION), INT2NUM(FREEIMAGE_RELEASE_SERIAL));
}

static VALUE rb_rfi_string_version(VALUE self)
{
	VALUE result = Qnil;
	const char *v = FreeImage_GetVersion();
	result = rb_str_new(v, strlen(v));
	return result;
}

struct native_image {
	int w;
	int h;
	int bpp;
	int stride;
	FREE_IMAGE_FORMAT fif;
	FIBITMAP *handle;
};

void Image_free(struct native_image* img)
{
	if(!img)
		return;
	if(img->handle)
		FreeImage_Unload(img->handle);
	free(img);
}

VALUE Image_alloc(VALUE self)
{
	/* allocate */
	struct native_image* img = malloc(sizeof(struct native_image));
	memset(img, 0, sizeof(struct native_image));

	/* wrap */
	return Data_Wrap_Struct(self, NULL, Image_free, img);
}

static inline char *rfi_value_to_str(VALUE v)
{
	char *filename;
	long f_len;
	Check_Type(v, T_STRING);
	f_len = RSTRING_LEN(v);
	filename = malloc(f_len + 1);
	memcpy(filename, RSTRING_PTR(v), f_len);
	filename[f_len] = 0;
	return filename;
}

static FIBITMAP *
convert_bpp(FIBITMAP *orig, unsigned int bpp) {
	FIBITMAP *h = NULL;
	switch(bpp) {
		case 8:
			h = FreeImage_ConvertToGreyscale(orig);
			break;
		case 32:
			h = FreeImage_ConvertTo32Bits(orig);
			break;
	}
	return h;
}

static void
rd_image(VALUE clazz, VALUE file, struct native_image *img, unsigned int bpp, BOOL ping,
		int max_size_hint)
{
	char *filename;
	int flags = 0;
	FIBITMAP *h = NULL, *orig = NULL;
	FREE_IMAGE_FORMAT in_fif;

	filename = rfi_value_to_str(file);

	in_fif = FreeImage_GetFileType(filename, 0);
	if (in_fif == FIF_UNKNOWN) {
		free(filename);
		rb_raise(rb_eIOError, "Invalid image file");
	}
	if (max_size_hint < 0 || max_size_hint > 65535)
		rb_raise(rb_eArgError, "Invalid max_size_hint");

	if (ping) flags |= FIF_LOAD_NOPIXELS;
	if (!ping) flags |= max_size_hint << 16;
	// use JPEG_ACCURATE to keep sync with opencv
	if (in_fif == FIF_JPEG)
		flags |= JPEG_EXIFROTATE | JPEG_ACCURATE;
	orig = FreeImage_Load(in_fif, filename, flags);
	free(filename);
	if (!orig)
		rb_raise(rb_eIOError, "Fail to load image file");
	if (ping) {
		h = orig;
	} else {
		if (bpp <= 0) bpp = 32;
		h = convert_bpp(orig, bpp);
		FreeImage_Unload(orig);
		if (!h) rb_raise(rb_eArgError, "Invalid bpp");
	}
	img->handle = h;
	img->w = FreeImage_GetWidth(h);
	img->h = FreeImage_GetHeight(h);
	img->bpp = FreeImage_GetBPP(h);
	img->stride = FreeImage_GetPitch(h);
	img->fif = in_fif;
}

static void
rd_image_blob(VALUE clazz, VALUE blob, struct native_image *img, unsigned int bpp, BOOL ping, int max_size_hint)
{
	FIBITMAP *h = NULL, *orig = NULL;
	FIMEMORY *fmh;
	int flags = 0;
	FREE_IMAGE_FORMAT in_fif;

	Check_Type(blob, T_STRING);
	fmh = FreeImage_OpenMemory((BYTE*)RSTRING_PTR(blob), RSTRING_LEN(blob));

	in_fif = FreeImage_GetFileTypeFromMemory(fmh, 0);
	if (in_fif == FIF_UNKNOWN) {
		FreeImage_CloseMemory(fmh);
		rb_raise(rb_eIOError, "Invalid image blob");
	}
	if (max_size_hint < 0 || max_size_hint > 65535)
		rb_raise(rb_eArgError, "Invalid max_size_hint");

	if (ping) flags |= FIF_LOAD_NOPIXELS;
	if (!ping) flags |= max_size_hint << 16;
	if (in_fif == FIF_JPEG)
		flags |= JPEG_EXIFROTATE | JPEG_ACCURATE;
	orig = FreeImage_LoadFromMemory(in_fif, fmh, flags);
	FreeImage_CloseMemory(fmh);
	if (!orig)
		rb_raise(rb_eIOError, "Fail to load image from memory");

	if (ping) {
		h = orig;
	} else {
		if (bpp <= 0) bpp = 32;
		h = convert_bpp(orig, bpp);
		FreeImage_Unload(orig);
		if (!h) rb_raise(rb_eArgError, "Invalid bpp");
	}
	img->handle = h;
	img->w = FreeImage_GetWidth(h);
	img->h = FreeImage_GetHeight(h);
	img->bpp = FreeImage_GetBPP(h);
	img->stride = FreeImage_GetPitch(h);
	img->fif = in_fif;
}

VALUE Image_initialize(int argc, VALUE *argv, VALUE self)
{
	struct native_image* img;
	/* unwrap */
	Data_Get_Struct(self, struct native_image, img);

	switch (argc)
	{
		case 1:
			rd_image(self, argv[0], img, 0, 0, 0);
			break;
		case 2:
			rd_image(self, argv[0], img, NUM2INT(argv[1]), 0, 0);
			break;
		case 3:
			rd_image(self, argv[0], img, NUM2INT(argv[1]), 0, NUM2INT(argv[2]));
			break;
		default:
			rb_raise(rb_eArgError, "wrong number of arguments (%d for 1)", argc);
			break;
	}

	return self;
}

#define RFI_CHECK_IMG(x) \
	if (!img->handle) rb_raise(Class_RFIError, "Image pixels not loaded");

VALUE Image_save(VALUE self, VALUE file)
{
	char *filename;
	struct native_image* img;
	BOOL result;
	FREE_IMAGE_FORMAT out_fif;

	Data_Get_Struct(self, struct native_image, img);
	RFI_CHECK_IMG(img);

	Check_Type(file, T_STRING);
	filename = rfi_value_to_str(file);

	out_fif = FreeImage_GetFIFFromFilename(filename);
	if (out_fif == FIF_UNKNOWN) {
		free(filename);
		rb_raise(Class_RFIError, "Invalid format");
	}

	if (out_fif == FIF_JPEG && img->bpp != 8 && img->bpp != 24) {
		FIBITMAP *to_save = FreeImage_ConvertTo24Bits(img->handle);
		result = FreeImage_Save(out_fif, to_save, filename, JPEG_BASELINE);
		FreeImage_Unload(to_save);
	} else {
		result = FreeImage_Save(out_fif, img->handle, filename, 0);
	}

	free(filename);

	if(!result)
		rb_raise(rb_eIOError, "Fail to save image");
	return Qnil;
}

VALUE Image_to_blob(VALUE self, VALUE type)
{
	char *filetype;
	struct native_image* img;
	FIMEMORY *hmem;
	BOOL result;
	FREE_IMAGE_FORMAT out_fif;
	VALUE ret;
	BYTE *raw = NULL;
	DWORD file_size;

	Data_Get_Struct(self, struct native_image, img);
	RFI_CHECK_IMG(img);

	Check_Type(type, T_STRING);
	filetype = rfi_value_to_str(type);

	out_fif = FreeImage_GetFIFFromFormat(filetype);
	free(filetype);
	if (out_fif == FIF_UNKNOWN)
		rb_raise(Class_RFIError, "Invalid format");

	hmem = FreeImage_OpenMemory(0, 0);
	if (!hmem)
		rb_raise(rb_eIOError, "Fail to allocate blob");
	if (out_fif == FIF_JPEG && img->bpp != 8 && img->bpp != 24) {
		FIBITMAP *to_save = FreeImage_ConvertTo24Bits(img->handle);
		result = FreeImage_SaveToMemory(out_fif, to_save, hmem, JPEG_BASELINE);
		FreeImage_Unload(to_save);
	} else {
		result = FreeImage_SaveToMemory(out_fif, img->handle, hmem, 0);
	}

	if(!result) {
		FreeImage_CloseMemory(hmem);
		rb_raise(rb_eIOError, "Fail to save image to blob");
	}
	file_size = FreeImage_TellMemory(hmem);
	FreeImage_SeekMemory(hmem, 0, SEEK_SET);
	FreeImage_AcquireMemory(hmem, &raw, &file_size);
	ret = rb_str_new((char*)raw, (long)file_size);
	FreeImage_CloseMemory(hmem);
	return ret;
}




VALUE Image_cols(VALUE self)
{
	struct native_image* img;
	Data_Get_Struct(self, struct native_image, img);
	return INT2NUM(img->w);
}

VALUE Image_rows(VALUE self)
{
	struct native_image* img;
	Data_Get_Struct(self, struct native_image, img);
	return INT2NUM(img->h);
}

VALUE Image_bpp(VALUE self)
{
	struct native_image* img;
	Data_Get_Struct(self, struct native_image, img);
	return INT2NUM(img->bpp);
}

VALUE Image_stride(VALUE self)
{
	struct native_image* img;
	Data_Get_Struct(self, struct native_image, img);
	return INT2NUM(img->stride);
}

VALUE Image_format(VALUE self)
{
	struct native_image* img;
	const char *p;
	Data_Get_Struct(self, struct native_image, img);
	p = FreeImage_GetFormatFromFIF(img->fif);
	return rb_str_new(p, strlen(p));
}

VALUE Image_release(VALUE self)
{
	struct native_image* img;
	Data_Get_Struct(self, struct native_image, img);
	if (img->handle)
		FreeImage_Unload(img->handle);
	img->handle = NULL;
	return Qnil;
}


VALUE Image_read_bytes(VALUE self)
{
	struct native_image* img;
	const char *p;
	char *ptr;
	unsigned stride_dst;
	int i;
	VALUE v;

	Data_Get_Struct(self, struct native_image, img);
	RFI_CHECK_IMG(img);
	p = (const char*)FreeImage_GetBits(img->handle);
	stride_dst = img->w * (img->bpp / 8);
	v = rb_str_new(NULL, stride_dst * img->h);

	/* up-side-down */
	ptr = RSTRING_PTR(v) + img->h * stride_dst;
	for(i = 0; i < img->h; i++) {
		ptr -= stride_dst;
		memcpy(ptr, p, stride_dst);
		p += img->stride;
	}
	return v;
}

VALUE Image_buffer_addr(VALUE self)
{
	struct native_image* img;
	const char *p;

	Data_Get_Struct(self, struct native_image, img);
	RFI_CHECK_IMG(img);
	p = (const char*)FreeImage_GetBits(img->handle);
	return ULONG2NUM((uintptr_t)p);
}

VALUE Image_has_bytes(VALUE self)
{
	struct native_image* img;
	Data_Get_Struct(self, struct native_image, img);
	return img->handle ? Qtrue : Qfalse;
}


static inline VALUE rfi_get_image(FIBITMAP *nh)
{
	struct native_image *new_img;
	new_img = malloc(sizeof(struct native_image));
	memset(new_img, 0, sizeof(struct native_image));
	new_img->handle = nh;
	new_img->stride = FreeImage_GetPitch(nh);
	new_img->bpp = FreeImage_GetBPP(nh);
	new_img->w = FreeImage_GetWidth(nh);
	new_img->h = FreeImage_GetHeight(nh);

	return Data_Wrap_Struct(Class_Image, NULL, Image_free, new_img);
}

VALUE Image_to_bpp(VALUE self, VALUE _bpp)
{
	struct native_image *img;
	FIBITMAP *nh;
	int bpp = NUM2INT(_bpp);
	Data_Get_Struct(self, struct native_image, img);
	RFI_CHECK_IMG(img);
	if (bpp == img->bpp)
		return self;

	nh = convert_bpp(img->handle, bpp);
	if (!nh) rb_raise(rb_eArgError, "Invalid bpp");

	return rfi_get_image(nh);
}

VALUE Image_rotate(VALUE self, VALUE _angle)
{
	struct native_image *img;
	FIBITMAP *nh;
	double angle = NUM2DBL(_angle);

	Data_Get_Struct(self, struct native_image, img);
	RFI_CHECK_IMG(img);
	nh = FreeImage_Rotate(img->handle, angle, NULL);
	return rfi_get_image(nh);
}

VALUE Image_clone(VALUE self)
{
	struct native_image *img;
	FIBITMAP *nh;

	Data_Get_Struct(self, struct native_image, img);
	RFI_CHECK_IMG(img);
	nh = FreeImage_Clone(img->handle);
	return rfi_get_image(nh);
}

VALUE Image_rescale(VALUE self, VALUE dst_width, VALUE dst_height, VALUE filter_type)
{
	struct native_image *img;
	FIBITMAP *nh;
	int w = NUM2INT(dst_width);
	int h = NUM2INT(dst_height);
	int f = NUM2INT(filter_type);
	if (w <= 0 || h <= 0)
		rb_raise(rb_eArgError, "Invalid size");

	if (f < FILTER_BOX || f > FILTER_LANCZOS3)
		rb_raise(rb_eArgError, "Invalid image filter type");

	Data_Get_Struct(self, struct native_image, img);
	RFI_CHECK_IMG(img);

	nh = FreeImage_Rescale(img->handle, w, h, f);
	return rfi_get_image(nh);
}

VALUE Image_downscale(VALUE self, VALUE max_size) {
	// down-sample resize
	struct native_image *img;
	FIBITMAP *nh;
	int i;
	int j;
	int w;
	int h;
	int scale;
	int mlen;
	int msize = NUM2INT(max_size);

	Data_Get_Struct(self, struct native_image, img);
	RFI_CHECK_IMG(img);

	mlen = img->w > img->h ? img->w : img->h;
	if (msize <= 0 || msize >= mlen) {
		nh = FreeImage_Copy(img->handle, 0, 0, img->w, img->h);
	} else {
		unsigned char *ph;
		unsigned char *pnh;
		int dst_stride;
		if (img->bpp != 8 && img->bpp != 32)
			rb_raise(rb_eArgError, "bpp not supported");

		scale = (mlen + msize - 1)  / msize;
		w = img->w / scale;
		h = img->h / scale;
		nh = FreeImage_Allocate(w, h, img->bpp, 0, 0, 0);
		if (!nh)
			rb_raise(rb_eArgError, "fail to allocate image");

		ph = FreeImage_GetBits(img->handle);
		pnh = FreeImage_GetBits(nh);
		dst_stride = FreeImage_GetPitch(nh);
		if (img->bpp == 8) {
			for(i = 0; i < h; i++) {
				for(j = 0; j < w; j++)
					*(pnh + j) = *(ph + j * scale);
				ph += img->stride * scale;
				pnh += dst_stride;
			}
		} else if (img->bpp == 32) {
			for(i = 0; i < h; i++) {
				for(j = 0; j < w; j++)
					*((unsigned int*)pnh + j) = *((unsigned int*)ph + j * scale);
				ph += img->stride * scale;
				pnh += dst_stride;
			}
		}
	}
	return rfi_get_image(nh);
}

VALUE Image_crop(VALUE self, VALUE _left, VALUE _top, VALUE _right, VALUE _bottom)
{
	struct native_image *img;
	FIBITMAP *nh;
	int left = NUM2INT(_left);
	int top = NUM2INT(_top);
	int right = NUM2INT(_right);
	int bottom = NUM2INT(_bottom);
	Data_Get_Struct(self, struct native_image, img);
	RFI_CHECK_IMG(img);

	if (left < 0 || top < 0
		|| right < left || bottom < top
		|| bottom > img->h || right > img->w )
		rb_raise(rb_eArgError, "Invalid boundary");

	nh = FreeImage_Copy(img->handle, left, top, right, bottom);
	return rfi_get_image(nh);
}

#define ALLOC_NEW_IMAGE(__v, img) \
	VALUE __v = Image_alloc(Class_Image);            \
	struct native_image* img;                        \
	Data_Get_Struct(__v, struct native_image, img)   \

VALUE Image_ping(VALUE self, VALUE file)
{
	ALLOC_NEW_IMAGE(v, img);

	rd_image(self, file, img, 0, 1, 0);
	if (img->handle)
		FreeImage_Unload(img->handle);
	img->handle = NULL;

	return v;
}

VALUE Image_from_blob(int argc, VALUE *argv, VALUE self)
{
	ALLOC_NEW_IMAGE(v, img);

	switch (argc)
	{
		case 1:
			rd_image_blob(self, argv[0], img, 0, 0, 0);
			break;
		case 2:
			rd_image_blob(self, argv[0], img, NUM2INT(argv[1]), 0, 0);
			break;
		case 3:
			rd_image_blob(self, argv[0], img, NUM2INT(argv[1]), 0, NUM2INT(argv[2]));
			break;
		default:
			rb_raise(rb_eArgError, "wrong number of arguments (%d for 1)", argc);
			break;
	}

	return v;
}

VALUE Image_ping_blob(VALUE self, VALUE blob)
{
	ALLOC_NEW_IMAGE(v, img);

	rd_image_blob(self, blob, img, 0, 1, 0);
	if (img->handle)
		FreeImage_Unload(img->handle);
	img->handle = NULL;

	return v;
}

VALUE Image_from_bytes(VALUE self, VALUE bytes, VALUE width,
		VALUE height, VALUE stride, VALUE bpp)
{
	long f_len;
	int _bpp = NUM2INT(bpp);
	char *ptr;
	unsigned char *p;
	int i;
	int src_stride = NUM2INT(stride);
	FIBITMAP *h;

	ALLOC_NEW_IMAGE(v, img);

	if (_bpp != 8 && _bpp != 32)
		rb_raise(rb_eArgError, "bpp must be 8 or 32");
	Check_Type(bytes, T_STRING);
	f_len = RSTRING_LEN(bytes);
	if (f_len < (long)src_stride * NUM2INT(height))
		rb_raise(rb_eArgError, "buffer too small");

	h = FreeImage_Allocate(NUM2INT(width), NUM2INT(height), _bpp, 0, 0, 0);
	if (!h)
		rb_raise(rb_eArgError, "fail to allocate image");

	img->handle = h;
	img->w = FreeImage_GetWidth(h);
	img->h = FreeImage_GetHeight(h);
	img->bpp = FreeImage_GetBPP(h);
	img->stride = FreeImage_GetPitch(h);
	img->fif = FIF_BMP;

	/* up-side-down */
	p = FreeImage_GetBits(img->handle);
	ptr = RSTRING_PTR(bytes) + img->h * src_stride;
	for(i = 0; i < img->h; i++) {
		ptr -= src_stride;
		memcpy(p, ptr, img->stride);
		p += img->stride;
	}

	return v;
}

/* draw */
VALUE Image_draw_point(VALUE self, VALUE _x, VALUE _y, VALUE color, VALUE _size)
{
	struct native_image* img;
	int x = NUM2INT(_x);
	int y = NUM2INT(_y);
	int size = NUM2INT(_size);
	int hs = size / 2, i, j;
	unsigned int bgra = NUM2UINT(color);
	if (size < 0)
		rb_raise(rb_eArgError, "Invalid point size: %d", size);
	Data_Get_Struct(self, struct native_image, img);
	RFI_CHECK_IMG(img);

	for(i = -hs; i <= hs; i++) {
		for(j = -hs; j <= hs; j++) {
			if (i*i + j*j <= hs*hs)
				FreeImage_SetPixelColor(img->handle, x + i, img->h - (y + j) - 1, (RGBQUAD*)&bgra);
		}
	}

	return self;
}

VALUE Image_draw_rectangle(VALUE self, VALUE _x1, VALUE _y1,
		VALUE _x2, VALUE _y2,
		VALUE color, VALUE _width)
{
	struct native_image* img;
	int x1 = NUM2INT(_x1);
	int y1 = NUM2INT(_y1);
	int x2 = NUM2INT(_x2);
	int y2 = NUM2INT(_y2);
	int size = NUM2INT(_width);
	int hs = size / 2, i, j;
	unsigned int bgra = NUM2UINT(color);
	if (size < 0)
		rb_raise(rb_eArgError, "Invalid line width: %d", size);
	Data_Get_Struct(self, struct native_image, img);
	RFI_CHECK_IMG(img);

	for(i = -hs; i <= hs; i++) {
		for(j = x1; j <= x2; j++) {
			FreeImage_SetPixelColor(img->handle, j, img->h - (y1 + i) - 1, (RGBQUAD*)&bgra);
			FreeImage_SetPixelColor(img->handle, j, img->h - (y2 + i) - 1, (RGBQUAD*)&bgra);
		}
	}

	for(i = -hs; i <= hs; i++) {
		for(j = y1; j <= y2; j++) {
			FreeImage_SetPixelColor(img->handle, x1 + i, img->h - j - 1, (RGBQUAD*)&bgra);
			FreeImage_SetPixelColor(img->handle, x2 + i, img->h - j - 1, (RGBQUAD*)&bgra);
		}
	}

	return self;
}



void Init_rfreeimage(void)
{
	rb_mFI = rb_define_module("RFreeImage");
	rb_define_module_function(rb_mFI, "freeimage_version", rb_rfi_version, 0);
	rb_define_module_function(rb_mFI, "freeimage_string_version", rb_rfi_string_version, 0);

	Class_Image = rb_define_class_under(rb_mFI, "Image", rb_cObject);
	Class_RFIError = rb_define_class_under(rb_mFI, "ImageError", rb_eStandardError);
	// rb_define_singleton_method(Class_Image, "read", Image_read, 1);
	rb_define_alloc_func(Class_Image, Image_alloc);
	rb_define_method(Class_Image, "initialize", Image_initialize, -1);
	rb_define_method(Class_Image, "cols", Image_cols, 0);
	rb_define_method(Class_Image, "rows", Image_rows, 0);
	rb_define_method(Class_Image, "bpp", Image_bpp, 0);
	rb_define_method(Class_Image, "stride", Image_stride, 0);
	rb_define_method(Class_Image, "format", Image_format, 0);
	rb_define_method(Class_Image, "buffer_addr", Image_buffer_addr, 0);
	rb_define_method(Class_Image, "read_bytes", Image_read_bytes, 0);
	rb_define_method(Class_Image, "bytes?", Image_has_bytes, 0);
	rb_define_method(Class_Image, "save", Image_save, 1);
	rb_define_method(Class_Image, "clone", Image_clone, 0);
	rb_define_method(Class_Image, "release", Image_release, 0);

	rb_define_method(Class_Image, "to_bpp", Image_to_bpp, 1);
	rb_define_method(Class_Image, "rotate", Image_rotate, 1);
	rb_define_method(Class_Image, "rescale", Image_rescale, 3);
	rb_define_method(Class_Image, "downscale", Image_downscale, 1);
	rb_define_method(Class_Image, "crop", Image_crop, 4);
	rb_define_method(Class_Image, "to_blob", Image_to_blob, 1);

	/* draw */
	rb_define_method(Class_Image, "draw_point", Image_draw_point, 4);
	rb_define_method(Class_Image, "draw_rectangle", Image_draw_rectangle, 4 + 2);

	rb_define_singleton_method(Class_Image, "ping", Image_ping, 1);
	rb_define_singleton_method(Class_Image, "from_blob", Image_from_blob, -1);
	rb_define_singleton_method(Class_Image, "ping_blob", Image_ping_blob, 1);
	rb_define_singleton_method(Class_Image, "from_bytes", Image_from_bytes, 5);
}