#include <ruby.h>
#include <stdint.h>

#define STB_IMAGE_IMPLEMENTATION
#define STB_IMAGE_WRITE_IMPLEMENTATION
#define STB_IMAGE_RESIZE_IMPLEMENTATION

#include "../../third_party/stb_image.h"
#include "../../third_party/stb_image_write.h"
#include "../../third_party/stb_image_resize.h"

// STBIDEF stbi_uc *stbi_load(char const *filename, int *x, int *y, int *comp, int req_comp);
static VALUE rb_stbi_load(VALUE self, VALUE rb_filename, VALUE rb_req_comp) {
  char* filename = StringValuePtr(rb_filename);
  int32_t x, y, n;
  int32_t req_comp = FIX2INT(rb_req_comp);
  uint8_t* data;
  int32_t ch;
  VALUE rb_x, rb_y, rb_n;
  VALUE rb_data;

  data = stbi_load(filename, &x, &y, &n, req_comp);
  rb_x = INT2FIX(x);
  rb_y = INT2FIX(y);
  rb_n = INT2FIX(n);
  ch = req_comp == 0 ? n : req_comp;
  rb_data = rb_str_new((char*)data, y * x * ch);
  stbi_image_free(data);
  return rb_ary_new3(4, rb_data, rb_x, rb_y, rb_n);
}

// STBIWDEF int stbi_write_png(char const *filename, int w, int h, int comp, const void  *data, int stride_in_bytes);
static VALUE rb_stbi_write_png(VALUE self, VALUE rb_filename, VALUE rb_w, VALUE rb_h, VALUE rb_comp, VALUE rb_data, VALUE rb_stride_in_bytes) {
  char* filename = StringValuePtr(rb_filename);
  int32_t w = FIX2INT(rb_w);
  int32_t h = FIX2INT(rb_h);
  int32_t comp = FIX2INT(rb_comp);
  uint8_t* data = (uint8_t*)StringValuePtr(rb_data);
  int32_t stride_in_bytes = FIX2INT(rb_stride_in_bytes);
  int32_t result;

  result = stbi_write_png(filename, w, h, comp, data, stride_in_bytes);
  return INT2FIX(result);
}

// STBIWDEF int stbi_write_bmp(char const *filename, int w, int h, int comp, const void  *data);
static VALUE rb_stbi_write_bmp(VALUE self, VALUE rb_filename, VALUE rb_w, VALUE rb_h, VALUE rb_comp, VALUE rb_data) {
  char* filename = StringValuePtr(rb_filename);
  int32_t w = FIX2INT(rb_w);
  int32_t h = FIX2INT(rb_h);
  int32_t comp = FIX2INT(rb_comp);
  uint8_t* data = (uint8_t*)StringValuePtr(rb_data);
  int32_t result;

  result = stbi_write_bmp(filename, w, h, comp, data);
  return INT2FIX(result);
}

// STBIWDEF int stbi_write_tga(char const *filename, int w, int h, int comp, const void  *data);
static VALUE rb_stbi_write_tga(VALUE self, VALUE rb_filename, VALUE rb_w, VALUE rb_h, VALUE rb_comp, VALUE rb_data) {
  char* filename = StringValuePtr(rb_filename);
  int32_t w = FIX2INT(rb_w);
  int32_t h = FIX2INT(rb_h);
  int32_t comp = FIX2INT(rb_comp);
  uint8_t* data = (uint8_t*)StringValuePtr(rb_data);
  int32_t result;

  result = stbi_write_tga(filename, w, h, comp, data);
  return INT2FIX(result);
}

// STBIWDEF int stbi_write_hdr(char const *filename, int w, int h, int comp, const float *data);
static VALUE rb_stbi_write_hdr(VALUE self, VALUE rb_filename, VALUE rb_w, VALUE rb_h, VALUE rb_comp, VALUE rb_data) {
  char* filename = StringValuePtr(rb_filename);
  int32_t w = FIX2INT(rb_w);
  int32_t h = FIX2INT(rb_h);
  int32_t comp = FIX2INT(rb_comp);
  float* data = (float*)StringValuePtr(rb_data);
  int32_t result;

  result = stbi_write_hdr(filename, w, h, comp, data);
  return INT2FIX(result);
}

// STBIWDEF int stbi_write_jpg(char const *filename, int x, int y, int comp, const void  *data, int quality);
static VALUE rb_stbi_write_jpg(VALUE self, VALUE rb_filename, VALUE rb_w, VALUE rb_h, VALUE rb_comp, VALUE rb_data, VALUE rb_quality) {
  char* filename = StringValuePtr(rb_filename);
  int32_t w = FIX2INT(rb_w);
  int32_t h = FIX2INT(rb_h);
  int32_t comp = FIX2INT(rb_comp);
  uint8_t* data = (uint8_t*)StringValuePtr(rb_data);
  int32_t quality = FIX2INT(rb_quality);
  int32_t result;

  result = stbi_write_jpg(filename, w, h, comp, data, quality);
  return INT2FIX(result);
}

// STBIRDEF int stbir_resize_uint8(     const unsigned char *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
//                                            unsigned char *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
//                                      int num_channels);
static VALUE rb_stbir_resize_uint8(VALUE self, VALUE rb_input_pixels, VALUE rb_input_w, VALUE rb_input_h, VALUE rb_input_stride_in_bytes,
                                   VALUE rb_output_w, VALUE rb_output_h, VALUE rb_output_stride_in_bytes, VALUE rb_num_channels) {
  uint8_t* input_pixels = (uint8_t*)StringValuePtr(rb_input_pixels);
  int32_t input_w = FIX2INT(rb_input_w);
  int32_t input_h = FIX2INT(rb_input_h);
  int32_t input_stride_in_bytes = FIX2INT(rb_input_stride_in_bytes);
  int32_t output_w = FIX2INT(rb_output_w);
  int32_t output_h = FIX2INT(rb_output_h);
  int32_t output_stride_in_bytes = FIX2INT(rb_output_stride_in_bytes);
  int32_t num_channels = FIX2INT(rb_num_channels);
  uint8_t* output_pixels;
  VALUE rb_output_pixels;
  int32_t result;
  const int32_t output_size = output_h * output_w * num_channels;

  output_pixels = (uint8_t*)malloc(output_size);
  result = stbir_resize_uint8(input_pixels, input_w, input_h, input_stride_in_bytes,
                              output_pixels, output_w, output_h, output_stride_in_bytes, num_channels);
  rb_output_pixels = rb_str_new((char*)output_pixels, output_size);
  free(output_pixels);
  return rb_ary_new3(2, rb_output_pixels, INT2FIX(result));
}

// STBIRDEF int stbir_resize_uint8_srgb(const unsigned char *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
//                                            unsigned char *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
//                                      int num_channels, int alpha_channel, int flags);
static VALUE rb_stbir_resize_uint8_srgb(VALUE self, VALUE rb_input_pixels, VALUE rb_input_w, VALUE rb_input_h, VALUE rb_input_stride_in_bytes,
                                   VALUE rb_output_w, VALUE rb_output_h, VALUE rb_output_stride_in_bytes, VALUE rb_num_channels,
                                   VALUE rb_alpha_channel, VALUE rb_flags) {
  uint8_t* input_pixels = (uint8_t*)StringValuePtr(rb_input_pixels);
  int32_t input_w = FIX2INT(rb_input_w);
  int32_t input_h = FIX2INT(rb_input_h);
  int32_t input_stride_in_bytes = FIX2INT(rb_input_stride_in_bytes);
  int32_t output_w = FIX2INT(rb_output_w);
  int32_t output_h = FIX2INT(rb_output_h);
  int32_t output_stride_in_bytes = FIX2INT(rb_output_stride_in_bytes);
  int32_t num_channels = FIX2INT(rb_num_channels);
  int32_t alpha_channel = FIX2INT(rb_alpha_channel);
  int32_t flags = FIX2INT(rb_flags);
  uint8_t* output_pixels;
  VALUE rb_output_pixels;
  int32_t result;
  const int32_t output_size = output_h * output_w * num_channels;

  output_pixels = (uint8_t*)malloc(output_size);
  result = stbir_resize_uint8_srgb(input_pixels, input_w, input_h, input_stride_in_bytes,
                                   output_pixels, output_w, output_h, output_stride_in_bytes,
                                   num_channels, alpha_channel, flags);
  rb_output_pixels = rb_str_new((char*)output_pixels, output_size);
  free(output_pixels);
  return rb_ary_new3(2, rb_output_pixels, INT2FIX(result));
}

// STBIRDEF int stbir_resize_uint8_srgb_edgemode(const unsigned char *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
//                                                    unsigned char *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
//                                              int num_channels, int alpha_channel, int flags,
//                                              stbir_edge edge_wrap_mode);
static VALUE rb_stbir_resize_uint8_srgb_edgemode(VALUE self, VALUE rb_input_pixels, VALUE rb_input_w, VALUE rb_input_h, VALUE rb_input_stride_in_bytes,
                                   VALUE rb_output_w, VALUE rb_output_h, VALUE rb_output_stride_in_bytes, VALUE rb_num_channels,
                                   VALUE rb_alpha_channel, VALUE rb_flags, VALUE rb_edge_wrap_mode) {
  uint8_t* input_pixels = (uint8_t*)StringValuePtr(rb_input_pixels);
  int32_t input_w = FIX2INT(rb_input_w);
  int32_t input_h = FIX2INT(rb_input_h);
  int32_t input_stride_in_bytes = FIX2INT(rb_input_stride_in_bytes);
  int32_t output_w = FIX2INT(rb_output_w);
  int32_t output_h = FIX2INT(rb_output_h);
  int32_t output_stride_in_bytes = FIX2INT(rb_output_stride_in_bytes);
  int32_t num_channels = FIX2INT(rb_num_channels);
  int32_t alpha_channel = FIX2INT(rb_alpha_channel);
  int32_t flags = FIX2INT(rb_flags);
  stbir_edge edge_wrap_mode = (stbir_edge)FIX2INT(rb_edge_wrap_mode);
  uint8_t* output_pixels;
  VALUE rb_output_pixels;
  int32_t result;
  const int32_t output_size = output_h * output_w * num_channels;

  output_pixels = (uint8_t*)malloc(output_size);
  result = stbir_resize_uint8_srgb_edgemode(input_pixels, input_w, input_h, input_stride_in_bytes,
                                            output_pixels, output_w, output_h, output_stride_in_bytes,
                                            num_channels, alpha_channel, flags, edge_wrap_mode);
  rb_output_pixels = rb_str_new((char*)output_pixels, output_size);
  free(output_pixels);
  return rb_ary_new3(2, rb_output_pixels, INT2FIX(result));
}

void Init_rb_stb_image() {
  VALUE rb_dnn = rb_define_module("DNN");
  VALUE rb_stb = rb_define_module_under(rb_dnn, "Stb");

  rb_define_const(rb_stb, "STBIR_ALPHA_CHANNEL_NONE", INT2FIX(STBIR_ALPHA_CHANNEL_NONE));

  rb_define_const(rb_stb, "STBIR_FLAG_ALPHA_PREMULTIPLIED", INT2FIX(STBIR_FLAG_ALPHA_PREMULTIPLIED));
  rb_define_const(rb_stb, "STBIR_FLAG_ALPHA_USES_COLORSPACE", INT2FIX(STBIR_FLAG_ALPHA_USES_COLORSPACE));

  rb_define_const(rb_stb, "STBIR_EDGE_CLAMP", INT2FIX(STBIR_EDGE_CLAMP));
  rb_define_const(rb_stb, "STBIR_EDGE_REFLECT", INT2FIX(STBIR_EDGE_REFLECT));
  rb_define_const(rb_stb, "STBIR_EDGE_WRAP", INT2FIX(STBIR_EDGE_WRAP));
  rb_define_const(rb_stb, "STBIR_EDGE_ZERO", INT2FIX(STBIR_EDGE_ZERO));

  rb_define_module_function(rb_stb, "stbi_load", rb_stbi_load, 2);
  rb_define_module_function(rb_stb, "stbi_write_png", rb_stbi_write_png, 6);
  rb_define_module_function(rb_stb, "stbi_write_bmp", rb_stbi_write_bmp, 5);
  rb_define_module_function(rb_stb, "stbi_write_tga", rb_stbi_write_tga, 5);
  rb_define_module_function(rb_stb, "stbi_write_hdr", rb_stbi_write_hdr, 5);
  rb_define_module_function(rb_stb, "stbi_write_jpg", rb_stbi_write_jpg, 6);
  rb_define_module_function(rb_stb, "stbir_resize_uint8", rb_stbir_resize_uint8, 8);
  rb_define_module_function(rb_stb, "stbir_resize_uint8_srgb", rb_stbir_resize_uint8_srgb, 10);
  rb_define_module_function(rb_stb, "stbir_resize_uint8_srgb_edgemode", rb_stbir_resize_uint8_srgb_edgemode, 11);
}