#include <stdbool.h>
#include <stdlib.h>
#include <cairo/cairo.h>
#include <pango/pangocairo.h>
#include <wand/MagickWand.h>
#include "draw.h"


// Used for MagickWand
#define ThrowWandException(wand) \
{ \
   char \
   *description; \
   \
   ExceptionType \
   severity; \
   \
   description=MagickGetException(wand,&severity); \
   (void) fprintf(stderr,"%s %s %lu %s\n",GetMagickModule(),description); \
   description=(char *) MagickRelinquishMemory(description); \
   exit(-1); \
}



// Draw an image at a specific point
int draw_image(cairo_t *c, char *path, double x, double y) {
   cairo_surface_t *image;

   // Checks if the file exists. If it doesn't, warn the user that it was not found.
   // A file not existing will not terminate the program, but simply not render the image.
   FILE *file;
   if((file = fopen(path, "r")) != NULL)
   {
      // file exists
      fclose(file);
   }
   else
   {
      printf("Warning: image \'%s\' does not exist.\n", path);
      return 1;
   }

   image = cairo_image_surface_create_from_png(path);
   cairo_set_source_surface(c, image, x, y);
   cairo_paint(c);

   cairo_surface_destroy (image);
   return 0;
}






unsigned long get_image_width(char *path) {
   MagickBooleanType status;
   MagickWand *wand;

   MagickWandGenesis();
   wand = NewMagickWand();
   status = MagickReadImage(wand, path);

   if (status == MagickFalse) {
      ThrowWandException(wand);
   }

   unsigned long width = MagickGetImageWidth(wand);

   wand = DestroyMagickWand(wand);
   MagickWandTerminus();
   return width;
}



unsigned long get_image_height(char *path) {
   MagickBooleanType status;
   MagickWand *wand;

   MagickWandGenesis();
   wand = NewMagickWand();
   status = MagickReadImage(wand, path);

   if (status == MagickFalse) {
      ThrowWandException(wand);
   }

   unsigned long height = MagickGetImageHeight(wand);

   wand = DestroyMagickWand(wand);
   MagickWandTerminus();
   return height;
}





// Resize an image to a specific width and height.
// Optionally create a new file to preserve the source image.
int resize_image(char *path, double width, double height, bool create_new) {
   MagickBooleanType status;
   MagickWand *wand;

   MagickWandGenesis();
   wand = NewMagickWand();
   status = MagickReadImage(wand, path);

   if (status == MagickFalse) {
      ThrowWandException(wand);
   }

   MagickResetIterator(wand);

   MagickResizeImage(wand, width, height, LanczosFilter, 1.0);

   if (create_new == true) {
      char new_path[30];
      snprintf(new_path, sizeof(new_path), "%s.tmp", path);
      status = MagickWriteImages(wand, new_path, MagickTrue);
   } else {
      status = MagickWriteImages(wand, path, MagickTrue);
   }

   if (status == MagickFalse) {
      ThrowWandException(wand);
   }
   wand = DestroyMagickWand(wand);
   MagickWandTerminus();
   return 0;
}


// Create a cropped version of an image to a certain dimensions and position.
// Optionally create a new file to preserve the source image.
int crop_image(char *path, double width, double height, double x, double y, bool create_new) {
   MagickBooleanType status;
   MagickWand *wand;

   MagickWandGenesis();
   wand = NewMagickWand();
   status = MagickReadImage(wand, path);

   if (status == MagickFalse) {
      ThrowWandException(wand);
   }

   MagickResetIterator(wand);

   MagickCropImage(wand, width, height, x, y);

   if (create_new == true) {
      char new_path[30];
      snprintf(new_path, sizeof(new_path), "%s.tmp", path);
      status = MagickWriteImages(wand, new_path, MagickTrue);
   } else {
      status = MagickWriteImages(wand, path, MagickTrue);
   }

   if (status == MagickFalse) {
      ThrowWandException(wand);
   }
   wand = DestroyMagickWand(wand);
   MagickWandTerminus();
   return 0;
}


int prepare_month_art(char *path, struct dimensions *d) {
   if (!d->header_width || !d->header_height) {
      printf("Error: header_width and header_height unknown.\n");
      return 1;
   }

   double desired_ratio = d->header_width / d->header_height;

   unsigned long width = get_image_width(path);
   unsigned long height = get_image_height(path);
   //double original_ratio = width / height;


   // Landscape
   if (desired_ratio > 1.0) {
   }

   // Portrait
   if (desired_ratio < 1.0) {
   }



   printf("%lu x %lu\n", width, height);


  return 0; 

}




// Draw month art
int draw_month_art(cairo_t *c, struct dimensions *d, char *path) {
   cairo_save(c);
   double width = d->header_width;
   // TODO: Make this relative to text height
   double height = d->header_height - (d->margin * 3.0);

   double cursor_x = d->margin;
   double cursor_y = d->margin;
   cairo_rectangle (c, d->margin, d->margin, width, height);
   cairo_clip(c);

   
   draw_image(c, path, cursor_x, cursor_y);
   cairo_restore(c);
   return 0;
}