//calp: printable calendar generator

#include <stdio.h>
#include <stdlib.h>
#include <cairo/cairo-pdf.h>
#include <pango/pangocairo.h>

#include "draw.h"
#include "date.h"
#include "color.h"

// Metric
#define A4_WIDTH 210
#define A4_HEIGHT 297

#define US_LETTER_WIDTH 216
#define US_LETTER_HEIGHT 279

// Font Settings
#define FONT_FAMILY "Sans"
#define FONT_SIZE_NORMAL 10
#define FONT_SIZE_LARGE 40

int main (void) {
   // Definitions
   // -----------
   double width = A4_WIDTH;
   double height = A4_HEIGHT;

   // Convert to inches, then 1 unit = 1/72th inch
   width = (width / 25.4) * 72.0;
   height = (height / 25.4) * 72.0;

   extern char *months[];
   int num_of_months = 12;
   extern int days_in_month[12];


   // Create dimensions struct to hold measurements
   struct dimensions dim;

   // Create dimensions struct to hold information about a
   // month
   struct month_info month;


   // Leap year adjustment: increment February day count by one if
   // it is a leap year.
   int year = 3043;
   if (isleap(year)) {
      days_in_month[1]++;
   }

   int verbose_output = 1;


   // TBD: Add ability to choose filename
   // Defaults to the year being generated
   char filename[20];
   snprintf(filename, sizeof(filename), "%d.pdf", year);


   // Initialization
   // --------------
   // Calculates measurements, stores them in dimensions struct. See "draw.h"
   calculate_dimensions(width, height, &dim);

   if (!CAIRO_HAS_PDF_SURFACE) {
      printf("Error: PDF backend not available.\n");
      return 1;
   }

   cairo_surface_t *surface = cairo_pdf_surface_create(filename, dim.paper_width, dim.paper_height);
   cairo_t *paper = cairo_create(surface);

   // Sub-surface for rendering content in day boxes
   cairo_surface_t *day = 
      cairo_surface_create_similar(surface, CAIRO_CONTENT_COLOR_ALPHA, dim.day_width, dim.day_height);
   // cd = context day
   cairo_t *cd = cairo_create(day);



   // Fill background with white color
   set_color(paper, WHITE);
   fill_bg(paper);




   // Construction
   // ------------
   // Print dimensions, for debugging

   if (verbose_output) {
      print_dimensions(&dim);
   }


   // Range of months to be rendered (Default: Full calendar year, 12 months)
   int first_month = 0;
   int end_month = num_of_months;


   // Month generation loop
   for (int i = first_month; i < end_month; i++) {
      // Initialize month struct
      month.first_day = day_of_week(1, i + 1, year);
      month.num_of_days = days_in_month[i];
      month.month_position = i;
      month.minimum_rows = calculate_minimum_rows(&month, &dim);
      printf("month.minimum_rows: %d\n", month.minimum_rows);

      dim.header_width = dim.paper_width - (dim.margin * 2.0);
      dim.header_height = dim.paper_height - (dim.margin * 3.0) - (month.minimum_rows * dim.day_height);

      cairo_surface_t *header = cairo_surface_create_similar(surface, CAIRO_CONTENT_COLOR_ALPHA, dim.header_width, dim.header_height);
      cairo_t *ch = cairo_create(header);

      //set_color(ch, BLUE);
      //fill_bg(ch);

      set_color(ch, BLACK);
      draw_month_title(ch, &dim, "Sans", 40, months[i]);

      printf("header width: %f\n", dim.header_width);
      printf("header height: %f\n", dim.header_height);

      char path[20];

      snprintf(path, 20, "assets/%d.png", i + 1);

      if (verbose_output) {
         printf("Drawing month \'%s\'\n", months[i]);
      }
      draw_month_art(paper, &dim, path);
      

      cairo_set_source_surface(paper, header, dim.margin, dim.margin);
      cairo_paint(paper);

      draw_month(paper, cd, day, &month, &dim);
      draw_month_grid(paper, &month, &dim);

      // Go to the next page in pdf
      cairo_show_page(paper); 

      cairo_destroy(ch);
      cairo_surface_destroy(header);
   }


   if (verbose_output) {
      printf("Finished generating \'%s\'.\n", filename);
   }
   

   // Clean up
   // --------
   cairo_destroy(paper);
   cairo_surface_destroy(surface);

   cairo_destroy(cd);
   cairo_surface_destroy(day);

   return 0;
}