//calp: printable calendar generator

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

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

   const int row_count = 6;
   const int column_count = 7;

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

   //const nl_item nl_abmons[12] = {ABMON_1, ABMON_2, ABMON_3, ABMON_4,
   //   ABMON_5, ABMON_6, ABMON_7, ABMON_8,
   //   ABMON_9, ABMON_10, ABMON_11, ABMON_12};
   const nl_item nl_months[12] = {MON_1, MON_2, MON_3, MON_4, MON_5, MON_6,
      MON_7, MON_8, MON_9, MON_10, MON_11, MON_12};

   int i;
   setlocale(LC_ALL, "");
   for (i = 0; i < 12; i++) {
      months[i] = nl_langinfo(nl_months[i]);
   }



   // 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.
   const int year = 2026;
   if (isleap(year)) {
      days_in_month[1]++;
   }

   int verbose_output = 0;


   // 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);



   struct extents paper_extents = {
      .width = width, 
      .height = height
   };

   const double margin = 0.05 * paper_extents.width;

   struct extents day_extents = {
   .width = paper_extents.width / 10.0,
   .height = paper_extents.width / 10.0
   };

   struct extents month_extents = {
      .x = (paper_extents.width - (day_extents.width * column_count)) / 2.0,
      .y = paper_extents.height - margin - (day_extents.height * row_count),
      .width = day_extents.width * column_count,
      .height = day_extents.height * row_count,
   };

   printf("%f\n", month_extents.x);


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

   cairo_surface_t *surface = cairo_pdf_surface_create(filename, paper_extents.width, paper_extents.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, day_extents.width, day_extents.height);
   // cd = context day
   cairo_t *cd = cairo_create(day);



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




   // Construction
   // ------------
   
   // Month generation loop
   for (int i = 0; i < num_of_months; 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.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, BLACK);
      draw_month_title(ch, &dim, "Sans", 40, months[i]);

      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, &month_extents, &day_extents);

      // 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;
}