//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"

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

int main (void) {
   // Definitions
   // -----------
   double paper_width = A4_WIDTH;
   double paper_height = A4_HEIGHT;

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


   

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

   char *week_names[7];

   //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 locale_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};

   const nl_item locale_days[7] = {ABDAY_1, ABDAY_2, ABDAY_3, ABDAY_4,
      ABDAY_5, ABDAY_6, ABDAY_7};

   setlocale(LC_ALL, "");

   for (int i = 0; i < 12; i++) {
      months[i] = nl_langinfo(locale_months[i]);
   }

   for (int i = 0; i < 7; i++) {
      week_names[i] = nl_langinfo(locale_days[i]);
      printf("%s\n", week_names[i]);
   }



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

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


   // Create dimensions struct to hold information about a
   // month
   struct month_info month = {
      .row_count = row_count,
      .column_count = column_count
   };



   // 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]++;
   }



   // 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(paper_width, paper_height, &dim);



   // Height and width of the paper
   // .x and .y are empty
   struct extents paper_extents = {
      .width = paper_width, 
      .height = paper_height
   };

   const double margin = 0.05 * paper_extents.width;

   struct alignment page_layout = {
      .margin = margin
   };

   // Width and Height of the boxes are set
   // No position data is set until later.
   struct extents day_extents = {
   .width = paper_extents.width / 10.0,
   .height = paper_extents.width / 10.0
   };

   //struct extents week_name_extents = {
   //   .width = day_extents.width
   //};

   // Position and dimensions of the month "grid"
   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,
   };


   // Position and width of the header
   // Height is set dynamically, based on the size of
   // the month grid
   struct extents header_extents = {
      .x = margin,
      .y = margin,
      .width = paper_extents.width - (margin * 2.0),
   };


   // Program fails if the PDF backend isn't available
   if (!CAIRO_HAS_PDF_SURFACE) {
      printf("Error: PDF backend not available.\n");
      return 1;
   }

   // Main surface and context are created
   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);

      double month_header_spacing = margin * 3.0;

      header_extents.height = paper_extents.height - month_header_spacing - ((month.minimum_rows + 1) * day_extents.height);


      // Create another surface and context for working with the 
      // header
      cairo_surface_t *header = cairo_surface_create_similar(
            surface,
            CAIRO_CONTENT_COLOR_ALPHA,
            header_extents.width,
            header_extents.height
            );

      cairo_t *ch = cairo_create(header);



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

      set_color(ch, BLACK);
      draw_month_title(ch, &header_extents, &page_layout, FONT_FAMILY, FONT_SIZE_LARGE, months[i]);
      

      // Draw the header
      cairo_set_source_surface(paper, header, header_extents.x, header_extents.y);
      cairo_paint(paper);

      draw_month_dates(paper, cd, day, &month, &month_extents, &day_extents);
      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);
   }


   

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

   cairo_destroy(cd);
   cairo_surface_destroy(day);

   return 0;
}