#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "linecut.h"
#include "error.h"

void
verify (data_t *gl, file_entry_t *queue)
{
    file_entry_t *current;

    for (current = queue; current; current = current->next)
      {
        unsigned int i;
        long lines;

        gl->file = current->file;

        if (!gl->read_from_stdin)
          {
            gl->input = xfopen (gl->file, "r");
            lines = count_lines (gl->input);
          }
        else
          lines = map_stdin_lines (gl);

        current->lines = lines;

        for (i = 0; gl->ranges[i]; i++)
          {
            long start_range = gl->ranges[i][0];
            long end_range   = gl->ranges[i][1];

            if ((start_range > lines) || (end_range > lines))
              error ("%s: %s", gl->file, range_errors[ERR_EXCEEDS_TOTAL_LINES]);

            range_to_absolute (lines, &start_range);
            range_to_absolute (lines, &end_range);

            if ((start_range < 0) || (end_range < 0))
              error ("%s: %s", gl->file, range_errors[ERR_OFFSET_EXCEEDS_BOUNDARY]);

            if ((start_range == 0) || (end_range == 0))
              error ("%s: %s", gl->file, range_errors[ERR_MUST_NOT_BE_NULL]);

            if ((start_range > lines) || (end_range > lines))
              error ("%s: %s", gl->file, range_errors[ERR_EXCEEDS_TOTAL_LINES]);
          }

          if (!gl->read_from_stdin)
            xfclose (gl->file, gl->input);
      }
}

void
extract (data_t *gl, file_entry_t *queue)
{
    file_entry_t *current;

    for (current = queue; current; current = current->next)
      {
        unsigned int i;
        long lines;
        fpos_t *offset_map;

        gl->file = current->file;

        if (!gl->read_from_stdin)
          gl->input = xfopen (gl->file, "r");

        if (gl->number_lines)
          fprintf (stdout, "==> %s\n", gl->file);

        gl->lines_count = lines = current->lines;

        if (!gl->read_from_stdin)
          offset_map = build_offset_map (gl);

        for (i = 0; gl->ranges[i]; i++)
          {
            long range_start = gl->ranges[i][0];
            long range_end   = gl->ranges[i][1];

            range_to_absolute (lines, &range_start);
            range_to_absolute (lines, &range_end);

            if (!gl->read_from_stdin)
              {
                seek_to_offset (gl, offset_map, range_start - 1);
                extract_range_file (gl, range_start, range_end);
              }
            else
              extract_range_stdin (gl, range_start, range_end);
          }

        if (!gl->read_from_stdin)
          {
            xfree (offset_map);
            xfclose (gl->file, gl->input);
          }
      }
}