/**
 * Dailytodo is an easy tool to review daily todo items
 * Copyright (C) 2022  Aaron Ball <nullspoon@oper.io>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#define _XOPEN_SOURCE
#include <stdio.h>

#include "common.h"
#include "config.h"

int print_section(char* path, char* prefix, char* title) {
  FILE* fd = NULL;
  char buf[4096] = {'\0'};
  char header[512] = {'\0'};
  char hprefix[32] = {'\0'};
  int headerlen = 0;
  int hprefixlen = 0;
  int output = 0;

  snprintf(header, 512, "%s %s\n", prefix, title);
  snprintf(hprefix, 32, "%s \n", prefix);
  headerlen = strlen(header);
  hprefixlen = strlen(hprefix);

  fd = fopen(path, "r");
  while(fgets(buf, 4096, fd) != NULL) {
    if(strncmp(buf, header, headerlen) == 0 ) {
      output = 1;
      continue;
    } else if(strncmp(buf, hprefix, hprefixlen) == 0 ) {
      output = 0;
    }
    if(output == 1)
      fputs(buf, stdout);
  }

  fclose(fd);
  return 0;
}

int main(int argc, char* argv[]) {
  char notepath[256] = {'\0'};
  char date[128]     = {'\0'};
  char* prefix       = "#";
  char* title        = "Todo";
  int days           = 0;
  int i              = 0;
  struct config c;

  memset(&c, sizeof(struct config), 1);
  config_init(&c);

  if(argc > 1)
    days = strtol(argv[1], NULL, 10);

  // If user requests negative days, we want to skip non-existant days. So `-2`
  // is really "two entries ago" rather than two days ago, which could yield
  // creating an empty historical note if one does not already exist (for
  // example: on Monday, opening Friday's entry which is -3 days, but -1
  // entry).
  if(days < 0) {
    while(days < 0) {
      i--;
      getpath(c.journaldir, i, notepath, c.extension);
      if(fexists(notepath))
        days++;
      // Stop traversing after a year to avoid infinite loops when no notes
      // exist (or exist very long ago)
      if(i < -365) {
        fprintf(stderr, "Refusing to search further back than one year\n");
        return 1;
      }
    }
  } else {
    getpath(c.journaldir, days, notepath, c.extension);
  }
  getdate(i, date, 128);

  printf("%s %s (%s)\n", prefix, title, date);
  print_section(notepath, prefix, title);

  return 0;
}