<?php

declare(strict_types=1);

/** 
 * @author Robert Strutts
 * @copyright Copyright (c) 2022, Robert Strutts.
 * @license MIT
 */

namespace CodeHydrater;

final class time_zones {

  /**
   * MySQL time conversion!
   * @param type $field time
   * @param type $time_zone_name, leave blank for users time zone!
   * @return type
   */
  public static function db_convert_tz($field, $time_zone_name = '') {
    $session_time_zone = (isset($_SESSION['time_zone'])) ? $_SESSION['time_zone'] : 'America/Detroit';
    $tz = (!empty($time_zone_name) ) ? $time_zone_name : $session_time_zone;
    $to_tz = self::current_time_for_time_zone($tz);
    return "CONVERT_TZ({$field}, '+00:00', '{$to_tz}')";
  }

  /**
   * Purpose: To convert time zone to offset time
   * @param type $time_zone_name
   * @return offset
   */
  public static function current_time_for_time_zone($time_zone_name) {
    $time = new \DateTime('now', new \DateTimeZone($time_zone_name));
    return $time->format('P');
  }

  /**
   * Purpose: To make a temporary valid timestamp for a database
   */
  public static function expires_in_hours(int $hours = 1) {
    $hours = ($hours > 0 && $hours < 10) ? $hours : 1;
    $expires = new DateTime('NOW', new \DateTimeZone('UTC'));
    $expires->add(new DateInterval("PT0{$hours}H"));
    return $expires->format('Y-m-d H:i:s');
  }
  
  private static function mdy($userTime, $format) {
    switch (bootstrap\common::string_to_lowercase($format)) {
      case 'actions':
        return $userTime->format('m-d-Y / h:iA');
      case 'report':
        return $userTime->format('l jS \of F\, Y\, h:i a');
      case 'fancy':
        return $userTime->format('l jS \of F Y h:i:s A');
      case 'logging':
      case 'log':
        return $userTime->format('g:i A \o\n l jS F Y');
      case 'legal_date':
        return $userTime->format('n/j/Y');
      case 'date':
        return $userTime->format('m/d/Y');
      case 'date-time':
        return $userTime->format('m/d/Y h:i:s A');
      case 'full':
        return $userTime->format('m-d-Y h:i:s A');
      case 'normal':
        return $userTime->format('m/d/Y h:i A');
      case 'default':
        return $userTime->format('m-d-Y h:i A');
      default:
        return $userTime->format($format);
    }
  }

  private static function dmy($userTime, $format) {
    switch (bootstrap\common::string_to_lowercase($format)) {
      case 'actions':
        return $userTime->format('d-m-Y / h:iA');
      case 'report':
        return $userTime->format('l jS \of F\, Y\, h:i a');
      case 'fancy':
        return $userTime->format('l jS \of F Y h:i:s A');
      case 'logging':
      case 'log':
        return $userTime->format('g:i A \o\n l jS F Y');
      case 'legal_date':
        return $userTime->format('j/n/Y');
      case 'date':
        return $userTime->format('d/m/Y');
      case 'date-time':
        return $userTime->format('d/m/Y h:i:s A');
      case 'full':
        return $userTime->format('d-m-Y h:i:s A');
      case 'normal':
        return $userTime->format('d/m/Y h:i A');
      case 'default':
        return $userTime->format('d-m-Y h:i A');
      default:
        return $userTime->format($format);
    }
  }

  private static function ymd($userTime, $format) {
    switch (bootstrap\common::string_to_lowercase($format)) {
      case 'actions':
        return $userTime->format('Y-m-d / h:iA');
      case 'report':
        return $userTime->format('l jS \of F\, Y\, h:i a');
      case 'fancy':
        return $userTime->format('l jS \of F Y h:i:s A');
      case 'logging':
      case 'log':
        return $userTime->format('g:i A \o\n l jS F Y');
      case 'legal_date':
        return $userTime->format('Y/n/j');
      case 'date':
        return $userTime->format('Y/m/d');
      case 'date-time':
        return $userTime->format('Y/m/d h:i:s A');
      case 'full':
        return $userTime->format('Y-m-d h:i:s A');
      case 'normal':
        return $userTime->format('Y/m/d h:i A');
      case 'default':
        return $userTime->format('Y-m-d h:i A');
      default:
        return $userTime->format($format);
    }
  }

  public static function dt_format($userTime, $format, $country) {
    switch (bootstrap\common::string_to_lowercase($format)) {
      case 'object':
        return $userTime;
      case 'unix':
        return $userTime->format('U');
      case 'day':
        return $userTime->format('l');
      case 'time':
        return $userTime->format('h:i A');
      case 'military':
        return $userTime->format('H:i:s');
      case 'atom':
        return $userTime->format(DateTime::ATOM);
      case 'cookie':
        return $userTime->format(DateTime::COOKIE);
      case 'iso8601':
      case 'iso':
      case '8601':
        return $userTime->format(DateTime::ISO8601);
      case 'rfc822':
        return $userTime->format(DateTime::RFC822);
      case 'rfc850':
        return $userTime->format(DateTime::RFC850);
      case 'rfc1036':
        return $userTime->format(DateTime::RFC1036);
      case 'rfc1123':
        return $userTime->format(DateTime::RFC1123);
      case 'rfc2822':
        return $userTime->format(DateTime::RFC2822);
      case 'rfc3339':
        return $userTime->format(DateTime::RFC3339);
      case 'rss':
        return $userTime->format(DateTime::RSS);
      case 'w3c':
        return $userTime->format(DateTime::W3C);
      case 'standard':
      case 'computer':
      case 'database':
        return $userTime->format('Y-m-d H:i:s');
    }
    
    switch (bootstrap\common::string_to_lowercase($country)) {
        case 'china':
            return self::ymd($userTime, $format);
        case 'int':
        case 'other':
            return self::dmy($userTime, $format);
        default:
            return self::mdy($userTime, $format);
    }

  }
  
  /**
   * Purpose: To convert a database timestamp into the users own Time Zone.
   */
  public static function convert_time_zone($options) {
    $format = (isset($options['format'])) ? $options['format'] : 'normal';

    $session_time_zone = (isset($_SESSION['time_zone'])) ? $_SESSION['time_zone'] : 'America/Detroit';
    $tz = (isset($options['time_zone']) && !empty($options['time_zone'])) ? $options['time_zone'] : $session_time_zone;

    $offset = (isset($options['offset'])) ? $options['offset'] : '';

    $db_time = (isset($options['time'])) ? $options['time'] : '';
    if ($db_time === '0000-00-00 00:00:00') {
      return false;
    }

    $new_time = (empty($db_time)) ? self::get_offset($offset) : self::get_offset_by($offset, $db_time);

    // Convert date("U"); unix timestamps to proper format for DateTime function...
    if (substr_count($new_time, ':') == 0) {
      $the_time = (empty($new_time) || $new_time == 'now' || $new_time == 'current') ? gmdate("Y-m-d H:i:s") : gmdate("Y-m-d H:i:s", $new_time);
    }

    $userTime = new \DateTime($the_time, new \DateTimeZone('UTC'));

    // Set the users time_zone to their zone
    if ($tz !== 'UTC') {
      $userTime->setTimezone(new \DateTimeZone($tz));
    }
    
    $country = (isset($options['country'])) ? $options['country'] : 'usa';
    
    return self::dt_format($userTime, $format, $country);
  }

  public static function human_date($input_date) {
    if (empty($input_date)) {
      return '';
    }
    $today = self::convert_time_zone(array('format' => 'm/d/Y'));
    $date = strtotime($input_date);
    if (date('m/d/Y', $date) == $today) {
      return date('g:i', $date) . "<span style=\"font-size: 0.65em; vertical-align: text-top; margin-left: 1px; text-transform: lowercase;\">" . date('A', $date) . "</span>";
    } elseif (date('Y', $date) == date('Y')) {
      return "<span style=\"font-weight: 500;\">" . date('M', $date) . " " . date('j', $date) . "<span style=\"font-size: 0.65em; vertical-align: text-top; margin-left: 1px;\">" . date('S', $date) . "</span></span>";
    } else {
      return date('m/d/y', $date);
    }
  }

  private static function is_valid_offset($offset) {
    if (substr_count($offset, 'second') > 0) {
      return true;
    } elseif (substr_count($offset, 'minute') > 0) {
      return true;
    } elseif (substr_count($offset, 'hour') > 0) {
      return true;
    } elseif (substr_count($offset, 'day') > 0) {
      return true;
    } elseif (substr_count($offset, 'week') > 0) {
      return true;
    } elseif (substr_count($offset, 'month') > 0) {
      return true;
    } elseif (substr_count($offset, 'year') > 0) {
      return true;
    } elseif (substr_count($offset, 'next') > 0) {
      return true;
    } elseif (substr_count($offset, 'last') > 0) {
      return true;
    } else {
      return false;
    }
  }

  private static function get_offset($offset) {
    return (self::is_valid_offset($offset)) ? strtotime($offset) : $offset;
  }

  private static function get_offset_by($offset, $db_time) {
    // strtotime requires a int timestamp
    if (substr_count($db_time, ':') > 0) {
      $UTC = new \DateTime($db_time, new \DateTimeZone('UTC'));
      $db_time = $UTC->format('U');
    }

    return (self::is_valid_offset($offset)) ? strtotime($offset, $db_time) : $db_time;
  }

}