<?php

namespace Yuvayana\Acadlix\Common\Helper;

use Yuvayana\Acadlix\Common\Models\Course;
use WP_Error;

defined('ABSPATH') || exit();

if (!class_exists('CourseHelper')) {
  class CourseHelper
  {
    protected static $instance = null;

    public static function instance()
    {
      if (!self::$instance) {
        self::$instance = new self();
      }
      return self::$instance;
    }

    /**
     * Return the course level name based on the given level string.
     *
     * @param string|null $level The course level, one of "all_level", "beginner", "intermediate", "advance"
     * @return string The course level name
     */
    public function getCourseLevelName(?string $level = null): string
    {
      $courseLevels = [
        "all_level" => __("All Level", "acadlix"),
        "beginner" => __("Beginner", "acadlix"),
        "intermediate" => __("Intermediate", "acadlix"),
        "advance" => __("Advance", "acadlix"),
      ];

      return $courseLevels[$level] ?? __("All Level", "acadlix");
    }

    public function formatPrice($price = 0, $asString = false)
    {
      // Fallback settings if not provided
      $decimals = acadlix()->helper()->acadlix_get_option('acadlix_number_of_decimals') ?? 2;
      $thousandSep = acadlix()->helper()->acadlix_get_option('acadlix_thousand_separator') ?? ',';
      $decimalSep = acadlix()->helper()->acadlix_get_option('acadlix_decimal_separator') ?? '.';

      if (!is_numeric($price)) {
        return $asString ? number_format(0, $decimals, $decimalSep, $thousandSep) : 0;
      }

      if ($asString) {
        // Return formatted string with thousand & decimal separator
        return number_format((float) $price, $decimals, $decimalSep, $thousandSep);
      }

      // Return numeric (no formatting)
      return round((float) $price, $decimals);
    }


    /**
     * Format the price according to the currency settings and return it as a string.
     *
     * @param float $price The price to be formatted.
     *
     * @return string|Wp_Error The formatted price or a Wp_Error object if an error occurs.
     */
    public function getCoursePrice(float $price): string|Wp_Error
    {
      $helper = acadlix()->helper();
      $currency_option = $helper->acadlix_get_option("acadlix_currency");
      $currency_position_option = $helper->acadlix_get_option("acadlix_currency_position");

      if (is_null($currency_option) || is_null($currency_position_option)) {
        return new WP_Error("currency_not_configured", __("Currency settings are not configured properly.", "acadlix"));
      }

      $currency_symbols = $helper->acadlix_currency_symbols();

      if (!array_key_exists($currency_option, $currency_symbols)) {
        return new Wp_Error("currency_symbol_not_found", __("Currency symbol not found for the selected currency.", "acadlix"));
      }

      $currency_symbol = $currency_symbols[$currency_option];

      $price = $this->formatPrice($price, true);

      return match ($currency_position_option) {
        "Left ( $99.99 )" => "$currency_symbol$price",
        "Right ( 99.99$ )" => "$price$currency_symbol",
        "Left with space ( $ 99.99 )" => "$currency_symbol $price",
        "Right with space ( 99.99 $ )" => "$price $currency_symbol",
        default => "$currency_symbol$price",
      };
    }


    /**
     * Generates an HTML string containing links to the profile pages of users enrolled in a course.
     *
     * @return string An HTML string containing the links to the user profile pages.
     *
     * @throws WP_Error If the course object is invalid or if the user objects in the course object are invalid.
     */
    public function getCourseUserHtml($course): string|WP_Error
    {
      if (is_null($course)) {
        return new WP_Error("invalid_course", __("The course object is invalid.", "acadlix"));
      }

      if (count($course->users) === 0) {
        return $this->getUserLinkHtml($course->post_author);
      }

      $userLinks = [];
      foreach ($course->users as $user) {
        if (is_null($user)) {
          return new WP_Error("invalid_user", __("The user objects in the course object are invalid.", "acadlix"));
        }
        $userLinks[] = $this->getUserLinkHtml($user->ID);
      }

      return implode(', ', $userLinks);
    }

    /**
     * Generates an HTML link to a user's profile page.
     *
     * @param int $userId The ID of the user to generate a link for.
     *
     * @return string An HTML link to the user's profile page.
     */
    public function getUserLinkHtml(int $userId): string
    {
      $userInfo = get_userdata($userId);

      return sprintf(
        '<a href="%s">%s</a>',
        esc_url(get_author_posts_url($userId)),
        esc_html($userInfo->display_name)
      );
    }

    /**
     * Converts an integer representation of time (hours, minutes, seconds) into a standardized string format (HH:MM:SS).
     *
     * @param int $hours   The number of hours.
     * @param int $minutes The number of minutes.
     * @param int $seconds The number of seconds.
     *
     * @return string The time in the standardized string format.
     */
    public function intToTimeFormat(int $hours, int $minutes, int $seconds): string
    {
      return sprintf('%02d:%02d:%02d', $hours, $minutes, $seconds);
    }

    /**
     * Converts an integer representation of time (weeks, days, hours, minutes) into a readable string format.
     *
     * @param int $weeks   The number of weeks.
     * @param int $days    The number of days.
     * @param int $hours   The number of hours.
     * @param int $minutes The number of minutes.
     *
     * @return string The time in a readable string format.
     */
    public function getCourseDuration(int $weeks, int $days, int $hours, int $minutes): string
    {
      $parts = [];
      $timeUnits = [
        'week' => $weeks,
        'day' => $days,
        'hour' => $hours,
        'minute' => $minutes,
      ];

      foreach ($timeUnits as $unit => $value) {
        if ($value > 0) {
          $parts[] = $value . ' ' . $unit . ($value > 1 ? 's' : '');
        }
      }

      return implode(' ', $parts);
    }

    /**
     * Checks if a course registration is open based on the given start and end dates.
     * 
     * @param string $start_date The start date of the registration period.
     * @param string $end_date The end date of the registration period.
     * 
     * @return array An associative array containing the status of the registration (true or false) and a message.
     */
    public function checkRegistrationDate($start_date, $end_date)
    {
      // Initialize the response array
      $response = [
        'status' => true,
        'message' => __('Registration is open.', 'acadlix'),
      ];

      // Check for null or empty values
      if (empty($start_date) && empty($end_date)) {
        return $response;
      }
      $timezone_string = acadlix()->helper()->acadlix_get_time_zone_string();
      $dateTimeFormat = acadlix()->helper()->acadlix_get_date_time_format();
      // Get current date/time in WordPress timezone
      // $current_timestamp = current_time('timestamp');
      $current_timestamp = time();
      $wp_timezone = wp_timezone();
      // Check start_date
      if (!empty($start_date)) {
        $start_datetime = new \DateTime($start_date, $wp_timezone);
        $start_timestamp = $start_datetime->getTimestamp();
        // $start_timestamp = strtotime($start_date);
        if ($current_timestamp < $start_timestamp) {
          return [
            'status' => false,
            'message' => sprintf(
              /* translators: 1: Registration start date, 2: Timezone string */
              esc_html__('Registration opens after: %1$s %2$s', 'acadlix'),
              wp_date($dateTimeFormat, $start_timestamp),
              esc_html($timezone_string)
            ),
          ];
        }
      }

      // Check end_date
      if (!empty($end_date)) {
        $end_datetime = new \DateTime($end_date, $wp_timezone);
        $end_timestamp = $end_datetime->getTimestamp();
        // $end_timestamp = strtotime($end_date);

        if ($current_timestamp > $end_timestamp) {
          return [
            'status' => false,
            'message' => __('Registration is closed', 'acadlix'),
          ];
        }
      }

      return $response;
    }

    public function courseSingleReviewStar(
      $type = 'filled', // 'filled', 'half', 'unfilled',
      $fs = 6 // font size in rem 1-9
    ) {
      $class = '';
      match ($type) {
        'filled' => $class = 'fas fa-star',
        'half' => $class = 'fas fa-star-half-alt', // Placeholder for half star
        'unfilled' => $class = 'far fa-star',
        default => $class = 'far fa-star',
      };
      return [
        'component' => 'div',
        'props' => [
          'class' => 'acadlix-rating-star-icon acadlix-fs-' . esc_attr($fs),
          'style' => 'color: var(--acadlix-star-color);' // Gold color for stars
        ],
        'children' => [
          [
            'component' => 'i',
            'props' => [
              'class' => esc_attr($class)
            ]
          ],
        ]
      ];
    }

    public function courseReviewStar(
      $rating = 0,
      $fs = 6 // font size in rem 1-9 
    ) {
      $stars = [];
      $filled_stars = floor($rating); // Number of filled stars
      $has_half = ($rating - $filled_stars) > 0; // Check if there's a decimal part

      for ($i = 1; $i <= 5; $i++) {
        if ($i <= $filled_stars) {
          $stars[] = $this->courseSingleReviewStar("filled", $fs);
        } elseif ($has_half && $i == $filled_stars + 1) {
          $stars[] = $this->courseSingleReviewStar("half", $fs);
        } else {
          $stars[] = $this->courseSingleReviewStar("unfilled", $fs);
        }
      }
      return $stars;
    }

  }
}