<?php
/**
 * User level + integral XP — Zibll user_level / user_integral parity.
 *
 * Meta:
 *   aksrt_level_integral              int total XP
 *   aksrt_user_level                  int resolved level
 *   aksrt_level_integral_detail       array reason => [value, integral]
 *   aksrt_level_integral_date_detail  array Y-m-d => int
 *
 * @package AKSRT
 */

defined('ABSPATH') || exit;

class AKSRT_User_Level {

	public const META_INTEGRAL      = 'aksrt_level_integral';
	public const META_LEVEL         = 'aksrt_user_level';
	public const META_DETAIL        = 'aksrt_level_integral_detail';
	public const META_DATE_DETAIL   = 'aksrt_level_integral_date_detail';
	public const META_TODAY_FOLLOW  = 'aksrt_level_integral_followed';

	/** @var self|null */
	private static $instance = null;

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

	public function init(): void {
		add_action('user_register', [$this, 'on_register'], 20, 1);
		add_action('wp_login', [$this, 'on_login'], 20, 2);
		add_action('aksrt_user_signed_in', [$this, 'on_sign_in'], 20, 1);
		add_action('publish_post', [$this, 'on_publish_post'], 20, 2);
		add_action('comment_post', [$this, 'on_comment_post'], 20, 3);
		add_action('aksrt_user_followed', [$this, 'on_followed'], 20, 2);
		add_action('aksrt_post_liked', [$this, 'on_post_like'], 20, 2);
		add_action('aksrt_comment_liked', [$this, 'on_comment_like'], 20, 2);
		add_action('aksrt_post_favorited', [$this, 'on_post_favorite'], 20, 2);
	}

	/**
	 * @return array{enabled:bool,public_display:bool,prefix:string,max:int,source:string,level_opt:array<string,mixed>,integral_opt:array<string,mixed>,notify:bool}
	 */
	public static function settings(): array {
		$all = class_exists('AKSRT_Settings') ? AKSRT_Settings::get_all() : [];
		$enabled = !empty($all['user_level_s']) || !empty($all['user_level_enabled']);
		$max     = max(3, min(30, (int) ($all['user_level_max'] ?? 10)));
		$source  = (string) ($all['user_level_source'] ?? 'integral');
		if (!in_array($source, ['integral', 'manual_meta'], true)) {
			$source = 'integral';
		}
		$level_opt = $all['user_level_opt'] ?? [];
		if (is_string($level_opt)) {
			$decoded   = json_decode($level_opt, true);
			$level_opt = is_array($decoded) ? $decoded : [];
		}
		if (!is_array($level_opt)) {
			$level_opt = [];
		}
		$integral_opt = $all['user_integral_opt'] ?? [];
		if (is_string($integral_opt)) {
			$decoded      = json_decode($integral_opt, true);
			$integral_opt = is_array($decoded) ? $decoded : [];
		}
		if (!is_array($integral_opt)) {
			$integral_opt = [];
		}
		$prefix = trim((string) ($all['user_level_prefix'] ?? 'Lv.'));

		return [
			'enabled'        => $enabled,
			'public_display' => !isset($all['user_level_public_display']) || !empty($all['user_level_public_display']),
			'prefix'         => $prefix !== '' ? $prefix : 'Lv.',
			'max'            => $max,
			'source'         => $source,
			'level_opt'      => $level_opt,
			'integral_opt'   => $integral_opt,
			'notify'         => !isset($all['user_level_notify']) || !empty($all['user_level_notify']),
		];
	}

	/**
	 * Catalog of integral earn keys (defaults).
	 *
	 * @return array<string,int>
	 */
	public static function integral_defaults(): array {
		return [
			'day_max'         => 100,
			'sign_up'         => 20,
			'sign_in'         => 5,
			'followed'        => 5,
			'post_new'        => 5,
			'post_like'       => 1,
			'post_favorite'   => 2,
			'comment_new'     => 2,
			'comment_like'    => 1,
			'bbs_posts_new'   => 3,
			'bbs_score_extra' => 1,
			'bbs_essence'     => 2,
			'bbs_posts_hot'   => 2,
			'bbs_plate_new'   => 2,
			'bbs_plate_hot'   => 2,
			'bbs_adopt'       => 2,
			'bbs_comment_hot' => 2,
		];
	}

	public static function task_points(string $key): int {
		$cfg = self::settings();
		$opt = $cfg['integral_opt'];
		$def = self::integral_defaults();
		if (array_key_exists($key, $opt)) {
			return max(0, (int) $opt[$key]);
		}
		return max(0, (int) ($def[$key] ?? 0));
	}

	public static function day_max(): int {
		$cfg = self::settings();
		$opt = $cfg['integral_opt'];
		if (array_key_exists('day_max', $opt)) {
			return max(0, (int) $opt['day_max']);
		}
		return 100;
	}

	public static function get_integral(int $user_id): int {
		if ($user_id <= 0) {
			return 0;
		}
		return max(0, (int) get_user_meta($user_id, self::META_INTEGRAL, true));
	}

	public static function get_level(int $user_id): int {
		if ($user_id <= 0) {
			return 0;
		}
		$cfg = self::settings();
		if (!$cfg['enabled']) {
			return 0;
		}
		if ($cfg['source'] === 'manual_meta') {
			return max(0, (int) get_user_meta($user_id, self::META_LEVEL, true));
		}
		return self::resolve_level(self::get_integral($user_id), $cfg);
	}

	/**
	 * @param array{max:int,level_opt:array} $cfg
	 */
	public static function resolve_level(int $integral, ?array $cfg = null): int {
		$cfg = $cfg ?? self::settings();
		$max = (int) $cfg['max'];
		$opt = $cfg['level_opt'];
		$level = 1;
		for ($i = 1; $i <= $max; $i++) {
			$need = (int) ($opt['upgrade_integral_' . $i] ?? ($i === 1 ? 0 : PHP_INT_MAX));
			if ($integral >= $need) {
				$level = $i;
			} else {
				break;
			}
		}
		return max(0, min($max, $level));
	}

	/**
	 * Grant integral for a task key. Respects day_max.
	 *
	 * @return int|false points granted or false
	 */
	public static function add(int $user_id, string $key, int $points = 0) {
		if ($user_id <= 0) {
			return false;
		}
		$cfg = self::settings();
		if (!$cfg['enabled'] || $cfg['source'] !== 'integral') {
			return false;
		}
		$key = sanitize_key($key);
		if ($key === '' || $key === 'day_max') {
			return false;
		}
		if ($points <= 0) {
			$points = self::task_points($key);
		}
		if ($points <= 0) {
			return false;
		}

		$day_max = self::day_max();
		$today   = gmdate('Y-m-d', current_time('timestamp'));
		$date_detail = get_user_meta($user_id, self::META_DATE_DETAIL, true);
		$date_detail = is_array($date_detail) ? $date_detail : [];
		$today_sum = max(0, (int) ($date_detail[$today] ?? 0));
		if ($day_max > 0 && $today_sum >= $day_max) {
			return false;
		}
		if ($day_max > 0) {
			$points = min($points, $day_max - $today_sum);
		}
		if ($points <= 0) {
			return false;
		}

		$before = self::get_integral($user_id);
		$after  = $before + $points;
		update_user_meta($user_id, self::META_INTEGRAL, $after);

		$date_detail[$today] = $today_sum + $points;
		// Keep last 90 days.
		if (count($date_detail) > 90) {
			krsort($date_detail);
			$date_detail = array_slice($date_detail, 0, 90, true);
		}
		update_user_meta($user_id, self::META_DATE_DETAIL, $date_detail);

		$detail = get_user_meta($user_id, self::META_DETAIL, true);
		$detail = is_array($detail) ? $detail : [];
		$prev   = is_array($detail[$key] ?? null) ? $detail[$key] : ['value' => 0, 'integral' => 0];
		$detail[$key] = [
			'value'    => (int) ($prev['value'] ?? 0) + $points,
			'integral' => (int) ($prev['integral'] ?? 0) + $points,
		];
		update_user_meta($user_id, self::META_DETAIL, $detail);

		$old_level = (int) get_user_meta($user_id, self::META_LEVEL, true);
		$new_level = self::resolve_level($after, $cfg);
		if ($new_level !== $old_level) {
			update_user_meta($user_id, self::META_LEVEL, $new_level);
			/**
			 * @param int $user_id
			 * @param int $new_level
			 * @param int $old_level
			 */
			do_action('aksrt_user_level_changed', $user_id, $new_level, $old_level);
		} else {
			update_user_meta($user_id, self::META_LEVEL, $new_level);
		}

		return $points;
	}

	public function on_register(int $user_id): void {
		self::add($user_id, 'sign_up');
	}

	/**
	 * @param string  $user_login
	 * @param WP_User $user
	 */
	public function on_login($user_login, $user): void {
		$user_id = $user instanceof WP_User ? (int) $user->ID : 0;
		if ($user_id <= 0) {
			return;
		}
		// Once per calendar day for login XP.
		$today = gmdate('Y-m-d', current_time('timestamp'));
		$flag  = (string) get_user_meta($user_id, '_aksrt_integral_sign_in_day', true);
		if ($flag === $today) {
			return;
		}
		$granted = self::add($user_id, 'sign_in');
		if ($granted) {
			update_user_meta($user_id, '_aksrt_integral_sign_in_day', $today);
		}
	}

	public function on_sign_in(int $user_id): void {
		// Dedicated check-in hook can also grant if separate from login; reuse sign_in key once/day.
		$this->on_login('', get_userdata($user_id) ?: new WP_User($user_id));
	}

	/**
	 * @param int     $post_id
	 * @param WP_Post $post
	 */
	public function on_publish_post($post_id, $post): void {
		if (!$post instanceof WP_Post || $post->post_type !== 'post' || $post->post_status !== 'publish') {
			return;
		}
		// Only when transitioning to publish first time.
		if ((string) get_post_meta($post_id, '_aksrt_integral_post_new', true) === '1') {
			return;
		}
		$author = (int) $post->post_author;
		if ($author <= 0) {
			return;
		}
		if (self::add($author, 'post_new')) {
			update_post_meta($post_id, '_aksrt_integral_post_new', '1');
		}
	}

	/**
	 * @param int        $comment_id
	 * @param int|string $approved
	 * @param array      $commentdata
	 */
	public function on_comment_post($comment_id, $approved, $commentdata): void {
		if ((string) $approved !== '1' && $approved !== 1) {
			return;
		}
		$user_id = (int) ($commentdata['user_id'] ?? 0);
		if ($user_id <= 0) {
			$user_id = (int) get_comment($comment_id)->user_id;
		}
		if ($user_id <= 0) {
			return;
		}
		self::add($user_id, 'comment_new');
	}

	/**
	 * @param int $follower_id
	 * @param int $followed_id
	 */
	public function on_followed($follower_id, $followed_id): void {
		$followed_id = (int) $followed_id;
		if ($followed_id <= 0) {
			return;
		}
		self::add($followed_id, 'followed');
	}

	/**
	 * @param int $post_id
	 * @param int $user_id liker
	 */
	public function on_post_like($post_id, $user_id): void {
		$post = get_post((int) $post_id);
		if (!$post instanceof WP_Post) {
			return;
		}
		$author = (int) $post->post_author;
		if ($author <= 0 || $author === (int) $user_id) {
			return;
		}
		self::add($author, 'post_like');
	}

	/**
	 * @param int $comment_id
	 * @param int $user_id
	 */
	public function on_comment_like($comment_id, $user_id): void {
		$c = get_comment((int) $comment_id);
		if (!$c) {
			return;
		}
		$author = (int) $c->user_id;
		if ($author <= 0 || $author === (int) $user_id) {
			return;
		}
		self::add($author, 'comment_like');
	}

	/**
	 * @param int $post_id
	 * @param int $user_id
	 */
	public function on_post_favorite($post_id, $user_id): void {
		$post = get_post((int) $post_id);
		if (!$post instanceof WP_Post) {
			return;
		}
		$author = (int) $post->post_author;
		if ($author <= 0 || $author === (int) $user_id) {
			return;
		}
		self::add($author, 'post_favorite');
	}
}