<?php
namespace JVBase\managers;

use WP_User;
use WP_Error;

if (!defined('ABSPATH')) {
	exit;
}

/**
 * Referral Tracking Manager
 *
 * Handles user referral codes, tracking, rewards, and reporting.
 * Keeps referrals separate from invitations system.
 */
class ReferralManager
{
	protected $wpdb;
	protected CacheManager $cache;
	protected string $referrals_table;
	protected string $rewards_table;

	// Default reward settings
	protected array $default_settings = [
		'referrer_reward_applies_to' => 'per_user',  // 'per_user' or 'flat_total'
		'referrer_reward_amount' => 25.00,
		'referrer_reward_type'	=> 'fixed',
		'referee_reward_type' => 'percentage',  // 'percentage' or 'fixed'
		'referee_reward_amount' => 20,  // 20% or $20
		'referee_reward_applies_to' => 'first_order'  // 'first_order' or 'all_orders'
	];

	public function __construct()
	{
		global $wpdb;
		$this->wpdb = $wpdb;
		$this->cache = new CacheManager('referrals');
		$this->referrals_table = BASE . 'referrals';
		$this->rewards_table = BASE . 'referral_rewards';

		// Hook into user registration to track referrals
		add_action('user_register', [$this, 'processReferral'], 10, 1);

		// Add meta boxes for admin to manage referrals
		add_action('show_user_profile', [$this, 'displayUserReferralInfo']);
		add_action('edit_user_profile', [$this, 'displayUserReferralInfo']);

		// Save referral code changes
		add_action('personal_options_update', [$this, 'saveUserReferralCode']);
		add_action('edit_user_profile_update', [$this, 'saveUserReferralCode']);

		add_filter(BASE.'new_user_email_content', [$this, 'addReferralToWelcomeEmail'], 99, 2);

		if (is_user_logged_in()) {
			add_action('wp_footer', [$this, 'outputShareWidget']);
		}

		add_action('template_redirect', [$this, 'trackReferralCode']);;
		// Schedule cron jobs for reports
		$this->registerCronJobs();
	}

	/**
	 * Register cron jobs for automated reporting
	 */
	protected function registerCronJobs(): void
	{
		add_action(BASE . 'referral_daily_report', [$this, 'sendDailyReport']);
		add_action(BASE . 'referral_weekly_report', [$this, 'sendWeeklyReport']);

		// Schedule if not already scheduled
		if (!wp_next_scheduled(BASE . 'referral_daily_report')) {
			wp_schedule_event(strtotime('tomorrow 9:00'), 'daily', BASE . 'referral_daily_report');
		}

		if (!wp_next_scheduled(BASE . 'referral_weekly_report')) {
			wp_schedule_event(strtotime('next Monday 9:00'), 'weekly', BASE . 'referral_weekly_report');
		}
	}

	/**
	 * Generate or get existing referral code for a user
	 *
	 * @param int $user_id
	 * @param string|null $custom_code Optional custom code
	 * @return string|WP_Error
	 */
	public function getUserReferralCode(int $user_id, ?string $custom_code = null)
	{
		$user = get_user_by('ID', $user_id);
		if (!$user) {
			return new WP_Error('invalid_user', 'User not found');
		}

		// Check if user already has a code
		$existing_code = get_user_meta($user_id, BASE . 'referral_code', true);

		if ($existing_code && !$custom_code) {
			return $existing_code;
		}

		// Generate new code if custom provided or none exists
		$code = $custom_code ?: $this->generateReferralCode($user);

		// Validate uniqueness
		if ($this->isCodeTaken($code, $user_id)) {
			return new WP_Error('code_taken', 'This referral code is already in use');
		}

		// Save the code
		update_user_meta($user_id, BASE . 'referral_code', $code);

		return $code;
	}

	/**
	 * Generate a referral code based on user info
	 *
	 * @param WP_User $user
	 * @return string
	 */
	protected function generateReferralCode(WP_User $user): string
	{
		// Create code from first and last name
		$first = sanitize_title($user->first_name ?: 'user');
		$last = sanitize_title($user->last_name ?: wp_generate_password(4, false));

		$base_code = strtoupper(substr($first, 0, 4) . substr($last, 0, 4));

		// Ensure uniqueness
		$code = $base_code;
		$suffix = 1;

		while ($this->isCodeTaken($code)) {
			$code = $base_code . $suffix;
			$suffix++;
		}

		return $code;
	}

	/**
	 * Check if a referral code is already taken
	 *
	 * @param string $code
	 * @param int|null $exclude_user_id
	 * @return bool
	 */
	protected function isCodeTaken(string $code, ?int $exclude_user_id = null): bool
	{
		$args = [
			'meta_key' => BASE . 'referral_code',
			'meta_value' => $code,
			'fields' => 'ID',
			'number' => 1
		];

		if ($exclude_user_id) {
			$args['exclude'] = [$exclude_user_id];
		}

		$users = get_users($args);
		return !empty($users);
	}

	/**
	 * Track a new referral when user registers
	 *
	 * @param int $user_id
	 */
	public function processReferral(int $user_id): void
	{
		// Check if there's a referral code in the session/cookie
		$referral_code = $this->getReferralCodeFromSession();

		if (!$referral_code) {
			return;
		}

		// Find the referrer
		$referrer = $this->getUserByReferralCode($referral_code);

		if (!$referrer) {
			return;
		}

		// Check if this user was already referred (prevent duplicates)
		$existing = $this->getReferralByReferee($user_id);
		if ($existing) {
			return;
		}

		// Create referral record
		$this->createReferral($referrer->ID, $user_id, $referral_code);

		// Clear the session
		$this->clearReferralSession();
	}

	/**
	 * Create a referral record in the database
	 *
	 * @param int $referrer_id
	 * @param int $referee_id
	 * @param string $code
	 * @return int|false
	 */
	protected function createReferral(int $referrer_id, int $referee_id, string $code)
	{
		$user = get_user_by('ID', $referee_id);

		return $this->wpdb->insert(
			$this->referrals_table,
			[
				'referrer_id' => $referrer_id,
				'referee_id' => $referee_id,
				'referee_name' => $user->display_name,
				'referee_email' => $user->user_email,
				'referee_phone' => get_user_meta($referee_id, BASE . 'phone', true) ?: '',
				'referral_code' => $code,
				'status' => 'pending',
				'referred_at' => current_time('mysql')
			],
			['%d', '%d', '%s', '%s', '%s', '%s', '%s', '%s']
		);
	}

	/**
	 * Get user by referral code
	 *
	 * @param string $code
	 * @return WP_User|null
	 */
	protected function getUserByReferralCode(string $code): ?WP_User
	{
		$users = get_users([
			'meta_key' => BASE . 'referral_code',
			'meta_value' => $code,
			'number' => 1
		]);

		return $users[0] ?? null;
	}

	/**
	 * Get referral record by referee ID
	 *
	 * @param int $referee_id
	 * @return object|null
	 */
	public function getReferralByReferee(int $referee_id): ?object
	{
		$result = $this->wpdb->get_row($this->wpdb->prepare(
			"SELECT * FROM {$this->referrals_table} WHERE referee_id = %d",
			$referee_id
		));

		return $result ?: null;
	}

	/**
	 * Mark a referral as treated/rewarded
	 *
	 * @param int $referral_id
	 * @param bool $treated
	 * @return bool
	 */
	public function markAsTreated(int $referral_id, bool $treated = true): bool
	{
		$status = $treated ? 'treated' : 'pending';

		$result = $this->wpdb->update(
			$this->referrals_table,
			[
				'status' => $status,
				'treated_at' => $treated ? current_time('mysql') : null
			],
			['id' => $referral_id],
			['%s', '%s'],
			['%d']
		);

		if ($result && $treated) {
			// Create reward records when marking as treated
			$this->createRewardRecords($referral_id);
		}

		return $result !== false;
	}

	/**
	 * Create reward records for both referrer and referee
	 *
	 * @param int $referral_id
	 */
	protected function createRewardRecords(int $referral_id): void
	{
		$referral = $this->wpdb->get_row($this->wpdb->prepare(
			"SELECT * FROM {$this->referrals_table} WHERE id = %d",
			$referral_id
		));

		if (!$referral) {
			return;
		}

		$settings = $this->getRewardSettings();

		// Create referrer reward
		$this->wpdb->insert(
			$this->rewards_table,
			[
				'referral_id' => $referral_id,
				'user_id' => $referral->referrer_id,
				'reward_type' => 'referrer',
				'amount' => $settings['referrer_reward_amount'],
				'status' => 'available',
				'created_at' => current_time('mysql')
			],
			['%d', '%d', '%s', '%f', '%s', '%s']
		);

		// Create referee reward
		$referee_amount = $settings['referee_reward_type'] === 'percentage'
			? $settings['referee_reward_amount']  // Store as percentage
			: $settings['referee_reward_amount'];  // Store as fixed amount

		$this->wpdb->insert(
			$this->rewards_table,
			[
				'referral_id' => $referral_id,
				'user_id' => $referral->referee_id,
				'reward_type' => 'referee',
				'amount' => $referee_amount,
				'reward_calculation' => $settings['referee_reward_type'],
				'status' => 'available',
				'created_at' => current_time('mysql')
			],
			['%d', '%d', '%s', '%f', '%s', '%s', '%s']
		);
	}

	/**
	 * Get referrals for a user
	 *
	 * @param int $user_id
	 * @param array $args
	 * @return array
	 */
	public function getUserReferrals(int $user_id, array $args = []): array
	{
		$defaults = [
			'status' => 'all',
			'limit' => 100,
			'offset' => 0,
			'orderby' => 'referred_at',
			'order' => 'DESC'
		];

		$args = wp_parse_args($args, $defaults);

		$where = $this->wpdb->prepare("WHERE referrer_id = %d", $user_id);

		if ($args['status'] !== 'all') {
			$where .= $this->wpdb->prepare(" AND status = %s", $args['status']);
		}

		$query = "SELECT * FROM {$this->referrals_table}
                  {$where}
                  ORDER BY {$args['orderby']} {$args['order']}
                  LIMIT {$args['limit']} OFFSET {$args['offset']}";

		return $this->wpdb->get_results($query);
	}

	/**
	 * Get referral statistics for a user
	 *
	 * @param int $user_id
	 * @return array
	 */
	public function getUserStats(int $user_id): array
	{
		$cache_key = 'stats_' . $user_id;
		$cached = $this->cache->get($cache_key);

		if ($cached !== false) {
			return $cached;
		}

		$stats = $this->wpdb->get_row($this->wpdb->prepare(
			"SELECT
                COUNT(*) as total_referrals,
                SUM(CASE WHEN status = 'treated' THEN 1 ELSE 0 END) as treated_count,
                SUM(CASE WHEN status = 'pending' THEN 1 ELSE 0 END) as pending_count
            FROM {$this->referrals_table}
            WHERE referrer_id = %d",
			$user_id
		), ARRAY_A);

		// Get total rewards
		$rewards = $this->wpdb->get_row($this->wpdb->prepare(
			"SELECT
                SUM(CASE WHEN status = 'available' THEN amount ELSE 0 END) as available_rewards,
                SUM(CASE WHEN status = 'redeemed' THEN amount ELSE 0 END) as redeemed_rewards
            FROM {$this->rewards_table}
            WHERE user_id = %d AND reward_type = 'referrer'",
			$user_id
		), ARRAY_A);

		$stats = array_merge($stats, $rewards);

		$this->cache->set($cache_key, $stats, HOUR_IN_SECONDS);

		return $stats;
	}

	/**
	 * Get top referrers for a time period
	 *
	 * @param int $limit
	 * @param string $period 'day'|'week'|'month'|'all'
	 * @return array
	 */
	public function getTopReferrers(int $limit = 10, string $period = 'all'): array
	{
		$where = '';

		if ($period !== 'all') {
			$date_where = match($period) {
				'day' => "referred_at >= DATE_SUB(NOW(), INTERVAL 1 DAY)",
				'week' => "referred_at >= DATE_SUB(NOW(), INTERVAL 1 WEEK)",
				'month' => "referred_at >= DATE_SUB(NOW(), INTERVAL 1 MONTH)",
				default => "1=1"
			};

			$where = "WHERE {$date_where}";
		}

		$query = "SELECT
                    referrer_id,
                    COUNT(*) as referral_count,
                    SUM(CASE WHEN status = 'treated' THEN 1 ELSE 0 END) as treated_count
                  FROM {$this->referrals_table}
                  {$where}
                  GROUP BY referrer_id
                  ORDER BY referral_count DESC
                  LIMIT {$limit}";

		$results = $this->wpdb->get_results($query);

		// Enrich with user data
		foreach ($results as &$result) {
			$user = get_user_by('ID', $result->referrer_id);
			$result->user_name = $user ? $user->display_name : 'Unknown';
			$result->user_email = $user ? $user->user_email : '';
		}

		return $results;
	}

	/**
	 * Send daily report if there are new referrals
	 */
	public function sendDailyReport(): void
	{
		// Get referrals from the last 24 hours
		$referrals = $this->wpdb->get_results(
			"SELECT r.*, u.display_name as referrer_name, u.user_email as referrer_email
             FROM {$this->referrals_table} r
             LEFT JOIN {$this->wpdb->users} u ON r.referrer_id = u.ID
             WHERE r.referred_at >= DATE_SUB(NOW(), INTERVAL 1 DAY)
             ORDER BY r.referred_at DESC"
		);

		if (empty($referrals)) {
			return;  // No referrals, no email
		}

		// Generate CSV
		$csv_content = $this->generateCSV($referrals);
		$csv_filename = 'referrals-' . date('Y-m-d') . '.csv';

		// Save CSV temporarily
		$upload_dir = wp_upload_dir();
		$csv_path = $upload_dir['basedir'] . '/' . $csv_filename;
		file_put_contents($csv_path, $csv_content);

		// Send email with attachment
		$to = get_option('admin_email');
		$subject = '[' . get_bloginfo('name') . '] Daily Referral Report - ' . date('F j, Y');

		$message = $this->generateReportEmail($referrals, 'daily');

		$attachments = [$csv_path];

		wp_mail($to, $subject, $message, ['Content-Type: text/html; charset=UTF-8'], $attachments);

		// Clean up temporary file
		unlink($csv_path);
	}

	/**
	 * Send weekly report with top referrers
	 */
	public function sendWeeklyReport(): void
	{
		$top_referrers = $this->getTopReferrers(10, 'week');
		$total_referrals = $this->wpdb->get_var(
			"SELECT COUNT(*) FROM {$this->referrals_table}
             WHERE referred_at >= DATE_SUB(NOW(), INTERVAL 1 WEEK)"
		);

		if ($total_referrals == 0) {
			return;
		}

		$to = get_option('admin_email');
		$subject = '[' . get_bloginfo('name') . '] Weekly Referral Summary - ' . date('F j, Y');

		$message = $this->generateWeeklyReportEmail($top_referrers, $total_referrals);

		wp_mail($to, $subject, $message, ['Content-Type: text/html; charset=UTF-8']);
	}

	/**
	 * Generate CSV content from referrals
	 *
	 * @param array $referrals
	 * @return string
	 */
	protected function generateCSV(array $referrals): string
	{
		$csv = "Referred By,Referee Name,Referee Email,Referee Phone,Referral Code,Status,Referred At,Treated At\n";

		foreach ($referrals as $referral) {
			$csv .= sprintf(
				'"%s","%s","%s","%s","%s","%s","%s","%s"' . "\n",
				$referral->referrer_name ?? 'Unknown',
				$referral->referee_name,
				$referral->referee_email,
				$referral->referee_phone,
				$referral->referral_code,
				$referral->status,
				$referral->referred_at,
				$referral->treated_at ?? 'Not yet'
			);
		}

		return $csv;
	}

	/**
	 * Generate HTML email for daily report
	 *
	 * @param array $referrals
	 * @param string $period
	 * @return string
	 */
	protected function generateReportEmail(array $referrals, string $period): string
	{
		$count = count($referrals);

		$content = sprintf('<p>You have <strong>%d new referral%s</strong> today.</p>',
			$count,
			$count !== 1 ? 's' : ''
		);

		$content .= '<table style="width:100%; border-collapse: collapse; margin: 20px 0;">';
		$content .= '<thead><tr style="background: #f5f5f5; text-align: left;">';
		$content .= '<th style="padding: 10px; border: 1px solid #ddd;">Referred By</th>';
		$content .= '<th style="padding: 10px; border: 1px solid #ddd;">New User</th>';
		$content .= '<th style="padding: 10px; border: 1px solid #ddd;">Email</th>';
		$content .= '<th style="padding: 10px; border: 1px solid #ddd;">Status</th>';
		$content .= '<th style="padding: 10px; border: 1px solid #ddd;">Time</th>';
		$content .= '</tr></thead><tbody>';

		foreach ($referrals as $referral) {
			$content .= '<tr>';
			$content .= sprintf('<td style="padding: 10px; border: 1px solid #ddd;">%s</td>',
				esc_html($referral->referrer_name ?? 'Unknown'));
			$content .= sprintf('<td style="padding: 10px; border: 1px solid #ddd;">%s</td>',
				esc_html($referral->referee_name));
			$content .= sprintf('<td style="padding: 10px; border: 1px solid #ddd;">%s</td>',
				esc_html($referral->referee_email));
			$content .= sprintf('<td style="padding: 10px; border: 1px solid #ddd;">%s</td>',
				esc_html(ucfirst($referral->status)));
			$content .= sprintf('<td style="padding: 10px; border: 1px solid #ddd;">%s</td>',
				esc_html(date('g:i A', strtotime($referral->referred_at))));
			$content .= '</tr>';
		}

		$content .= '</tbody></table>';
		$content .= '<p><small>See attached CSV for full details.</small></p>';

		return jvbGetEmailTemplate($content, 'Daily Referral Report');
	}

	/**
	 * Generate HTML email for weekly report
	 *
	 * @param array $top_referrers
	 * @param int $total_referrals
	 * @return string
	 */
	protected function generateWeeklyReportEmail(array $top_referrers, int $total_referrals): string
	{
		$content = sprintf(
			'<p>This week you had <strong>%d total referral%s</strong>.</p>',
			$total_referrals,
			$total_referrals !== 1 ? 's' : ''
		);

		$content .= '<h3>Top 10 Referrers This Week</h3>';
		$content .= '<table style="width:100%; border-collapse: collapse; margin: 20px 0;">';
		$content .= '<thead><tr style="background: #f5f5f5; text-align: left;">';
		$content .= '<th style="padding: 10px; border: 1px solid #ddd;">Rank</th>';
		$content .= '<th style="padding: 10px; border: 1px solid #ddd;">User</th>';
		$content .= '<th style="padding: 10px; border: 1px solid #ddd;">Total Referrals</th>';
		$content .= '<th style="padding: 10px; border: 1px solid #ddd;">Treated</th>';
		$content .= '</tr></thead><tbody>';

		$rank = 1;
		foreach ($top_referrers as $referrer) {
			$content .= '<tr>';
			$content .= sprintf('<td style="padding: 10px; border: 1px solid #ddd;">%d</td>', $rank++);
			$content .= sprintf('<td style="padding: 10px; border: 1px solid #ddd;">%s</td>',
				esc_html($referrer->user_name));
			$content .= sprintf('<td style="padding: 10px; border: 1px solid #ddd;">%d</td>',
				$referrer->referral_count);
			$content .= sprintf('<td style="padding: 10px; border: 1px solid #ddd;">%d</td>',
				$referrer->treated_count);
			$content .= '</tr>';
		}

		$content .= '</tbody></table>';

		return jvbGetEmailTemplate($content, 'Weekly Referral Summary');
	}

	/**
	 * Get reward settings
	 *
	 * @return array
	 */
	protected function getRewardSettings(): array
	{
		$saved = get_option(BASE . 'referral_settings', []);
		return wp_parse_args($saved, $this->default_settings);
	}

	/**
	 * Session/Cookie handling for referral codes
	 */
	protected function getReferralCodeFromSession(): ?string
	{
		if (session_status() === PHP_SESSION_NONE) {
			session_start();
		}

		return $_SESSION[BASE . 'referral_code'] ?? $_COOKIE[BASE . 'referral_code'] ?? null;
	}

	protected function clearReferralSession(): void
	{
		if (session_status() === PHP_SESSION_NONE) {
			session_start();
		}

		unset($_SESSION[BASE . 'referral_code']);
		setcookie(BASE . 'referral_code', '', time() - 3600, '/');
	}

	/**
	 * Display referral info in user profile
	 *
	 * @param WP_User $user
	 */
	public function displayUserReferralInfo(WP_User $user): void
	{
		if (!current_user_can('edit_user', $user->ID)) {
			return;
		}

		$referral_code = get_user_meta($user->ID, BASE . 'referral_code', true);
		$stats = $this->getUserStats($user->ID);
		$referrals = $this->getUserReferrals($user->ID, ['limit' => 10]);

		?>
		<h2>Referral Information</h2>
		<table class="form-table">
			<tr>
				<th><label for="referral_code">Referral Code</label></th>
				<td>
					<input type="text"
						   name="referral_code"
						   id="referral_code"
						   value="<?php echo esc_attr($referral_code); ?>"
						   class="regular-text" />
					<p class="description">
						Users can sign up with this code.
						<?php if ($referral_code): ?>
							Share link: <?php echo home_url('/?ref=' . $referral_code); ?>
						<?php endif; ?>
					</p>
				</td>
			</tr>
		</table>

		<h3>Referral Statistics</h3>
		<table class="form-table">
			<tr>
				<th>Total Referrals:</th>
				<td><?php echo $stats['total_referrals'] ?? 0; ?></td>
			</tr>
			<tr>
				<th>Treated:</th>
				<td><?php echo $stats['treated_count'] ?? 0; ?></td>
			</tr>
			<tr>
				<th>Pending:</th>
				<td><?php echo $stats['pending_count'] ?? 0; ?></td>
			</tr>
			<tr>
				<th>Available Rewards:</th>
				<td>$<?php echo number_format($stats['available_rewards'] ?? 0, 2); ?></td>
			</tr>
			<tr>
				<th>Redeemed Rewards:</th>
				<td>$<?php echo number_format($stats['redeemed_rewards'] ?? 0, 2); ?></td>
			</tr>
		</table>

		<?php if (!empty($referrals)): ?>
		<h3>Recent Referrals</h3>
		<table class="widefat">
			<thead>
			<tr>
				<th>Name</th>
				<th>Email</th>
				<th>Status</th>
				<th>Referred At</th>
				<th>Actions</th>
			</tr>
			</thead>
			<tbody>
			<?php foreach ($referrals as $referral): ?>
				<tr>
					<td><?php echo esc_html($referral->referee_name); ?></td>
					<td><?php echo esc_html($referral->referee_email); ?></td>
					<td><?php echo esc_html(ucfirst($referral->status)); ?></td>
					<td><?php echo esc_html($referral->referred_at); ?></td>
					<td>
						<?php if ($referral->status === 'pending'): ?>
							<button type="button"
									onclick="markReferralTreated(<?php echo $referral->id; ?>)">
								Mark as Treated
							</button>
						<?php endif; ?>
					</td>
				</tr>
			<?php endforeach; ?>
			</tbody>
		</table>
	<?php endif; ?>

		<script>
			function markReferralTreated(referralId) {
				if (!confirm('Mark this referral as treated? This will create reward records.')) {
					return;
				}

				fetch('<?php echo rest_url(BASE . '/v1/referrals/' ); ?>' + referralId + '/treat', {
					method: 'POST',
					headers: {
						'X-WP-Nonce': '<?php echo wp_create_nonce('wp_rest'); ?>'
					}
				})
					.then(response => response.json())
					.then(data => {
						if (data.success) {
							alert('Referral marked as treated!');
							location.reload();
						} else {
							alert('Error: ' + (data.message || 'Unknown error'));
						}
					});
			}
		</script>
		<?php
	}

	/**
	 * Save custom referral code
	 *
	 * @param int $user_id
	 */
	public function saveUserReferralCode(int $user_id): void
	{
		if (!current_user_can('edit_user', $user_id)) {
			return;
		}

		if (!isset($_POST['referral_code'])) {
			return;
		}

		$code = sanitize_text_field($_POST['referral_code']);

		if (empty($code)) {
			delete_user_meta($user_id, BASE . 'referral_code');
			return;
		}

		// Validate code format (alphanumeric only)
		if (!preg_match('/^[A-Z0-9]+$/i', $code)) {
			add_action('user_profile_update_errors', function($errors) {
				$errors->add('invalid_referral_code',
					'Referral code can only contain letters and numbers.');
			});
			return;
		}

		// Check if code is unique
		if ($this->isCodeTaken($code, $user_id)) {
			add_action('user_profile_update_errors', function($errors) {
				$errors->add('referral_code_taken',
					'This referral code is already in use.');
			});
			return;
		}

		update_user_meta($user_id, BASE . 'referral_code', strtoupper($code));
	}

	public function trackReferralCode(): void
	{
		if (!isset($_GET['ref'])) {
			return;
		}

		$referral_code = strtoupper(sanitize_text_field($_GET['ref']));

		// Start session if not already started
		if (session_status() === PHP_SESSION_NONE) {
			session_start();
		}

		// Store in both session and cookie (30 day expiry)
		$_SESSION[BASE . 'referral_code'] = $referral_code;
		setcookie(BASE . 'referral_code', $referral_code, time() + (30 * DAY_IN_SECONDS), '/');

		// Optional: Redirect to clean URL (removes ?ref= from address bar)
		$clean_url = remove_query_arg('ref');
		wp_safe_redirect($clean_url);
		exit;
	}

	/**
	 * Display user's referral code and share options
	 * Use in templates or dashboard with: echo jvbReferralShareWidget();
	 *
	 * @return string HTML output
	 */
	public function outputShareWidget(): string
	{
		$user_id = get_current_user_id();

		if (!$user_id) {
			return '';
		}

		$referral_code = get_user_meta($user_id, BASE . 'referral_code', true);

		// Generate code if user doesn't have one
		if (empty($referral_code)) {
			$manager = new \JVBase\managers\ReferralManager();
			$referral_code = $manager->getUserReferralCode($user_id);
		}

		$share_url = home_url('/?ref=' . $referral_code);
		$encoded_url = urlencode($share_url);
		$site_name = get_bloginfo('name');

		ob_start();
		?>
		<div class="jvb-referral-widget" style="background: #f9f9f9; padding: 20px; border-radius: 8px; margin: 20px 0;">
			<h3 style="margin-top: 0;">Share & Earn Rewards</h3>
			<p>Share your unique referral code with friends and earn rewards when they book!</p>

			<div class="referral-code-display" style="background: white; padding: 15px; border-radius: 4px; margin: 15px 0; text-align: center;">
				<label style="display: block; font-size: 12px; color: #666; margin-bottom: 5px;">Your Referral Code</label>
				<div style="font-size: 24px; font-weight: bold; letter-spacing: 2px; color: #2271b1;">
					<?php echo esc_html($referral_code); ?>
				</div>
			</div>

			<div class="referral-url" style="margin: 15px 0;">
				<label style="display: block; font-size: 12px; color: #666; margin-bottom: 5px;">Share Link</label>
				<div style="display: flex; gap: 10px;">
					<input type="text"
						   readonly
						   value="<?php echo esc_url($share_url); ?>"
						   id="referral-url-<?php echo $user_id; ?>"
						   style="flex: 1; padding: 8px; border: 1px solid #ddd; border-radius: 4px; font-family: monospace; font-size: 14px;">
					<button type="button"
							onclick="jvbCopyReferralUrl('referral-url-<?php echo $user_id; ?>')"
							style="padding: 8px 16px; background: #2271b1; color: white; border: none; border-radius: 4px; cursor: pointer;">
						Copy
					</button>
				</div>
			</div>

			<div class="referral-share-buttons" style="display: flex; gap: 10px; margin-top: 15px; flex-wrap: wrap;">
				<a href="mailto:?subject=Check out <?php echo esc_attr($site_name); ?>&body=I thought you might like <?php echo esc_url($share_url); ?>"
				   class="share-button"
				   style="padding: 10px 20px; background: #666; color: white; text-decoration: none; border-radius: 4px; display: inline-flex; align-items: center; gap: 8px;">
					📧 Email
				</a>
				<a href="sms:?&body=Check out <?php echo esc_attr($site_name); ?>: <?php echo esc_url($share_url); ?>"
				   class="share-button"
				   style="padding: 10px 20px; background: #25D366; color: white; text-decoration: none; border-radius: 4px; display: inline-flex; align-items: center; gap: 8px;">
					💬 Text
				</a>
				<a href="https://www.facebook.com/sharer/sharer.php?u=<?php echo $encoded_url; ?>"
				   target="_blank"
				   class="share-button"
				   style="padding: 10px 20px; background: #1877f2; color: white; text-decoration: none; border-radius: 4px; display: inline-flex; align-items: center; gap: 8px;">
					f Facebook
				</a>
				<a href="https://twitter.com/intent/tweet?url=<?php echo $encoded_url; ?>&text=Check out <?php echo esc_attr($site_name); ?>"
				   target="_blank"
				   class="share-button"
				   style="padding: 10px 20px; background: #1da1f2; color: white; text-decoration: none; border-radius: 4px; display: inline-flex; align-items: center; gap: 8px;">
					𝕏 Twitter
				</a>
			</div>

			<div id="referral-stats-<?php echo $user_id; ?>" class="referral-stats" style="margin-top: 20px; padding-top: 20px; border-top: 1px solid #ddd;">
				<div style="display: grid; grid-template-columns: repeat(auto-fit, minmax(120px, 1fr)); gap: 15px; text-align: center;">
					<div>
						<div style="font-size: 24px; font-weight: bold; color: #2271b1;" data-stat="total">-</div>
						<div style="font-size: 12px; color: #666;">Total Referrals</div>
					</div>
					<div>
						<div style="font-size: 24px; font-weight: bold; color: #00a32a;" data-stat="treated">-</div>
						<div style="font-size: 12px; color: #666;">Completed</div>
					</div>
					<div>
						<div style="font-size: 24px; font-weight: bold; color: #dba617;" data-stat="pending">-</div>
						<div style="font-size: 12px; color: #666;">Pending</div>
					</div>
					<div>
						<div style="font-size: 24px; font-weight: bold; color: #2271b1;" data-stat="rewards">$0</div>
						<div style="font-size: 12px; color: #666;">Earned</div>
					</div>
				</div>
			</div>
		</div>

		<script>
			function jvbCopyReferralUrl(elementId) {
				const input = document.getElementById(elementId);
				input.select();
				document.execCommand('copy');

				// Visual feedback
				const button = input.nextElementSibling;
				const originalText = button.textContent;
				button.textContent = 'Copied!';
				button.style.background = '#00a32a';

				setTimeout(() => {
					button.textContent = originalText;
					button.style.background = '#2271b1';
				}, 2000);
			}

			// Load stats via AJAX
			(function() {
				fetch('<?php echo rest_url(BASE . '/v1/referrals/stats'); ?>', {
					headers: {
						'X-WP-Nonce': '<?php echo wp_create_nonce('wp_rest'); ?>'
					}
				})
					.then(response => response.json())
					.then(data => {
						if (data.success && data.stats) {
							const container = document.getElementById('referral-stats-<?php echo $user_id; ?>');
							container.querySelector('[data-stat="total"]').textContent = data.stats.total_referrals || 0;
							container.querySelector('[data-stat="treated"]').textContent = data.stats.treated_count || 0;
							container.querySelector('[data-stat="pending"]').textContent = data.stats.pending_count || 0;
							container.querySelector('[data-stat="rewards"]').textContent =
								'$' + parseFloat(data.stats.available_rewards || 0).toFixed(2);
						}
					})
					.catch(error => console.error('Error loading referral stats:', error));
			})();
		</script>
		<?php
		return ob_get_clean();
	}

	function addReferralToWelcomeEmail(string $content, WP_User $user): string
	{
		$referral = $this->getReferralByReferee($user->ID);

		if (!$referral) {
			return $content;
		}

		$settings = get_option(BASE . 'referral_settings', []);
		$reward_amount = $settings['referee_reward_amount'] ?? 20;
		$reward_type = $settings['referee_reward_type'] ?? 'percentage';

		$reward_text = $reward_type === 'percentage'
			? $reward_amount . '% off'
			: '$' . number_format($reward_amount, 2) . ' off';

		$bonus_content = '<div style="background: #e7f5ff; padding: 20px; border-radius: 8px; margin: 20px 0;">';
		$bonus_content .= '<h3 style="margin-top: 0; color: #2271b1;">🎉 Welcome Bonus!</h3>';
		$bonus_content .= '<p>Since you were referred by a friend, you\'ve earned <strong>' . $reward_text . '</strong> your first booking!</p>';
		$bonus_content .= '<p>Your reward will be automatically applied when you book.</p>';
		$bonus_content .= '</div>';

		// Insert bonus content after the first paragraph
		$parts = explode('</p>', $content, 2);
		if (count($parts) === 2) {
			return $parts[0] . '</p>' . $bonus_content . $parts[1];
		}

		return $content . $bonus_content;
	}
}