<?php
namespace JVBase\rest\routes;

use JVBase\base\Site;
use JVBase\importers\JaneAppClientImporter;
use JVBase\importers\JaneAppSalesImporter;
use JVBase\managers\CustomTable;
use JVBase\rest\Rest;
use JVBase\rest\Route;
use WP_REST_Request;
use WP_REST_Response;
use WP_Error;

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

/**
 * REST API routes for referral system
 */
class ReferralRoutes extends Rest
{
	protected CustomTable $referrals;
	protected CustomTable $rewards;
	protected CustomTable $treatments;

	public function __construct()
	{
		$this->cacheName = 'referrals';
		$this->cacheTtl = (int)HOUR_IN_SECONDS;
		parent::__construct();

		$this->referrals = CustomTable::for('referrals');
		$this->rewards = CustomTable::for('referral_rewards');
		$this->treatments = CustomTable::for('referral_treatments');

		add_filter(BASE.'handle_bulk_operation', [$this, 'processOperation'], 10, 3);
	}

	public function registerRoutes(): void
	{
		// Main referrals endpoint - list and manage referrals
		Route::for('referrals')
			->get([$this, 'getReferrals'])
			->args([
				'user' => 'integer',
				'status' => 'string|enum:all,pending,consulted,treated,unused,registered,completed|default:all',
				'date_start' => 'string',
				'date_end' => 'string',
				'limit' => 'integer|default:50',
				'offset' => 'integer|default:0',
				'search' => 'string'
			])
			->rateLimit()
			->post([$this, 'handleAction'])
			->args([
				'action' => 'string|required|enum:invite,consulted,treated,remove,resend'
			])
			->auth('user')
			->rateLimit(10)
			->register();

		// Referral code endpoint
		Route::for('referrals/code')
			->get([$this, 'getCode'])
			->args(['user' => 'integer'])
			->auth('user')
			->rateLimit(30)
			->post([$this, 'validateCode'])
			->args(['code' => 'string|required'])
			->auth('public')
			->rateLimit(10)
			->register();

		// Stats endpoint
		Route::for('referrals/stats')
			->get([$this, 'getStats'])
			->args(['user' => 'integer'])
			->auth('user')
			->rateLimit(30)
			->register();

		// Settings endpoint (admin only)
		Route::for('referrals/settings')
			->get([$this, 'getSettings'])
			->post([$this, 'updateSettings'])
			->auth('admin')
			->rateLimit(10)
			->register();

		// CSV Upload endpoints (admin only)
		Route::for('referrals/upload-clients')
			->post([$this, 'handleClientUpload'])
			->auth('admin')
			->rateLimit(3)
			->register();

		Route::for('referrals/upload-sales')
			->post([$this, 'handleSalesUpload'])
			->auth('admin')
			->rateLimit(3)
			->register();
	}

	/**
	 * GET /referrals
	 * Get referrals with optional filters
	 * - User gets their own referrals
	 * - Admin with no user param gets all referrals
	 */
	public function getReferrals(WP_REST_Request $request): WP_REST_Response
	{
		$user_id = $request->get_param('user');

		// Determine scope: admin without user param gets all referrals
		if (!$user_id) {
			$current_user_id = get_current_user_id();
			if (current_user_can('manage_options')) {
				return $this->getAllReferrals($request);
			}
			$user_id = $current_user_id;
		}

		// Build cache key
		$args = [
			'status' => $request->get_param('status') ?? 'all',
			'limit' => $request->get_param('limit') ?? 50,
			'offset' => $request->get_param('offset') ?? 0,
			'date_start' => $request->get_param('date_start'),
			'date_end' => $request->get_param('date_end'),
		];
		$cache_key = "user_{$user_id}_" . $this->cache->generateKey($args);

		// Check 304 Not Modified
		$cache_check = $this->checkHeaders($request, $cache_key);
		if ($cache_check instanceof WP_REST_Response) {
			return $cache_check;
		}

		// Get referrals from manager
		$referrals = JVB()->referrals()->getUserReferrals($user_id, $args);

		$data = [
			'items' => $referrals,
			'total' => count($referrals)
		];

		$response = $this->success($data);
		return $this->addCacheHeaders($response);
	}

	/**
	 * POST /referrals
	 * Handle various referral actions based on 'action' parameter
	 */
	public function handleAction(WP_REST_Request $request): WP_REST_Response
	{
		$action = $request->get_param('action');

		return match($action) {
			'invite' => $this->actionInvite($request),
			'consulted' => $this->actionUpdateStatus($request, 'consulted'),
			'treated' => $this->actionUpdateStatus($request, 'treated'),
			'remove' => $this->actionRemove($request),
			'resend' => $this->actionResend($request),
			default => $this->error('Invalid action', 'invalid_action', 400)
		};
	}

	/**
	 * Action: Send batch referral invitations
	 */
	protected function actionInvite(WP_REST_Request $request): WP_REST_Response
	{
		$user = absint($request->get_param('user'));
		if (!$user || !get_userdata($user)) {
			return $this->error('Invalid user', 'invalid_user', 400);
		}

		//Additional check to not send too many emails in an hour
		$user = absint($request->get_param('user'));
		$transient_key = "referral_invite_limit_{$user}";
		$recent_invites = get_transient($transient_key) ?: 0;

		if ($recent_invites >= 20) { // Max 5 batch invites per hour
			return $this->error('Too many invitations sent. Please try again later.', 'rate_limit', 429);
		}
		set_transient($transient_key, $recent_invites + 1, HOUR_IN_SECONDS);

		$subject = sanitize_text_field($request->get_param('subject'));
		$message = sanitize_textarea_field($request->get_param('message'));
		$invitations = $request->get_param('invite');

		// Validate and sanitize invitations
		$sanitized_invitations = [];
		foreach ($invitations as $invite) {
			if (isset($invite['name'], $invite['email'])) {
				$sanitized_invitations[] = [
					'name' => sanitize_text_field($invite['name']),
					'email' => sanitize_email($invite['email'])
				];
			}
		}

		if (empty($sanitized_invitations)) {
			return $this->error('No valid invitations provided', 'no_invitations', 400);
		}

		$operationID = sanitize_text_field($request->get_param('id'));
		JVB()->queue()->queueOperation(
			'referral_invite',
			$user,
			[
				'subject' => $subject,
				'message' => $message,
				'invitations' => $sanitized_invitations
			],
			['operation_id' => $operationID]
		);

		return $this->queued($operationID, 'Referral invitations queued');
	}

	/**
	 * Action: Update referral status (admin only)
	 */
	protected function actionUpdateStatus(WP_REST_Request $request, string $status): WP_REST_Response
	{
		if (!current_user_can('manage_options')) {
			return $this->forbidden('Admin permission required');
		}

		$referral_id = $request->get_param('referral_id');
		if (!$referral_id) {
			return $this->error('referral_id required', 'missing_id', 400);
		}

		// Get referral using CustomTable
		$referral = $this->referrals->get(['id' => $referral_id]);
		if (!$referral) {
			return $this->notFound('Referral not found');
		}

		// Update status
		$update_data = ['status' => $status];
		$update_data["{$status}_at"] = current_time('mysql');

		if ($status === 'treated') {
			$update_data['treatment_count'] = ($referral->treatment_count ?? 0) + 1;
		}

		$updated = $this->referrals->update($update_data, ['id' => $referral_id]);

		if ($updated !== false) {
			// Create rewards if treated
			if ($status === 'treated') {
				$this->createRewards($referral);
			}

			$this->cache->flush();
			return $this->success(['message' => "Referral marked as {$status}"]);
		}

		return $this->error('Failed to update referral', 'update_failed', 500);
	}

	/**
	 * Action: Remove referral
	 */
	protected function actionRemove(WP_REST_Request $request): WP_REST_Response
	{
		$referral_id = $request->get_param('referral_id');
		if (!$referral_id) {
			return $this->error('referral_id required', 'missing_id', 400);
		}

		// Get referral
		$referral = $this->referrals->get(['id' => $referral_id]);
		if (!$referral) {
			return $this->notFound('Referral not found');
		}

		// Check ownership
		$current_user_id = get_current_user_id();
		if ($referral->referrer_id != $current_user_id && !current_user_can('manage_options')) {
			return $this->forbidden('Unauthorized');
		}

		// Can only remove pending referrals
		if ($referral->status !== 'pending') {
			return $this->error('Can only remove pending referrals', 'invalid_status', 400);
		}

		$this->referrals->delete(['id' => $referral_id]);
		$this->cache->flush();

		return $this->success(['message' => 'Referral removed']);
	}

	/**
	 * Action: Resend invitation
	 */
	protected function actionResend(WP_REST_Request $request): WP_REST_Response
	{
		$referral_id = $request->get_param('referral_id');
		if (!$referral_id) {
			return $this->error('referral_id required', 'missing_id', 400);
		}

		$current_user_id = get_current_user_id();

		// Get referral with ownership check
		$referral = $this->referrals->where([
			'id' => $referral_id,
			'referrer_id' => $current_user_id
		])->first();

		if (!$referral) {
			return $this->notFound('Referral not found');
		}

		// Check rate limit (once per week)
		$transient_key = 'referral_last_invite_' . md5($referral->referee_email);
		$last_invite = get_transient($transient_key);

		if ($last_invite && (time() - $last_invite) < WEEK_IN_SECONDS) {
			return $this->error(
				'Can only resend once per week',
				'rate_limit',
				429
			);
		}

		// Resend via referral manager
		$result = JVB()->referrals()->sendReferralInvitation(
			$current_user_id,
			$referral->referee_email,
			$referral->referee_name,
			sprintf('Reminder: Join %s', get_bloginfo('name')),
			'Just a friendly reminder about my invitation!'
		);

		if (is_wp_error($result)) {
			return $this->error($result->get_error_message(), 'send_failed', 500);
		}

		set_transient($transient_key, time(), WEEK_IN_SECONDS);
		return $this->success(['message' => 'Invitation resent']);
	}

	/**
	 * GET /referrals/code
	 * Get user's referral code
	 */
	public function getCode(WP_REST_Request $request): WP_REST_Response
	{
		$user_id = $request->get_param('user') ?? get_current_user_id();

		// Check permission
		if ($user_id != get_current_user_id() && !current_user_can('manage_options')) {
			return $this->forbidden('Unauthorized');
		}

		$code = JVB()->referrals()->getUserReferralCode($user_id);

		if (is_wp_error($code)) {
			return $this->error($code->get_error_message(), 'code_error', 400);
		}

		return $this->success([
			'code' => $code,
			'share_url' => home_url('/?ref=' . $code)
		]);
	}

	/**
	 * POST /referrals/code
	 * Validate a referral code
	 */
	public function validateCode(WP_REST_Request $request): WP_REST_Response
	{
		$code = strtoupper(sanitize_text_field($request->get_param('code')));

		if (empty($code)) {
			return $this->error('Code required', 'missing_code', 400);
		}

		$referrer = JVB()->referrals()->getUserByReferralCode($code);

		if (!$referrer) {
			return $this->error('Invalid referral code', 'invalid_code', 404);
		}

		// Check self-referral
		if (is_user_logged_in() && get_current_user_id() === $referrer->ID) {
			return $this->error('Cannot use your own referral code', 'self_referral', 400);
		}

		return $this->success([
			'valid' => true,
			'code' => $code,
			'referrer_name' => $referrer->display_name
		]);
	}

	/**
	 * GET /referrals/stats
	 * Get user's referral statistics
	 */
	public function getStats(WP_REST_Request $request): WP_REST_Response
	{
		$user_id = $request->get_param('user') ?? get_current_user_id();
		$cache_key = "stats_{$user_id}";

		// Check 304 Not Modified
		$cache_check = $this->checkHeaders($request, $cache_key);
		if ($cache_check instanceof WP_REST_Response) {
			return $cache_check;
		}

		$stats = JVB()->referrals()->getUserStats($user_id);

		$response = $this->success(['items' => [$stats]]);
		return $this->addCacheHeaders($response);
	}

	/**
	 * GET /referrals/settings
	 */
	public function getSettings(WP_REST_Request $request): WP_REST_Response
	{
		$settings = JVB()->referrals()->getRewardSettings();
		return $this->success(['settings' => $settings]);
	}

	/**
	 * POST /referrals/settings
	 */
	public function updateSettings(WP_REST_Request $request): WP_REST_Response
	{
		$settings = [
			'referrer_reward_type' => $request->get_param('referrer_reward_type') ?? 'fixed',
			'referrer_reward_amount' => floatval($request->get_param('referrer_reward_amount') ?? 25),
			'referrer_reward_applies_to' => $request->get_param('referrer_reward_applies_to') ?? 'per_user',
			'referee_reward_type' => $request->get_param('referee_reward_type') ?? 'percentage',
			'referee_reward_amount' => floatval($request->get_param('referee_reward_amount') ?? 20),
			'referee_reward_applies_to' => $request->get_param('referee_reward_applies_to') ?? 'first_order'
		];

		update_option(BASE . 'referral_settings', $settings);
		$this->cache->flush();

		return $this->success([
			'message' => 'Settings updated',
			'settings' => $settings
		]);
	}

	/**
	 * Helper: Get all referrals (admin only)
	 */
	protected function getAllReferrals(WP_REST_Request $request): WP_REST_Response
	{
		global $wpdb;

		$where = ['1=1'];
		$where_params = [];

		// Build WHERE conditions
		$status = $request->get_param('status');
		if ($status && $status !== 'all') {
			$where[] = 'status = %s';
			$where_params[] = $status;
		}

		if ($date_start = $request->get_param('date_start')) {
			$where[] = 'referred_at >= %s';
			$where_params[] = $date_start;
		}

		if ($date_end = $request->get_param('date_end')) {
			$where[] = 'referred_at <= %s';
			$where_params[] = $date_end;
		}

		$search = $request->get_param('search');
		if (!empty($search)) {
			$search_term = '%' . $wpdb->esc_like($search) . '%';
			$where[] = '(r.referee_name LIKE %s OR r.referee_email LIKE %s OR r.referral_code LIKE %s OR u.display_name LIKE %s)';
			$where_params[] = $search_term;
			$where_params[] = $search_term;
			$where_params[] = $search_term;
			$where_params[] = $search_term;
		}

		$limit = $request->get_param('limit') ?? 50;
		$offset = $request->get_param('offset') ?? 0;

		$where_params[] = $limit;
		$where_params[] = $offset;

		// Use CustomTable's query method
		$query = "SELECT r.*, u.display_name as referrer_name
			FROM {table} r
			LEFT JOIN {$wpdb->users} u ON r.referrer_id = u.ID
			WHERE " . implode(' AND ', $where) . "
			ORDER BY referred_at DESC
			LIMIT %d OFFSET %d";

		$items = $this->referrals->queryResults($query, $where_params);

		return $this->success([
			'items' => $items,
			'total' => count($items)
		]);
	}

	/**
	 * Helper: Create rewards for completed referral
	 */
	protected function createRewards(object $referral): void
	{
		$settings = JVB()->referrals()->getRewardSettings();

		// Referrer reward
		$this->rewards->insert([
			'referral_id' => $referral->id,
			'user_id' => $referral->referrer_id,
			'reward_type' => 'referrer',
			'amount' => $settings['referrer_reward_amount'],
			'reward_calculation' => $settings['referrer_reward_type'],
			'status' => 'available'
		]);

		// Referee reward
		if ($referral->referee_id) {
			$this->rewards->insert([
				'referral_id' => $referral->id,
				'user_id' => $referral->referee_id,
				'reward_type' => 'referee',
				'amount' => $settings['referee_reward_amount'],
				'reward_calculation' => $settings['referee_reward_type'],
				'status' => 'available'
			]);
		}
	}

	/**
	 * Process queued referral operations
	 */
	public function processOperation(WP_Error|array $result, object $operation, array $data): array|WP_Error
	{
		if ($operation->type !== 'referral_invite') {
			return $result;
		}

		$result = JVB()->referrals()->sendBatchReferralInvitations(
			$operation->user_id,
			$data['invitations'],
			$data['subject'],
			$data['message']
		);

		if ($result['success']) {
			$this->cache->flush();
		}

		return [
			'success' => true,
			'message' => sprintf(
				'Sent invitations. Success: %d. Failed: %d.',
				count($result['result']['success']),
				count($result['result']['failed'])
			),
			'details' => [
				'successful' => $result['result']['success'],
				'failed' => $result['result']['failed'],
				'total' => count($data['invitations'])
			]
		];
	}

	/**
	 * Handle client CSV upload
	 */
	public function handleClientUpload(WP_REST_Request $request): WP_REST_Response
	{
		if (empty($_FILES['file'])) {
			return $this->error('No file uploaded', 'no_file', 400);
		}

		$file = $_FILES['file'];

		if ($file['error'] !== UPLOAD_ERR_OK) {
			return $this->error('File upload error: ' . $file['error'], 'upload_error', 400);
		}

		// Validate file type
		$allowed_types = ['text/csv', 'application/vnd.ms-excel', 'text/plain'];
		$finfo = finfo_open(FILEINFO_MIME_TYPE);
		$mime_type = finfo_file($finfo, $file['tmp_name']);
		finfo_close($finfo);

		if (!in_array($mime_type, $allowed_types) && !in_array($file['type'], $allowed_types)) {
			return $this->error('File must be a CSV', 'invalid_file_type', 400);
		}

		// Validate file size (10MB max)
		if ($file['size'] > 10 * 1024 * 1024) {
			return $this->error('File size exceeds 10MB limit', 'file_too_large', 400);
		}

		// Import using JaneAppClientImporter
		$importer = new JaneAppClientImporter();
		$default_role = get_option(BASE . 'referral_role', Site::getDefaultReferralRole());

		$options = [
			'update_existing' => true,
			'send_welcome_email' => false,
			'create_users' => true,
			'default_role' => $default_role
		];

		$result = $importer->importFromCSV($file['tmp_name'], $options);

		if (is_wp_error($result)) {
			return $this->error($result->get_error_message(), 'import_failed', 500);
		}

		$this->cache->flush();

		return $this->success([
			'message' => sprintf(
				'Import complete: %d created, %d updated, %d skipped',
				$result['created'],
				$result['updated'],
				$result['skipped']
			),
			'stats' => $result,
			'skipped_details' => $result['skipped_details'] ?? []
		]);
	}

	/**
	 * Handle sales CSV upload
	 */
	public function handleSalesUpload(WP_REST_Request $request): WP_REST_Response
	{
		if (empty($_FILES['file'])) {
			return $this->error('No file uploaded', 'no_file', 400);
		}

		$file = $_FILES['file'];

		if ($file['error'] !== UPLOAD_ERR_OK) {
			return $this->error('File upload error: ' . $file['error'], 'upload_error', 400);
		}

		// Validate file type
		$allowed_types = ['text/csv', 'application/vnd.ms-excel', 'text/plain'];
		$finfo = finfo_open(FILEINFO_MIME_TYPE);
		$mime_type = finfo_file($finfo, $file['tmp_name']);
		finfo_close($finfo);

		if (!in_array($mime_type, $allowed_types) && !in_array($file['type'], $allowed_types)) {
			return $this->error('File must be a CSV', 'invalid_file_type', 400);
		}

		// Validate file size (10MB max)
		if ($file['size'] > 10 * 1024 * 1024) {
			return $this->error('File size exceeds 10MB limit', 'file_too_large', 400);
		}

		// Import using JaneAppSalesImporter
		$importer = new JaneAppSalesImporter();
		$result = $importer->importFromCSV($file['tmp_name'], ['skip_existing' => true]);

		if (is_wp_error($result)) {
			return $this->error($result->get_error_message(), 'import_failed', 500);
		}

		$this->cache->flush();

		return $this->success([
			'message' => 'Sales imported successfully',
			'stats' => $result
		]);
	}
}