<?php
/**
 * Canonical ref-code attribution, registration binding, and referral rewards.
 *
 * @package AKSRT
 */

namespace AKSRT\Payment;

defined('ABSPATH') || exit;

final class ReferralAttribution {

	private const COOKIE = 'aksrt_referral';
	private const META_CODE = 'aksrt_referral_code';
	private const META_STATUS = 'aksrt_referral_code_status';
	private const STATUS_ACTIVE = 'active';
	private const STATUS_DISABLED = 'disabled';

	private static ?self $instance = null;
	private static string $pending_registration_ref = '';
	private static string $registration_notice = '';

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

	private function __construct() {}

	public function init(): void {
		add_action('init', [$this, 'capture'], 1);
		add_action('user_register', [$this, 'bind_registered_user'], 20, 1);
		add_action('aksrt_email_verified', [$this, 'reward_registered_user'], 10, 1);
		add_action('rest_api_init', [$this, 'register_routes']);
	}

	public function capture(): void {
		if (is_admin() || !$this->feature_enabled()) {
			return;
		}

		$raw = isset($_GET['ref']) ? sanitize_key(wp_unslash((string) $_GET['ref'])) : '';
		if ($raw === '') {
			return;
		}

		$promoter_id = $this->resolve_promoter($raw);
		if ($promoter_id <= 0 || (is_user_logged_in() && $promoter_id === get_current_user_id())) {
			return;
		}

		if ($this->cookie_ref() !== '') {
			return;
		}

		if (!headers_sent()) {
			$ttl_days = (int) ($this->shared_settings()['window_days'] ?? 30);
			setcookie(self::COOKIE, $raw, [
				'expires'  => time() + DAY_IN_SECONDS * max(1, min(365, $ttl_days)),
				'path'     => COOKIEPATH ?: '/',
				'domain'   => COOKIE_DOMAIN,
				'secure'   => is_ssl(),
				'httponly' => true,
				'samesite' => 'Lax',
			]);
			$_COOKIE[self::COOKIE] = $raw;
		}
	}

	/** @return array{ref:string,valid:bool,submitted_valid:bool,conflict:bool,source:string} */
	public function prepare_registration(string $submitted_ref): array {
		self::$registration_notice = '';
		$submitted_ref = sanitize_key($submitted_ref);
		$cookie_ref = $this->cookie_ref();
		$submitted_valid = $submitted_ref !== '' && $this->resolve_promoter($submitted_ref) > 0;

		$conflict = $cookie_ref !== '' && $submitted_ref !== '' && $submitted_ref !== $cookie_ref;
		if ($conflict) {
			self::$registration_notice = __('检测到不同的推广码，已按首次访问的推广关系绑定。', 'aksrt');
		}

		$ref = $cookie_ref !== '' ? $cookie_ref : ($submitted_valid ? $submitted_ref : '');
		self::$pending_registration_ref = $ref;

		return [
			'ref'             => $ref,
			'valid'           => $ref !== '',
			'submitted_valid' => $submitted_valid,
			'conflict'        => $conflict,
			'source'          => $cookie_ref !== '' ? 'cookie' : ($submitted_valid ? 'submitted' : 'none'),
		];
	}

	public function clear_registration_context(): void {
		self::$pending_registration_ref = '';
	}

	public function take_registration_notice(): string {
		$notice = self::$registration_notice;
		self::$registration_notice = '';
		return $notice;
	}

	public function bind_registered_user(int $invitee_id): void {
		if ($invitee_id <= 0 || !$this->feature_enabled()) {
			self::$pending_registration_ref = '';
			return;
		}

		$ref = self::$pending_registration_ref !== ''
			? self::$pending_registration_ref
			: $this->cookie_ref();
		self::$pending_registration_ref = '';

		$promoter_id = $this->resolve_promoter($ref);
		if ($ref === '' || $promoter_id <= 0 || $promoter_id === $invitee_id) {
			return;
		}

		global $wpdb;
		$table = \AKSRT\Core\DBMigrator::table('affiliate_relation');
		if ($table === '') {
			return;
		}

		$existing = (int) $wpdb->get_var($wpdb->prepare(
			"SELECT id FROM {$table} WHERE invitee_id = %d LIMIT 1",
			$invitee_id
		));
		if ($existing > 0) {
			$this->clear_cookie();
			return;
		}

		$reward = $this->reward_settings();
		$now = current_time('mysql', true);
		$inserted = $wpdb->insert($table, [
			'referral_code'   => $ref,
			'promoter_id'     => $promoter_id,
			'invitee_id'      => $invitee_id,
			'first_touch_at'  => $now,
			'bound_at'        => $now,
			'status'          => 'bound',
			'reward_status'   => !empty($reward['enabled']) ? 'pending' : 'skipped',
			'registration_ip' => $this->client_ip(),
			'created_at'      => $now,
		], ['%s', '%d', '%d', '%s', '%s', '%s', '%s', '%s', '%s']);

		if ($inserted) {
			$this->clear_cookie();
			if (!empty($reward['enabled']) && (empty($reward['require_verify']) || $this->is_verified($invitee_id))) {
				$this->reward_registered_user($invitee_id);
			}
		}
	}

	public function reward_registered_user(int $invitee_id): void {
		$settings = $this->reward_settings();
		if ($invitee_id <= 0) {
			return;
		}

		global $wpdb;
		$table = \AKSRT\Core\DBMigrator::table('affiliate_relation');
		if ($table === '') {
			return;
		}
		if (empty($settings['enabled'])) {
			$wpdb->update(
				$table,
				['reward_status' => 'skipped'],
				['invitee_id' => $invitee_id, 'reward_status' => 'pending'],
				['%s'],
				['%d', '%s']
			);
			return;
		}
		if (!empty($settings['require_verify']) && !$this->is_verified($invitee_id)) {
			return;
		}

		$row = $wpdb->get_row($wpdb->prepare(
			"SELECT * FROM {$table} WHERE invitee_id = %d AND status = 'bound'",
			$invitee_id
		), ARRAY_A);
		if (!is_array($row) || (string) ($row['reward_status'] ?? 'pending') !== 'pending') {
			return;
		}
		$relation_id = (int) $row['id'];
		$promoter_id = (int) $row['promoter_id'];
		if ($promoter_id <= 0) {
			$wpdb->update($table, ['reward_status' => 'skipped'], ['id' => $relation_id, 'reward_status' => 'pending'], ['%s'], ['%d', '%s']);
			return;
		}
		$promoter_amount = max(0, (int) ($settings['promoter_amount'] ?? 0));
		$referred_amount = max(0, (int) ($settings['referred_amount'] ?? 0));
		$entries = [];
		if ($promoter_amount > 0) {
			$entries[] = ['user_id' => $promoter_id, 'asset' => \AKSRT\Ledger\AssetType::POINTS->value, 'delta_minor' => $promoter_amount, 'entry_type' => 'credit', 'counterparty_user_id' => $invitee_id, 'remark' => __('推广注册奖励', 'aksrt')];
		}
		if ($referred_amount > 0) {
			$entries[] = ['user_id' => $invitee_id, 'asset' => \AKSRT\Ledger\AssetType::POINTS->value, 'delta_minor' => $referred_amount, 'entry_type' => 'credit', 'counterparty_user_id' => $promoter_id, 'remark' => __('推广注册新用户奖励', 'aksrt')];
		}
		if ($entries === []) {
			$wpdb->update($table, ['reward_status' => 'rewarded', 'rewarded_at' => current_time('mysql', true)], ['id' => $relation_id, 'reward_status' => 'pending'], ['%s', '%s'], ['%d', '%s']);
			return;
		}
		$level_points = max(0, (int) ($settings['level_points'] ?? 0));
		$command = new \AKSRT\Ledger\LedgerCommand(
			\AKSRT\Ledger\OperationKey::deterministic('referral-reward', [$relation_id]),
			'referral',
			$entries,
			'referral',
			(string) $relation_id,
			0,
			['invitee_id' => $invitee_id, 'promoter_id' => $promoter_id]
		);
		$guard = function () use ($wpdb, $table, $relation_id, $settings, $row) {
			$locked = $wpdb->get_row($wpdb->prepare("SELECT reward_status FROM {$table} WHERE id = %d FOR UPDATE", $relation_id), ARRAY_A);
			if (!is_array($locked) || (string) $locked['reward_status'] !== 'pending') {
				return new \WP_Error('aksrt_referral_state', __('推广奖励状态已变化', 'aksrt'), ['status' => 409]);
			}
			return $this->ip_daily_check($row, $settings)
				? true
				: new \WP_Error('aksrt_referral_daily_limit', __('当前网络今日推广奖励次数已达上限', 'aksrt'), ['status' => 409]);
		};
		$mutation = function () use ($wpdb, $table, $relation_id, $level_points, $promoter_id) {
			if ($level_points > 0 && class_exists('\AKSRT\User\Level')) {
				\AKSRT\User\Level::add($promoter_id, 'referral', $level_points, true);
			}
			$updated = $wpdb->update(
				$table,
				['reward_status' => 'rewarded', 'rewarded_at' => current_time('mysql', true)],
				['id' => $relation_id, 'reward_status' => 'pending'],
				['%s', '%s'],
				['%d', '%s']
			);
			return $updated === 1 ? true : new \WP_Error('aksrt_referral_update', __('推广奖励状态更新失败', 'aksrt'), ['status' => 500]);
		};
		$result = \AKSRT\Ledger\LedgerService::get_instance()->post($command, $guard, $mutation);
		if (!is_wp_error($result) && !$result->replayed) {
			do_action('aksrt_referral_rewarded', $relation_id, $promoter_id, $invitee_id);
		}
	}

	public function create_link(int $user_id, string $url = ''): array {
		$record = $this->code_record($user_id);
		if ($record['status'] === 'missing' && $this->feature_enabled()) {
			$code = $this->generate_code($user_id, false);
			$record = ['code' => $code, 'status' => $code !== '' ? self::STATUS_ACTIVE : 'missing'];
		}
		$target = $url !== '' ? $url : home_url('/');
		$active_code = $record['status'] === self::STATUS_ACTIVE ? $record['code'] : '';
		return [
			'ref'    => $active_code,
			'url'    => $active_code !== '' ? add_query_arg('ref', $active_code, $target) : '',
			'status' => $record['status'],
		];
	}

	public function get_or_create_code(int $user_id): string {
		return (string) ($this->create_link($user_id)['ref'] ?? '');
	}

	public function validate_ref(string $ref): bool {
		return $this->resolve_promoter($ref) > 0;
	}

	public function resolve(int $user_id = 0): int {
		$user_id = $user_id > 0 ? $user_id : get_current_user_id();
		if ($user_id <= 0) {
			return 0;
		}
		global $wpdb;
		$table = \AKSRT\Core\DBMigrator::table('affiliate_relation');
		$bound = $table !== '' ? (int) $wpdb->get_var($wpdb->prepare(
			"SELECT promoter_id FROM {$table} WHERE invitee_id = %d AND status = 'bound' LIMIT 1",
			$user_id
		)) : 0;
		return $bound > 0 && $bound !== $user_id ? $bound : 0;
	}

	public function stats(int $promoter_id): array {
		global $wpdb;
		$table = \AKSRT\Core\DBMigrator::table('affiliate_relation');
		if ($promoter_id <= 0 || $table === '') {
			return ['promoters' => 0, 'effective_payers' => 0];
		}
		$promoters = (int) $wpdb->get_var($wpdb->prepare(
			"SELECT COUNT(*) FROM {$table} WHERE promoter_id = %d AND status = 'bound'",
			$promoter_id
		));
		$ledger = \AKSRT\Core\DBMigrator::table('commission_ledger');
		$payers = $ledger !== '' ? (int) $wpdb->get_var($wpdb->prepare(
			"SELECT COUNT(DISTINCT source_user_id) FROM {$ledger} WHERE promoter_id = %d AND original_amount > 0",
			$promoter_id
		)) : 0;
		return ['promoters' => $promoters, 'effective_payers' => $payers];
	}

	/** @return array{items:array<int,array<string,mixed>>,total:int,page:int,per_page:int,max_pages:int} */
	public function list_referred_users(int $promoter_id, int $page = 1, int $per_page = 10): array {
		global $wpdb;
		$table = \AKSRT\Core\DBMigrator::table('affiliate_relation');
		$page = max(1, $page);
		$per_page = max(1, min(50, $per_page));
		if ($promoter_id <= 0 || $table === '') {
			return ['items' => [], 'total' => 0, 'page' => $page, 'per_page' => $per_page, 'max_pages' => 1];
		}
		$total = (int) $wpdb->get_var($wpdb->prepare(
			"SELECT COUNT(*) FROM {$table} WHERE promoter_id=%d AND status='bound' AND invitee_id > 0",
			$promoter_id
		));
		$rows = $wpdb->get_results($wpdb->prepare(
			"SELECT invitee_id, bound_at, status FROM {$table} WHERE promoter_id=%d AND status='bound' AND invitee_id > 0 ORDER BY id DESC LIMIT %d OFFSET %d",
			$promoter_id,
			$per_page,
			($page - 1) * $per_page
		), ARRAY_A);
		$items = [];
		foreach ((array) $rows as $row) {
			$user_id = (int) ($row['invitee_id'] ?? 0);
			$user = $user_id > 0 ? get_userdata($user_id) : null;
			if (!$user instanceof \WP_User) {
				continue;
			}
			$items[] = [
				'user_id' => $user_id,
				'name' => $user->display_name,
				'avatar' => get_avatar_url($user_id, ['size' => 64]),
				'bound_at' => (string) ($row['bound_at'] ?? ''),
				'status' => (string) ($row['status'] ?? 'bound'),
			];
		}
		return [
			'items' => $items,
			'total' => $total,
			'page' => $page,
			'per_page' => $per_page,
			'max_pages' => max(1, (int) ceil($total / $per_page)),
		];
	}

	public function register_routes(): void {
		register_rest_route('aksrt/v1', '/revenue/me', [
			'methods' => \WP_REST_Server::READABLE,
			'callback' => [$this, 'rest_me'],
			'permission_callback' => static fn() => is_user_logged_in(),
		]);

		register_rest_route('aksrt/v1', '/revenue/codes', [
			'methods' => \WP_REST_Server::READABLE,
			'callback' => [$this, 'rest_codes'],
			'permission_callback' => [$this, 'can_manage_codes'],
			'args' => [
				'page' => ['type' => 'integer', 'default' => 1, 'minimum' => 1],
				'per_page' => ['type' => 'integer', 'default' => 20, 'minimum' => 1, 'maximum' => 100],
				'search' => ['type' => 'string', 'default' => '', 'sanitize_callback' => 'sanitize_text_field'],
				'status' => [
					'type' => 'string',
					'default' => 'all',
					'enum' => ['all', self::STATUS_ACTIVE, self::STATUS_DISABLED, 'missing'],
				],
			],
		]);

		foreach (['generate', 'disable', 'regenerate'] as $action) {
			register_rest_route('aksrt/v1', '/revenue/codes/(?P<user_id>\d+)/' . $action, [
				'methods' => \WP_REST_Server::CREATABLE,
				'callback' => function (\WP_REST_Request $request) use ($action) {
					return $this->rest_mutate_code($request, $action);
				},
				'permission_callback' => [$this, 'can_manage_codes'],
				'args' => [
					'user_id' => ['type' => 'integer', 'required' => true, 'minimum' => 1],
				],
			]);
		}
	}

	public function can_manage_codes(): bool {
		return current_user_can('edit_users');
	}

	public function rest_me(): \WP_REST_Response {
		$user_id = get_current_user_id();
		$link = $this->create_link($user_id);
		$stats = $this->stats($user_id);
		$affiliate = \AKSRT\Settings\Settings::get_affiliate_settings();
		$registration = $this->registration_settings();
		$reward = $this->reward_settings();
		return new \WP_REST_Response([
			'ref' => $link['ref'],
			'url' => $link['url'],
			'status' => $link['status'],
			'features' => [
				'registration' => !empty($registration['enabled']),
				'points_reward' => !empty($reward['enabled']),
				'affiliate' => !empty($affiliate['enabled']),
			],
			'current_ratio' => (int) \AKSRT\Settings\Settings::affiliate_ratio_for_user($user_id),
			'ratios' => (array) ($affiliate['ratios'] ?? []),
			'order_types' => (array) ($affiliate['order_types'] ?? ['membership', 'content']),
			'rules' => [
				'window_days' => (int) ($this->shared_settings()['window_days'] ?? 30),
				'settlement_days' => (int) ($affiliate['settlement_days'] ?? 7),
			],
			'stats' => $stats,
		], 200);
	}

	public function rest_codes(\WP_REST_Request $request): \WP_REST_Response {
		return new \WP_REST_Response($this->list_codes([
			'page' => (int) $request['page'],
			'per_page' => (int) $request['per_page'],
			'search' => (string) $request['search'],
			'status' => (string) $request['status'],
		]), 200);
	}

	public function rest_mutate_code(\WP_REST_Request $request, string $action) {
		$user_id = (int) $request['user_id'];
		if (!get_userdata($user_id)) {
			return new \WP_Error('aksrt_ref_user_missing', __('用户不存在', 'aksrt'), ['status' => 404]);
		}

		$record = $this->code_record($user_id);
		if ($action === 'generate') {
			if ($record['status'] !== 'missing') {
				return new \WP_Error('aksrt_ref_exists', __('该用户已有推广码', 'aksrt'), ['status' => 409]);
			}
			$code = $this->generate_code($user_id, false);
		} elseif ($action === 'disable') {
			if ($record['status'] !== self::STATUS_ACTIVE) {
				return new \WP_Error('aksrt_ref_not_active', __('推广码当前不可禁用', 'aksrt'), ['status' => 409]);
			}
			update_user_meta($user_id, self::META_STATUS, self::STATUS_DISABLED);
			if ($this->code_record($user_id)['status'] !== self::STATUS_DISABLED) {
				return new \WP_Error('aksrt_ref_disable_failed', __('推广码禁用失败', 'aksrt'), ['status' => 500]);
			}
			$code = $record['code'];
		} elseif ($action === 'regenerate') {
			if ($record['status'] === 'missing') {
				return new \WP_Error('aksrt_ref_missing', __('该用户尚未生成推广码', 'aksrt'), ['status' => 409]);
			}
			$code = $this->generate_code($user_id, true);
		} else {
			return new \WP_Error('aksrt_ref_action', __('不支持的推广码操作', 'aksrt'), ['status' => 400]);
		}

		if ($code === '') {
			return new \WP_Error('aksrt_ref_generate_failed', __('推广码生成失败', 'aksrt'), ['status' => 500]);
		}
		return rest_ensure_response([
			'user_id' => $user_id,
			'ref' => $code,
			'status' => $action === 'disable' ? self::STATUS_DISABLED : self::STATUS_ACTIVE,
		]);
	}

	private function list_codes(array $args): array {
		global $wpdb;
		$page = max(1, (int) ($args['page'] ?? 1));
		$per_page = max(1, min(100, (int) ($args['per_page'] ?? 20)));
		$status = (string) ($args['status'] ?? 'all');
		$search = trim((string) ($args['search'] ?? ''));
		$where = ['1=1'];
		$params = [];

		if ($search !== '') {
			$like = '%' . $wpdb->esc_like($search) . '%';
			$where[] = '(u.user_login LIKE %s OR u.display_name LIKE %s OR u.user_email LIKE %s OR code.meta_value LIKE %s)';
			array_push($params, $like, $like, $like, $like);
		}
		if ($status === 'missing') {
			$where[] = "(code.meta_value IS NULL OR code.meta_value = '')";
		} elseif ($status === self::STATUS_DISABLED) {
			$where[] = "code.meta_value <> '' AND state.meta_value = 'disabled'";
		} elseif ($status === self::STATUS_ACTIVE) {
			$where[] = "code.meta_value <> '' AND (state.meta_value IS NULL OR state.meta_value <> 'disabled')";
		}

		$where_sql = implode(' AND ', $where);
		$joins = $wpdb->prepare(
			"LEFT JOIN {$wpdb->usermeta} code ON code.user_id=u.ID AND code.meta_key=%s LEFT JOIN {$wpdb->usermeta} state ON state.user_id=u.ID AND state.meta_key=%s",
			self::META_CODE,
			self::META_STATUS
		);
		$count_sql = "SELECT COUNT(DISTINCT u.ID) FROM {$wpdb->users} u {$joins} WHERE {$where_sql}";
		$total = (int) ($params
			? $wpdb->get_var($wpdb->prepare($count_sql, $params))
			: $wpdb->get_var($count_sql));

		$relation_table = \AKSRT\Core\DBMigrator::table('affiliate_relation');
		$ledger_table = \AKSRT\Core\DBMigrator::table('commission_ledger');
		$stats_joins = "LEFT JOIN (SELECT promoter_id, COUNT(*) AS bound_count FROM {$relation_table} WHERE status='bound' GROUP BY promoter_id) relation_stats ON relation_stats.promoter_id=u.ID "
			. "LEFT JOIN (SELECT promoter_id, COUNT(DISTINCT source_user_id) AS effective_payers FROM {$ledger_table} WHERE original_amount > 0 GROUP BY promoter_id) payer_stats ON payer_stats.promoter_id=u.ID";
		$list_sql = "SELECT DISTINCT u.ID, u.user_login, u.display_name, u.user_email, code.meta_value AS ref, state.meta_value AS ref_status, "
			. "COALESCE(relation_stats.bound_count, 0) AS bound_count, COALESCE(payer_stats.effective_payers, 0) AS effective_payers "
			. "FROM {$wpdb->users} u {$joins} {$stats_joins} WHERE {$where_sql} ORDER BY u.ID DESC LIMIT %d OFFSET %d";
		$list_params = array_merge($params, [$per_page, ($page - 1) * $per_page]);
		$rows = $wpdb->get_results($wpdb->prepare($list_sql, $list_params), ARRAY_A);

		$items = [];
		foreach ((array) $rows as $row) {
			$user_id = (int) $row['ID'];
			$ref = sanitize_key((string) ($row['ref'] ?? ''));
			$items[] = [
				'user' => [
					'id' => $user_id,
					'login' => (string) $row['user_login'],
					'name' => (string) $row['display_name'],
					'email' => (string) $row['user_email'],
				],
				'ref' => $ref,
				'status' => $ref === '' ? 'missing' : ((string) ($row['ref_status'] ?? '') === self::STATUS_DISABLED ? self::STATUS_DISABLED : self::STATUS_ACTIVE),
				'bound_count' => (int) ($row['bound_count'] ?? 0),
				'effective_payers' => (int) ($row['effective_payers'] ?? 0),
			];
		}

		return [
			'items' => $items,
			'total' => $total,
			'page' => $page,
			'per_page' => $per_page,
			'max_pages' => max(1, (int) ceil($total / $per_page)),
		];
	}

	private function generate_code(int $user_id, bool $force): string {
		if ($user_id <= 0) {
			return '';
		}
		$record = $this->code_record($user_id);
		if (!$force && $record['status'] !== 'missing') {
			return $record['status'] === self::STATUS_ACTIVE ? $record['code'] : '';
		}

		$length = (int) ($this->shared_settings()['code_length'] ?? 12);
		$alphabet = 'abcdefghjkmnpqrstuvwxyz23456789';
		for ($attempt = 0; $attempt < 20; $attempt++) {
			$code = '';
			for ($i = 0; $i < $length; $i++) {
				$code .= $alphabet[random_int(0, strlen($alphabet) - 1)];
			}
			$owners = get_users([
				'meta_key' => self::META_CODE,
				'meta_value' => $code,
				'number' => 1,
				'fields' => 'ID',
			]);
			if (empty($owners)) {
				update_user_meta($user_id, self::META_CODE, $code);
				update_user_meta($user_id, self::META_STATUS, self::STATUS_ACTIVE);
				$updated = $this->code_record($user_id);
				if ($updated['code'] === $code && $updated['status'] === self::STATUS_ACTIVE) {
					return $code;
				}
			}
		}
		return '';
	}

	/** @return array{code:string,status:string} */
	private function code_record(int $user_id): array {
		$code = sanitize_key((string) get_user_meta($user_id, self::META_CODE, true));
		if ($code === '') {
			return ['code' => '', 'status' => 'missing'];
		}
		$status = (string) get_user_meta($user_id, self::META_STATUS, true);
		return [
			'code' => $code,
			'status' => $status === self::STATUS_DISABLED ? self::STATUS_DISABLED : self::STATUS_ACTIVE,
		];
	}

	private function resolve_promoter(string $code): int {
		$code = sanitize_key($code);
		if ($code === '') {
			return 0;
		}
		$users = get_users([
			'meta_key' => self::META_CODE,
			'meta_value' => $code,
			'number' => 1,
			'fields' => 'ID',
		]);
		if (empty($users)) {
			return 0;
		}
		$user_id = (int) $users[0];
		return $this->code_record($user_id)['status'] === self::STATUS_ACTIVE ? $user_id : 0;
	}

	private function cookie_ref(): string {
		$code = isset($_COOKIE[self::COOKIE]) ? sanitize_key((string) wp_unslash($_COOKIE[self::COOKIE])) : '';
		return $code !== '' && $this->resolve_promoter($code) > 0 ? $code : '';
	}

	private function clear_cookie(): void {
		if (!headers_sent()) {
			setcookie(self::COOKIE, '', time() - HOUR_IN_SECONDS, COOKIEPATH ?: '/', COOKIE_DOMAIN);
		}
		unset($_COOKIE[self::COOKIE]);
	}

	private function feature_enabled(): bool {
		$registration = $this->registration_settings();
		$reward = $this->reward_settings();
		$affiliate = class_exists('\AKSRT\Settings\Settings') && \AKSRT\Settings\Settings::affiliate_enabled();
		return !empty($registration['enabled']) || !empty($reward['enabled']) || $affiliate;
	}

	private function shared_settings(): array {
		return class_exists('\AKSRT\Settings\Settings')
			? \AKSRT\Settings\Settings::get_referral_settings()
			: ['code_length' => 12, 'window_days' => 30];
	}

	private function registration_settings(): array {
		return class_exists('\AKSRT\Settings\Settings')
			? \AKSRT\Settings\Settings::get_referral_registration_settings()
			: ['enabled' => false, 'register_field' => 'hidden', 'reject_invalid' => true];
	}

	private function reward_settings(): array {
		return class_exists('\AKSRT\Settings\Settings')
			? \AKSRT\Settings\Settings::get_referral_reward_settings()
			: ['enabled' => false];
	}

	private function is_verified(int $user_id): bool {
		return (int) get_user_meta($user_id, 'aksrt_email_verified', true) === 1;
	}

	private function ip_daily_check(array $relation, array $settings): bool {
		$cap = max(0, (int) ($settings['ip_daily_cap'] ?? 0));
		$ip = (string) ($relation['registration_ip'] ?? '');
		if ($cap <= 0 || $ip === '') {
			return true;
		}
		global $wpdb;
		$table = \AKSRT\Core\DBMigrator::table('affiliate_relation');
		$today_utc = (new \DateTimeImmutable('today', wp_timezone()))
			->setTimezone(new \DateTimeZone('UTC'))
			->format('Y-m-d H:i:s');
		$ids = $wpdb->get_col($wpdb->prepare(
			"SELECT id FROM {$table} WHERE registration_ip = %s AND reward_status = 'rewarded' AND rewarded_at >= %s ORDER BY id ASC FOR UPDATE",
			$ip,
			$today_utc
		));
		return count($ids) < $cap;
	}

	private function client_ip(): string {
		return function_exists('aksrt_get_client_ip')
			? substr((string) aksrt_get_client_ip(), 0, 64)
			: '';
	}
}