<?php
/**
 * AKSRT Withdrawal — 提现台账 + 状态副作用（冻结退回）
 *
 * @package AKSRT
 */

defined('ABSPATH') || exit;

class AKSRT_Withdrawal {

	public const STATUS_PENDING    = 'pending';
	public const STATUS_APPROVED   = 'approved';
	public const STATUS_PROCESSING = 'processing';
	public const STATUS_COMPLETED  = 'completed';
	public const STATUS_REJECTED   = 'rejected';

	private static $instance = null;

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

	private function table(): string {
		return AKSRT_DB_Migrator::table('withdrawal');
	}

	/**
	 * 创建提现申请
	 */
	public function create(int $user_id, float $amount, string $method = '', string $account_info = ''): int {
		global $wpdb;

		if ($user_id <= 0 || $amount <= 0) {
			return 0;
		}

		$wpdb->insert($this->table(), [
			'user_id'      => $user_id,
			'amount'       => $amount,
			'method'       => sanitize_key($method),
			'account_info' => sanitize_textarea_field($account_info),
			'status'       => self::STATUS_PENDING,
			'created_at'   => current_time('mysql'),
		], ['%d', '%f', '%s', '%s', '%s', '%s']);

		return (int) $wpdb->insert_id;
	}

	/**
	 * Get single row.
	 *
	 * @return array<string,mixed>|null
	 */
	public function get(int $withdrawal_id): ?array {
		global $wpdb;
		if ($withdrawal_id <= 0) {
			return null;
		}
		$row = $wpdb->get_row(
			$wpdb->prepare("SELECT * FROM {$this->table()} WHERE id = %d LIMIT 1", $withdrawal_id),
			ARRAY_A
		);
		return is_array($row) ? $row : null;
	}

	/**
	 * 更新提现状态（无余额副作用）。优先使用 process_status_change()。
	 */
	public function update_status(int $withdrawal_id, string $new_status, string $note = ''): bool {
		global $wpdb;

		$update = ['status' => sanitize_key($new_status)];
		$format = ['%s'];

		if ($new_status === self::STATUS_COMPLETED || $new_status === self::STATUS_REJECTED) {
			$update['processed_at'] = current_time('mysql');
			$format[]               = '%s';
		}

		if ($note !== '') {
			$update['note'] = sanitize_textarea_field($note);
			$format[]       = '%s';
		}

		return $wpdb->update($this->table(), $update, ['id' => $withdrawal_id], $format, ['%d']) !== false;
	}

	/**
	 * Status transition with balance side-effects.
	 * Reject of balance-source holds refunds gross_amount once (idempotent).
	 *
	 * @return true|WP_Error
	 */
	public function process_status_change(int $withdrawal_id, string $new_status, string $note = '') {
		$new_status = sanitize_key($new_status);
		$allowed    = [
			self::STATUS_PENDING,
			self::STATUS_APPROVED,
			self::STATUS_PROCESSING,
			self::STATUS_COMPLETED,
			self::STATUS_REJECTED,
		];
		if ($withdrawal_id <= 0 || !in_array($new_status, $allowed, true)) {
			return new WP_Error('aksrt_withdraw_status', __('提现状态无效', 'aksrt'));
		}

		$row = $this->get($withdrawal_id);
		if (!$row) {
			return new WP_Error('aksrt_withdraw_missing', __('提现记录不存在', 'aksrt'));
		}

		$old_status = sanitize_key((string) ($row['status'] ?? ''));
		if ($old_status === $new_status && $note === '') {
			return true;
		}

		$meta = $this->parse_account_meta((string) ($row['account_info'] ?? ''));
		$user_id = (int) ($row['user_id'] ?? 0);

		// Refund frozen balance when moving into rejected (once).
		if (
			$new_status === self::STATUS_REJECTED
			&& $old_status !== self::STATUS_REJECTED
			&& empty($meta['balance_refunded'])
			&& $this->is_balance_source($meta)
			&& class_exists('AKSRT_Balance')
			&& $user_id > 0
		) {
			$gross = $this->resolve_gross_amount($row, $meta);
			if ($gross > 0) {
				$refund = AKSRT_Balance::add(
					$user_id,
					$gross,
					'withdraw_refund',
					['type' => 'withdraw', 'id' => $withdrawal_id],
					sprintf(__('提现拒绝退回 #%d', 'aksrt'), $withdrawal_id)
				);
				if (is_wp_error($refund)) {
					return $refund;
				}
				$meta['balance_refunded'] = true;
				$meta['refunded_at']      = current_time('mysql');
			}
		}

		$account_info = $this->encode_account_meta($meta, (string) ($row['account_info'] ?? ''));
		$merged_note  = $this->merge_note((string) ($row['note'] ?? ''), $note);

		global $wpdb;
		$update = [
			'status'       => $new_status,
			'account_info' => $account_info,
		];
		$format = ['%s', '%s'];

		if ($new_status === self::STATUS_COMPLETED || $new_status === self::STATUS_REJECTED) {
			$update['processed_at'] = current_time('mysql');
			$format[]               = '%s';
		}
		if ($merged_note !== '') {
			$update['note'] = $merged_note;
			$format[]       = '%s';
		}

		$ok = $wpdb->update($this->table(), $update, ['id' => $withdrawal_id], $format, ['%d']) !== false;
		if (!$ok) {
			return new WP_Error('aksrt_withdraw_update', __('提现状态更新失败', 'aksrt'));
		}

		// Notify user on terminal status (Zibll withdraw_reply parity).
		if (class_exists('AKSRT_Message') && $user_id > 0 && in_array($new_status, [self::STATUS_COMPLETED, self::STATUS_REJECTED], true)) {
			$gross = $this->resolve_gross_amount($row, $meta);
			$amount_txt = class_exists('AKSRT_Balance') ? AKSRT_Balance::format($gross) : number_format($gross, 2);
			if ($new_status === self::STATUS_REJECTED) {
				$title = __('提现已拒绝', 'aksrt');
				$body  = sprintf(__('您申请提现 %s 元已被拒绝，冻结金额已退回钱包。', 'aksrt'), $amount_txt);
				if ($note !== '') {
					$body .= ' ' . sprintf(__('备注：%s', 'aksrt'), $note);
				}
			} else {
				$title = __('提现已完成', 'aksrt');
				$body  = sprintf(__('您申请提现 %s 元已处理完成。', 'aksrt'), $amount_txt);
			}
			AKSRT_Message::get_instance()->send($user_id, 'withdraw', $body, [
				'title'      => $title,
				'target_url' => function_exists('aksrt_get_user_center_url') ? aksrt_get_user_center_url('credits') : '',
			]);
		}

		return true;
	}

	/**
	 * Whether user has open (pending/processing/approved) withdrawals.
	 */
	public function has_open_withdrawal(int $user_id): bool {
		return $this->count_open($user_id) > 0;
	}

	/**
	 * Count open withdrawals.
	 */
	public function count_open(int $user_id): int {
		global $wpdb;
		if ($user_id <= 0) {
			return 0;
		}
		return (int) $wpdb->get_var($wpdb->prepare(
			"SELECT COUNT(*) FROM {$this->table()}
			 WHERE user_id = %d AND status IN ('pending','approved','processing')",
			$user_id
		));
	}

	/**
	 * Sum of frozen gross amounts still open (balance source).
	 */
	public function sum_pending_hold(int $user_id): float {
		global $wpdb;
		if ($user_id <= 0) {
			return 0.0;
		}
		$rows = $wpdb->get_results($wpdb->prepare(
			"SELECT amount, account_info FROM {$this->table()}
			 WHERE user_id = %d AND status IN ('pending','approved','processing')",
			$user_id
		), ARRAY_A);
		$total = 0.0;
		foreach ((array) $rows as $row) {
			$meta  = $this->parse_account_meta((string) ($row['account_info'] ?? ''));
			if (!$this->is_balance_source($meta) || !empty($meta['balance_refunded'])) {
				continue;
			}
			$total += $this->resolve_gross_amount($row, $meta);
		}
		return round($total, 2);
	}

	/**
	 * 获取用户提现列表
	 *
	 * @param array{status?:string,limit?:int,offset?:int,open_only?:bool} $args
	 * @return list<array<string,mixed>>
	 */
	public function get_user_withdrawals(int $user_id, array $args = []): array {
		global $wpdb;

		$where  = ['user_id = %d'];
		$params = [$user_id];

		if (!empty($args['open_only'])) {
			$where[] = "status IN ('pending','approved','processing')";
		} else {
			$status = sanitize_key((string) ($args['status'] ?? ''));
			if ($status !== '') {
				$where[]  = 'status = %s';
				$params[] = $status;
			}
		}

		$limit  = max(1, min(100, (int) ($args['limit'] ?? 20)));
		$offset = max(0, (int) ($args['offset'] ?? 0));

		$sql      = "SELECT * FROM {$this->table()} WHERE " . implode(' AND ', $where) . ' ORDER BY created_at DESC LIMIT %d OFFSET %d';
		$params[] = $limit;
		$params[] = $offset;

		$rows = (array) $wpdb->get_results($wpdb->prepare($sql, $params), ARRAY_A);
		return array_map([$this, 'normalize_row'], $rows);
	}

	/**
	 * 获取所有提现列表（管理后台）
	 *
	 * @return list<array<string,mixed>>
	 */
	public function get_all(array $args = []): array {
		global $wpdb;

		$where  = [];
		$params = [];

		$status = sanitize_key((string) ($args['status'] ?? ''));
		if ($status !== '') {
			$where[]  = 'status = %s';
			$params[] = $status;
		}

		$limit  = max(1, min(100, (int) ($args['limit'] ?? 20)));
		$offset = max(0, (int) ($args['offset'] ?? 0));

		$where_sql = $where ? 'WHERE ' . implode(' AND ', $where) : '';
		$sql       = "SELECT * FROM {$this->table()} {$where_sql} ORDER BY created_at DESC LIMIT %d OFFSET %d";
		$params[]  = $limit;
		$params[]  = $offset;

		if (!empty($params)) {
			$rows = (array) $wpdb->get_results($wpdb->prepare($sql, $params), ARRAY_A);
		} else {
			$rows = (array) $wpdb->get_results($sql, ARRAY_A);
		}
		return array_map([$this, 'normalize_row'], $rows);
	}

	public function get_count(array $args = []): int {
		global $wpdb;

		$status = sanitize_key((string) ($args['status'] ?? ''));
		if ($status !== '') {
			return (int) $wpdb->get_var($wpdb->prepare(
				"SELECT COUNT(*) FROM {$this->table()} WHERE status = %s",
				$status
			));
		}
		return (int) $wpdb->get_var("SELECT COUNT(*) FROM {$this->table()}");
	}

	public function get_stats(): array {
		global $wpdb;

		$row = $wpdb->get_row(
			"SELECT
				COUNT(*) as total,
				SUM(CASE WHEN status = 'pending' THEN 1 ELSE 0 END) as pending,
				SUM(CASE WHEN status = 'completed' THEN 1 ELSE 0 END) as completed,
				COALESCE(SUM(CASE WHEN status = 'completed' THEN amount ELSE 0 END), 0) as total_paid
			FROM {$this->table()}",
			ARRAY_A
		);

		return [
			'total'      => (int) ($row['total'] ?? 0),
			'pending'    => (int) ($row['pending'] ?? 0),
			'completed'  => (int) ($row['completed'] ?? 0),
			'total_paid' => (float) ($row['total_paid'] ?? 0),
		];
	}

	/**
	 * @param array<string,mixed> $row
	 * @return array<string,mixed>
	 */
	private function normalize_row(array $row): array {
		$meta  = $this->parse_account_meta((string) ($row['account_info'] ?? ''));
		$gross = $this->resolve_gross_amount($row, $meta);
		$row['meta']          = $meta;
		$row['gross_amount']  = $gross;
		$row['fee_rate']      = (int) ($meta['fee_rate'] ?? 0);
		$row['display_account'] = (string) ($meta['account'] ?? $row['account_info'] ?? '');
		$row['source']        = (string) ($meta['source'] ?? 'balance');
		return $row;
	}

	/**
	 * @return array<string,mixed>
	 */
	private function parse_account_meta(string $raw): array {
		$raw = trim($raw);
		if ($raw === '') {
			return [];
		}
		$decoded = json_decode($raw, true);
		return is_array($decoded) ? $decoded : ['account' => $raw];
	}

	/**
	 * @param array<string,mixed> $meta
	 */
	private function encode_account_meta(array $meta, string $fallback_raw): string {
		if ($meta === []) {
			return $fallback_raw;
		}
		$json = wp_json_encode($meta, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
		return is_string($json) ? $json : $fallback_raw;
	}

	/**
	 * @param array<string,mixed> $meta
	 */
	private function is_balance_source(array $meta): bool {
		$source = sanitize_key((string) ($meta['source'] ?? 'balance'));
		// Empty / balance = cash wallet freeze path.
		return $source === '' || $source === 'balance';
	}

	/**
	 * @param array<string,mixed> $row
	 * @param array<string,mixed> $meta
	 */
	private function resolve_gross_amount(array $row, array $meta): float {
		if (isset($meta['gross_amount'])) {
			return max(0, round((float) $meta['gross_amount'], 2));
		}
		// Legacy rows: amount was net or gross without meta.
		return max(0, round((float) ($row['amount'] ?? 0), 2));
	}

	private function merge_note(string $old, string $new): string {
		$new = sanitize_textarea_field($new);
		if ($new === '') {
			return sanitize_textarea_field($old);
		}
		$old = sanitize_textarea_field($old);
		if ($old === '') {
			return $new;
		}
		return $old . "\n" . $new;
	}
}