<?php
/**
 * @package AKSRT
 */

namespace AKSRT\Payment;

defined('ABSPATH') || exit;

/**
 * 站内余额支付网关（内置实现）。
 *
 * 仅扣统一资产账本中的现金余额。
 */

class BalanceGateway implements GatewayInterface {

    public function get_id(): string {
        return 'balance';
    }

    public function get_name(): string {
        return __('站内余额', 'aksrt');
    }

    public function is_configured(): bool {
        if (!$this->balance_enabled()) {
            return false;
        }
        if (class_exists('\AKSRT\Settings\PaymentRuntime')) {
            return \AKSRT\Settings\PaymentRuntime::is_gateway_enabled('balance');
        }
        return true;
    }

    public function create_payment(array $order): array {
        $user_id = (int) ($order['user_id'] ?? 0);
        $order_number = (string) ($order['order_number'] ?? '');

        if (!$this->balance_enabled()) {
            return ['success' => false, 'message' => __('余额功能未启用', 'aksrt')];
        }
        if ($user_id <= 0) {
            return ['success' => false, 'message' => __('请先登录', 'aksrt')];
		}
		global $wpdb;
		$table = \AKSRT\Core\DBMigrator::table('order');
		$amount = $wpdb->get_var($wpdb->prepare(
			"SELECT amount FROM {$table} WHERE order_number = %s",
			$order_number
		));
        try {
			$amount_minor = \AKSRT\Ledger\AssetAmount::balance(is_string($amount) ? $amount : '')->minor();
        } catch (\InvalidArgumentException $e) {
            return ['success' => false, 'message' => __('支付金额无效', 'aksrt')];
        }
        $transaction_code = 'BAL_' . $order_number;
		$guard = static function () use ($order_number, $user_id, $amount_minor) {
			global $wpdb;
			$table = \AKSRT\Core\DBMigrator::table('order');
			$current = $wpdb->get_row($wpdb->prepare(
				"SELECT user_id, amount, status FROM {$table} WHERE order_number = %s FOR UPDATE",
				$order_number
			), ARRAY_A);
			try {
				$current_minor = is_array($current)
					? \AKSRT\Ledger\AssetAmount::balance((string) ($current['amount'] ?? ''))->minor()
					: -1;
			} catch (\InvalidArgumentException $e) {
				$current_minor = -1;
			}
			if (!is_array($current)
				|| (int) ($current['user_id'] ?? 0) !== $user_id
				|| $current_minor !== $amount_minor
				|| (string) ($current['status'] ?? '') !== Order::STATUS_PENDING
			) {
				return new \WP_Error('aksrt_order_confirm_failed', __('订单状态或金额已变化', 'aksrt'), ['status' => 409]);
			}
			return true;
		};
        $result = \AKSRT\Ledger\LedgerService::get_instance()->debit(
            $user_id,
            \AKSRT\Ledger\AssetType::BALANCE,
            $amount_minor,
            \AKSRT\Ledger\OperationKey::deterministic('order-payment', [$order_number]),
            'order_payment',
            ['type' => 'order', 'key' => $order_number],
            sprintf(__('订单 %s 支付', 'aksrt'), $order_number),
            $user_id,
            ['order_number' => $order_number],
			static function () use ($order_number, $transaction_code, $order) {
                $paid = OrderRepository::get_instance()->update_status($order_number, Order::STATUS_PAID, [
                    'payment_method' => 'balance',
                    'payment_transaction_id' => $transaction_code,
                    'note' => (string) ($order['_ledger_paid_note'] ?? __('余额支付成功', 'aksrt')),
                    'require_transition' => true,
                ]);
                return $paid ? true : new \WP_Error('aksrt_order_confirm_failed', __('订单状态确认失败', 'aksrt'), ['status' => 409]);
			},
			$guard
        );
        if (is_wp_error($result)) {
            $error_data = $result->get_error_data();
            return [
                'success' => false,
                'code' => $result->get_error_code(),
                'status' => is_array($error_data) ? (int) ($error_data['status'] ?? 500) : 500,
                'message' => $result->get_error_message() ?: __('扣款失败', 'aksrt'),
            ];
        }
        return [
            'success'        => true,
            'transaction_id' => $transaction_code,
            'ledger_transaction_id' => $result->transaction_id,
			'flow_number' => $result->flow_number,
            'replayed' => $result->replayed,
            'order_committed' => true,
            'message'        => __('余额支付成功', 'aksrt'),
        ];
    }

    public function verify_callback(\WP_REST_Request $request): array {
        // Balance payment is synchronous — no callback needed
        return ['success' => false, 'message' => __('余额支付无需回调验证', 'aksrt')];
    }

    public function query_status(string $order_number): array {
        $order_repo = OrderRepository::get_instance();
        $order = $order_repo->get($order_number);

        if (!$order) {
            return ['success' => false, 'message' => __('订单不存在', 'aksrt')];
        }

        return [
            'success'        => true,
            'status'         => $order['status'],
            'transaction_id' => $order['payment_transaction_id'] ?? '',
        ];
    }

	public function refund(string $order_number, string $amount, string $request_id = ''): array {
        $order_repo = OrderRepository::get_instance();
        $order = $order_repo->get($order_number);

        if (!$order) {
            return ['success' => false, 'message' => __('订单不存在', 'aksrt')];
        }

        $user_id = (int) $order['user_id'];
        if (!$this->balance_enabled()) {
            return ['success' => false, 'message' => __('余额功能未启用', 'aksrt')];
        }

        $request_id = sanitize_text_field($request_id);
		try {
			$amount_minor = \AKSRT\Ledger\AssetAmount::balance($amount)->minor();
			if ($amount_minor <= 0) {
				return ['success' => false, 'message' => __('退款金额无效', 'aksrt')];
			}
			$operation_key = \AKSRT\Ledger\OperationKey::deterministic('order-refund', [$request_id !== '' ? $request_id : $order_number]);
			$history = \AKSRT\Ledger\LedgerQuery::get_instance()->history(['operation_key' => $operation_key, 'page' => 1, 'per_page' => 1]);
			if (!empty($history['items'][0])) {
				$committed = $history['items'][0];
				$refund_entry = null;
				foreach ((array) ($committed['entries'] ?? []) as $entry) {
					if ((int) ($entry['user_id'] ?? 0) === $user_id
						&& (string) ($entry['asset'] ?? '') === \AKSRT\Ledger\AssetType::BALANCE->value
						&& (string) ($entry['entry_type'] ?? '') === 'refund'
					) {
						$refund_entry = $entry;
						break;
					}
				}
				if ((string) ($committed['reason'] ?? '') !== 'order_refund'
					|| (string) ($committed['ref_type'] ?? '') !== 'order'
					|| (string) ($committed['ref_key'] ?? '') !== $order_number
					|| !is_array($refund_entry)
					|| (int) ($refund_entry['delta_minor'] ?? 0) !== $amount_minor
				) {
					return ['success' => false, 'message' => __('相同退款标识已用于其他请求', 'aksrt')];
				}
				return [
					'success' => true,
					'refund_id' => 'BAL_REF_' . $order_number,
					'transaction_id' => (int) ($committed['id'] ?? 0),
					'ledger_transaction_id' => (int) ($committed['id'] ?? 0),
					'replayed' => true,
					'balance' => \AKSRT\Ledger\LedgerService::get_instance()->balance_decimal($user_id),
					'message' => __('退款成功', 'aksrt'),
				];
			}
			$commission = CommissionLedger::get_instance();
			$commission_plan = $commission->prepare_full_refund($order_number);
			if (is_wp_error($commission_plan)) {
				return ['success' => false, 'message' => $commission_plan->get_error_message()];
			}
			$guard = static function () use ($order_number, $user_id, $amount_minor, $commission, $commission_plan) {
				global $wpdb;
				$table = \AKSRT\Core\DBMigrator::table('order');
				$current = $wpdb->get_row($wpdb->prepare(
					"SELECT user_id, amount, payment_method, status FROM {$table} WHERE order_number = %s FOR UPDATE",
					$order_number
				), ARRAY_A);
				try {
					$order_minor = is_array($current)
						? \AKSRT\Ledger\AssetAmount::balance((string) ($current['amount'] ?? ''))->minor()
						: -1;
				} catch (\InvalidArgumentException $e) {
					$order_minor = -1;
				}
				if (!is_array($current)
					|| (int) ($current['user_id'] ?? 0) !== $user_id
					|| sanitize_key((string) ($current['payment_method'] ?? '')) !== 'balance'
					|| $order_minor !== $amount_minor
					|| !in_array((string) ($current['status'] ?? ''), [Order::STATUS_PAID, Order::STATUS_REFUNDING], true)
				) {
					return new \WP_Error('aksrt_order_refund_conflict', __('退款订单状态或金额已变化', 'aksrt'), ['status' => 409]);
				}
				return $commission->guard_full_refund($commission_plan);
			};
			$mutation = static function () use ($order_number, $commission, $commission_plan) {
				$repo = OrderRepository::get_instance();
				$current = $repo->get($order_number);
				if (!is_array($current)) {
					return new \WP_Error('aksrt_order_refund_failed', __('退款订单不存在', 'aksrt'), ['status' => 404]);
				}
				if ((string) ($current['status'] ?? '') !== Order::STATUS_REFUNDING
					&& !$repo->update_status($order_number, Order::STATUS_REFUNDING, ['note' => __('余额退款处理中', 'aksrt')])) {
					return new \WP_Error('aksrt_order_refund_failed', __('退款状态更新失败', 'aksrt'), ['status' => 409]);
				}
				if (!$repo->update_status($order_number, Order::STATUS_REFUNDED, ['note' => __('余额退款已完成', 'aksrt')])) {
					return new \WP_Error('aksrt_order_refund_failed', __('退款状态更新失败', 'aksrt'), ['status' => 409]);
				}
				return $commission->apply_full_refund($commission_plan);
			};
			$entries = [[
				'user_id' => $user_id,
				'asset' => \AKSRT\Ledger\AssetType::BALANCE->value,
				'delta_minor' => $amount_minor,
				'entry_type' => 'refund',
				'remark' => sprintf(__('订单 %s 退款', 'aksrt'), $order_number),
			]];
			if (!empty($commission_plan['active']) && (string) ($commission_plan['status'] ?? '') === 'settled') {
				$entries[] = [
					'user_id' => (int) $commission_plan['promoter_id'],
					'asset' => \AKSRT\Ledger\AssetType::BALANCE->value,
					'delta_minor' => -(int) $commission_plan['amount_minor'],
					'entry_type' => 'commission_reversal',
					'counterparty_user_id' => $user_id,
					'remark' => sprintf(__('订单 %s 返佣退款冲正', 'aksrt'), $order_number),
				];
			}
			$result = \AKSRT\Ledger\LedgerService::get_instance()->post(new \AKSRT\Ledger\LedgerCommand(
				$operation_key,
				'order_refund',
				$entries,
				'order',
				$order_number,
				0,
				['request_id' => $request_id, 'commission_id' => (int) ($commission_plan['id'] ?? 0)]
			), $guard, $mutation);
            if (is_wp_error($result)) {
                return ['success' => false, 'message' => $result->get_error_message() ?: __('退款失败', 'aksrt')];
            }
			return [
				'success' => true,
				'refund_id' => 'BAL_REF_' . $order_number,
				'transaction_id' => $result->transaction_id,
				'ledger_transaction_id' => $result->transaction_id,
				'flow_number' => $result->flow_number,
				'replayed' => $result->replayed,
				'balance' => \AKSRT\Ledger\LedgerService::get_instance()->balance_decimal($user_id),
				'message' => __('退款成功', 'aksrt'),
			];
        } catch (\Throwable $e) {
            return ['success' => false, 'message' => $e->getMessage()];
        }
    }

    private function balance_enabled(): bool {
        if (!class_exists('\AKSRT\Settings\Settings')) {
            return false;
        }
        $settings = \AKSRT\Settings\Settings::get_payment_recharge_settings();
        return !empty($settings['enabled']);
    }
}