<?php
namespace App\Models;

/**
 * Class Payment
 * POS Billing & Cashier Payment Model (PromptPay QR / Receipt / Tax Invoice)
 *
 * @package App\Models
 */
class Payment extends Model
{
    protected string $table = 'payments';

    /**
     * Generate Receipt Number e.g. REC-202607-0001
     */
    public function generateReceiptNo(int $branchId): string
    {
        $prefix = "REC-" . date('Ym') . "-";
        $sql = "SELECT COUNT(*) as cnt FROM `{$this->table}` 
                WHERE `branch_id` = :bid AND `receipt_no` LIKE :pfx";
        $stmt = self::getDB()->prepare($sql);
        $stmt->execute(['bid' => $branchId, 'pfx' => "%{$prefix}%"]);
        $row = $stmt->fetch();
        $nextNum = ((int)($row['cnt'] ?? 0)) + 1;

        return sprintf("%s%04d", $prefix, $nextNum);
    }

    /**
     * Generate Tax Invoice Number e.g. TAX-202607-0001
     */
    public function generateTaxInvoiceNo(int $branchId): string
    {
        $prefix = "TAX-" . date('Ym') . "-";
        $sql = "SELECT COUNT(*) as cnt FROM `{$this->table}` 
                WHERE `branch_id` = :bid AND `tax_invoice_no` LIKE :pfx";
        $stmt = self::getDB()->prepare($sql);
        $stmt->execute(['bid' => $branchId, 'pfx' => "%{$prefix}%"]);
        $row = $stmt->fetch();
        $nextNum = ((int)($row['cnt'] ?? 0)) + 1;

        return sprintf("%s%04d", $prefix, $nextNum);
    }

    /**
     * Process Checkout & Issue Receipt
     */
    public function processCheckout(array $data): array
    {
        $branchId = (int)$data['branch_id'];
        $receiptNo = $this->generateReceiptNo($branchId);
        $taxNo = !empty($data['request_tax_invoice']) ? $this->generateTaxInvoiceNo($branchId) : null;

        $subtotal = (float)$data['subtotal'];
        $discount = (float)($data['discount'] ?? 0.00);
        $netAmount = max(0.00, $subtotal - $discount);
        $method = $data['payment_method'] ?? 'Cash';
        $status = 'Paid';

        // Generate PromptPay Ref ID if method is PromptPay
        $ppRef = ($method === 'PromptPay') ? ('PP-' . date('ymd') . rand(100000, 999999)) : null;

        $paymentId = $this->create([
            'queue_id' => (int)$data['queue_id'],
            'patient_id' => (int)$data['patient_id'],
            'branch_id' => $branchId,
            'receipt_no' => $receiptNo,
            'tax_invoice_no' => $taxNo,
            'subtotal' => $subtotal,
            'discount' => $discount,
            'net_amount' => $netAmount,
            'payment_method' => $method,
            'payment_status' => $status,
            'promptpay_ref' => $ppRef,
            'paid_at' => date('Y-m-d H:i:s'),
            'cashier_id' => (int)$data['cashier_id'],
            'created_at' => date('Y-m-d H:i:s'),
            'updated_at' => date('Y-m-d H:i:s'),
        ]);

        // อัปเดตสถานะคิวเป็น Completed เมื่อชำระเงินเรียบร้อย
        (new Queue())->update((int)$data['queue_id'], [
            'status' => 'Completed',
            'actual_end_time' => date('Y-m-d H:i:s'),
        ]);

        return [
            'payment_id' => $paymentId,
            'receipt_no' => $receiptNo,
            'tax_invoice_no' => $taxNo,
            'net_amount' => $netAmount,
            'payment_method' => $method,
            'promptpay_ref' => $ppRef,
            'paid_at' => date('Y-m-d H:i:s'),
        ];
    }
}