<?php

namespace App\Http\Controllers;

use App\Models\FinanceDocument;
use App\Models\PaymentOrder;
use App\Support\AuditLogger;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Storage;

class PaymentOrderController extends Controller
{
    /**
     * Display a listing of payment orders
     */
    public function index(Request $request)
    {
        $query = PaymentOrder::query()
            ->with([
                'financeDocument',
                'createdByAccountant',
                'verifiedByCashier',
                'executedByCashier'
            ])
            ->orderByDesc('created_at');

        // Filter by status
        if ($request->filled('status')) {
            $query->where('status', $request->status);
        }

        // Filter by verification status
        if ($request->filled('verification_status')) {
            $query->where('verification_status', $request->verification_status);
        }

        // Filter by execution status
        if ($request->filled('execution_status')) {
            $query->where('execution_status', $request->execution_status);
        }

        $paymentOrders = $query->paginate(15);

        return view('admin.payment-orders.index', [
            'paymentOrders' => $paymentOrders,
        ]);
    }

    /**
     * Show the form for creating a new payment order (accountant only)
     */
    public function create(FinanceDocument $financeDocument)
    {
        // Check authorization
        $this->authorize('create_payment_order');

        // Check if document is ready for payment order creation
        if (!$financeDocument->canCreatePaymentOrder()) {
            return redirect()
                ->route('admin.finance.show', $financeDocument)
                ->with('error', '此財務申請單尚未完成審核流程，無法製作付款單。');
        }

        // Check if payment order already exists
        if ($financeDocument->paymentOrder !== null) {
            return redirect()
                ->route('admin.payment-orders.show', $financeDocument->paymentOrder)
                ->with('error', '此財務申請單已有付款單。');
        }

        $financeDocument->load(['member', 'submittedBy']);

        return view('admin.payment-orders.create', [
            'financeDocument' => $financeDocument,
        ]);
    }

    /**
     * Store a newly created payment order (accountant creates)
     */
    public function store(Request $request)
    {
        // Check authorization
        $this->authorize('create_payment_order');

        $financeDocument = FinanceDocument::findOrFail($request->input('finance_document_id'));

        // Check if document is ready
        if (!$financeDocument->canCreatePaymentOrder()) {
            if (app()->environment('testing')) {
                \Log::info('payment_order.store.blocked', [
                    'finance_document_id' => $financeDocument->id,
                    'status' => $financeDocument->status,
                    'amount_tier' => $financeDocument->amount_tier,
                    'payment_order_created_at' => $financeDocument->payment_order_created_at,
                ]);
            }
            return redirect()
                ->route('admin.finance.show', $financeDocument)
                ->with('error', '此財務申請單尚未完成審核流程，無法製作付款單。');
        }

        $validated = $request->validate([
            'finance_document_id' => ['required', 'exists:finance_documents,id'],
            'payee_name' => ['required', 'string', 'max:100'],
            'payee_bank_code' => ['nullable', 'string', 'max:10'],
            'payee_account_number' => ['nullable', 'string', 'max:30'],
            'payee_bank_name' => ['nullable', 'string', 'max:100'],
            'payment_amount' => ['required', 'numeric', 'min:0'],
            'payment_method' => ['required', 'in:bank_transfer,check,cash'],
            'notes' => ['nullable', 'string'],
        ]);

        DB::beginTransaction();
        try {
            // Generate payment order number
            $paymentOrderNumber = PaymentOrder::generatePaymentOrderNumber();

            // Create payment order
            $paymentOrder = PaymentOrder::create([
                'finance_document_id' => $financeDocument->id,
                'payee_name' => $validated['payee_name'],
                'payee_bank_code' => $validated['payee_bank_code'] ?? null,
                'payee_account_number' => $validated['payee_account_number'] ?? null,
                'payee_bank_name' => $validated['payee_bank_name'] ?? null,
                'payment_amount' => $validated['payment_amount'],
                'payment_method' => $validated['payment_method'],
                'created_by_accountant_id' => $request->user()->id,
                'payment_order_number' => $paymentOrderNumber,
                'notes' => $validated['notes'] ?? null,
                'status' => PaymentOrder::STATUS_PENDING_VERIFICATION,
                'verification_status' => PaymentOrder::VERIFICATION_PENDING,
                'execution_status' => PaymentOrder::EXECUTION_PENDING,
            ]);

            // Update finance document
            $financeDocument->update([
                'payment_order_created_by_accountant_id' => $request->user()->id,
                'payment_order_created_at' => now(),
                'payment_method' => $validated['payment_method'],
                'payee_name' => $validated['payee_name'],
                'payee_account_number' => $validated['payee_account_number'] ?? null,
                'payee_bank_name' => $validated['payee_bank_name'] ?? null,
            ]);

            AuditLogger::log('payment_order.created', $paymentOrder, $validated);

            DB::commit();

            return redirect()
                ->route('admin.payment-orders.show', $paymentOrder)
                ->with('status', "付款單 {$paymentOrderNumber} 已建立，等待出納覆核。");

        } catch (\Exception $e) {
            if (app()->environment('testing')) {
                \Log::error('payment_order.store.failed', [
                    'finance_document_id' => $financeDocument->id ?? null,
                    'error' => $e->getMessage(),
                ]);
            }
            DB::rollBack();
            return redirect()
                ->back()
                ->withInput()
                ->with('error', '建立付款單時發生錯誤：' . $e->getMessage());
        }
    }

    /**
     * Display the specified payment order
     */
    public function show(PaymentOrder $paymentOrder)
    {
        $paymentOrder->load([
            'financeDocument.member',
            'financeDocument.submittedBy',
            'createdByAccountant',
            'verifiedByCashier',
            'executedByCashier'
        ]);

        return view('admin.payment-orders.show', [
            'paymentOrder' => $paymentOrder,
        ]);
    }

    /**
     * Cashier verifies the payment order
     */
    public function verify(Request $request, PaymentOrder $paymentOrder)
    {
        // Check authorization
        $this->authorize('verify_payment_order');

        // Check if can be verified
        if (!$paymentOrder->canBeVerifiedByCashier()) {
            return redirect()
                ->route('admin.payment-orders.show', $paymentOrder)
                ->with('error', '此付款單無法覆核。');
        }

        $validated = $request->validate([
            'action' => ['required', 'in:approve,reject'],
            'verification_notes' => ['nullable', 'string'],
        ]);

        DB::beginTransaction();
        try {
            if ($validated['action'] === 'approve') {
                // Approve
                $paymentOrder->update([
                    'verified_by_cashier_id' => $request->user()->id,
                    'verified_at' => now(),
                    'verification_status' => PaymentOrder::VERIFICATION_APPROVED,
                    'verification_notes' => $validated['verification_notes'] ?? null,
                    'status' => PaymentOrder::STATUS_VERIFIED,
                ]);

                // Update finance document
                $paymentOrder->financeDocument->update([
                    'payment_verified_by_cashier_id' => $request->user()->id,
                    'payment_verified_at' => now(),
                ]);

                AuditLogger::log('payment_order.verified_approved', $paymentOrder, $validated);

                $message = '付款單已覆核通過，可以執行付款。';
            } else {
                // Reject
                $paymentOrder->update([
                    'verified_by_cashier_id' => $request->user()->id,
                    'verified_at' => now(),
                    'verification_status' => PaymentOrder::VERIFICATION_REJECTED,
                    'verification_notes' => $validated['verification_notes'] ?? null,
                    'status' => PaymentOrder::STATUS_CANCELLED,
                ]);

                AuditLogger::log('payment_order.verified_rejected', $paymentOrder, $validated);

                $message = '付款單已駁回。';
            }

            DB::commit();

            return redirect()
                ->route('admin.payment-orders.show', $paymentOrder)
                ->with('status', $message);

        } catch (\Exception $e) {
            DB::rollBack();
            return redirect()
                ->back()
                ->with('error', '覆核付款單時發生錯誤：' . $e->getMessage());
        }
    }

    /**
     * Cashier executes the payment
     */
    public function execute(Request $request, PaymentOrder $paymentOrder)
    {
        // Check authorization
        $this->authorize('execute_payment');

        // Check if can be executed
        if (!$paymentOrder->canBeExecuted()) {
            return redirect()
                ->route('admin.payment-orders.show', $paymentOrder)
                ->with('error', '此付款單無法執行。');
        }

        $validated = $request->validate([
            'transaction_reference' => ['required', 'string', 'max:100'],
            'payment_receipt' => ['nullable', 'file', 'max:10240'], // 10MB max
            'execution_notes' => ['nullable', 'string'],
        ]);

        DB::beginTransaction();
        try {
            // Handle receipt upload
            $receiptPath = null;
            if ($request->hasFile('payment_receipt')) {
                $receiptPath = $request->file('payment_receipt')->store('payment-receipts', 'local');
            }

            // Execute payment
            $paymentOrder->update([
                'executed_by_cashier_id' => $request->user()->id,
                'executed_at' => now(),
                'execution_status' => PaymentOrder::EXECUTION_COMPLETED,
                'transaction_reference' => $validated['transaction_reference'],
                'payment_receipt_path' => $receiptPath,
                'status' => PaymentOrder::STATUS_EXECUTED,
            ]);

            // Update finance document
            $paymentOrder->financeDocument->update([
                'payment_executed_by_cashier_id' => $request->user()->id,
                'payment_executed_at' => now(),
                'payment_transaction_id' => $validated['transaction_reference'],
                'payment_receipt_path' => $receiptPath,
                'actual_payment_amount' => $paymentOrder->payment_amount,
            ]);

            AuditLogger::log('payment_order.executed', $paymentOrder, $validated);

            DB::commit();

            return redirect()
                ->route('admin.payment-orders.show', $paymentOrder)
                ->with('status', '付款已執行完成。');

        } catch (\Exception $e) {
            DB::rollBack();
            return redirect()
                ->back()
                ->with('error', '執行付款時發生錯誤：' . $e->getMessage());
        }
    }

    /**
     * Download payment receipt
     */
    public function downloadReceipt(PaymentOrder $paymentOrder)
    {
        if (!$paymentOrder->payment_receipt_path) {
            abort(404, '找不到付款憑證');
        }

        if (!Storage::disk('local')->exists($paymentOrder->payment_receipt_path)) {
            abort(404, '付款憑證檔案不存在');
        }

        return Storage::disk('local')->download($paymentOrder->payment_receipt_path);
    }

    /**
     * Cancel a payment order
     */
    public function cancel(Request $request, PaymentOrder $paymentOrder)
    {
        // Check authorization
        $this->authorize('create_payment_order'); // Only accountant can cancel

        // Cannot cancel if already executed
        if ($paymentOrder->isExecuted()) {
            return redirect()
                ->route('admin.payment-orders.show', $paymentOrder)
                ->with('error', '已執行的付款單無法取消。');
        }

        DB::beginTransaction();
        try {
            $paymentOrder->update([
                'status' => PaymentOrder::STATUS_CANCELLED,
            ]);

            AuditLogger::log('payment_order.cancelled', $paymentOrder, [
                'cancelled_by' => $request->user()->id,
            ]);

            DB::commit();

            return redirect()
                ->route('admin.payment-orders.index')
                ->with('status', '付款單已取消。');

        } catch (\Exception $e) {
            DB::rollBack();
            return redirect()
                ->back()
                ->with('error', '取消付款單時發生錯誤：' . $e->getMessage());
        }
    }
}