<?php

namespace App\Http\Controllers;

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

class CashierLedgerController extends Controller
{
    /**
     * Display a listing of cashier ledger entries
     */
    public function index(Request $request)
    {
        $query = CashierLedgerEntry::query()
            ->with(['financeDocument', 'recordedByCashier'])
            ->orderByDesc('entry_date')
            ->orderByDesc('id');

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

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

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

        // Filter by date range
        if ($request->filled('date_from')) {
            $query->where('entry_date', '>=', $request->date_from);
        }
        if ($request->filled('date_to')) {
            $query->where('entry_date', '<=', $request->date_to);
        }

        $entries = $query->paginate(20);

        // Get latest balance for each bank account
        $balances = DB::table('cashier_ledger_entries')
            ->select('bank_account', DB::raw('MAX(id) as latest_id'))
            ->groupBy('bank_account')
            ->get()
            ->mapWithKeys(function ($item) {
                $latest = CashierLedgerEntry::find($item->latest_id);
                return [$item->bank_account => $latest->balance_after ?? 0];
            });

        return view('admin.cashier-ledger.index', [
            'entries' => $entries,
            'balances' => $balances,
        ]);
    }

    /**
     * Show the form for creating a new ledger entry
     */
    public function create(Request $request)
    {
        // Check authorization
        $this->authorize('record_cashier_ledger');

        // Get finance document if specified
        $financeDocument = null;
        if ($request->filled('finance_document_id')) {
            $financeDocument = FinanceDocument::with('paymentOrder')->findOrFail($request->finance_document_id);
        }

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

    /**
     * Store a newly created ledger entry
     */
    public function store(Request $request)
    {
        // Check authorization
        $this->authorize('record_cashier_ledger');

        $validated = $request->validate([
            'finance_document_id' => ['nullable', 'exists:finance_documents,id'],
            'entry_date' => ['required', 'date'],
            'entry_type' => ['required', 'in:receipt,payment'],
            'payment_method' => ['required', 'in:bank_transfer,check,cash'],
            'bank_account' => ['nullable', 'string', 'max:100'],
            'amount' => ['required', 'numeric', 'min:0.01'],
            'receipt_number' => ['nullable', 'string', 'max:50'],
            'transaction_reference' => ['nullable', 'string', 'max:100'],
            'notes' => ['nullable', 'string'],
        ]);

        DB::beginTransaction();
        try {
            // Get latest balance for the bank account
            $bankAccount = $validated['bank_account'] ?? 'default';
            $balanceBefore = CashierLedgerEntry::getLatestBalance($bankAccount);

            // Create new entry
            $entry = new CashierLedgerEntry([
                'finance_document_id' => $validated['finance_document_id'] ?? null,
                'entry_date' => $validated['entry_date'],
                'entry_type' => $validated['entry_type'],
                'payment_method' => $validated['payment_method'],
                'bank_account' => $bankAccount,
                'amount' => $validated['amount'],
                'balance_before' => $balanceBefore,
                'receipt_number' => $validated['receipt_number'] ?? null,
                'transaction_reference' => $validated['transaction_reference'] ?? null,
                'recorded_by_cashier_id' => $request->user()->id,
                'recorded_at' => now(),
                'notes' => $validated['notes'] ?? null,
            ]);

            // Calculate balance after
            $entry->balance_after = $entry->calculateBalanceAfter($balanceBefore);
            $entry->save();

            // Update finance document if linked
            if ($validated['finance_document_id']) {
                $financeDocument = FinanceDocument::find($validated['finance_document_id']);
                $financeDocument->update([
                    'cashier_ledger_entry_id' => $entry->id,
                ]);
            }

            AuditLogger::log('cashier_ledger_entry.created', $entry, $validated);

            DB::commit();

            return redirect()
                ->route('admin.cashier-ledger.show', $entry)
                ->with('status', '現金簿記錄已建立。');

        } catch (\Exception $e) {
            DB::rollBack();
            return redirect()
                ->back()
                ->withInput()
                ->with('error', '建立現金簿記錄時發生錯誤：' . $e->getMessage());
        }
    }

    /**
     * Display the specified ledger entry
     */
    public function show(CashierLedgerEntry $cashierLedgerEntry)
    {
        $cashierLedgerEntry->load([
            'financeDocument.member',
            'financeDocument.paymentOrder',
            'recordedByCashier'
        ]);

        return view('admin.cashier-ledger.show', [
            'entry' => $cashierLedgerEntry,
        ]);
    }

    /**
     * Show ledger balance report
     */
    public function balanceReport(Request $request)
    {
        // Check authorization
        $this->authorize('view_cashier_ledger');

        // Get all bank accounts with their latest balances
        $accounts = DB::table('cashier_ledger_entries')
            ->select('bank_account')
            ->distinct()
            ->get()
            ->map(function ($account) {
                $latest = CashierLedgerEntry::where('bank_account', $account->bank_account)
                    ->orderBy('entry_date', 'desc')
                    ->orderBy('id', 'desc')
                    ->first();

                return [
                    'bank_account' => $account->bank_account,
                    'balance' => $latest->balance_after ?? 0,
                    'last_updated' => $latest->entry_date ?? null,
                ];
            });

        // Get transaction summary for current month
        $startOfMonth = now()->startOfMonth();
        $endOfMonth = now()->endOfMonth();

        $monthlySummary = [
            'receipts' => CashierLedgerEntry::where('entry_type', CashierLedgerEntry::ENTRY_TYPE_RECEIPT)
                ->whereBetween('entry_date', [$startOfMonth, $endOfMonth])
                ->sum('amount'),
            'payments' => CashierLedgerEntry::where('entry_type', CashierLedgerEntry::ENTRY_TYPE_PAYMENT)
                ->whereBetween('entry_date', [$startOfMonth, $endOfMonth])
                ->sum('amount'),
        ];

        return view('admin.cashier-ledger.balance-report', [
            'accounts' => $accounts,
            'monthlySummary' => $monthlySummary,
        ]);
    }

    /**
     * Export ledger entries to CSV
     */
    public function export(Request $request)
    {
        // Check authorization
        $this->authorize('view_cashier_ledger');

        $query = CashierLedgerEntry::query()
            ->with(['financeDocument', 'recordedByCashier'])
            ->orderBy('entry_date')
            ->orderBy('id');

        // Apply filters
        if ($request->filled('date_from')) {
            $query->where('entry_date', '>=', $request->date_from);
        }
        if ($request->filled('date_to')) {
            $query->where('entry_date', '<=', $request->date_to);
        }
        if ($request->filled('bank_account')) {
            $query->where('bank_account', $request->bank_account);
        }

        $entries = $query->get();

        $filename = 'cashier_ledger_' . now()->format('Ymd_His') . '.csv';

        $headers = [
            'Content-Type' => 'text/csv; charset=UTF-8',
            'Content-Disposition' => "attachment; filename=\"{$filename}\"",
        ];

        $callback = function() use ($entries) {
            $file = fopen('php://output', 'w');

            // Add BOM for UTF-8
            fprintf($file, chr(0xEF).chr(0xBB).chr(0xBF));

            // Header row
            fputcsv($file, [
                '記帳日期',
                '類型',
                '付款方式',
                '銀行帳戶',
                '金額',
                '交易前餘額',
                '交易後餘額',
                '收據編號',
                '交易參考號',
                '記錄人',
                '備註',
            ]);

            // Data rows
            foreach ($entries as $entry) {
                fputcsv($file, [
                    $entry->entry_date->format('Y-m-d'),
                    $entry->getEntryTypeText(),
                    $entry->getPaymentMethodText(),
                    $entry->bank_account ?? '',
                    $entry->amount,
                    $entry->balance_before,
                    $entry->balance_after,
                    $entry->receipt_number ?? '',
                    $entry->transaction_reference ?? '',
                    $entry->recordedByCashier->name ?? '',
                    $entry->notes ?? '',
                ]);
            }

            fclose($file);
        };

        return response()->stream($callback, 200, $headers);
    }
}