<?php

namespace App\Http\Controllers;

use App\Models\ChartOfAccount;
use App\Models\Income;
use App\Models\Member;
use App\Support\AuditLogger;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;

class IncomeController extends Controller
{
    /**
     * 收入列表
     */
    public function index(Request $request)
    {
        $query = Income::query()
            ->with(['chartOfAccount', 'member', 'recordedByCashier', 'confirmedByAccountant'])
            ->orderByDesc('income_date')
            ->orderByDesc('id');

        // 篩選狀態
        if ($request->filled('status')) {
            $query->where('status', $request->status);
        }

        // 篩選收入類型
        if ($request->filled('income_type')) {
            $query->where('income_type', $request->income_type);
        }

        // 篩選付款方式
        if ($request->filled('payment_method')) {
            $query->where('payment_method', $request->payment_method);
        }

        // 篩選會員
        if ($request->filled('member_id')) {
            $query->where('member_id', $request->member_id);
        }

        // 篩選日期範圍
        if ($request->filled('date_from')) {
            $query->where('income_date', '>=', $request->date_from);
        }
        if ($request->filled('date_to')) {
            $query->where('income_date', '<=', $request->date_to);
        }

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

        // 統計資料
        $statistics = [
            'pending_count' => Income::pending()->count(),
            'pending_amount' => Income::pending()->sum('amount'),
            'confirmed_count' => Income::confirmed()->count(),
            'confirmed_amount' => Income::confirmed()->sum('amount'),
        ];

        return view('admin.incomes.index', [
            'incomes' => $incomes,
            'statistics' => $statistics,
        ]);
    }

    /**
     * 新增收入表單
     */
    public function create(Request $request)
    {
        // 取得收入類會計科目
        $chartOfAccounts = ChartOfAccount::where('account_type', 'income')
            ->where('is_active', true)
            ->orderBy('account_code')
            ->get();

        // 取得會員列表（可選關聯）
        $members = Member::orderBy('full_name')->get();

        // 預選會員
        $selectedMember = null;
        if ($request->filled('member_id')) {
            $selectedMember = Member::find($request->member_id);
        }

        return view('admin.incomes.create', [
            'chartOfAccounts' => $chartOfAccounts,
            'members' => $members,
            'selectedMember' => $selectedMember,
        ]);
    }

    /**
     * 儲存收入（出納記錄）
     */
    public function store(Request $request)
    {
        $validated = $request->validate([
            'title' => ['required', 'string', 'max:255'],
            'income_date' => ['required', 'date'],
            'amount' => ['required', 'numeric', 'min:0.01'],
            'income_type' => ['required', 'in:membership_fee,entrance_fee,donation,activity,grant,interest,other'],
            'chart_of_account_id' => ['required', 'exists:chart_of_accounts,id'],
            'payment_method' => ['required', 'in:cash,bank_transfer,check'],
            'bank_account' => ['nullable', 'string', 'max:255'],
            'payer_name' => ['nullable', 'string', 'max:255'],
            'member_id' => ['nullable', 'exists:members,id'],
            'receipt_number' => ['nullable', 'string', 'max:255'],
            'transaction_reference' => ['nullable', 'string', 'max:255'],
            'description' => ['nullable', 'string'],
            'notes' => ['nullable', 'string'],
            'attachment' => ['nullable', 'file', 'max:10240'],
        ]);

        // 處理附件上傳
        $attachmentPath = null;
        if ($request->hasFile('attachment')) {
            $attachmentPath = $request->file('attachment')->store('incomes', 'local');
        }

        $income = Income::create([
            'title' => $validated['title'],
            'income_date' => $validated['income_date'],
            'amount' => $validated['amount'],
            'income_type' => $validated['income_type'],
            'chart_of_account_id' => $validated['chart_of_account_id'],
            'payment_method' => $validated['payment_method'],
            'bank_account' => $validated['bank_account'] ?? null,
            'payer_name' => $validated['payer_name'] ?? null,
            'member_id' => $validated['member_id'] ?? null,
            'receipt_number' => $validated['receipt_number'] ?? null,
            'transaction_reference' => $validated['transaction_reference'] ?? null,
            'description' => $validated['description'] ?? null,
            'notes' => $validated['notes'] ?? null,
            'attachment_path' => $attachmentPath,
            'status' => Income::STATUS_PENDING,
            'recorded_by_cashier_id' => $request->user()->id,
            'recorded_at' => now(),
        ]);

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

        return redirect()
            ->route('admin.incomes.show', $income)
            ->with('status', '收入記錄已建立，等待會計確認。收入編號：' . $income->income_number);
    }

    /**
     * 收入詳情
     */
    public function show(Income $income)
    {
        $income->load([
            'chartOfAccount',
            'member',
            'recordedByCashier',
            'confirmedByAccountant',
            'cashierLedgerEntry',
            'accountingEntries.chartOfAccount',
        ]);

        return view('admin.incomes.show', [
            'income' => $income,
        ]);
    }

    /**
     * 會計確認收入
     */
    public function confirm(Request $request, Income $income)
    {
        $user = $request->user();

        // 檢查權限
        $canConfirm = $user->hasRole('admin') ||
                      $user->hasRole('finance_accountant');

        if (!$canConfirm) {
            abort(403, '您無權確認此收入。');
        }

        if (!$income->canBeConfirmed()) {
            return redirect()
                ->route('admin.incomes.show', $income)
                ->with('error', '此收入無法確認。');
        }

        try {
            $income->confirmByAccountant($user);

            AuditLogger::log('income.confirmed', $income, [
                'confirmed_by' => $user->name,
            ]);

            return redirect()
                ->route('admin.incomes.show', $income)
                ->with('status', '收入已確認。已自動產生出納日記帳和會計分錄。');
        } catch (\Exception $e) {
            return redirect()
                ->route('admin.incomes.show', $income)
                ->with('error', '確認失敗：' . $e->getMessage());
        }
    }

    /**
     * 取消收入
     */
    public function cancel(Request $request, Income $income)
    {
        $user = $request->user();

        // 檢查權限
        $canCancel = $user->hasRole('admin') ||
                     $user->hasRole('finance_accountant');

        if (!$canCancel) {
            abort(403, '您無權取消此收入。');
        }

        if (!$income->canBeCancelled()) {
            return redirect()
                ->route('admin.incomes.show', $income)
                ->with('error', '此收入無法取消。');
        }

        $validated = $request->validate([
            'cancel_reason' => ['nullable', 'string', 'max:1000'],
        ]);

        $income->cancel();

        AuditLogger::log('income.cancelled', $income, [
            'cancelled_by' => $user->name,
            'reason' => $validated['cancel_reason'] ?? null,
        ]);

        return redirect()
            ->route('admin.incomes.show', $income)
            ->with('status', '收入已取消。');
    }

    /**
     * 收入統計
     */
    public function statistics(Request $request)
    {
        $year = $request->input('year', date('Y'));
        $month = $request->input('month');

        // 依收入類型統計
        $byTypeQuery = Income::confirmed()
            ->whereYear('income_date', $year);

        if ($month) {
            $byTypeQuery->whereMonth('income_date', $month);
        }

        $byType = $byTypeQuery
            ->selectRaw('income_type, SUM(amount) as total_amount, COUNT(*) as count')
            ->groupBy('income_type')
            ->get();

        // 依月份統計
        $byMonth = Income::confirmed()
            ->whereYear('income_date', $year)
            ->selectRaw("CAST(strftime('%m', income_date) AS INTEGER) as month, SUM(amount) as total_amount, COUNT(*) as count")
            ->groupBy('month')
            ->orderBy('month')
            ->get();

        // 依會計科目統計
        $byAccountQuery = Income::confirmed()
            ->whereYear('income_date', $year);

        if ($month) {
            $byAccountQuery->whereMonth('income_date', $month);
        }

        $byAccountResults = $byAccountQuery
            ->selectRaw('chart_of_account_id, SUM(amount) as total_amount, COUNT(*) as count')
            ->groupBy('chart_of_account_id')
            ->get();

        // 手動載入會計科目關聯
        $accountIds = $byAccountResults->pluck('chart_of_account_id')->filter()->unique();
        $accounts = \App\Models\ChartOfAccount::whereIn('id', $accountIds)->get()->keyBy('id');

        $byAccount = $byAccountResults->map(function ($item) use ($accounts) {
            $item->chartOfAccount = $accounts->get($item->chart_of_account_id);
            return $item;
        });

        // 總計
        $totalQuery = Income::confirmed()
            ->whereYear('income_date', $year);

        if ($month) {
            $totalQuery->whereMonth('income_date', $month);
        }

        $total = [
            'amount' => $totalQuery->sum('amount'),
            'count' => $totalQuery->count(),
        ];

        return view('admin.incomes.statistics', [
            'year' => $year,
            'month' => $month,
            'byType' => $byType,
            'byMonth' => $byMonth,
            'byAccount' => $byAccount,
            'total' => $total,
        ]);
    }

    /**
     * 匯出收入
     */
    public function export(Request $request)
    {
        $query = Income::confirmed()
            ->with(['chartOfAccount', 'member', 'recordedByCashier'])
            ->orderByDesc('income_date');

        // 篩選日期範圍
        if ($request->filled('date_from')) {
            $query->where('income_date', '>=', $request->date_from);
        }
        if ($request->filled('date_to')) {
            $query->where('income_date', '<=', $request->date_to);
        }

        $incomes = $query->get();

        // 產生 CSV
        $filename = 'incomes_' . date('Y-m-d_His') . '.csv';

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

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

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

            // Header
            fputcsv($file, [
                '收入編號',
                '日期',
                '標題',
                '金額',
                '收入類型',
                '會計科目',
                '付款方式',
                '付款人',
                '會員',
                '收據編號',
                '狀態',
                '記錄人',
                '確認人',
            ]);

            foreach ($incomes as $income) {
                fputcsv($file, [
                    $income->income_number,
                    $income->income_date->format('Y-m-d'),
                    $income->title,
                    $income->amount,
                    $income->getIncomeTypeText(),
                    $income->chartOfAccount->account_name_zh ?? '',
                    $income->getPaymentMethodText(),
                    $income->payer_name,
                    $income->member->full_name ?? '',
                    $income->receipt_number,
                    $income->getStatusText(),
                    $income->recordedByCashier->name ?? '',
                    $income->confirmedByAccountant->name ?? '',
                ]);
            }

            fclose($file);
        };

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

    /**
     * 下載附件
     */
    public function download(Income $income)
    {
        if (!$income->attachment_path) {
            abort(404, '找不到附件。');
        }

        $path = storage_path('app/' . $income->attachment_path);

        if (!file_exists($path)) {
            abort(404, '附件檔案不存在。');
        }

        return response()->download($path);
    }
}