<?php

namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use App\Models\ImportBatch;
use App\Models\Setting;
use App\Services\ActivityLogger;
use App\Services\ImportService;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Gate;
use Illuminate\Support\Facades\Storage;
use Maatwebsite\Excel\Facades\Excel;
use PhpOffice\PhpSpreadsheet\Spreadsheet;
use PhpOffice\PhpSpreadsheet\Writer\Xlsx;

class ImportController extends Controller
{
    public function __construct(private ImportService $importService) {}

    public function upload(Request $request): JsonResponse
    {
        Gate::authorize('import', ImportBatch::class);

        $allowedTypes = Setting::where('key', 'import_allowed_file_types')->value('value') ?: 'xlsx,xls,csv';
        $maxMb = max(1, (int) (Setting::where('key', 'import_max_file_size_mb')->value('value') ?: 10));
        $request->validate([
            'file' => 'required|file|mimes:'.$allowedTypes.'|max:'.($maxMb * 1024),
        ], [
            'file.mimes' => 'نوع فایل import مجاز نیست.',
            'file.max' => "حجم فایل import نباید بیشتر از {$maxMb} مگابایت باشد.",
        ]);

        $file = $request->file('file');
        $path = $file->store('imports');

        $batch = ImportBatch::create([
            'user_id' => auth()->id(),
            'filename' => $file->getClientOriginalName(),
            'status' => 'pending',
            'can_rollback' => Setting::where('key', 'import_rollback_allowed')->value('value') !== 'false',
        ]);

        try {
            $fullPath = Storage::path($path);
            $preview = $this->importService->preview($fullPath);

            // Store rows for later processing
            $rows = Excel::toArray([], $fullPath)[0] ?? [];
            $dataRows = array_slice($rows, 1);

            foreach ($dataRows as $index => $row) {
                $batch->rows()->create([
                    'original_data' => $row,
                    'status' => 'pending',
                ]);
            }

            $batch->update(['total_rows' => count($dataRows)]);
            ActivityLogger::log('lead_import_uploaded', "Import batch {$batch->id} uploaded", $batch);

            return response()->json([
                'batch_id' => $batch->id,
                'filename' => $file->getClientOriginalName(),
                'headers' => $preview['headers'],
                'total_rows' => $preview['total_rows'],
                'preview' => $preview['preview'],
            ]);
        } catch (\Exception $e) {
            $batch->update(['status' => 'failed', 'errors' => $e->getMessage()]);

            return response()->json(['message' => $e->getMessage()], 422);
        }
    }

    public function confirm(Request $request): JsonResponse
    {
        $user = auth()->user();
        Gate::authorize('import', ImportBatch::class);

        $validated = $request->validate([
            'batch_id' => 'required|exists:import_batches,id',
            'column_mapping' => 'required|array',
            'column_mapping.company' => 'required|integer',
            'column_mapping.first_name' => 'nullable|integer',
            'column_mapping.last_name' => 'nullable|integer',
            'column_mapping.phone' => 'required|integer',
            'column_mapping.phone_secondary' => 'nullable|integer',
            'column_mapping.email' => 'nullable|integer',
            'column_mapping.city' => 'nullable|integer',
            'column_mapping.province' => 'nullable|integer',
            'column_mapping.source' => 'nullable|integer',
            'column_mapping.product_interest' => 'nullable|integer',
            'column_mapping.priority' => 'nullable|integer',
            'column_mapping.lead_score' => 'nullable|integer',
            'column_mapping.interest_level' => 'nullable|integer',
            'column_mapping.notes' => 'nullable|integer',
            'column_mapping.tags' => 'nullable|integer',
            'campaign_id' => 'nullable|exists:campaigns,id',
            'agent_ids' => 'nullable|array',
            'agent_ids.*' => 'exists:users,id',
        ]);

        $agentIds = $validated['agent_ids'] ?? null;
        if ($user?->hasRole('agent')) {
            $agentIds = [$user->id];
        }

        $pendingBatch = ImportBatch::findOrFail($validated['batch_id']);
        Gate::authorize('view', $pendingBatch);

        $batch = $this->importService->confirm(
            $validated['batch_id'],
            $validated['column_mapping'],
            $validated['campaign_id'] ?? null,
            $agentIds,
            auth()->id()
        );
        ActivityLogger::log('lead_import_confirmed', "Import batch {$batch->id} confirmed", $batch);

        return response()->json($batch->load('rows'));
    }

    public function rollback(int $batchId): JsonResponse
    {
        $batch = ImportBatch::findOrFail($batchId);
        Gate::authorize('rollback', $batch);

        $this->importService->rollback($batchId);
        ActivityLogger::log('lead_import_rolled_back', "Import batch {$batchId} rolled back", $batch);

        return response()->json(['message' => 'بازگشت import انجام شد']);
    }

    public function index(): JsonResponse
    {
        Gate::authorize('viewAny', ImportBatch::class);

        return response()->json(
            ImportBatch::with('user:id,name')
                ->orderBy('created_at', 'desc')
                ->paginate(15)
        );
    }

    public function template()
    {
        Gate::authorize('import', ImportBatch::class);

        $spreadsheet = new Spreadsheet;
        $sheet = $spreadsheet->getActiveSheet();
        $sheet->fromArray([
            ['company', 'phone', 'phone_secondary', 'first_name', 'last_name', 'email', 'city', 'province', 'source', 'product_interest', 'priority', 'lead_score', 'interest_level', 'notes', 'tags'],
            ['Acme Industrial', '02112345678', '09121234567', 'Ali', 'Karimi', 'ali@example.com', 'Tehran', 'Tehran', 'Website', 'CRM', '5', '70', 'warm', 'Initial import note', 'b2b,website'],
            ['Pars Co', '02187654321', '', 'Sara', 'Ahmadi', 'sara@example.com', 'Shiraz', 'Fars', 'Exhibition', 'Support', '3', '40', 'cold', '', 'exhibition'],
        ]);

        $path = storage_path('app/import-template-b2b.xlsx');
        (new Xlsx($spreadsheet))->save($path);

        return response()->download($path, 'sample-leads-b2b.xlsx')->deleteFileAfterSend(true);
    }
}