<?php

namespace App\Http\Controllers\Api\V1\Admin;

use App\Http\Controllers\Api\V1\ApiController;
use App\Http\Requests\Qr\GenerateBatchRequest;
use App\Http\Resources\QrCodeBatchResource;
use App\Http\Resources\QrCodeResource;
use App\Models\QrCodeBatch;
use App\Models\ServiceArea;
use App\Services\Qr\BatchGenerator;
use Barryvdh\DomPDF\Facade\Pdf;
use Endroid\QrCode\Builder\Builder;
use Endroid\QrCode\ErrorCorrectionLevel;
use Endroid\QrCode\Writer\PngWriter;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Picqer\Barcode\BarcodeGeneratorPNG;
use Symfony\Component\HttpFoundation\Response;

class AdminQrBatchController extends ApiController
{
    public function index(Request $request): JsonResponse
    {
        $request->validate([
            'purpose' => ['nullable', 'in:free_allocation,store_inventory,promotional'],
            'target_area_id' => ['nullable', 'integer'],
            'q' => ['nullable', 'string', 'max:100'],
            'per_page' => ['nullable', 'integer', 'min:1', 'max:100'],
        ]);

        $perPage = (int) $request->input('per_page', 25);

        $batches = QrCodeBatch::query()
            ->with(['targetArea', 'createdBy'])
            ->withCount('codes')
            ->when($request->filled('purpose'), fn ($q) => $q->where('purpose', $request->string('purpose')))
            ->when(
                $request->filled('target_area_id'),
                fn ($q) => $q->where('target_area_id', $request->integer('target_area_id')),
            )
            ->when(
                $request->filled('q'),
                fn ($q) => $q->where('batch_number', 'like', '%'.$request->string('q').'%'),
            )
            ->orderByDesc('id')
            ->paginate($perPage);

        return $this->ok(
            QrCodeBatchResource::collection($batches),
            null,
            [
                'page' => $batches->currentPage(),
                'per_page' => $batches->perPage(),
                'total' => $batches->total(),
                'last_page' => $batches->lastPage(),
            ],
        );
    }

    public function store(GenerateBatchRequest $request, BatchGenerator $generator): JsonResponse
    {
        $data = $request->validated();
        $area = isset($data['target_area_id'])
            ? ServiceArea::where('uuid', $data['target_area_id'])->first()
            : null;

        $batch = $generator->generate(
            quantity: (int) $data['quantity'],
            purpose: $data['purpose'],
            targetArea: $area,
            targetStoreId: $data['target_store_id'] ?? null,
            createdBy: $request->user(),
            expiresAt: isset($data['expires_at']) ? \Carbon\Carbon::parse($data['expires_at']) : null,
            notes: $data['notes'] ?? null,
        );

        $batch->load(['targetArea', 'createdBy', 'codes']);

        return $this->created(new QrCodeBatchResource($batch), 'Batch generated');
    }

    public function show(QrCodeBatch $qrCodeBatch): JsonResponse
    {
        $qrCodeBatch->load(['targetArea', 'createdBy', 'codes']);

        return $this->ok(new QrCodeBatchResource($qrCodeBatch));
    }

    public function markPrinted(QrCodeBatch $qrCodeBatch): JsonResponse
    {
        if ($qrCodeBatch->printed_at) {
            return $this->fail('Batch already marked as printed', null, 422);
        }

        $qrCodeBatch->forceFill(['printed_at' => now()])->save();

        return $this->ok(
            new QrCodeBatchResource($qrCodeBatch->fresh()->load(['targetArea', 'createdBy', 'codes'])),
            'Batch marked as printed',
        );
    }

    public function showCode(string $serial): JsonResponse
    {
        $code = \App\Models\QrCode::query()
            ->with(['batch.targetArea', 'household.head', 'usedAtDropOff', 'scannedBy'])
            ->where('serial', $serial)
            ->firstOrFail();

        return $this->ok(new QrCodeResource($code));
    }

    public function printPdf(QrCodeBatch $qrCodeBatch): Response
    {
        $codes = $qrCodeBatch->codes()->orderBy('id')->get();

        $rendered = $codes->map(function ($c) {
            return [
                'serial' => $c->serial,
                'qr_data_uri' => $this->qrDataUri($c->serial),
                'barcode_data_uri' => $this->barcodeDataUri($c->serial),
            ];
        })->all();

        $perPage = 24;
        $pages = array_chunk($rendered, $perPage);

        $pdf = Pdf::loadView('pdf.qr-batch', [
            'batch' => $qrCodeBatch,
            'pages' => $pages,
        ])->setPaper('a4');

        $filename = "verde-{$qrCodeBatch->batch_number}.pdf";

        return $pdf->download($filename);
    }

    private function qrDataUri(string $serial): string
    {
        $result = (new Builder(
            writer: new PngWriter(),
            data: $serial,
            errorCorrectionLevel: ErrorCorrectionLevel::Medium,
            size: 140,
            margin: 4,
        ))->build();

        return $result->getDataUri();
    }

    private function barcodeDataUri(string $serial): string
    {
        $generator = new BarcodeGeneratorPNG();
        $png = $generator->getBarcode($serial, BarcodeGeneratorPNG::TYPE_CODE_128, 1, 28);

        return 'data:image/png;base64,'.base64_encode($png);
    }
}