<?php

namespace App\Http\Controllers;

use App\Models\Document;
use App\Services\DocumentPdfPreviewService;
use App\Services\DocumentService;
use Illuminate\Support\Facades\Gate;

class DocumentController extends Controller
{
    protected DocumentService $documentService;
    protected DocumentPdfPreviewService $pdfPreviewService;

    public function __construct(
        DocumentService $documentService,
        DocumentPdfPreviewService $pdfPreviewService
    ) {
        $this->documentService = $documentService;
        $this->pdfPreviewService = $pdfPreviewService;
    }

    /**
     * 预览文档的 PDF 内容
     * 需求：11.1, 11.3, 11.4
     * 
     * @param Document $document
     * @return \Illuminate\View\View|\Illuminate\Http\RedirectResponse
     */
    public function preview(Document $document)
    {
        if (!Gate::allows('view', $document)) {
            abort(403, '您没有权限预览此文档');
        }

        return view('documents.preview', [
            'document' => $document,
            'canPreviewPdf' => $this->pdfPreviewService->canPreview($document),
            'previewPdfUrl' => $this->pdfPreviewService->previewUrl($document),
        ]);
    }

    public function previewPdf(Document $document)
    {
        if (! Gate::allows('view', $document)) {
            abort(403, '您没有权限预览此文档');
        }

        try {
            $path = $this->pdfPreviewService->getPreviewPath($document);
        } catch (\Throwable $e) {
            \Log::error('PDF 预览生成失败', [
                'document_id' => $document->id,
                'error' => $e->getMessage(),
            ]);

            abort(500, 'PDF 预览生成失败：' . $e->getMessage());
        }

        return response()->file($path, [
            'Content-Type' => 'application/pdf',
            'Content-Disposition' => 'inline; filename="document-' . $document->getKey() . '.pdf"',
        ]);
    }

    /**
     * 下载文档
     * 
     * @param Document $document
     * @return \Symfony\Component\HttpFoundation\StreamedResponse
     */
    public function download(Document $document)
    {
        // 验证用户权限
        if (!Gate::allows('download', $document)) {
            abort(403, '您没有权限下载此文档');
        }

        $user = auth()->user();

        try {
            // 记录下载日志
            $this->documentService->logDownload($document, $user);
            
            // 返回文件下载响应
            return $this->documentService->downloadDocument($document, $user);
        } catch (\Exception $e) {
            abort(500, '下载失败：' . $e->getMessage());
        }
    }
}