<?php

namespace App\Jobs;

use App\Models\Document;
use Illuminate\Bus\Queueable;
use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Foundation\Bus\Dispatchable;
use Illuminate\Queue\InteractsWithQueue;
use Illuminate\Queue\SerializesModels;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Facades\Storage;

class GenerateDocumentPreview implements ShouldQueue
{
    use Dispatchable, InteractsWithQueue, Queueable, SerializesModels;

    public function __construct(public int $documentId)
    {
    }

    public function handle(): void
    {
        $doc = Document::find($this->documentId);
        if (!$doc)
            return;

        $disk = $doc->disk ?: 'public';
        if (!Storage::disk($disk)->exists($doc->path))
            return;

        $ext = strtolower(pathinfo($doc->original_name ?: $doc->file_name, PATHINFO_EXTENSION));
        if (!in_array($ext, ['doc', 'docx']))
            return; // only convert office docs here

        // Prepare temp files - keep original extension so LibreOffice can detect filter
        $tmpBase = sys_get_temp_dir() . DIRECTORY_SEPARATOR . 'doc_in_' . uniqid();
        $tmpIn = $tmpBase . '.' . $ext; // e.g., .doc or .docx
        file_put_contents($tmpIn, Storage::disk($disk)->get($doc->path));

        $outDir = sys_get_temp_dir();
        // Ensure exec is available
        if (!function_exists('exec')) {
            Log::error('Preview generation failed: exec() not available in this PHP environment', ['document_id' => $doc->id]);
            return;
        }
        $disabled = array_map('trim', explode(',', (string) ini_get('disable_functions')));
        if (in_array('exec', $disabled, true)) {
            Log::error('Preview generation failed: exec() is disabled in php.ini (disable_functions)', ['document_id' => $doc->id]);
            return;
        }

        // Run soffice headless to convert to PDF
        $binCfg = config('files.libreoffice_bin');
        $bin = $binCfg ? (string) $binCfg : 'soffice';
        // Windows quoting differs from POSIX. Build command parts safely.
        $isWin = strtoupper(substr(PHP_OS, 0, 3)) === 'WIN';
        if ($isWin) {
            $binPart = '"' . $bin . '"';
            $outDirPart = '"' . $outDir . '"';
            $inPart = '"' . $tmpIn . '"';
        } else {
            $binPart = escapeshellcmd($bin);
            $outDirPart = escapeshellarg($outDir);
            $inPart = escapeshellarg($tmpIn);
        }
        // Use a temporary user profile to avoid permissions/profile lock issues
        $loProfileDir = sys_get_temp_dir() . DIRECTORY_SEPARATOR . 'lo_profile_' . $doc->id;
        if (!is_dir($loProfileDir)) {
            @mkdir($loProfileDir, 0700, true);
        }
        $loProfileUri = 'file:///' . ltrim(str_replace('\\', '/', $loProfileDir), '/');

        $cmd = sprintf(
            '%s --headless --norestore --nolockcheck -env:UserInstallation=%s --convert-to pdf --outdir %s %s',
            $binPart,
            $isWin ? '"' . $loProfileUri . '"' : escapeshellarg($loProfileUri),
            $outDirPart,
            $inPart
        );

        // Capture stderr as well for diagnostics
        $cmdWithStderr = $cmd . ' 2>&1';
        Log::info('Starting LibreOffice preview conversion', [
            'document_id' => $doc->id,
            'cmd' => $cmd,
            'is_windows' => $isWin,
        ]);
        $out = [];
        $ret = 0;
        exec($cmdWithStderr, $out, $ret);
        if ($ret !== 0) {
            Log::warning('Preview generation failed', [
                'document_id' => $doc->id,
                'ret' => $ret,
                'cmd' => $cmd,
                'output' => implode("\n", $out),
            ]);
            @unlink($tmpIn);
            return;
        }

        $pdfPathLocal = $tmpIn . '.pdf';
        // LibreOffice writes output with source filename base; derive path
        $base = pathinfo($tmpIn, PATHINFO_FILENAME);
        $pdfPathLocal = $outDir . DIRECTORY_SEPARATOR . $base . '.pdf';
        if (!file_exists($pdfPathLocal)) {
            // fallback: try with original name base
            $origBase = pathinfo($doc->original_name ?: $doc->file_name, PATHINFO_FILENAME);
            $try = $outDir . DIRECTORY_SEPARATOR . $origBase . '.pdf';
            if (file_exists($try))
                $pdfPathLocal = $try;
        }
        if (!file_exists($pdfPathLocal)) {
            Log::warning('Preview generation did not produce expected PDF output', [
                'document_id' => $doc->id,
                'out_dir' => $outDir,
                'tmp_base' => $base,
                'command' => $cmd,
                'output' => implode("\n", $out),
            ]);
            @unlink($tmpIn);
            return;
        }

        // Store preview PDF to configured disk inside configured previews base path
        $previewDisk = config('files.preview_disk', 'public');
        $base = trim(config('files.preview_base', 'previews/cases'), '/');
        $previewDir = $base . '/' . ($doc->documentable?->uuid ?? 'unknown');
        $stored = Storage::disk($previewDisk)->put($previewDir . '/' . ($doc->uuid) . '.pdf', file_get_contents($pdfPathLocal));
        if ($stored) {
            $doc->preview_path = $previewDir . '/' . $doc->uuid . '.pdf';
            $doc->preview_mime = 'application/pdf';
            $doc->preview_generated_at = now();
            $doc->save();
        }

        @unlink($tmpIn);
        @unlink($pdfPathLocal);
        // Clean up temporary LO profile directory
        try {
            if (is_dir($loProfileDir)) {
                @rmdir($loProfileDir);
            }
        } catch (\Throwable $e) {
            // ignore
        }
    }
}