<?php

namespace App\Services\RegisterCreator;

use Illuminate\Support\Facades\Log;
use Exception;

class PdfConverter
{
    /**
     * Convert Excel to PDF using xlsx_to_pdf_legacy helper
     */
    public function convert(string $excelPath, string $pdfPath, bool $override = true): string
    {
        $fullExcelPath = storage_path('documents/' . $excelPath);
        $fullPdfPath = storage_path('documents/' . $pdfPath);
        
        if (!file_exists($fullExcelPath)) {
            throw new Exception("Excel file not found: {$fullExcelPath}");
        }
        
        // Prepare PDF filename
        $pdfFileName = rtrim($fullPdfPath, '/') . 'Register.pdf';
        
        // Check override setting
        if (!$override && file_exists($pdfFileName)) {
            $pdfFileName = $this->generateUniquePdfFilename($pdfFileName);
            $pdfPath = str_replace(storage_path('documents/'), '', dirname($pdfFileName)) . '/';
            Log::debug('PDF exists and override is false, using unique name', [
                'path' => $pdfFileName
            ]);
        }
        
        Log::debug('Converting Excel to PDF', [
            'excel' => $fullExcelPath,
            'pdf_dir' => $fullPdfPath
        ]);
        
        try {
            // Use existing helper function
            $result = xlsx_to_pdf_legacy($fullExcelPath, $fullPdfPath);
            
            if (!$result) {
                throw new Exception("PDF conversion failed");
            }
            
            // Fix file permissions if PDF was created
            if (file_exists($pdfFileName)) {
                try {
                    // Change owner to www-data for web access
                    chown($pdfFileName, 'www-data');
                    chgrp($pdfFileName, 'www-data');
                    chmod($pdfFileName, 0644);
                } catch (\Throwable $th) {
                    Log::warning('Could not change PDF file permissions', [
                        'file' => $pdfFileName,
                        'error' => $th->getMessage()
                    ]);
                }
            }
            
            Log::debug('PDF conversion successful', [
                'pdf_file' => $pdfFileName,
                'exists' => file_exists($pdfFileName)
            ]);
            
            return $pdfPath;
            
        } catch (\Throwable $th) {
            Log::error('PDF conversion error', [
                'error' => $th->getMessage(),
                'excel' => $fullExcelPath,
                'pdf_dir' => $fullPdfPath
            ]);
            throw $th;
        }
    }
    
    /**
     * Generate unique PDF filename if file exists
     */
    private function generateUniquePdfFilename(string $filePath): string
    {
        $counter = 1;
        $pathInfo = pathinfo($filePath);
        
        do {
            $newFileName = $pathInfo['dirname'] . '/' . 
                          $pathInfo['filename'] . '_' . $counter . '.' . 
                          $pathInfo['extension'];
            $counter++;
        } while (file_exists($newFileName));
        
        return $newFileName;
    }
}