/*
 * PDF optimization (PDF/A standard applying) example.
 *
 * Run as: go run pdf_apply_standard.go <input.pdf> <output.pdf>
 */

package main

import (
	"fmt"
	"log"
	"os"
	"time"

	"github.com/unidoc/unipdf/v4/common/license"
	"github.com/unidoc/unipdf/v4/model"
	"github.com/unidoc/unipdf/v4/model/pdfa"
)

func init() {
	// Make sure to load your metered License API key prior to using the library.
	// If you need a key, you can sign up and create a free one at https://cloud.unidoc.io
	err := license.SetMeteredKey(os.Getenv(`UNIDOC_LICENSE_API_KEY`))
	if err != nil {
		panic(err)
	}
}

func main() {
	args := os.Args
	if len(args) < 3 {
		fmt.Printf("Usage: %s INPUT_PDF_PATH OUTPUT_PDF_PATH", os.Args[0])
		return
	}
	inputPath := args[1]
	outputPath := args[2]

	// Initialize starting time.
	start := time.Now()

	// Create reader.
	reader, file, err := model.NewPdfReaderFromFile(inputPath, nil)
	if err != nil {
		log.Fatalf("Fail: %v\n", err)
	}
	defer file.Close()

	// Generate a PDFWriter from PDFReader.
	pdfWriter, err := reader.ToWriter(nil)
	if err != nil {
		log.Fatalf("Fail: %v\n", err)
	}

	// Apply standard PDF/A-1B.
	pdfWriter.ApplyStandard(pdfa.NewProfile1B(nil))

	// Create output file.
	err = pdfWriter.WriteToFile(outputPath)
	if err != nil {
		log.Fatalf("Fail: %v\n", err)
	}

	duration := float64(time.Since(start)) / float64(time.Millisecond)
	fmt.Printf("Processing time: %.2f ms\n", duration)
}