//go:build !nofitz

package services

import (
	"fmt"
	"image"
	"image/jpeg"
	"image/png"
	"os"
	"path/filepath"
	"strings"

	"github.com/gen2brain/go-fitz"
)

func extractTextWithFitz(inputPath string) (string, error) {
	doc, err := fitz.New(inputPath)
	if err != nil {
		return "", fmt.Errorf("open PDF failed: %v", err)
	}
	defer doc.Close()

	var texts []string
	for i := 0; i < doc.NumPage(); i++ {
		text, err := doc.Text(i)
		if err != nil {
			continue
		}
		if text != "" {
			texts = append(texts, text)
		}
	}
	return strings.Join(texts, "\n\n"), nil
}

func pdfToImagesWithFitz(inputPath, outputDir, format string, dpi float64) ([]string, error) {
	if outputDir == "" {
		outputDir = filepath.Dir(inputPath)
	}
	if dpi <= 0 {
		dpi = 150
	}

	doc, err := fitz.New(inputPath)
	if err != nil {
		return nil, fmt.Errorf("open PDF failed: %v", err)
	}
	defer doc.Close()

	baseName := GetBaseName(inputPath)
	var results []string

	for i := 0; i < doc.NumPage(); i++ {
		img, err := doc.ImageDPI(i, dpi)
		if err != nil {
			continue
		}

		var outPath string
		if format == "jpeg" || format == "jpg" {
			outPath = filepath.Join(outputDir, fmt.Sprintf("%s_page_%d.jpg", baseName, i+1))
			err = saveJPEGFile(img, outPath, 90)
		} else {
			outPath = filepath.Join(outputDir, fmt.Sprintf("%s_page_%d.png", baseName, i+1))
			err = savePNGFile(img, outPath)
		}
		if err == nil {
			results = append(results, outPath)
		}
	}

	if len(results) == 0 {
		return nil, fmt.Errorf("no images generated")
	}
	return results, nil
}

func savePNGFile(img image.Image, path string) error {
	f, err := os.Create(path)
	if err != nil {
		return err
	}
	defer f.Close()
	return png.Encode(f, img)
}

func saveJPEGFile(img image.Image, path string, quality int) error {
	f, err := os.Create(path)
	if err != nil {
		return err
	}
	defer f.Close()
	return jpeg.Encode(f, img, &jpeg.Options{Quality: quality})
}