package main

// Download images from web URLs and convert them to a pdf file with one click

import (
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"strconv"
)

func main() {

	fmt.Println("SCRIPT SUCCESFULLY STARTED")
	flag := 0
	fmt.Println("Is files ready? (1/0) (to just convert images to pdf and skip download section press 1)")
	fmt.Scanln(&flag)

	var name string
	if flag == 0 {

		var baseURL, fileFormat string
		var startNumber, endNumber int
		fmt.Println("Folder Name: (enter for default) ")
		fmt.Scanln(&name)

		fmt.Println("Base URL: ")
		fmt.Scanln(&baseURL)

		fmt.Println("Start Number: ")
		fmt.Scanln(&startNumber)

		fmt.Println("End Number: ")
		fmt.Scanln(&endNumber)

		fmt.Println("File Format: (enter for default .jpg format) ")
		fmt.Scanln(&fileFormat)

		if name == "" {
			name = "url-img-pdf_FOLDER"
		}
		if fileFormat == "" {
			fileFormat = "jpg"
		}

		name = "output/" + name

		if err := os.MkdirAll(name, os.ModePerm); err != nil {
			log.Fatal(err)
		}

		for i := startNumber; i <= endNumber; i++ {
			err := DownloadFile(name+"/img"+strconv.Itoa(i)+"."+fileFormat, baseURL+strconv.Itoa(i))
			if err != nil {
				panic(err)
			}
			fmt.Println("Downloaded: " + baseURL + strconv.Itoa(i))
		}
	}

	fmt.Println("installed all images, you can use a tool like pdfarranger for converting (too lazy to implement)")

}

// DownloadFile will download a url to a local file. It's efficient because it will
// write as it downloads and not load the whole file into memory. (NEEDS TEST!)
func DownloadFile(filepath string, url string) error {

	// Get the data
	resp, err := http.Get(url)
	if err != nil {
		return err
	}
	defer resp.Body.Close()

	// Create the file
	out, err := os.Create(filepath)
	if err != nil {
		return err
	}
	defer out.Close()

	// Write the body to file
	_, err = io.Copy(out, resp.Body)
	return err
}