episode ranges

README.md

@@ -5,7 +5,14 @@ Download [webtoon](https://www.webtoons.com/en/) comics as PDFs using a terminal
 ## Usage
 
 ```shell
-webtoon-dl <your-webtoon-url>
+# download single episodes
+webtoon-dl <your-webtoon-episode-url>
+
+# download entire series
+webtoon-dl <your-webtoon-series-url>
+
+# create single pdfs from a range of episodes (inclusive)
+webtoon-dl --min-ep=10 --max-ep=20 <your-webtoon-series-url>
 ```
 
 ## Installation

main.go

@@ -2,11 +2,13 @@ package main
 
 import (
 	"bytes"
+	"flag"
 	"fmt"
 	"github.com/anaskhan96/soup"
 	"github.com/signintech/gopdf"
 	"image"
 	"io"
+	"math"
 	"net/http"
 	"os"
 	"regexp"
@@ -18,7 +20,7 @@ import (
 
 func getImgLinksForEpisode(url string) []string {
 	resp, err := soup.Get(url)
-	time.Sleep(500 * time.Millisecond)
+	time.Sleep(200 * time.Millisecond)
 	if err != nil {
 		fmt.Println(fmt.Sprintf("Error fetching page: %v", err))
 		os.Exit(1)
@@ -37,7 +39,7 @@ func getImgLinksForEpisode(url string) []string {
 
 func getEpisodeLinksForPage(url string) ([]string, error) {
 	resp, err := soup.Get(url)
-	time.Sleep(500 * time.Millisecond)
+	time.Sleep(200 * time.Millisecond)
 	if err != nil {
 		return []string{}, fmt.Errorf("error fetching page: %v", err)
 	}
@@ -52,14 +54,31 @@ func getEpisodeLinksForPage(url string) ([]string, error) {
 	return links, nil
 }
 
-func getImgLinks(url string) []string {
+func getImgLinks(url string, minEp, maxEp int) ([]string, int, int) {
 	if strings.Contains(url, "/viewer") {
 		// assume viewing single episode
-		return getImgLinksForEpisode(url)
+		return getImgLinksForEpisode(url), episodeNo(url), episodeNo(url)
 	} else {
 		// assume viewing list of episodes
+		println("scanning all pages to get all episode links")
+		allEpisodeLinks := getAllEpisodeLinks(url)
+		println(fmt.Sprintf("found %d total episodes", len(allEpisodeLinks)))
+
+		var desiredEpisodeLinks []string
+		for _, episodeLink := range allEpisodeLinks {
+			epNo := episodeNo(episodeLink)
+			if epNo >= minEp && epNo <= maxEp {
+				desiredEpisodeLinks = append(desiredEpisodeLinks, episodeLink)
+			}
+		}
+
+		return getImgLinksForEpisodes(desiredEpisodeLinks), episodeNo(desiredEpisodeLinks[0]), episodeNo(desiredEpisodeLinks[len(desiredEpisodeLinks)-1])
+	}
+}
+
+func getAllEpisodeLinks(url string) []string {
 	re := regexp.MustCompile("&page=[0-9]+")
-		allEpisodeLinks := make(map[string]struct{})
+	episodeLinkSet := make(map[string]struct{})
 	foundLastPage := false
 	for page := 1; !foundLastPage; page++ {
 		url = re.ReplaceAllString(url, "") + fmt.Sprintf("&page=%d", page)
@@ -69,23 +88,31 @@ func getImgLinks(url string) []string {
 		}
 		for _, episodeLink := range episodeLinks {
 			// when you go past the last page, it just rerenders the last page
-				if _, ok := allEpisodeLinks[episodeLink]; ok {
+			if _, ok := episodeLinkSet[episodeLink]; ok {
 				foundLastPage = true
 				break
 			}
-				allEpisodeLinks[episodeLink] = struct{}{}
+			episodeLinkSet[episodeLink] = struct{}{}
 		}
 		if !foundLastPage {
 			println(url)
 		}
 	}
-		keys := make([]string, 0, len(allEpisodeLinks))
+
-		for k := range allEpisodeLinks {
+	allEpisodeLinks := make([]string, 0, len(episodeLinkSet))
-			keys = append(keys, k)
+	for episodeLink := range episodeLinkSet {
+		allEpisodeLinks = append(allEpisodeLinks, episodeLink)
 	}
+
 	// extract episode_no from url and sort by it
-		re = regexp.MustCompile("episode_no=([0-9]+)")
+	sort.Slice(allEpisodeLinks, func(i, j int) bool {
-		episodeNo := func(episodeLink string) int {
+		return episodeNo(allEpisodeLinks[i]) < episodeNo(allEpisodeLinks[j])
+	})
+	return allEpisodeLinks
+}
+
+func episodeNo(episodeLink string) int {
+	re := regexp.MustCompile("episode_no=([0-9]+)")
 	matches := re.FindStringSubmatch(episodeLink)
 	if len(matches) != 2 {
 		return 0
@@ -95,18 +122,15 @@ func getImgLinks(url string) []string {
 		return 0
 	}
 	return episodeNo
-		}
+}
-		sort.Slice(keys, func(i, j int) bool {
-			return episodeNo(keys[i]) < episodeNo(keys[j])
-		})
 
+func getImgLinksForEpisodes(episodeLinks []string) []string {
 	var allImgLinks []string
-		for _, episodeLink := range keys {
+	for _, episodeLink := range episodeLinks {
-			println(episodeLink)
+		println(fmt.Sprintf("fetching images for episode %d (last episode %d)", episodeNo(episodeLink), episodeNo(episodeLinks[len(episodeLinks)-1])))
 		allImgLinks = append(allImgLinks, getImgLinksForEpisode(episodeLink)...)
 	}
 	return allImgLinks
-	}
 }
 
 func fetchImage(imgLink string) []byte {
@@ -139,30 +163,16 @@ func fetchImage(imgLink string) []byte {
 	return buff.Bytes()
 }
 
-func main() {
+func addImgToPdf(pdf *gopdf.GoPdf, imgLink string) error {
-	if len(os.Args) < 2 {
-		fmt.Println("Usage: webtoon-dl <url>")
-		os.Exit(1)
-	}
-	url := os.Args[1]
-	imgLinks := getImgLinks(url)
-	fmt.Println(fmt.Sprintf("found %d pages", len(imgLinks)))
-
-	pdf := gopdf.GoPdf{}
-	pdf.Start(gopdf.Config{Unit: gopdf.UnitPT, PageSize: *gopdf.PageSizeA4})
-	for _, imgLink := range imgLinks {
-		fmt.Println(imgLink)
 	img := fetchImage(imgLink)
 	holder, err := gopdf.ImageHolderByBytes(img)
 	if err != nil {
-			fmt.Println(err.Error())
+		return err
-			os.Exit(1)
 	}
 
 	d, _, err := image.DecodeConfig(bytes.NewReader(img))
 	if err != nil {
-			fmt.Println(err.Error())
+		return err
-			os.Exit(1)
 	}
 
 	// gopdf assumes dpi 128 https://github.com/signintech/gopdf/issues/168
@@ -173,11 +183,35 @@ func main() {
 		W: float64(d.Width)*72/128 - 1,
 		H: float64(d.Height)*72/128 - 1,
 	}})
-		err = pdf.ImageByHolder(holder, 0, 0, nil)
+	return pdf.ImageByHolder(holder, 0, 0, nil)
+}
+
+func main() {
+	if len(os.Args) < 2 {
+		fmt.Println("Usage: webtoon-dl <url>")
+		os.Exit(1)
+	}
+	minEp := flag.Int("min-ep", 0, "Minimum episode number to download (inclusive)")
+	maxEp := flag.Int("max-ep", math.MaxInt, "Maximum episode number to download (inclusive)")
+	flag.Parse()
+	if *minEp > *maxEp {
+		fmt.Println("min-ep must be less than or equal to max-ep")
+		os.Exit(1)
+	}
+
+	url := os.Args[len(os.Args)-1]
+	imgLinks, actualMinEp, actualMaxEp := getImgLinks(url, *minEp, *maxEp)
+	fmt.Println(fmt.Sprintf("found %d pages", len(imgLinks)))
+
+	pdf := gopdf.GoPdf{}
+	pdf.Start(gopdf.Config{Unit: gopdf.UnitPT, PageSize: *gopdf.PageSizeA4})
+	for idx, imgLink := range imgLinks {
+		err := addImgToPdf(&pdf, imgLink)
 		if err != nil {
 			fmt.Println(err.Error())
 			os.Exit(1)
 		}
+		fmt.Println(fmt.Sprintf("added page %d/%d", idx+1, len(imgLinks)))
 	}
 
 	outURL := strings.ReplaceAll(url, "http://", "")
@@ -187,6 +221,11 @@ func main() {
 	outURL = strings.Split(outURL, "?")[0]
 	outURL = strings.ReplaceAll(outURL, "/viewer", "")
 	outURL = strings.ReplaceAll(outURL, "/", "-")
+	if actualMinEp != actualMaxEp {
+		outURL = fmt.Sprintf("%s-ep%d-%d", outURL, actualMinEp, actualMaxEp)
+	} else {
+		outURL = fmt.Sprintf("%s-ep%d", outURL, actualMinEp)
+	}
 	outPath := outURL + ".pdf"
 	err := pdf.WritePdf(outPath)
 	if err != nil {