mashingan · November 7, 2022 12:27 · Apr 30, 2019 · Apr 30, 2019
diff --git a/downloadmanga.go b/downloadmanga.go
@@ -11,6 +11,7 @@ import (
 	"strconv"
 	"strings"
 	"sync"
+	"time"
 )
 
 func toString(name xml.Name) string {
@@ -150,6 +151,7 @@ func main() {
 	var nextlink, imglink string
 	nextlink = mangaurl
 
+	start := time.Now()
 fetchingpage:
 	for {
 		nextlink, imglink, err = pageExtract(nextlink)
@@ -186,5 +188,6 @@ fetchingpage:
 		}
 	}
 	wg.Wait()
+	fmt.Println("ended after:", time.Now().Sub(start))
 
 }
diff --git a/downloadmanga.go b/downloadmanga.go
@@ -0,0 +1,190 @@
+package main
+
+import (
+	"encoding/xml"
+	"flag"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"os"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+func toString(name xml.Name) string {
+	return name.Space + ":" + name.Local
+
+}
+
+func isPageClass(t xml.StartElement) bool {
+	return t.Name == xml.Name{Space: "", Local: "div"} &&
+		len(t.Attr) > 0 &&
+		t.Attr[0].Value == "page"
+}
+
+func nextToken(d *xml.Decoder) (token xml.Token, err error) {
+	token, err = d.Token()
+	if err != nil {
+		return
+	}
+	switch v := token.(type) {
+	default:
+		fmt.Printf("the type: %T\n", v)
+	}
+	return
+}
+
+func pageExtract(linkurl string) (nextlink string, imglink string, err error) {
+	resp, err := http.Get(linkurl)
+	if err != nil {
+		return "", "", err
+	}
+	decoder := xml.NewDecoder(resp.Body)
+	decoder.AutoClose = []string{"link", "meta"}
+	decoder.Strict = false
+searching:
+	for {
+		token, err := decoder.Token()
+		if err != nil {
+			fmt.Println(err)
+			if err == io.EOF {
+				break searching
+			}
+		} else {
+			switch v := token.(type) {
+			case xml.StartElement:
+				if isPageClass(v) {
+					fmt.Println("found!")
+					break searching
+				}
+			default:
+			}
+		}
+	}
+	_, err = nextToken(decoder)
+	if err != nil {
+		fmt.Println(err)
+	}
+	stelm, err := nextToken(decoder)
+	nstelm, ok := stelm.(xml.StartElement)
+	if !ok {
+		fmt.Println("cannot convert to start element")
+		return "", "", fmt.Errorf("Error pageExtract: cannot convert to start element")
+	}
+	fmt.Println("next link:", nstelm.Attr[0].Value)
+
+	img, err := nextToken(decoder)
+	nimg, ok := img.(xml.StartElement)
+	if !ok {
+		fmt.Println("cannot convert to start element")
+		return "", "", fmt.Errorf("Error pageExtract: cannot convert to start element")
+	}
+	base, _ := url.Parse(linkurl)
+	nexturl, _ := url.Parse(nstelm.Attr[0].Value)
+	nextlink = base.ResolveReference(nexturl).String()
+	imglink = "https:" + nimg.Attr[1].Value
+	err = nil
+	return
+}
+
+func downloadFile(imglink string) error {
+	lenImgName := strings.Split(imglink, "/")
+	fname := lenImgName[len(lenImgName)-1]
+	file, err := os.Create(fname)
+	defer file.Close()
+	if err != nil {
+		fmt.Println(err)
+		return err
+	}
+	imgresp, err := http.Get(imglink)
+	if err != nil {
+		fmt.Println(err)
+		return err
+	}
+	defer imgresp.Body.Close()
+	size, err := io.Copy(file, imgresp.Body)
+	if err != nil {
+		fmt.Println(err)
+		return err
+	}
+	fmt.Printf("downloaded a file %s with size %d\n", fname, size)
+	return nil
+}
+
+func chapterExtract(link string) (int, error) {
+	rpos := strings.Index(link, "/r/")
+	if rpos == -1 {
+		return rpos, nil
+	}
+	nextslash := strings.Index(link[rpos+3:], "/")
+	nextslash += rpos + 3
+	chapstr := strings.Index(link[nextslash+1:], "/")
+	chapstr += nextslash + 1
+	intonly := link[nextslash+1 : chapstr]
+	result, err := strconv.Atoi(intonly)
+	if err != nil {
+		return -1, err
+	}
+	return result, nil
+
+}
+
+func main() {
+	mangaurl := ""
+	flag.StringVar(&mangaurl, "url", "", "Please specify the url")
+	flag.Parse()
+	if mangaurl == "" {
+		fmt.Println("url:", mangaurl)
+		panic("No url specified")
+	}
+
+	var wg sync.WaitGroup
+	thisChapter, err := chapterExtract(mangaurl)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+	fmt.Println("This chapter:", thisChapter)
+	var nextlink, imglink string
+	nextlink = mangaurl
+
+fetchingpage:
+	for {
+		nextlink, imglink, err = pageExtract(nextlink)
+		if err != nil {
+			fmt.Println(err)
+			return
+		}
+		fmt.Println("Next link:", nextlink)
+		fmt.Println("img link:", imglink)
+
+		if imglink == "" {
+			break fetchingpage
+		}
+
+		wg.Add(1)
+		go func(w *sync.WaitGroup, link string) {
+			defer w.Done()
+			if err := downloadFile(link); err != nil {
+				fmt.Println(err)
+			}
+		}(&wg, imglink)
+
+		nextChapter, err := chapterExtract(nextlink)
+		if err != nil {
+			fmt.Println(err)
+			return
+		} else if nextChapter == -1 {
+			break fetchingpage
+		}
+		fmt.Printf("old %d and current %d\n", thisChapter, nextChapter)
+
+		if nextChapter != thisChapter {
+			break fetchingpage
+		}
+	}
+	wg.Wait()
+
+}