Move all the code to a lib folder

lib/cover.go

@@ -0,0 +1,190 @@
+package trantor
+
+import (
+	_ "image/gif"
+	_ "image/jpeg"
+	_ "image/png"
+
+	log "github.com/cihub/seelog"
+
+	"bytes"
+	"image"
+	"image/jpeg"
+	"io"
+	"io/ioutil"
+	"regexp"
+	"strings"
+
+	"github.com/gorilla/mux"
+	"github.com/meskio/epubgo"
+	"github.com/nfnt/resize"
+	"gitlab.com/trantor/trantor/lib/storage"
+)
+
+func coverHandler(h handler) {
+	vars := mux.Vars(h.r)
+	book, err := h.db.GetBookId(vars["id"])
+	if err != nil {
+		notFound(h)
+		return
+	}
+
+	if !book.Active {
+		if !h.sess.IsAdmin() {
+			notFound(h)
+			return
+		}
+	}
+
+	file := COVER_FILE
+	if vars["size"] == "small" {
+		file = COVER_SMALL_FILE
+	}
+	f, err := h.store.Get(book.Id, file)
+	if err != nil {
+		log.Error("Error while opening image: ", err)
+		notFound(h)
+		return
+	}
+	defer f.Close()
+
+	headers := h.w.Header()
+	headers["Content-Type"] = []string{"image/jpeg"}
+
+	_, err = io.Copy(h.w, f)
+	if err != nil {
+		log.Error("Error while copying image: ", err)
+		notFound(h)
+		return
+	}
+}
+
+func GetCover(e *epubgo.Epub, id string, store *storage.Store) bool {
+	if coverFromMetadata(e, id, store) {
+		return true
+	}
+
+	if searchCommonCoverNames(e, id, store) {
+		return true
+	}
+
+	/* search for img on the text */
+	exp, _ := regexp.Compile("<.*ima?g.*[(src)(href)]=[\"']([^\"']*(\\.[^\\.\"']*))[\"']")
+	it, errNext := e.Spine()
+	for errNext == nil {
+		file, err := it.Open()
+		if err != nil {
+			break
+		}
+		defer file.Close()
+
+		txt, err := ioutil.ReadAll(file)
+		if err != nil {
+			break
+		}
+		res := exp.FindSubmatch(txt)
+		if res != nil {
+			href := string(res[1])
+			urlPart := strings.Split(it.URL(), "/")
+			url := strings.Join(urlPart[:len(urlPart)-1], "/")
+			if href[:3] == "../" {
+				href = href[3:]
+				url = strings.Join(urlPart[:len(urlPart)-2], "/")
+			}
+			href = strings.Replace(href, "%20", " ", -1)
+			href = strings.Replace(href, "%27", "'", -1)
+			href = strings.Replace(href, "%28", "(", -1)
+			href = strings.Replace(href, "%29", ")", -1)
+			if url == "" {
+				url = href
+			} else {
+				url = url + "/" + href
+			}
+
+			img, err := e.OpenFile(url)
+			if err == nil {
+				defer img.Close()
+				return storeImg(img, id, store)
+			}
+		}
+		errNext = it.Next()
+	}
+	return false
+}
+
+func coverFromMetadata(e *epubgo.Epub, id string, store *storage.Store) bool {
+	metaList, _ := e.MetadataAttr("meta")
+	for _, meta := range metaList {
+		if meta["name"] == "cover" {
+			img, err := e.OpenFileId(meta["content"])
+			if err == nil {
+				defer img.Close()
+				return storeImg(img, id, store)
+			}
+		}
+	}
+	return false
+}
+
+func searchCommonCoverNames(e *epubgo.Epub, id string, store *storage.Store) bool {
+	for _, p := range []string{"cover.jpg", "Images/cover.jpg", "images/cover.jpg", "cover.jpeg", "cover1.jpg", "cover1.jpeg"} {
+		img, err := e.OpenFile(p)
+		if err == nil {
+			defer img.Close()
+			return storeImg(img, id, store)
+		}
+	}
+	return false
+}
+
+func storeImg(img io.Reader, id string, store *storage.Store) bool {
+	/* open the files */
+	fBig, err := store.Create(id, COVER_FILE)
+	if err != nil {
+		log.Error("Error creating cover ", id, ": ", err.Error())
+		return false
+	}
+	defer fBig.Close()
+
+	fSmall, err := store.Create(id, COVER_SMALL_FILE)
+	if err != nil {
+		log.Error("Error creating small cover ", id, ": ", err.Error())
+		return false
+	}
+	defer fSmall.Close()
+
+	/* resize img */
+	var img2 bytes.Buffer
+	img1 := io.TeeReader(img, &img2)
+	jpgOptions := jpeg.Options{IMG_QUALITY}
+	imgResized, err := resizeImg(img1, IMG_WIDTH_BIG)
+	if err != nil {
+		log.Error("Error resizing big image: ", err.Error())
+		return false
+	}
+	err = jpeg.Encode(fBig, imgResized, &jpgOptions)
+	if err != nil {
+		log.Error("Error encoding big image: ", err.Error())
+		return false
+	}
+	imgSmallResized, err := resizeImg(&img2, IMG_WIDTH_SMALL)
+	if err != nil {
+		log.Error("Error resizing small image: ", err.Error())
+		return false
+	}
+	err = jpeg.Encode(fSmall, imgSmallResized, &jpgOptions)
+	if err != nil {
+		log.Error("Error encoding small image: ", err.Error())
+		return false
+	}
+	return true
+}
+
+func resizeImg(imgReader io.Reader, width uint) (image.Image, error) {
+	img, _, err := image.Decode(imgReader)
+	if err != nil {
+		return nil, err
+	}
+
+	return resize.Resize(width, 0, img, resize.NearestNeighbor), nil
+}