load images, simplify generator

internal/epub/core.go

@@ -3,7 +3,6 @@ package epub
 import (
 	"archive/zip"
 	"fmt"
-	"io"
 	"io/fs"
 	"os"
 	"path/filepath"
@@ -21,16 +20,11 @@ import (
 	imageconverter "go-comic-converter/internal/image-converter"
 )
 
-type ImageDetails struct {
-	*Images
-	Data   io.Reader
-	Width  int
-	Height int
-}
-
 type Images struct {
 	Id     int
-	Title string
+	Data   []byte
+	Width  int
+	Height int
 }
 
 type EPub struct {
@@ -47,11 +41,11 @@ type EPub struct {
 	Crop       bool
 	LimitMb    int
 
-	Images          []*Images
-	FirstImageTitle string
 	Error error
 
-	ProcessingImages func() chan *ImageDetails
+	ImagesCount       int
+	ProcessingImages  func() chan *Images
+	TemplateProcessor *template.Template
 }
 
 func NewEpub(path string) *EPub {
@@ -60,6 +54,12 @@ func NewEpub(path string) *EPub {
 		panic(err)
 	}
 
+	tmpl := template.New("parser")
+	tmpl.Funcs(template.FuncMap{
+		"mod":  func(i, j int) bool { return i%j == 0 },
+		"zoom": func(s int, z float32) int { return int(float32(s) * z) },
+	})
+
 	return &EPub{
 		Path: path,
 
@@ -71,6 +71,8 @@ func NewEpub(path string) *EPub {
 		ViewWidth:  0,
 		ViewHeight: 0,
 		Quality:    75,
+
+		TemplateProcessor: tmpl,
 	}
 }
 
@@ -105,11 +107,17 @@ func (e *EPub) SetLimitMb(l int) *EPub {
 	return e
 }
 
-func (e *EPub) WriteString(wz *zip.Writer, file string, content string) error {
+func (e *EPub) WriteFile(wz *zip.Writer, file string, data any) error {
-	return e.WriteBuffer(wz, file, strings.NewReader(content))
+	var content []byte
+	switch b := data.(type) {
+	case string:
+		content = []byte(b)
+	case []byte:
+		content = b
+	default:
+		return fmt.Errorf("support string of []byte")
 	}
 
-func (e *EPub) WriteBuffer(wz *zip.Writer, file string, content io.Reader) error {
 	m, err := wz.CreateHeader(&zip.FileHeader{
 		Name:     file,
 		Modified: time.Now(),
@@ -117,15 +125,12 @@ func (e *EPub) WriteBuffer(wz *zip.Writer, file string, content io.Reader) error
 	if err != nil {
 		return err
 	}
-	_, err = io.Copy(m, content)
+	_, err = m.Write(content)
 	return err
 }
 
 func (e *EPub) Render(templateString string, data any) string {
-	tmpl := template.New("parser")
+	tmpl, err := e.TemplateProcessor.Parse(templateString)
-	tmpl.Funcs(template.FuncMap{"mod": func(i, j int) bool { return i%j == 0 }})
-	tmpl.Funcs(template.FuncMap{"zoom": func(s int, z float32) int { return int(float32(s) * z) }})
-	tmpl, err := tmpl.Parse(templateString)
 	if err != nil {
 		panic(err)
 	}
@@ -164,38 +169,40 @@ func (e *EPub) LoadDir(dirname string) *EPub {
 	}
 	sort.Strings(images)
 
-	titleFormat := fmt.Sprintf("%%0%dd", len(fmt.Sprint(len(images)-1)))
+	e.ImagesCount = len(images)
-
-	for i := range images {
-		e.Images = append(e.Images, &Images{
-			Id:    i,
-			Title: fmt.Sprintf(titleFormat, i),
-		})
-	}
 
 	type Todo struct {
-		*Images
+		Id   int
 		Path string
 	}
 
 	todo := make(chan *Todo)
 
-	e.ProcessingImages = func() chan *ImageDetails {
+	e.ProcessingImages = func() chan *Images {
 		wg := &sync.WaitGroup{}
-		results := make(chan *ImageDetails)
+		results := make(chan *Images)
 		for i := 0; i < runtime.NumCPU(); i++ {
 			wg.Add(1)
 			go func() {
 				defer wg.Done()
 				for task := range todo {
 					data, w, h := imageconverter.Convert(task.Path, e.Crop, e.ViewWidth, e.ViewHeight, e.Quality)
-					results <- &ImageDetails{task.Images, data, w, h}
+					results <- &Images{
+						task.Id,
+						data,
+						w,
+						h,
+					}
 				}
 			}()
 		}
 		go func() {
 			for i, path := range images {
-				todo <- &Todo{e.Images[i], path}
+				if i == 0 {
+					todo <- &Todo{i, path}
+				} else {
+					todo <- &Todo{i, path}
+				}
 			}
 			close(todo)
 			wg.Wait()
@@ -204,8 +211,6 @@ func (e *EPub) LoadDir(dirname string) *EPub {
 		return results
 	}
 
-	e.FirstImageTitle = e.Images[0].Title
-
 	return e
 }
 
@@ -219,35 +224,59 @@ func (e *EPub) Write() error {
 		return err
 	}
 
-	zipContent := [][]string{
+	images := make([]*Images, e.ImagesCount)
+	totalSize := 0
+	bar := progressbar.Default(int64(e.ImagesCount), "Processing")
+	for img := range e.ProcessingImages() {
+		images[img.Id] = img
+		totalSize += len(img.Data)
+		bar.Add(1)
+	}
+	bar.Close()
+
+	cover := images[0]
+	images = images[1:]
+
+	fmt.Println(len(images))
+	fmt.Println("Total Size:", totalSize)
+
+	type ZipContent struct {
+		Name    string
+		Content any
+	}
+
+	zipContent := []ZipContent{
 		{"mimetype", TEMPLATE_MIME_TYPE},
 		{"META-INF/container.xml", gohtml.Format(TEMPLATE_CONTAINER)},
-		{"OEBPS/content.opf", e.Render(TEMPLATE_CONTENT, e)},
+		{"OEBPS/content.opf", e.Render(TEMPLATE_CONTENT, map[string]any{"Info": e, "Images": images})},
-		{"OEBPS/toc.ncx", e.Render(TEMPLATE_TOC, e)},
+		{"OEBPS/toc.ncx", e.Render(TEMPLATE_TOC, map[string]any{"Info": e, "Images": images})},
-		{"OEBPS/nav.xhtml", e.Render(TEMPLATE_NAV, e)},
+		{"OEBPS/nav.xhtml", e.Render(TEMPLATE_NAV, map[string]any{"Info": e, "Images": images})},
 		{"OEBPS/Text/style.css", TEMPLATE_STYLE},
+		{"OEBPS/Text/cover.xhtml", e.Render(TEMPLATE_TEXT, map[string]any{
+			"Id":     "cover",
+			"Width":  cover.Width,
+			"Height": cover.Height,
+		})},
+		{"OEBPS/Images/cover.jpg", cover.Data},
 	}
 
 	wz := zip.NewWriter(w)
 	defer wz.Close()
 	for _, content := range zipContent {
-		if err := e.WriteString(wz, content[0], content[1]); err != nil {
+		if err := e.WriteFile(wz, content.Name, content.Content); err != nil {
 			return err
 		}
 	}
 
-	bar := progressbar.Default(int64(len(e.Images)), "Processing")
+	for _, img := range images {
-	defer bar.Close()
+		text := fmt.Sprintf("OEBPS/Text/%d.xhtml", img.Id)
-	for img := range e.ProcessingImages() {
+		image := fmt.Sprintf("OEBPS/Images/%d.jpg", img.Id)
-		text := fmt.Sprintf("OEBPS/Text/%s.xhtml", img.Title)
+		if err := e.WriteFile(wz, text, e.Render(TEMPLATE_TEXT, img)); err != nil {
-		image := fmt.Sprintf("OEBPS/Images/%s.jpg", img.Title)
-		if err := e.WriteString(wz, text, e.Render(TEMPLATE_TEXT, img)); err != nil {
 			return err
 		}
-		if err := e.WriteBuffer(wz, image, img.Data); err != nil {
+		if err := e.WriteFile(wz, image, img.Data); err != nil {
 			return err
 		}
-		bar.Add(1)
 	}
 
 	return nil

internal/epub/templates/content.opf.tmpl

@@ -1,15 +1,15 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <package version="3.0" unique-identifier="BookID" xmlns="http://www.idpf.org/2007/opf">
 <metadata xmlns:opf="http://www.idpf.org/2007/opf" xmlns:dc="http://purl.org/dc/elements/1.1/">
-<dc:title>{{ .Title }}</dc:title>
+<dc:title>{{ .Info.Title }}</dc:title>
 <dc:language>en-US</dc:language>
-<dc:identifier id="BookID">urn:uuid:{{ .UID }}</dc:identifier>
+<dc:identifier id="BookID">urn:uuid:{{ .Info.UID }}</dc:identifier>
 <dc:contributor id="contributor">GO Comic Converter</dc:contributor>
 <dc:creator>GO Comic Converter</dc:creator>
-<meta property="dcterms:modified">{{ .UpdatedAt }}</meta>
+<meta property="dcterms:modified">{{ .Info.UpdatedAt }}</meta>
 <meta name="cover" content="cover"/>
 <meta name="fixed-layout" content="true"/>
-<meta name="original-resolution" content="{{ .ViewWidth }}x{{ .ViewHeight }}"/>
+<meta name="original-resolution" content="{{ .Info.ViewWidth }}x{{ .Info.ViewHeight }}"/>
 <meta name="book-type" content="comic"/>
 <meta name="primary-writing-mode" content="horizontal-lr"/>
 <meta name="zero-gutter" content="true"/>
@@ -22,20 +22,20 @@
 <manifest>
 <item id="ncx" href="toc.ncx" media-type="application/x-dtbncx+xml"/>
 <item id="nav" href="nav.xhtml" properties="nav" media-type="application/xhtml+xml"/>
+<item id="page_cover" href="Text/cover.xhtml" media-type="application/xhtml+xml"/>
+<item id="img_cover" href="Images/cover.jpg" media-type="image/jpeg" properties="cover-image"/>
 {{ range .Images }}
-{{ if eq .Id 0 }}
+<item id="page_{{ .Id }}" href="Text/{{ .Id }}.xhtml" media-type="application/xhtml+xml"/>
-<item id="cover" href="Images/{{ .Title }}.jpg" media-type="image/jpeg" properties="cover-image"/>
+<item id="img_{{ .Id }}" href="Images/{{ .Id }}.jpg" media-type="image/jpeg"/>
-{{ end }}
-<item id="page_{{ .Id }}" href="Text/{{ .Title }}.xhtml" media-type="application/xhtml+xml"/>
-<item id="img_{{ .Id }}" href="Images/{{ .Title }}.jpg" media-type="image/jpeg"/>
 {{ end }}
 </manifest>
 <spine page-progression-direction="ltr" toc="ncx">
-{{ range .Images }}
+<itemref idref="page_cover" linear="yes" properties="page-spread-left"/>
-{{ if mod .Id 2 }}
+{{ range $idx, $ := .Images }}
-<itemref idref="page_{{ .Id }}" linear="yes" properties="page-spread-left"/>
+{{ if mod $idx 2 }}
+<itemref idref="page_{{ $.Id }}" linear="yes" properties="page-spread-right"/>
 {{ else }}
-<itemref idref="page_{{ .Id }}" linear="yes" properties="page-spread-right"/>
+<itemref idref="page_{{ $.Id }}" linear="yes" properties="page-spread-left"/>
 {{ end }}
 {{ end }}
 </spine>

internal/epub/templates/nav.xhtml.tmpl

@@ -2,18 +2,18 @@
 <!DOCTYPE html>
 <html xmlns="http://www.w3.org/1999/xhtml" xmlns:epub="http://www.idpf.org/2007/ops">
 <head>
-<title>{{ .Title }}</title>
+<title>{{ .Info.Title }}</title>
 <meta charset="utf-8"/>
 </head>
 <body>
 <nav xmlns:epub="http://www.idpf.org/2007/ops" epub:type="toc" id="toc">
 <ol>
-<li><a href="Text/{{ .FirstImageTitle }}.xhtml">{{ .Title }}</a></li>
+<li><a href="Text/cover.xhtml">{{ .Info.Title }}</a></li>
 </ol>
 </nav>
 <nav epub:type="page-list">
 <ol>
-<li><a href="Text/{{ .FirstImageTitle }}.xhtml">{{ .Title }}</a></li>
+<li><a href="Text/cover.xhtml">{{ .Info.Title }}</a></li>
 </ol>
 </nav>
 </body>

internal/epub/templates/text.xhtml.tmpl

@@ -2,13 +2,13 @@
 <!DOCTYPE html>
 <html xmlns="http://www.w3.org/1999/xhtml" xmlns:epub="http://www.idpf.org/2007/ops">
 <head>
-<title>{{ .Title }}</title>
+<title>Page {{ .Id }}</title>
 <link href="style.css" type="text/css" rel="stylesheet"/>
 <meta name="viewport" content="width={{ .Width }}, height={{ .Height }}"/>
 </head>
 <body style="">
 <div style="text-align:center;top:0.0%;">
-<img width="{{ .Width }}" height="{{ .Height }}" src="../Images/{{ .Title }}.jpg"/>
+<img width="{{ .Width }}" height="{{ .Height }}" src="../Images/{{ .Id }}.jpg"/>
 </div>
 <div id="PV">
 <div id="PV-TL">
@@ -25,16 +25,16 @@
 </div>
 </div>
 <div class="PV-P" id="PV-TL-P" style="">
-<img style="position:absolute;left:0;top:0;" src="../Images/{{ .Title }}.jpg" width="{{ zoom .Width 1.5 }}" height="{{ zoom .Height 1.5 }}"/>
+<img style="position:absolute;left:0;top:0;" src="../Images/{{ .Id }}.jpg" width="{{ zoom .Width 1.5 }}" height="{{ zoom .Height 1.5 }}"/>
 </div>
 <div class="PV-P" id="PV-TR-P" style="">
-<img style="position:absolute;right:0;top:0;" src="../Images/{{ .Title }}.jpg" width="{{ zoom .Width 1.5 }}" height="{{ zoom .Height 1.5 }}"/>
+<img style="position:absolute;right:0;top:0;" src="../Images/{{ .Id }}.jpg" width="{{ zoom .Width 1.5 }}" height="{{ zoom .Height 1.5 }}"/>
 </div>
 <div class="PV-P" id="PV-BL-P" style="">
-<img style="position:absolute;left:0;bottom:0;" src="../Images/{{ .Title }}.jpg" width="{{ zoom .Width 1.5 }}" height="{{ zoom .Height 1.5 }}"/>
+<img style="position:absolute;left:0;bottom:0;" src="../Images/{{ .Id }}.jpg" width="{{ zoom .Width 1.5 }}" height="{{ zoom .Height 1.5 }}"/>
 </div>
 <div class="PV-P" id="PV-BR-P" style="">
-<img style="position:absolute;right:0;bottom:0;" src="../Images/{{ .Title }}.jpg" width="{{ zoom .Width 1.5 }}" height="{{ zoom .Height 1.5 }}"/>
+<img style="position:absolute;right:0;bottom:0;" src="../Images/{{ .Id }}.jpg" width="{{ zoom .Width 1.5 }}" height="{{ zoom .Height 1.5 }}"/>
 </div>
 </body>
 </html>

internal/epub/templates/toc.ncx.tmpl

@@ -1,14 +1,14 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ncx version="2005-1" xml:lang="en-US" xmlns="http://www.daisy.org/z3986/2005/ncx/">
 <head>
-<meta name="dtb:uid" content="urn:uuid:{{ .UID }}"/>
+<meta name="dtb:uid" content="urn:uuid:{{ .Info.UID }}"/>
 <meta name="dtb:depth" content="1"/>
 <meta name="dtb:totalPageCount" content="0"/>
 <meta name="dtb:maxPageNumber" content="0"/>
 <meta name="generated" content="true"/>
 </head>
-<docTitle><text>{{ .Title }}</text></docTitle>
+<docTitle><text>{{ .Info.Title }}</text></docTitle>
 <navMap>
-<navPoint id="Text"><navLabel><text>{{ .Title }}</text></navLabel><content src="Text/{{ .FirstImageTitle }}.xhtml"/></navPoint>
+<navPoint id="Text"><navLabel><text>{{ .Info.Title }}</text></navLabel><content src="Text/cover.xhtml"/></navPoint>
 </navMap>
 </ncx>

internal/image-converter/core.go

@@ -5,7 +5,6 @@ import (
 	"image"
 	"image/color"
 	"image/jpeg"
-	"io"
 	"os"
 
 	"golang.org/x/image/draw"
@@ -117,13 +116,13 @@ func Resize(img *image.Gray, w, h int) *image.Gray {
 	return newImg
 }
 
-func Get(img *image.Gray, quality int) io.Reader {
+func Get(img *image.Gray, quality int) []byte {
 	b := bytes.NewBuffer([]byte{})
 	err := jpeg.Encode(b, img, &jpeg.Options{Quality: quality})
 	if err != nil {
 		panic(err)
 	}
-	return b
+	return b.Bytes()
 }
 
 func Save(img *image.Gray, output string, quality int) {
@@ -143,7 +142,7 @@ func Save(img *image.Gray, output string, quality int) {
 	}
 }
 
-func Convert(path string, crop bool, w, h int, quality int) (io.Reader, int, int) {
+func Convert(path string, crop bool, w, h int, quality int) ([]byte, int, int) {
 	img := Load(path)
 	if crop {
 		img = CropMarging(img)