lots of fixes and additions:

- add color and color config support
- fix epub parsing
- add variable margin (left and right arrow keys)
- add help screen (hit `?`)
- add config file support

pkg/epub/book.go

@@ -14,6 +14,7 @@ type Book struct {
 	Opf       Opf       `json:"opf"`
 	Container Container `json:"-"`
 	Mimetype  string    `json:"-"`
+	Content   []Content
 
 	fd *zip.ReadCloser
 }
@@ -49,7 +50,12 @@ func (p *Book) readXML(n string, v interface{}) error {
 	}
 	defer fd.Close()
 	dec := xml.NewDecoder(fd)
-	return dec.Decode(v)
+
+	if err := dec.Decode(v); err != nil {
+		return fmt.Errorf("XML decoder error %w", err)
+	}
+
+	return nil
 }
 
 func (p *Book) readBytes(n string) ([]byte, error) {
@@ -59,8 +65,12 @@ func (p *Book) readBytes(n string) ([]byte, error) {
 	}
 	defer fd.Close()
 
-	return io.ReadAll(fd)
+	data, err := io.ReadAll(fd)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read contents from %s %w", n, err)
+	}
 
+	return data, nil
 }
 
 func (p *Book) open(n string) (io.ReadCloser, error) {
@@ -69,5 +79,6 @@ func (p *Book) open(n string) (io.ReadCloser, error) {
 			return f.Open()
 		}
 	}
+
 	return nil, fmt.Errorf("file %s not exist", n)
 }

pkg/epub/content.go

@@ -0,0 +1,46 @@
+package epub
+
+import (
+	"encoding/xml"
+	"fmt"
+	"strings"
+)
+
+// Content nav-point content
+type Content struct {
+	Src   string `xml:"src,attr" json:"src"`
+	Empty bool
+	Body  string
+	Title string
+	XML   []byte
+}
+
+func (c *Content) String(content []byte) error {
+	title := Title{}
+
+	err := xml.Unmarshal(content, &title)
+	if err != nil {
+		if !strings.HasPrefix(err.Error(), "XML syntax error") {
+			return fmt.Errorf("XML parser error %w", err)
+		}
+	}
+
+	c.Title = strings.TrimSpace(title.Content)
+
+	txt := cleantitle.ReplaceAllString(string(content), "")
+	txt = cleanh1.ReplaceAllString(txt, "")
+	txt = cleanmarkup.ReplaceAllString(txt, "")
+	txt = cleanentities.ReplaceAllString(txt, " ")
+	txt = cleancomments.ReplaceAllString(txt, "")
+
+	txt = strings.TrimSpace(txt)
+
+	c.Body = cleanspace.ReplaceAllString(txt, "")
+	c.XML = content
+
+	if len(c.Body) == 0 {
+		c.Empty = true
+	}
+
+	return nil
+}

pkg/epub/ncx.go

@@ -1,9 +1,7 @@
 package epub
 
 import (
-	"encoding/xml"
 	"regexp"
-	"strings"
 )
 
 var (
@@ -22,50 +20,10 @@ type Ncx struct {
 
 // NavPoint nav point
 type NavPoint struct {
-	Text    string     `xml:"navLabel>text" json:"text"`
-	Content Content    `xml:"content" json:"content"`
-	Points  []NavPoint `xml:"navPoint" json:"points"`
+	Text   string     `xml:"navLabel>text" json:"text"`
+	Points []NavPoint `xml:"navPoint" json:"points"`
 }
 
 type Title struct {
 	Content string `xml:"head>title"`
 }
-
-// Content nav-point content
-type Content struct {
-	Src   string `xml:"src,attr" json:"src"`
-	Empty bool
-	Body  string
-	Title string
-	XML   []byte
-}
-
-func (c *Content) String(content []byte) error {
-	title := Title{}
-
-	err := xml.Unmarshal(content, &title)
-	if err != nil {
-		if !strings.HasPrefix(err.Error(), "XML syntax error") {
-			return err
-		}
-	}
-
-	c.Title = title.Content
-
-	txt := cleantitle.ReplaceAllString(string(content), "")
-	txt = cleanh1.ReplaceAllString(txt, "")
-	txt = cleanmarkup.ReplaceAllString(txt, "")
-	txt = cleanentities.ReplaceAllString(txt, " ")
-	txt = cleancomments.ReplaceAllString(txt, "")
-
-	txt = strings.TrimSpace(txt)
-
-	c.Body = cleanspace.ReplaceAllString(txt, "")
-	c.XML = content
-
-	if len(c.Body) == 0 {
-		c.Empty = true
-	}
-
-	return nil
-}

pkg/epub/open.go

@@ -2,6 +2,7 @@ package epub
 
 import (
 	"archive/zip"
+	"strings"
 )
 
 // Open open a epub file
@@ -34,19 +35,29 @@ func Open(fn string) (*Book, error) {
 	for _, mf := range bk.Opf.Manifest {
 		if mf.ID == bk.Opf.Spine.Toc {
 			err = bk.readXML(bk.filename(mf.Href), &bk.Ncx)
+			if err != nil {
+				return &bk, err
+			}
+
 			break
 		}
 	}
 
-	for _, ncx := range bk.Ncx.Points {
-		content, err := bk.readBytes(bk.filename(ncx.Content.Src))
+	for _, file := range bk.Files() {
+		content, err := bk.readBytes(file)
 		if err != nil {
 			return &bk, err
 		}
 
-		if err := ncx.Content.String(content); err != nil {
-			return &bk, err
+		ct := Content{Src: file}
+
+		if strings.Contains(string(content), "DOCTYPE") {
+			if err := ct.String(content); err != nil {
+				return &bk, err
+			}
 		}
+
+		bk.Content = append(bk.Content, ct)
 	}
 
 	return &bk, nil