Dep (rag): better extractors

rag/extractors.go

@@ -10,21 +10,24 @@ import (
 	"path"
 	"strings"
 
-	"github.com/huantt/plaintext-extractor"
+	"github.com/PuerkitoBio/goquery"
 	"github.com/ledongthuc/pdf"
 	"github.com/n3integration/epub"
+	"github.com/yuin/goldmark"
+	"github.com/yuin/goldmark/extension"
+	"github.com/yuin/goldmark/parser"
+	"github.com/yuin/goldmark/renderer/html"
 )
 
 func ExtractText(fpath string) (string, error) {
 	ext := strings.ToLower(path.Ext(fpath))
-
 	switch ext {
 	case ".txt":
 		return extractTextFromFile(fpath)
 	case ".md", ".markdown":
 		return extractTextFromMarkdown(fpath)
 	case ".html", ".htm":
-		return extractTextFromHtml(fpath)
+		return extractTextFromHtmlFile(fpath)
 	case ".epub":
 		return extractTextFromEpub(fpath)
 	case ".pdf":
@@ -42,30 +45,48 @@ func extractTextFromFile(fpath string) (string, error) {
 	return string(data), nil
 }
 
+func extractTextFromHtmlFile(fpath string) (string, error) {
+	data, err := os.ReadFile(fpath)
+	if err != nil {
+		return "", err
+	}
+	return extractTextFromHtmlContent(data)
+}
+
+// non utf-8 encoding?
+func extractTextFromHtmlContent(data []byte) (string, error) {
+	doc, err := goquery.NewDocumentFromReader(bytes.NewReader(data))
+	if err != nil {
+		return "", err
+	}
+	// Remove script and style tags
+	doc.Find("script, style, noscript").Each(func(i int, s *goquery.Selection) {
+		s.Remove()
+	})
+	// Get text and clean it
+	text := doc.Text()
+	// Collapse all whitespace (newlines, tabs, multiple spaces) into single spaces
+	cleaned := strings.Join(strings.Fields(text), " ")
+	return cleaned, nil
+}
+
 func extractTextFromMarkdown(fpath string) (string, error) {
 	data, err := os.ReadFile(fpath)
 	if err != nil {
 		return "", err
 	}
-	extractor := plaintext.NewMarkdownExtractor()
-	text, err := extractor.PlainText(string(data))
-	if err != nil {
+	// Convert markdown to HTML
+	md := goldmark.New(
+		goldmark.WithExtensions(extension.GFM),
+		goldmark.WithParserOptions(parser.WithAutoHeadingID()),
+		goldmark.WithRendererOptions(html.WithUnsafe()), // allow raw HTML if needed
+	)
+	var buf bytes.Buffer
+	if err := md.Convert(data, &buf); err != nil {
 		return "", err
 	}
-	return *text, nil
-}
-
-func extractTextFromHtml(fpath string) (string, error) {
-	data, err := os.ReadFile(fpath)
-	if err != nil {
-		return "", err
-	}
-	extractor := plaintext.NewHtmlExtractor()
-	text, err := extractor.PlainText(string(data))
-	if err != nil {
-		return "", err
-	}
-	return *text, nil
+	// Now extract text from the resulting HTML (using goquery or similar)
+	return extractTextFromHtmlContent(buf.Bytes())
 }
 
 func extractTextFromEpub(fpath string) (string, error) {
@@ -74,30 +95,24 @@ func extractTextFromEpub(fpath string) (string, error) {
 		return "", fmt.Errorf("failed to open epub: %w", err)
 	}
 	defer book.Close()
-
 	var sb strings.Builder
-
 	err = book.Each(func(title string, xhtml io.ReadCloser) {
 		if sb.Len() > 0 {
 			sb.WriteString("\n\n")
 		}
 		sb.WriteString(title)
 		sb.WriteString("\n")
-
 		buf, readErr := io.ReadAll(xhtml)
 		if readErr == nil {
 			sb.WriteString(stripHTML(string(buf)))
 		}
 	})
-
 	if err != nil {
 		return "", fmt.Errorf("failed to iterate epub chapters: %w", err)
 	}
-
 	if sb.Len() == 0 {
 		return "", errors.New("no content extracted from epub")
 	}
-
 	return sb.String(), nil
 }
 
@@ -127,7 +142,6 @@ func extractTextFromPdf(fpath string) (string, error) {
 			return string(out), nil
 		}
 	}
-
 	return extractTextFromPdfPureGo(fpath)
 }
 
@@ -137,17 +151,14 @@ func extractTextFromPdfPureGo(fpath string) (string, error) {
 		return "", fmt.Errorf("failed to open pdf: %w", err)
 	}
 	defer df.Close()
-
 	textReader, err := r.GetPlainText()
 	if err != nil {
 		return "", fmt.Errorf("failed to extract text from pdf: %w", err)
 	}
-
 	var buf bytes.Buffer
 	_, err = io.Copy(&buf, textReader)
 	if err != nil {
 		return "", fmt.Errorf("failed to read pdf text: %w", err)
 	}
-
 	return buf.String(), nil
 }