feat: scaffold initial RSS reader project with Go backend and React frontend

internal/opml/opml.go

@@ -0,0 +1,157 @@
+package opml
+
+import (
+	"encoding/xml"
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/haopengzhan/rsspipe/internal/models"
+)
+
+type OPML struct {
+	XMLName xml.Name `xml:"opml"`
+	Version string   `xml:"version,attr"`
+	Head    Head     `xml:"head"`
+	Body    Body     `xml:"body"`
+}
+
+type Head struct {
+	Title        string `xml:"title"`
+	DateCreated  string `xml:"dateCreated,omitempty"`
+	DateModified string `xml:"dateModified,omitempty"`
+}
+
+type Body struct {
+	Outlines []Outline `xml:"outline"`
+}
+
+type Outline struct {
+	Text     string    `xml:"text,attr"`
+	Title    string    `xml:"title,attr,omitempty"`
+	Type     string    `xml:"type,attr,omitempty"`
+	XMLURL   string    `xml:"xmlUrl,attr,omitempty"`
+	HTMLURL  string    `xml:"htmlUrl,attr,omitempty"`
+	Outlines []Outline `xml:"outline,omitempty"`
+}
+
+type ImportedFeed struct {
+	Title         string
+	FeedURL       string
+	SiteURL       string
+	CategoryTitle string
+}
+
+func ParseOPML(data []byte) ([]ImportedFeed, error) {
+	var doc OPML
+	if err := xml.Unmarshal(data, &doc); err != nil {
+		return nil, fmt.Errorf("failed to parse OPML XML: %w", err)
+	}
+
+	var feeds []ImportedFeed
+	for _, topOutline := range doc.Body.Outlines {
+		if topOutline.XMLURL != "" {
+			// Top-level feed without category
+			title := topOutline.Title
+			if title == "" {
+				title = topOutline.Text
+			}
+			feeds = append(feeds, ImportedFeed{
+				Title:         title,
+				FeedURL:       strings.TrimSpace(topOutline.XMLURL),
+				SiteURL:       strings.TrimSpace(topOutline.HTMLURL),
+				CategoryTitle: "",
+			})
+		} else if len(topOutline.Outlines) > 0 {
+			// Category folder containing feeds
+			categoryTitle := topOutline.Title
+			if categoryTitle == "" {
+				categoryTitle = topOutline.Text
+			}
+			for _, child := range topOutline.Outlines {
+				if child.XMLURL != "" {
+					title := child.Title
+					if title == "" {
+						title = child.Text
+					}
+					feeds = append(feeds, ImportedFeed{
+						Title:         title,
+						FeedURL:       strings.TrimSpace(child.XMLURL),
+						SiteURL:       strings.TrimSpace(child.HTMLURL),
+						CategoryTitle: strings.TrimSpace(categoryTitle),
+					})
+				}
+			}
+		}
+	}
+
+	return feeds, nil
+}
+
+func GenerateOPML(feeds []models.Feed, categories []models.Category) ([]byte, error) {
+	doc := OPML{
+		Version: "2.0",
+		Head: Head{
+			Title:        "RSSPipe Subscriptions",
+			DateCreated:  time.Now().UTC().Format(time.RFC1123),
+			DateModified: time.Now().UTC().Format(time.RFC1123),
+		},
+		Body: Body{
+			Outlines: make([]Outline, 0),
+		},
+	}
+
+	// Map category ID to slice of feeds
+	catFeedMap := make(map[string][]models.Feed)
+	var uncategorized []models.Feed
+
+	for _, f := range feeds {
+		if f.CategoryID != nil && *f.CategoryID != "" {
+			catFeedMap[*f.CategoryID] = append(catFeedMap[*f.CategoryID], f)
+		} else {
+			uncategorized = append(uncategorized, f)
+		}
+	}
+
+	// Add categorized feeds
+	for _, c := range categories {
+		feedList, exists := catFeedMap[c.ID]
+		if !exists || len(feedList) == 0 {
+			continue
+		}
+		catOutline := Outline{
+			Text:     c.Title,
+			Title:    c.Title,
+			Outlines: make([]Outline, 0, len(feedList)),
+		}
+		for _, f := range feedList {
+			catOutline.Outlines = append(catOutline.Outlines, Outline{
+				Text:    f.Title,
+				Title:   f.Title,
+				Type:    "rss",
+				XMLURL:  f.FeedURL,
+				HTMLURL: f.SiteURL,
+			})
+		}
+		doc.Body.Outlines = append(doc.Body.Outlines, catOutline)
+	}
+
+	// Add uncategorized feeds
+	for _, f := range uncategorized {
+		doc.Body.Outlines = append(doc.Body.Outlines, Outline{
+			Text:    f.Title,
+			Title:   f.Title,
+			Type:    "rss",
+			XMLURL:  f.FeedURL,
+			HTMLURL: f.SiteURL,
+		})
+	}
+
+	xmlHeader := []byte(xml.Header)
+	data, err := xml.MarshalIndent(doc, "", "  ")
+	if err != nil {
+		return nil, err
+	}
+
+	return append(xmlHeader, data...), nil
+}