chore: update common utils (#1908)

api/v1/rss.go

@@ -0,0 +1,188 @@
+package v1
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/gorilla/feeds"
+	"github.com/labstack/echo/v4"
+	"github.com/usememos/memos/common/util"
+	"github.com/usememos/memos/store"
+	"github.com/yuin/goldmark"
+)
+
+const maxRSSItemCount = 100
+const maxRSSItemTitleLength = 100
+
+func (s *APIV1Service) registerRSSRoutes(g *echo.Group) {
+	g.GET("/explore/rss.xml", func(c echo.Context) error {
+		ctx := c.Request().Context()
+		systemCustomizedProfile, err := s.getSystemCustomizedProfile(ctx)
+		if err != nil {
+			return echo.NewHTTPError(http.StatusInternalServerError, "Failed to get system customized profile").SetInternal(err)
+		}
+
+		normalStatus := store.Normal
+		memoFind := store.FindMemo{
+			RowStatus:      &normalStatus,
+			VisibilityList: []store.Visibility{store.Public},
+		}
+		memoList, err := s.Store.ListMemos(ctx, &memoFind)
+		if err != nil {
+			return echo.NewHTTPError(http.StatusInternalServerError, "Failed to find memo list").SetInternal(err)
+		}
+
+		baseURL := c.Scheme() + "://" + c.Request().Host
+		rss, err := s.generateRSSFromMemoList(ctx, memoList, baseURL, systemCustomizedProfile)
+		if err != nil {
+			return echo.NewHTTPError(http.StatusInternalServerError, "Failed to generate rss").SetInternal(err)
+		}
+		c.Response().Header().Set(echo.HeaderContentType, echo.MIMEApplicationXMLCharsetUTF8)
+		return c.String(http.StatusOK, rss)
+	})
+
+	g.GET("/u/:id/rss.xml", func(c echo.Context) error {
+		ctx := c.Request().Context()
+		id, err := strconv.Atoi(c.Param("id"))
+		if err != nil {
+			return echo.NewHTTPError(http.StatusBadRequest, "User id is not a number").SetInternal(err)
+		}
+
+		systemCustomizedProfile, err := s.getSystemCustomizedProfile(ctx)
+		if err != nil {
+			return echo.NewHTTPError(http.StatusInternalServerError, "Failed to get system customized profile").SetInternal(err)
+		}
+
+		normalStatus := store.Normal
+		memoFind := store.FindMemo{
+			CreatorID:      &id,
+			RowStatus:      &normalStatus,
+			VisibilityList: []store.Visibility{store.Public},
+		}
+		memoList, err := s.Store.ListMemos(ctx, &memoFind)
+		if err != nil {
+			return echo.NewHTTPError(http.StatusInternalServerError, "Failed to find memo list").SetInternal(err)
+		}
+
+		baseURL := c.Scheme() + "://" + c.Request().Host
+		rss, err := s.generateRSSFromMemoList(ctx, memoList, baseURL, systemCustomizedProfile)
+		if err != nil {
+			return echo.NewHTTPError(http.StatusInternalServerError, "Failed to generate rss").SetInternal(err)
+		}
+		c.Response().Header().Set(echo.HeaderContentType, echo.MIMEApplicationXMLCharsetUTF8)
+		return c.String(http.StatusOK, rss)
+	})
+}
+
+func (s *APIV1Service) generateRSSFromMemoList(ctx context.Context, memoList []*store.Memo, baseURL string, profile *CustomizedProfile) (string, error) {
+	feed := &feeds.Feed{
+		Title:       profile.Name,
+		Link:        &feeds.Link{Href: baseURL},
+		Description: profile.Description,
+		Created:     time.Now(),
+	}
+
+	var itemCountLimit = util.Min(len(memoList), maxRSSItemCount)
+	feed.Items = make([]*feeds.Item, itemCountLimit)
+	for i := 0; i < itemCountLimit; i++ {
+		memo := memoList[i]
+		feed.Items[i] = &feeds.Item{
+			Title:       getRSSItemTitle(memo.Content),
+			Link:        &feeds.Link{Href: baseURL + "/m/" + strconv.Itoa(memo.ID)},
+			Description: getRSSItemDescription(memo.Content),
+			Created:     time.Unix(memo.CreatedTs, 0),
+			Enclosure:   &feeds.Enclosure{Url: baseURL + "/m/" + strconv.Itoa(memo.ID) + "/image"},
+		}
+		if len(memo.ResourceIDList) > 0 {
+			resourceID := memo.ResourceIDList[0]
+			resource, err := s.Store.GetResource(ctx, &store.FindResource{
+				ID: &resourceID,
+			})
+			if err != nil {
+				return "", err
+			}
+			if resource == nil {
+				return "", fmt.Errorf("Resource not found: %d", resourceID)
+			}
+			enclosure := feeds.Enclosure{}
+			if resource.ExternalLink != "" {
+				enclosure.Url = resource.ExternalLink
+			} else {
+				enclosure.Url = baseURL + "/o/r/" + strconv.Itoa(resource.ID) + "/" + resource.PublicID + "/" + resource.Filename
+			}
+			enclosure.Length = strconv.Itoa(int(resource.Size))
+			enclosure.Type = resource.Type
+			feed.Items[i].Enclosure = &enclosure
+		}
+	}
+
+	rss, err := feed.ToRss()
+	if err != nil {
+		return "", err
+	}
+	return rss, nil
+}
+
+func (s *APIV1Service) getSystemCustomizedProfile(ctx context.Context) (*CustomizedProfile, error) {
+	systemSetting, err := s.Store.GetSystemSetting(ctx, &store.FindSystemSetting{
+		Name: SystemSettingCustomizedProfileName.String(),
+	})
+	if err != nil {
+		return nil, err
+	}
+	customizedProfile := &CustomizedProfile{
+		Name:        "memos",
+		LogoURL:     "",
+		Description: "",
+		Locale:      "en",
+		Appearance:  "system",
+		ExternalURL: "",
+	}
+	if systemSetting != nil {
+		if err := json.Unmarshal([]byte(systemSetting.Value), customizedProfile); err != nil {
+			return nil, err
+		}
+	}
+	return customizedProfile, nil
+}
+
+func getRSSItemTitle(content string) string {
+	var title string
+	if isTitleDefined(content) {
+		title = strings.Split(content, "\n")[0][2:]
+	} else {
+		title = strings.Split(content, "\n")[0]
+		var titleLengthLimit = util.Min(len(title), maxRSSItemTitleLength)
+		if titleLengthLimit < len(title) {
+			title = title[:titleLengthLimit] + "..."
+		}
+	}
+	return title
+}
+
+func getRSSItemDescription(content string) string {
+	var description string
+	if isTitleDefined(content) {
+		var firstLineEnd = strings.Index(content, "\n")
+		description = strings.Trim(content[firstLineEnd+1:], " ")
+	} else {
+		description = content
+	}
+
+	// TODO: use our `./plugin/gomark` parser to handle markdown-like content.
+	var buf bytes.Buffer
+	if err := goldmark.Convert([]byte(description), &buf); err != nil {
+		panic(err)
+	}
+	return buf.String()
+}
+
+func isTitleDefined(content string) bool {
+	return strings.HasPrefix(content, "# ")
+}