Add OPML import functionality

6 files changed, 120 insertions, 14 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f8af81a..2a34834 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,7 +6,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ## [Unreleased]
 ### Added
-* Support for OPML exports
+* Support for OPML imports and exports
 
 ## [0.1.0] - 2022-04-14
 Initial release
diff --git a/walrss/internal/core/feeds.go b/walrss/internal/core/feeds.go
index 3aefd4c..9ba6545 100644
--- a/walrss/internal/core/feeds.go
+++ b/walrss/internal/core/feeds.go
@@ -87,3 +87,36 @@ func ExportFeedsForUser(st *state.State, userID string) ([]byte, error) {
 	}
 	return opml.FromFeeds(feeds, user.Email).ToBytes()
 }
+
+func ImportFeedsForUser(st *state.State, userID string, opmlXML []byte) error {
+	o, err := opml.FromBytes(opmlXML)
+	if err != nil {
+		return AsUserError(400, err)
+	}
+
+	// This will be used to filter out feeds included in OPML that would cause
+	// duplicates
+	existingURLs := make(map[string]struct{})
+	{
+		feeds, err := GetFeedsForUser(st, userID)
+		if err != nil {
+			return err
+		}
+		for _, feed := range feeds {
+			if _, found := existingURLs[feed.URL]; !found {
+				existingURLs[feed.URL] = struct{}{}
+			}
+		}
+	}
+
+	for _, feed := range o.ToFeeds() {
+		if _, found := existingURLs[feed.URL]; found {
+			continue
+		}
+		if _, err := NewFeed(st, userID, feed.Name, feed.URL); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
diff --git a/walrss/internal/core/opml/opml.go b/walrss/internal/core/opml/opml.go
index 809a6b8..7029d72 100644
--- a/walrss/internal/core/opml/opml.go
+++ b/walrss/internal/core/opml/opml.go
@@ -3,6 +3,8 @@ package opml
 import (
 	"encoding/xml"
 	"github.com/codemicro/walrss/walrss/internal/db"
+	"github.com/lithammer/shortuuid/v4"
+	"strings"
 	"time"
 )
 
@@ -19,15 +21,6 @@ type OPML struct {
 	} `xml:"body"`
 }
 
-// Outline holds all information about an outline.
-type Outline struct {
-	Outlines []*Outline `xml:"outline"`
-	Text     string     `xml:"text,attr"`
-	Title    string     `xml:"title,attr,omitempty"`
-	Type     string     `xml:"type,attr,omitempty"`
-	XMLURL   string     `xml:"xmlUrl,attr,omitempty"`
-}
-
 func FromBytes(x []byte) (*OPML, error) {
 	o := new(OPML)
 	if err := xml.Unmarshal(x, o); err != nil {
@@ -36,10 +29,6 @@ func FromBytes(x []byte) (*OPML, error) {
 	return o, nil
 }
 
-func (o *OPML) ToBytes() ([]byte, error) {
-	return xml.Marshal(o)
-}
-
 func FromFeeds(feeds []*db.Feed, userEmailAddress string) *OPML {
 	o := new(OPML)
 	o.Version = "2.0"
@@ -58,3 +47,46 @@ func FromFeeds(feeds []*db.Feed, userEmailAddress string) *OPML {
 
 	return o
 }
+
+func (o *OPML) ToBytes() ([]byte, error) {
+	return xml.Marshal(o)
+}
+
+func (o *OPML) ToFeeds() []*db.Feed {
+	var out []*db.Feed
+	for _, item := range o.Body.Outlines {
+		out = append(out, item.ToFeeds()...)
+	}
+	return out
+}
+
+type Outline struct {
+	Outlines []*Outline `xml:"outline"`
+	Text     string     `xml:"text,attr"`
+	Title    string     `xml:"title,attr,omitempty"`
+	Type     string     `xml:"type,attr,omitempty"`
+	XMLURL   string     `xml:"xmlUrl,attr,omitempty"`
+}
+
+func (o *Outline) ToFeeds() []*db.Feed {
+	var out []*db.Feed
+
+	if strings.EqualFold(o.Type, "rss") {
+		name := o.Text
+		if o.Title != "" {
+			name = o.Title
+		}
+
+		out = append(out, &db.Feed{
+			ID:   shortuuid.New(),
+			URL:  o.XMLURL,
+			Name: name,
+		})
+	}
+
+	for _, item := range o.Outlines {
+		out = append(out, item.ToFeeds()...)
+	}
+
+	return out
+}
diff --git a/walrss/internal/http/exportImport.go b/walrss/internal/http/exportImport.go
index 89b2ecf..c28ac02 100644
--- a/walrss/internal/http/exportImport.go
+++ b/walrss/internal/http/exportImport.go
@@ -1,8 +1,12 @@
 package http
 
 import (
+	"errors"
 	"github.com/codemicro/walrss/walrss/internal/core"
+	"github.com/codemicro/walrss/walrss/internal/urls"
 	"github.com/gofiber/fiber/v2"
+	"github.com/valyala/fasthttp"
+	"io"
 )
 
 func (s *Server) exportAsOPML(ctx *fiber.Ctx) error {
@@ -19,3 +23,36 @@ func (s *Server) exportAsOPML(ctx *fiber.Ctx) error {
 	ctx.Set(fiber.HeaderContentType, "application/xml")
 	return ctx.Send(exported)
 }
+
+func (s *Server) importFromOPML(ctx *fiber.Ctx) error {
+	currentUserID := getCurrentUserID(ctx)
+	if currentUserID == "" {
+		return requestFragmentSignIn(ctx, urls.Index)
+	}
+
+	file, err := ctx.FormFile("file")
+	if err != nil {
+		if errors.Is(err, fasthttp.ErrMissingFile) {
+			return core.NewUserError("missing file")
+		}
+		return err
+	}
+
+	fileHandle, err := file.Open()
+	if err != nil {
+		return err
+	}
+
+	fileContents, err := io.ReadAll(fileHandle)
+	if err != nil {
+		return err
+	}
+
+	if err := core.ImportFeedsForUser(s.state, currentUserID, fileContents); err != nil {
+		return err
+	}
+
+	ctx.Set("HX-Refresh", "true")
+	ctx.Status(fiber.StatusNoContent)
+	return nil
+}
diff --git a/walrss/internal/http/http.go b/walrss/internal/http/http.go
index 295a91f..3909772 100644
--- a/walrss/internal/http/http.go
+++ b/walrss/internal/http/http.go
@@ -92,6 +92,7 @@ func (s *Server) registerHandlers() {
 	s.app.Post(urls.SendTestEmail, s.sendTestEmail)
 
 	s.app.Get(urls.ExportAsOPML, s.exportAsOPML)
+	s.app.Post(urls.ImportFromOPML, s.importFromOPML)
 
 	s.app.Use(urls.Statics, static.NewHandler())
 }
diff --git a/walrss/internal/urls/urls.go b/walrss/internal/urls/urls.go
index 835bbc7..6452aab 100644
--- a/walrss/internal/urls/urls.go
+++ b/walrss/internal/urls/urls.go
@@ -21,6 +21,9 @@ const (
 	Export       = "/export"
 	ExportAsOPML = Export + "/opml"
 
+	Import         = "/import"
+	ImportFromOPML = Import + "/opml"
+
 	New         = "/new"
 	NewFeedItem = New + "/feed"