From 4a519952dc40ea57d871e9e0cc061956ef0c4f51 Mon Sep 17 00:00:00 2001
From: Akshay <nerdy@peppe.rs>
Date: Sat, 15 Feb 2025 13:27:09 +0000
Subject: [PATCH] add unfollow bits

---
 appview/db/db.go       |  1 +
 appview/db/follow.go   | 47 +++++++++++++++++++--
 appview/state/state.go | 92 +++++++++++++++++++++++++++++++++---------
 3 files changed, 117 insertions(+), 23 deletions(-)

diff --git a/appview/db/db.go b/appview/db/db.go
index aa5bea6e..4b1e10a9 100644
--- a/appview/db/db.go
+++ b/appview/db/db.go
@@ -43,6 +43,7 @@ func Make(dbPath string) (*DB, error) {
 		create table if not exists follows (
 			user_did text not null,
 			subject_did text not null,
+			at_uri text not null,
 			followed_at text not null default (strftime('%Y-%m-%dT%H:%M:%SZ', 'now')),
 			primary key (user_did, subject_did),
 			check (user_did <> subject_did)
diff --git a/appview/db/follow.go b/appview/db/follow.go
index d02e758d..4bce8d2c 100644
--- a/appview/db/follow.go
+++ b/appview/db/follow.go
@@ -1,7 +1,48 @@
 package db
 
-func (d *DB) AddFollow(userDid, subjectDid string) error {
-	query := `insert into follows (user_did, subject_did) values (?, ?)`
-	_, err := d.db.Exec(query, userDid, subjectDid)
+import (
+	"log"
+	"time"
+)
+
+type Follow struct {
+	UserDid    string
+	SubjectDid string
+	FollowedAt *time.Time
+	AtUri      string
+}
+
+func (d *DB) AddFollow(userDid, subjectDid, atUri string) error {
+	query := `insert into follows (user_did, subject_did, at_uri) values (?, ?, ?)`
+	_, err := d.db.Exec(query, userDid, subjectDid, atUri)
+	return err
+}
+
+// Get a follow record
+func (d *DB) GetFollow(userDid, subjectDid string) (*Follow, error) {
+	query := `select user_did, subject_did, followed_at, at_uri from follows where user_did = ? and subject_did = ?`
+	row := d.db.QueryRow(query, userDid, subjectDid)
+
+	var follow Follow
+	var followedAt string
+	err := row.Scan(&follow.UserDid, &follow.SubjectDid, &followedAt, &follow.AtUri)
+	if err != nil {
+		return nil, err
+	}
+
+	followedAtTime, err := time.Parse(time.RFC3339, followedAt)
+	if err != nil {
+		log.Println("unable to determine followed at time")
+		follow.FollowedAt = nil
+	} else {
+		follow.FollowedAt = &followedAtTime
+	}
+
+	return &follow, nil
+}
+
+// Get a follow record
+func (d *DB) DeleteFollow(userDid, subjectDid string) error {
+	_, err := d.db.Exec(`delete from follows where user_did = ? and subject_did = ?`, userDid, subjectDid)
 	return err
 }
diff --git a/appview/state/state.go b/appview/state/state.go
index ab13180f..81e67cc9 100644
--- a/appview/state/state.go
+++ b/appview/state/state.go
@@ -531,38 +531,87 @@ func (s *State) ProfilePage(w http.ResponseWriter, r *http.Request) {
 }
 
 func (s *State) Follow(w http.ResponseWriter, r *http.Request) {
-	subject := r.FormValue("subject")
+	currentUser := s.auth.GetUser(r)
 
+	subject := r.URL.Query().Get("subject")
 	if subject == "" {
 		log.Println("invalid form")
 		return
 	}
 
 	subjectIdent, err := s.resolver.ResolveIdent(r.Context(), subject)
-	currentUser := s.auth.GetUser(r)
+	if err != nil {
+		log.Println("failed to follow, invalid did")
+	}
+
+	if currentUser.Did == subjectIdent.DID.String() {
+		log.Println("cant follow or unfollow yourself")
+		return
+	}
 
 	client, _ := s.auth.AuthorizedClient(r)
-	createdAt := time.Now().Format(time.RFC3339)
-	resp, err := comatproto.RepoPutRecord(r.Context(), client, &comatproto.RepoPutRecord_Input{
-		Collection: tangled.GraphFollowNSID,
-		Repo:       currentUser.Did,
-		Rkey:       s.TID(),
-		Record: &lexutil.LexiconTypeDecoder{
-			Val: &tangled.GraphFollow{
-				Subject:   subjectIdent.DID.String(),
-				CreatedAt: createdAt,
-			}},
-	})
 
-	err = s.db.AddFollow(currentUser.Did, subjectIdent.DID.String())
-	if err != nil {
-		log.Println("failed to follow", err)
+	switch r.Method {
+	case http.MethodPost:
+		createdAt := time.Now().Format(time.RFC3339)
+		resp, err := comatproto.RepoPutRecord(r.Context(), client, &comatproto.RepoPutRecord_Input{
+			Collection: tangled.GraphFollowNSID,
+			Repo:       currentUser.Did,
+			Rkey:       s.TID(),
+			Record: &lexutil.LexiconTypeDecoder{
+				Val: &tangled.GraphFollow{
+					Subject:   subjectIdent.DID.String(),
+					CreatedAt: createdAt,
+				}},
+		})
+		if err != nil {
+			log.Println("failed to create atproto record", err)
+			return
+		}
+
+		err = s.db.AddFollow(currentUser.Did, subjectIdent.DID.String(), resp.Uri)
+		if err != nil {
+			log.Println("failed to follow", err)
+			return
+		}
+
+		log.Println("created atproto record: ", resp.Uri)
+
 		return
-	}
+	case http.MethodDelete:
+		// find the record in the db
 
-	log.Println("created atproto record: ", resp.Uri)
+		follow, err := s.db.GetFollow(currentUser.Did, subjectIdent.DID.String())
+		if err != nil {
+			log.Println("failed to get follow relationship")
+			return
+		}
+
+		existingRecordUri, _ := syntax.ParseATURI(follow.AtUri)
+
+		resp, err := comatproto.RepoDeleteRecord(r.Context(), client, &comatproto.RepoDeleteRecord_Input{
+			Collection: tangled.GraphFollowNSID,
+			Repo:       currentUser.Did,
+			Rkey:       existingRecordUri.RecordKey().String(),
+		})
+
+		log.Println(resp.Commit.Cid)
+
+		if err != nil {
+			log.Println("failed to unfollow")
+			return
+		}
+
+		err = s.db.DeleteFollow(currentUser.Did, subjectIdent.DID.String())
+		if err != nil {
+			log.Println("failed to delete follow from DB")
+			// this is not an issue, the firehose event might have already done this
+		}
+
+		w.WriteHeader(http.StatusNoContent)
+		return
+	}
 
-	return
 }
 
 func (s *State) Router() http.Handler {
@@ -655,7 +704,10 @@ func (s *State) StandardRouter() http.Handler {
 		// r.Post("/import", s.ImportRepo)
 	})
 
-	r.With(AuthMiddleware(s)).Put("/follow", s.Follow)
+	r.With(AuthMiddleware(s)).Route("/follow", func(r chi.Router) {
+		r.Post("/", s.Follow)
+		r.Delete("/", s.Follow)
+	})
 
 	r.Route("/settings", func(r chi.Router) {
 		r.Use(AuthMiddleware(s))
-- 
2.51.2