HTTP API: a chat's recent messages, and sending a message (closes #5)

`GET /api/v1/chats/{id}/messages?count=N` returns a chat's recent messages, oldest first (`count` 1 to 100, default 20), and `POST` to the same path sends a text message and returns it once the chat client has taken it. Both answer `404` for any id the chats list does not show, looked up in the same contact list. The message record is defined once, for the webhooks to reuse.

Disclosures: items are read five at a time, because one item can be many times its text and 100 at once could pass the 16 MiB read limit; text too long gets `413`, a contact who deleted the chat `409` (unverified for one still connecting); a query the server cannot read gets its own `400`.

Model: opus-5-5

internal/api/api_test.go

@@ -22,19 +22,26 @@ const (
 	bearer     = "Bearer " + credential
 
 	chatsPath    = "/api/v1/chats"
+	messagesPath = "/api/v1/chats/3/messages"
 	unauthorized = `{"error":"unauthorized"}` + "\n"
 )
 
 var errChat = errors.New("sqlite: database is locked at /var/lib/simplexcalc")
 
 // fakeClient stands in for the chat client. It answers with contacts,
-// or with err, and remembers what it was asked.
+// items or sent, or with an error: contactsErr from Contacts, err from
+// the others. It remembers what it was asked.
 type fakeClient struct {
-	contacts []simplex.Contact
-	err      error
+	contacts    []simplex.Contact
+	items       []simplex.ChatItem
+	sent        simplex.ChatItem
+	contactsErr error
+	err         error
 
-	userID      int64
-	hadDeadline bool
+	userID, contactID int64
+	count             int
+	text              string
+	hadDeadline       bool
 }
 
 func (f *fakeClient) Contacts(
@@ -43,7 +50,25 @@ func (f *fakeClient) Contacts(
 	f.userID = userID
 	_, f.hadDeadline = ctx.Deadline()
 
-	return f.contacts, f.err
+	return f.contacts, f.contactsErr
+}
+
+func (f *fakeClient) ChatItems(
+	ctx context.Context, contactID int64, count int,
+) ([]simplex.ChatItem, error) {
+	f.contactID, f.count = contactID, count
+	_, f.hadDeadline = ctx.Deadline()
+
+	return f.items, f.err
+}
+
+func (f *fakeClient) SendMessage(
+	ctx context.Context, contactID int64, text string,
+) (simplex.ChatItem, error) {
+	f.contactID, f.text = contactID, text
+	_, f.hadDeadline = ctx.Deadline()
+
+	return f.sent, f.err
 }
 
 func newAPI(token string, client api.ChatClient) *http.Server {
@@ -168,6 +193,10 @@ func TestNoPathIsExempt(t *testing.T) {
 			http.MethodPost, chatsPath, bearer,
 			http.StatusMethodNotAllowed, `{"error":"method not allowed"}` + "\n",
 		},
+		{
+			http.MethodPost, messagesPath, "",
+			http.StatusUnauthorized, unauthorized,
+		},
 	} {
 		rec := request(t, srv, tc.method, tc.path, tc.auth)
 		if rec.Code != tc.want || rec.Body.String() != tc.body {
@@ -242,7 +271,7 @@ func TestHeaders(t *testing.T) {
 		{&fakeClient{}, chatsPath, bearer},
 		{&fakeClient{}, chatsPath, ""},
 		{&fakeClient{}, "/nothing", bearer},
-		{&fakeClient{err: errChat}, chatsPath, bearer},
+		{&fakeClient{contactsErr: errChat}, chatsPath, bearer},
 	} {
 		rec := request(t, newAPI(credential, tc.client),
 			http.MethodGet, tc.path, tc.auth)