[feature] Dereference remote mentions when the account is not already known (#442)

* remove mention util function from db

* add ParseMentionFunc to gtsmodel

* add parseMentionFunc to processor

* refactor search to simplify it a bit

* add parseMentionFunc to account

* add parseMentionFunc to status

* some renaming for clarity

* test dereference of unknown mentioned account

internal/api/client/status/status_test.go

@@ -19,8 +19,18 @@
 package status_test
 
 import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+
 	"codeberg.org/gruf/go-store/kv"
 	"github.com/stretchr/testify/suite"
+	"github.com/superseriousbusiness/activity/pub"
+	"github.com/superseriousbusiness/activity/streams"
 	"github.com/superseriousbusiness/gotosocial/internal/api/client/status"
 	"github.com/superseriousbusiness/gotosocial/internal/db"
 	"github.com/superseriousbusiness/gotosocial/internal/email"
@@ -73,7 +83,7 @@ func (suite *StatusStandardTestSuite) SetupTest() {
 	suite.tc = testrig.NewTestTypeConverter(suite.db)
 	suite.storage = testrig.NewTestStorage()
 	suite.mediaManager = testrig.NewTestMediaManager(suite.db, suite.storage)
-	suite.federator = testrig.NewTestFederator(suite.db, testrig.NewTestTransportController(testrig.NewMockHTTPClient(nil), suite.db), suite.storage, suite.mediaManager)
+	suite.federator = testrig.NewTestFederator(suite.db, testrig.NewTestTransportController(suite.testHttpClient(), suite.db), suite.storage, suite.mediaManager)
 	suite.emailSender = testrig.NewEmailSender("../../../../web/template/", nil)
 	suite.processor = testrig.NewTestProcessor(suite.db, suite.storage, suite.federator, suite.emailSender, suite.mediaManager)
 	suite.statusModule = status.New(suite.processor).(*status.Module)
@@ -85,3 +95,89 @@ func (suite *StatusStandardTestSuite) TearDownTest() {
 	testrig.StandardDBTeardown(suite.db)
 	testrig.StandardStorageTeardown(suite.storage)
 }
+
+func (suite *StatusStandardTestSuite) testHttpClient() pub.HttpClient {
+	remoteAccount := suite.testAccounts["remote_account_1"]
+	remoteAccountNamestring := fmt.Sprintf("acct:%s@%s", remoteAccount.Username, remoteAccount.Domain)
+	remoteAccountWebfingerURI := fmt.Sprintf("https://%s/.well-known/webfinger?resource=%s", remoteAccount.Domain, remoteAccountNamestring)
+
+	fmt.Println(remoteAccountWebfingerURI)
+
+	httpClient := testrig.NewMockHTTPClient(func(req *http.Request) (*http.Response, error) {
+
+		// respond correctly to a webfinger lookup
+		if req.URL.String() == remoteAccountWebfingerURI {
+			responseJson := fmt.Sprintf(`
+			{
+				"subject": "%s",
+				"aliases": [
+				  "%s",
+				  "%s"
+				],
+				"links": [
+				  {
+					"rel": "http://webfinger.net/rel/profile-page",
+					"type": "text/html",
+					"href": "%s"
+				  },
+				  {
+					"rel": "self",
+					"type": "application/activity+json",
+					"href": "%s"
+				  }
+				]
+			}`, remoteAccountNamestring, remoteAccount.URI, remoteAccount.URL, remoteAccount.URL, remoteAccount.URI)
+			responseType := "application/json"
+
+			reader := bytes.NewReader([]byte(responseJson))
+			readCloser := io.NopCloser(reader)
+			response := &http.Response{
+				StatusCode:    200,
+				Body:          readCloser,
+				ContentLength: int64(len(responseJson)),
+				Header: http.Header{
+					"content-type": {responseType},
+				},
+			}
+			return response, nil
+		}
+
+		// respond correctly to an account dereference
+		if req.URL.String() == remoteAccount.URI {
+			satanAS, err := suite.tc.AccountToAS(context.Background(), remoteAccount)
+			if err != nil {
+				panic(err)
+			}
+
+			satanI, err := streams.Serialize(satanAS)
+			if err != nil {
+				panic(err)
+			}
+			satanJson, err := json.Marshal(satanI)
+			if err != nil {
+				panic(err)
+			}
+			responseType := "application/activity+json"
+
+			reader := bytes.NewReader(satanJson)
+			readCloser := io.NopCloser(reader)
+			response := &http.Response{
+				StatusCode:    200,
+				Body:          readCloser,
+				ContentLength: int64(len(satanJson)),
+				Header: http.Header{
+					"content-type": {responseType},
+				},
+			}
+			return response, nil
+		}
+
+		r := ioutil.NopCloser(bytes.NewReader([]byte{}))
+		return &http.Response{
+			StatusCode: 200,
+			Body:       r,
+		}, nil
+	})
+
+	return httpClient
+}