Initial commit

internal/bot/bot.go

@@ -0,0 +1,233 @@
+/*
+ * Copyright © 2022 Kevin Kandlbinder.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package bot
+
+import (
+	"github.com/Unkn0wnCat/matrix-veles/internal/config"
+	"github.com/spf13/viper"
+	"log"
+	"maunium.net/go/mautrix"
+	"maunium.net/go/mautrix/event"
+	"maunium.net/go/mautrix/id"
+	"os"
+	"os/signal"
+	"strings"
+	"syscall"
+	"time"
+)
+
+// Run starts the bot, blocking until an interrupt or SIGTERM is received
+func Run() {
+	// Set up signal channel for controlled shutdown
+	c := make(chan os.Signal)
+	signal.Notify(c, os.Interrupt, syscall.SIGTERM)
+
+	// Save Timestamp for filtering
+	startTs := time.Now().Unix()
+
+	checkConfig()
+
+	log.Printf("matrix-veles has started.")
+
+	// Initialize client, this does not check access key!
+	matrixClient, err := mautrix.NewClient(
+		viper.GetString("bot.homeserver_url"),
+		id.NewUserID(viper.GetString("bot.username"), viper.GetString("bot.homeserver")),
+		viper.GetString("bot.accessKey"))
+	if err != nil {
+		log.Printf("matrix-veles couldn't initialize matrix client, please check credentials")
+		log.Fatal(err)
+		return
+	}
+
+	// If no accessKey is set, perform login
+	if viper.GetString("bot.accessKey") == "" {
+		performLogin(matrixClient)
+	}
+
+	// Set up sync handlers for invites and messages
+	syncer := matrixClient.Syncer.(*mautrix.DefaultSyncer)
+	syncer.OnEventType(event.EventMessage, handleMessageEvent(matrixClient, startTs))
+	syncer.OnEventType(event.StateMember, handleMemberEvent(matrixClient, startTs))
+
+	// Set up async tasks
+	go startSync(matrixClient)
+	go doInitialUpdate(matrixClient)
+
+	<-c
+	log.Printf("Shutting down...")
+
+	matrixClient.StopSync()
+
+	log.Printf("Goodbye!")
+
+	os.Exit(0)
+}
+
+// checkConfig applies constraints to the configuration and exits the program on violation
+func checkConfig() {
+	// Both homeserver and username are required!
+	if viper.GetString("bot.homeserver") == "" || viper.GetString("bot.username") == "" {
+		log.Printf("matrix-veles is missing user identification (homeserver / username)")
+		os.Exit(1)
+		return
+	}
+
+	// Either accessKey or password are required
+	if viper.GetString("bot.accessKey") == "" && viper.GetString("bot.password") == "" {
+		log.Printf("matrix-veles is missing user credentials (access-key / password)")
+		log.Printf("Please provide either an access-key or password")
+		os.Exit(1)
+		return
+	}
+}
+
+// performLogin logs in the mautrix.Client using the username and password from config
+func performLogin(matrixClient *mautrix.Client) {
+	res, err := matrixClient.Login(&mautrix.ReqLogin{
+		Type:                     "m.login.password",
+		Identifier:               mautrix.UserIdentifier{Type: mautrix.IdentifierTypeUser, User: viper.GetString("bot.username")},
+		Password:                 viper.GetString("bot.password"),
+		StoreCredentials:         true,
+		InitialDeviceDisplayName: "github.com/Unkn0wnCat/matrix-veles",
+	})
+	if err != nil {
+		log.Printf("matrix-veles couldn't sign in, please check credentials")
+		log.Fatal(err)
+		return
+	}
+
+	accessToken := res.AccessToken
+
+	// Save accessKey to configuration
+	viper.Set("bot.accessKey", accessToken)
+	err = viper.WriteConfig()
+	if err != nil {
+		log.Printf("matrix-veles could not save the accessKey to config")
+		log.Fatal(err)
+		return
+	}
+}
+
+// doInitialUpdate updates the config right after startup to catch up with joined/left rooms
+func doInitialUpdate(matrixClient *mautrix.Client) {
+	resp, err := matrixClient.JoinedRooms()
+	if err != nil {
+		log.Printf("matrix-veles could not read joined rooms, something is horribly wrong")
+		log.Fatalln(err)
+	}
+
+	// Hand-off list to config helper
+	config.RoomConfigInitialUpdate(resp.JoinedRooms)
+}
+
+// handleMessageEvent wraps message handler taking the mautrix.Client and start timestamp as parameters
+func handleMessageEvent(matrixClient *mautrix.Client, startTs int64) mautrix.EventHandler {
+	return func(source mautrix.EventSource, evt *event.Event) {
+		if evt.Timestamp < (startTs * 1000) {
+			// Ignore old events
+			return
+		}
+
+		// Cast event to correct event type
+		content, ok := evt.Content.Parsed.(*event.MessageEventContent)
+
+		if !ok {
+			log.Println("Uh oh, could not typecast m.room.member event content...")
+			return
+		}
+
+		username, _, err := matrixClient.UserID.Parse()
+		if err != nil {
+			log.Panicln("Invalid user id in client")
+		}
+
+		if content.URL != "" {
+			handleHashing(content, evt, matrixClient)
+
+			return
+		}
+
+		if !strings.HasPrefix(content.Body, "!"+username) &&
+			!strings.HasPrefix(content.Body, "@"+username) &&
+			!(strings.HasPrefix(content.Body, username) && strings.HasPrefix(content.FormattedBody, "<a href=\"https://matrix.to/#/"+matrixClient.UserID.String()+"\">")) {
+			return
+		}
+
+		handleCommand(content.Body, evt.Sender, evt.RoomID, matrixClient)
+
+	}
+}
+
+// handleMemberEvent wraps m.room.member (invite, join, leave, ban etc.) handler taking the mautrix.Client and start timestamp as parameters
+func handleMemberEvent(matrixClient *mautrix.Client, startTs int64) func(source mautrix.EventSource, evt *event.Event) {
+	return func(source mautrix.EventSource, evt *event.Event) {
+		if *evt.StateKey != matrixClient.UserID.String() {
+			return
+		} // This does not concern us, as we are not the subject
+		if evt.Timestamp < (startTs * 1000) {
+			// Ignore old events, TODO: Handle missed invites.
+			return
+		}
+
+		// Cast event to correct event type
+		content, ok := evt.Content.Parsed.(*event.MemberEventContent)
+
+		if !ok {
+			log.Println("Uh oh, could not typecast m.room.member event content...")
+			return
+		}
+
+		// If it is an invite, accept it
+		if content.Membership == event.MembershipInvite {
+			doAcceptInvite(matrixClient, evt.RoomID)
+			return
+		}
+
+		// If it is our join event, set room to active
+		if content.Membership == event.MembershipJoin {
+			config.SetRoomConfigActive(evt.RoomID.String(), true)
+			return
+		}
+
+		// If we left or got banned, set room to inactive
+		if content.Membership.IsLeaveOrBan() {
+			config.SetRoomConfigActive(evt.RoomID.String(), false)
+			return
+		}
+	}
+}
+
+// startSync starts the mautrix.Client sync for receiving events
+func startSync(matrixClient *mautrix.Client) {
+	err := matrixClient.Sync()
+	if err != nil {
+		log.Printf("matrix-veles has encountered a fatal error whilst syncing")
+		log.Println(err)
+		os.Exit(2)
+	}
+	log.Println("sync exited.")
+}
+
+// formattedMessage is a helper struct for sending HTML content
+type formattedMessage struct {
+	Type          string `json:"msgtype"`
+	Body          string `json:"body"`
+	Format        string `json:"format"`
+	FormattedBody string `json:"formatted_body"`
+}