bot: Add linking command

internal/bot/commandParser.go

@@ -19,7 +19,9 @@ package bot
 
 import (
 	"context"
+	"github.com/Unkn0wnCat/matrix-veles/internal/db"
 	"github.com/Unkn0wnCat/matrix-veles/internal/tracer"
+	"go.mongodb.org/mongo-driver/bson/primitive"
 	"go.opentelemetry.io/otel/attribute"
 	"log"
 	"maunium.net/go/mautrix"
@@ -61,11 +63,46 @@ func handleCommand(command string, sender id.UserID, id id.RoomID, client *mautr
 		return
 	}
 
+	if strings.HasPrefix(command, "link ") {
+		commandLink(sender, id, client, strings.TrimPrefix(command, "link "))
+		return
+	}
+
 	// No match :( - display help
 	commandHelp(sender, id, client)
 	return
 }
 
+func commandLink(userId id.UserID, id id.RoomID, client *mautrix.Client, linkId string) {
+	linkId = strings.Trim(linkId, " \n\r")
+
+	linkIdP, err := primitive.ObjectIDFromHex(linkId)
+	if err != nil {
+		_, _ = client.SendNotice(id, "Invalid Link ID")
+		return
+	}
+
+	user, err := db.GetUserByID(linkIdP)
+	if err != nil {
+		_, _ = client.SendNotice(id, "Invalid Link ID")
+		return
+	}
+
+	err = user.ValidateMXID(userId.String())
+	if err != nil {
+		_, _ = client.SendNotice(id, "No matching link request pending")
+		return
+	}
+
+	err = db.SaveUser(user)
+	if err != nil {
+		_, _ = client.SendNotice(id, "Database error")
+		return
+	}
+
+	_, _ = client.SendNotice(id, "Successfully linked")
+}
+
 func commandHelp(_ id.UserID, id id.RoomID, client *mautrix.Client) {
 	// TODO: Improve help message
 

internal/db/model/user.go

@@ -2,8 +2,10 @@ package model
 
 import (
 	"encoding/base64"
+	"errors"
 	"go.mongodb.org/mongo-driver/bson/primitive"
 	"golang.org/x/crypto/bcrypt"
+	"strings"
 )
 
 type DBUser struct {
@@ -20,6 +22,20 @@ type DBUser struct {
 	Password *string `bson:"-" json:"-"` // Password may never be sent out!
 }
 
+func (usr *DBUser) ValidateMXID(mxid string) error {
+	for i, pendingMxid := range usr.PendingMatrixLinks {
+		if strings.EqualFold(*pendingMxid, mxid) {
+			usr.PendingMatrixLinks = append(usr.PendingMatrixLinks[:i], usr.PendingMatrixLinks[i+1:]...)
+
+			usr.MatrixLinks = append(usr.MatrixLinks, &mxid)
+
+			return nil
+		}
+	}
+
+	return errors.New("not pending")
+}
+
 func (usr *DBUser) HashPassword() error {
 	if usr.Password == nil {
 		return nil