Implement short deep links to start the bot

Store CreatedAt for users
Use sqids library to generate short links using a random LinkKey number and CreatedAt unix timestamps
Update guregu/dynamo library

.github/workflows/main.yml

@@ -62,7 +62,7 @@ jobs:
       - name: Terraform apply
         run: |
           cd infra
-          terraform apply -auto-approve -var aws_region=${{ vars.AWS_REGION }} -var lambda_bucket=${{ vars.S3_LAMBDA_BUCKET }} -var bot_token=${{ secrets.BOT_TOKEN }}
+          terraform apply -auto-approve -var aws_region=${{ vars.AWS_REGION }} -var lambda_bucket=${{ vars.S3_LAMBDA_BUCKET }} -var bot_token=${{ secrets.BOT_TOKEN }} -var sqids_alphabet=${{ secrets.SQIDS_ALPHABET }}
 
       - name: Set webhook URL
         shell: bash

README.md

@@ -57,7 +57,7 @@ Initialize the main Terraform stack:
 ```shell
 cd infra
 
-AWS_PROFILE=<AWS_PROFILE> init -backend-config backend_config.hcl # Run once
+AWS_PROFILE=<AWS_PROFILE> terraform init -backend-config backend_config.hcl # Run once
 ```
 
 #### Deploy

bot/common/init.go

@@ -27,6 +27,12 @@ func InitBot(request APIRequest) (APIResponse, error) {
 		return APIResponse{StatusCode: 500}, errors.New("TOKEN environment variable is empty")
 	}
 
+	// Get sqids alphabet from the environment variable.
+	alphabet := os.Getenv("SQIDS_ALPHABET")
+	if alphabet == "" {
+		return APIResponse{StatusCode: 500}, errors.New("SQIDS_ALPHABET environment variable is empty")
+	}
+
 	// Create bot from environment value.
 	b, err := gotgbot.NewBot(token, &gotgbot.BotOpts{
 		BotClient: &gotgbot.BaseBotClient{

bot/common/misc.go

@@ -5,6 +5,8 @@ import (
 	"github.com/PaulSonOfLars/gotgbot/v2"
 	"github.com/PaulSonOfLars/gotgbot/v2/ext"
 	"github.com/bugfloyd/anonymous-telegram-bot/common/i18n"
+	"github.com/sqids/sqids-go"
+	"os"
 	"strings"
 )
 
@@ -36,22 +38,33 @@ func (r *RootHandler) start(b *gotgbot.Bot, ctx *ext.Context) error {
 		return nil
 	}
 	if len(args) == 2 && args[0] == "/start" {
-
 		var err error
 		var receiverUser *User
 		var identity string
 
 		if strings.HasPrefix(args[1], "_") {
 			username := args[1][1:]
 			receiverUser, err = r.userRepo.readUserByUsername(username)
+			if err != nil {
+				return fmt.Errorf("failed to retrieve the link owner: %w", err)
+			}
+			identity = receiverUser.Username
 		} else {
-			receiverUser, err = r.userRepo.readUserByUUID(args[1])
+			linkKey, createdAt, err := readUserLinkKey(args[1])
+			if err != nil {
+				return fmt.Errorf("failed to read the link key: %w", err)
+			}
+			receiverUser, err = r.userRepo.readUserByLinkKey(linkKey, createdAt)
+			if err != nil {
+				return fmt.Errorf("failed to retrieve the link owner: %w", err)
+			}
+			identity = args[1]
 		}
 
-		if err != nil || receiverUser == nil {
+		if receiverUser == nil {
 			_, err = b.SendMessage(ctx.EffectiveChat.Id, i18n.T(i18n.UserNotFoundText), &gotgbot.SendMessageOpts{})
 			if err != nil {
-				return fmt.Errorf("failed to send bot info: %w", err)
+				return fmt.Errorf("failed to send wrong link response: %w", err)
 			}
 			return nil
 		}
@@ -106,14 +119,6 @@ func (r *RootHandler) start(b *gotgbot.Bot, ctx *ext.Context) error {
 			return fmt.Errorf("failed to update user state: %w", err)
 		}
 
-		if receiverUser.Name != "" {
-			identity = receiverUser.Name
-		} else if receiverUser.Username != "" {
-			identity = receiverUser.Username
-		} else {
-			identity = receiverUser.UUID
-		}
-
 		_, err = b.SendMessage(ctx.EffectiveChat.Id, fmt.Sprintf(i18n.T(i18n.InitialSendMessagePromptText), identity), &gotgbot.SendMessageOpts{})
 		if err != nil {
 			return fmt.Errorf("failed to send bot info: %w", err)
@@ -136,15 +141,24 @@ func (r *RootHandler) info(b *gotgbot.Bot, ctx *ext.Context) error {
 }
 
 func (r *RootHandler) getLink(b *gotgbot.Bot, ctx *ext.Context) error {
+	alphabet := os.Getenv("SQIDS_ALPHABET")
+	s, _ := sqids.New(sqids.Options{
+		Alphabet: alphabet,
+	})
+	genericLinkKey, err := s.Encode([]uint64{uint64(r.user.LinkKey), uint64(r.user.CreatedAt.Unix())})
+	if err != nil {
+		return err
+	}
+
 	var link string
 	if r.user.Username != "" {
 		usernameLink := fmt.Sprintf("https://t.me/%s?start=_%s", b.User.Username, r.user.Username)
-		uuidLink := fmt.Sprintf("https://t.me/%s?start=%s", b.User.Username, r.user.UUID)
-		link = fmt.Sprintf("%s\n%s\n\n%s\n\n%s", i18n.T(i18n.LinkText), usernameLink, i18n.T(i18n.OrText), uuidLink)
+		genericLink := fmt.Sprintf("https://t.me/%s?start=%s", b.User.Username, genericLinkKey)
+		link = fmt.Sprintf("%s\n%s\n\n%s\n\n%s", i18n.T(i18n.LinkText), usernameLink, i18n.T(i18n.OrText), genericLink)
 	} else {
-		link = fmt.Sprintf("https://t.me/%s?start=%s", b.User.Username, r.user.UUID)
+		link = fmt.Sprintf("https://t.me/%s?start=%s", b.User.Username, genericLinkKey)
 	}
-	_, err := ctx.EffectiveMessage.Reply(b, link, nil)
+	_, err = ctx.EffectiveMessage.Reply(b, link, nil)
 	if err != nil {
 		return err
 	}
@@ -174,3 +188,20 @@ func (r *RootHandler) sendError(b *gotgbot.Bot, ctx *ext.Context, message string
 	}
 	return nil
 }
+
+func readUserLinkKey(link string) (int32, int64, error) {
+	alphabet := os.Getenv("SQIDS_ALPHABET")
+	s, err := sqids.New(sqids.Options{
+		Alphabet: alphabet,
+	})
+
+	if err != nil {
+		return 0, 0, fmt.Errorf("failed to read user link key: %w", err)
+	}
+
+	numbers := s.Decode(link)
+	if len(numbers) != 2 {
+		return 0, 0, fmt.Errorf("failed to read user link key")
+	}
+	return int32(numbers[0]), int64(numbers[1]), nil
+}

bot/common/user.go

@@ -1,17 +1,21 @@
 package common
 
-import "github.com/bugfloyd/anonymous-telegram-bot/common/i18n"
+import (
+	"github.com/bugfloyd/anonymous-telegram-bot/common/i18n"
+	"time"
+)
 
 type User struct {
 	UUID           string `dynamo:",hash"`
 	UserID         int64  `index:"UserID-GSI,hash"`
 	Username       string `index:"Username-GSI,hash"`
 	State          State
-	Name           string
-	Blacklist      []string      `dynamo:",set,omitempty"`
+	Blacklist      []string      `dynamo:",set,omitempty,omitemptyelem"`
 	ContactUUID    string        `dynamo:",omitempty"`
 	ReplyMessageID int64         `dynamo:",omitempty"`
 	Language       i18n.Language `dynamo:",omitempty"`
+	LinkKey        int32         `index:"LinkKey-GSI,hash"`
+	CreatedAt      time.Time     `dynamo:",unixtime" index:"LinkKey-GSI,range"`
 }
 
 type State string

bot/common/user_repo.go

@@ -2,7 +2,9 @@ package common
 
 import (
 	"fmt"
+	"math/rand"
 	"os"
+	"time"
 
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/aws/session"
@@ -37,9 +39,11 @@ func NewUserRepository() (*UserRepository, error) {
 
 func (repo *UserRepository) createUser(userId int64) (*User, error) {
 	u := User{
-		UUID:   uuid.New().String(),
-		UserID: userId,
-		State:  Idle,
+		UUID:      uuid.New().String(),
+		UserID:    userId,
+		State:     Idle,
+		LinkKey:   int32(rand.Intn(900000) + 100000),
+		CreatedAt: time.Now(),
 	}
 	err := repo.table.Put(u).Run()
 	if err != nil {
@@ -75,6 +79,15 @@ func (repo *UserRepository) readUserByUsername(username string) (*User, error) {
 	return &u, nil
 }
 
+func (repo *UserRepository) readUserByLinkKey(linkKey int32, createdAt int64) (*User, error) {
+	var u User
+	err := repo.table.Get("LinkKey", linkKey).Index("LinkKey-GSI").Range("CreatedAt", dynamo.Equal, createdAt).One(&u)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get user: %w", err)
+	}
+	return &u, nil
+}
+
 func (repo *UserRepository) updateUser(uuid string, updates map[string]interface{}) error {
 	updateBuilder := repo.table.Update("UUID", uuid)
 	for key, value := range updates {

bot/go.mod

@@ -7,7 +7,8 @@ require (
 	github.com/aws/aws-lambda-go v1.47.0
 	github.com/aws/aws-sdk-go v1.51.25
 	github.com/google/uuid v1.6.0
-	github.com/guregu/dynamo v1.22.0
+	github.com/guregu/dynamo v1.22.1
+	github.com/sqids/sqids-go v0.4.1
 )
 
 require (

bot/go.sum

@@ -11,14 +11,16 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
-github.com/guregu/dynamo v1.22.0 h1:lRRjRyY+Xcvd0odbIJgzEg6rRsCvgALN56zRGl8q/yY=
-github.com/guregu/dynamo v1.22.0/go.mod h1:WCJu1jWjU/mEYnV9dDOqmAGdTgO7J9AnhkxcH/btXho=
+github.com/guregu/dynamo v1.22.1 h1:0exG5Er2fVs+9qYUaoUbpCPr+7pepwoVPYkDTyvVTaI=
+github.com/guregu/dynamo v1.22.1/go.mod h1:a0knvVZrDhT+q7eQlu1n041lf5vPi0sNfGjRh81mAnQ=
 github.com/jmespath/go-jmespath v0.4.0 h1:BEgLn5cpjn8UN1mAw4NjwDrS35OdebyEtFe+9YPoQUg=
 github.com/jmespath/go-jmespath v0.4.0/go.mod h1:T8mJZnbsbmF+m6zOOFylbeCJqk5+pHWvzYPziyZiYoo=
 github.com/jmespath/go-jmespath/internal/testify v1.5.1 h1:shLQSRRSCCPj3f2gpwzGwWFoC7ycTf1rcQZHOlsJ6N8=
 github.com/jmespath/go-jmespath/internal/testify v1.5.1/go.mod h1:L3OGu8Wl2/fWfCI6z80xFu9LTZmf1ZRjMHUOPmWr69U=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/sqids/sqids-go v0.4.1 h1:eQKYzmAZbLlRwHeHYPF35QhgxwZHLnlmVj9AkIj/rrw=
+github.com/sqids/sqids-go v0.4.1/go.mod h1:EMwHuPQgSNFS0A49jESTfIQS+066XQTVhukrzEPScl8=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.7.2 h1:4jaiDzPyXQvSd7D0EjG45355tLlV3VOECpq10pLC+8s=
 github.com/stretchr/testify v1.7.2/go.mod h1:R6va5+xMeoiuVRoj+gSkQ7d3FALtqAAGI1FQKckRals=

infra/main.tf

@@ -14,7 +14,8 @@ resource "aws_lambda_function" "anonymous_bot" {
 
   environment {
     variables = {
-      BOT_TOKEN = var.bot_token
+      BOT_TOKEN      = var.bot_token
+      SQIDS_ALPHABET = var.sqids_alphabet
     }
   }
 }
@@ -112,6 +113,16 @@ resource "aws_dynamodb_table" "main" {
     type = "S"
   }
 
+  attribute {
+    name = "LinkKey"
+    type = "N"
+  }
+
+  attribute {
+    name = "CreatedAt"
+    type = "N"
+  }
+
   global_secondary_index {
     name            = "UserID-GSI"
     hash_key        = "UserID"
@@ -124,6 +135,13 @@ resource "aws_dynamodb_table" "main" {
     projection_type = "ALL"
   }
 
+  global_secondary_index {
+    name            = "LinkKey-GSI"
+    hash_key        = "LinkKey"
+    range_key       = "CreatedAt"
+    projection_type = "ALL"
+  }
+
   lifecycle {
     prevent_destroy = false
   }
@@ -157,7 +175,8 @@ resource "aws_iam_policy" "lambda_dynamodb_policy" {
         Effect = "Allow",
         Resource = [
           "${aws_dynamodb_table.main.arn}/index/UserID-GSI",
-          "${aws_dynamodb_table.main.arn}/index/Username-GSI"
+          "${aws_dynamodb_table.main.arn}/index/Username-GSI",
+          "${aws_dynamodb_table.main.arn}/index/LinkKey-GSI"
         ]
       }
     ]

infra/variables.tf

@@ -13,6 +13,11 @@ variable "bot_token" {
   type        = string
 }
 
+variable "sqids_alphabet" {
+  description = "sqids alphabet"
+  type        = string
+}
+
 variable "zip_bundle_path" {
   description = "Local Lambda zip bundle path"
   type        = string