Files
mq/examples/email_notification_dag.go
Oarkflow d347e2e253 update
2025-08-05 19:33:35 +05:45

457 lines
15 KiB
Go

package main
import (
"context"
"fmt"
"os"
"regexp"
"strings"
"time"
"github.com/oarkflow/json"
"github.com/oarkflow/mq/dag"
"github.com/oarkflow/mq/handlers"
"github.com/oarkflow/mq/utils"
"github.com/oarkflow/jet"
"github.com/oarkflow/mq"
"github.com/oarkflow/mq/consts"
)
type ValidateLoginNode struct {
dag.Operation
}
func (v *ValidateLoginNode) ProcessTask(ctx context.Context, task *mq.Task) mq.Result {
var inputData map[string]any
if err := json.Unmarshal(task.Payload, &inputData); err != nil {
return mq.Result{Error: fmt.Errorf("invalid input data: %v", err), Ctx: ctx}
}
username, _ := inputData["username"].(string)
password, _ := inputData["password"].(string)
if username == "" || password == "" {
inputData["validation_error"] = "Username and password are required"
inputData["error_field"] = "credentials"
bt, _ := json.Marshal(inputData)
return mq.Result{Payload: bt, Ctx: ctx, ConditionStatus: "invalid"}
}
// Simulate user validation
if username == "admin" && password == "password" {
inputData["validation_status"] = "success"
} else {
inputData["validation_error"] = "Invalid username or password"
inputData["error_field"] = "credentials"
bt, _ := json.Marshal(inputData)
return mq.Result{Payload: bt, Ctx: ctx, ConditionStatus: "invalid"}
}
validatedData := map[string]any{
"username": username,
"validated_at": time.Now().Format("2006-01-02 15:04:05"),
"validation_status": "success",
}
bt, _ := json.Marshal(validatedData)
return mq.Result{Payload: bt, Ctx: ctx, ConditionStatus: "valid"}
}
func loginDAG() *dag.DAG {
flow := dag.NewDAG("Login Flow", "login-flow", func(taskID string, result mq.Result) {
fmt.Printf("Login flow completed for task %s: %s\n", taskID, string(result.Payload))
}, mq.WithSyncMode(true), mq.WithLogger(nil))
renderHTML := handlers.NewRenderHTMLNode("render-html")
renderHTML.Payload.Data = map[string]any{
"schema_file": "login.json",
}
flow.AddNode(dag.Page, "Login Form", "LoginForm", renderHTML, true)
flow.AddNode(dag.Function, "Validate Login", "ValidateLogin", &ValidateLoginNode{})
flow.AddNode(dag.Page, "Error Page", "ErrorPage", &EmailErrorPageNode{})
flow.AddEdge(dag.Simple, "Validate Login", "LoginForm", "ValidateLogin")
flow.AddCondition("ValidateLogin", map[string]string{
"invalid": "ErrorPage",
})
return flow
}
func main() {
flow := dag.NewDAG("Email Notification System", "email-notification", func(taskID string, result mq.Result) {
fmt.Printf("Email notification workflow completed for task %s: %s\n", taskID, string(utils.RemoveRecursiveFromJSON(result.Payload, "html_content")))
}, mq.WithSyncMode(true), mq.WithLogger(nil))
renderHTML := handlers.NewRenderHTMLNode("render-html")
renderHTML.Payload.Data = map[string]any{
"schema_file": "schema.json",
}
flow.AddDAGNode(dag.Page, "CheckLogin", "Login", loginDAG(), true)
flow.AddNode(dag.Page, "Contact Form", "ContactForm", renderHTML)
flow.AddNode(dag.Function, "Validate Contact Data", "ValidateContact", &ValidateContactNode{})
flow.AddNode(dag.Function, "Check User Type", "CheckUserType", &CheckUserTypeNode{})
flow.AddNode(dag.Function, "Send Welcome Email", "SendWelcomeEmail", &SendWelcomeEmailNode{})
flow.AddNode(dag.Function, "Send Premium Email", "SendPremiumEmail", &SendPremiumEmailNode{})
flow.AddNode(dag.Function, "Send Standard Email", "SendStandardEmail", &SendStandardEmailNode{})
flow.AddNode(dag.Page, "Success Page", "SuccessPage", &SuccessPageNode{})
flow.AddNode(dag.Page, "Error Page", "ErrorPage", &EmailErrorPageNode{})
flow.AddEdge(dag.Simple, "Login to Contact", "Login", "ContactForm")
// Define conditional flow
flow.AddEdge(dag.Simple, "Form to Validation", "ContactForm", "ValidateContact")
flow.AddCondition("ValidateContact", map[string]string{
"valid": "CheckUserType",
"invalid": "ErrorPage",
})
flow.AddCondition("CheckUserType", map[string]string{
"new_user": "SendWelcomeEmail",
"premium_user": "SendPremiumEmail",
"standard_user": "SendStandardEmail",
})
flow.AddCondition("SendWelcomeEmail", map[string]string{
"sent": "SuccessPage",
"failed": "ErrorPage",
})
flow.AddCondition("SendPremiumEmail", map[string]string{
"sent": "SuccessPage",
"failed": "ErrorPage",
})
flow.AddCondition("SendStandardEmail", map[string]string{
"sent": "SuccessPage",
"failed": "ErrorPage",
})
// Start the flow
if flow.Error != nil {
panic(flow.Error)
}
fmt.Println("Starting Email Notification DAG server on http://0.0.0.0:8084")
fmt.Println("Navigate to the URL to access the contact form")
flow.Start(context.Background(), "0.0.0.0:8084")
}
// RenderHTMLNode - Page node with JSONSchema-based fields and custom HTML layout
// Usage: Pass JSONSchema and HTML layout to the node for dynamic form rendering and validation
// ValidateContactNode - Validates contact form data
type ValidateContactNode struct {
dag.Operation
}
func (v *ValidateContactNode) ProcessTask(ctx context.Context, task *mq.Task) mq.Result {
var inputData map[string]any
if err := json.Unmarshal(task.Payload, &inputData); err != nil {
return mq.Result{
Error: fmt.Errorf("invalid input data: %v", err),
Ctx: ctx,
}
}
// Extract form data
firstName, _ := inputData["first_name"].(string)
lastName, _ := inputData["last_name"].(string)
email, _ := inputData["email"].(string)
userType, _ := inputData["user_type"].(string)
priority, _ := inputData["priority"].(string)
subject, _ := inputData["subject"].(string)
message, _ := inputData["message"].(string)
// Validate required fields
if firstName == "" {
inputData["validation_error"] = "First name is required"
inputData["error_field"] = "first_name"
bt, _ := json.Marshal(inputData)
return mq.Result{Payload: bt, Ctx: ctx, ConditionStatus: "invalid"}
}
if lastName == "" {
inputData["validation_error"] = "Last name is required"
inputData["error_field"] = "last_name"
bt, _ := json.Marshal(inputData)
return mq.Result{Payload: bt, Ctx: ctx, ConditionStatus: "invalid"}
}
if email == "" {
inputData["validation_error"] = "Email address is required"
inputData["error_field"] = "email"
bt, _ := json.Marshal(inputData)
return mq.Result{Payload: bt, Ctx: ctx, ConditionStatus: "invalid"}
}
// Validate email format
emailRegex := regexp.MustCompile(`^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$`)
if !emailRegex.MatchString(email) {
inputData["validation_error"] = "Please enter a valid email address"
inputData["error_field"] = "email"
bt, _ := json.Marshal(inputData)
return mq.Result{Payload: bt, Ctx: ctx, ConditionStatus: "invalid"}
}
if userType == "" {
inputData["validation_error"] = "Please select your user type"
inputData["error_field"] = "user_type"
bt, _ := json.Marshal(inputData)
return mq.Result{Payload: bt, Ctx: ctx, ConditionStatus: "invalid"}
}
if priority == "" {
inputData["validation_error"] = "Please select a priority level"
inputData["error_field"] = "priority"
bt, _ := json.Marshal(inputData)
return mq.Result{Payload: bt, Ctx: ctx, ConditionStatus: "invalid"}
}
if subject == "" {
inputData["validation_error"] = "Subject is required"
inputData["error_field"] = "subject"
bt, _ := json.Marshal(inputData)
return mq.Result{Payload: bt, Ctx: ctx, ConditionStatus: "invalid"}
}
if message == "" {
inputData["validation_error"] = "Message is required"
inputData["error_field"] = "message"
bt, _ := json.Marshal(inputData)
return mq.Result{Payload: bt, Ctx: ctx, ConditionStatus: "invalid"}
}
// Check for spam patterns
spamPatterns := []string{"click here", "free money", "act now", "limited time"}
messageLower := strings.ToLower(message)
subjectLower := strings.ToLower(subject)
for _, pattern := range spamPatterns {
if strings.Contains(messageLower, pattern) || strings.Contains(subjectLower, pattern) {
inputData["validation_error"] = "Message contains prohibited content"
inputData["error_field"] = "message"
bt, _ := json.Marshal(inputData)
return mq.Result{Payload: bt, Ctx: ctx, ConditionStatus: "invalid"}
}
}
// All validations passed
validatedData := map[string]any{
"first_name": firstName,
"last_name": lastName,
"full_name": fmt.Sprintf("%s %s", firstName, lastName),
"email": email,
"user_type": userType,
"priority": priority,
"subject": subject,
"message": message,
"validated_at": time.Now().Format("2006-01-02 15:04:05"),
"validation_status": "success",
"message_length": len(message),
}
bt, _ := json.Marshal(validatedData)
return mq.Result{Payload: bt, Ctx: ctx, ConditionStatus: "valid"}
}
// CheckUserTypeNode - Determines routing based on user type
type CheckUserTypeNode struct {
dag.Operation
}
func (c *CheckUserTypeNode) ProcessTask(ctx context.Context, task *mq.Task) mq.Result {
var inputData map[string]any
if err := json.Unmarshal(task.Payload, &inputData); err != nil {
return mq.Result{Error: err, Ctx: ctx}
}
userType, _ := inputData["user_type"].(string)
// Add timestamp and additional metadata
inputData["processed_at"] = time.Now().Format("2006-01-02 15:04:05")
inputData["routing_decision"] = userType
var conditionStatus string
switch userType {
case "new":
conditionStatus = "new_user"
inputData["email_template"] = "welcome"
case "premium":
conditionStatus = "premium_user"
inputData["email_template"] = "premium"
case "standard":
conditionStatus = "standard_user"
inputData["email_template"] = "standard"
default:
conditionStatus = "standard_user"
inputData["email_template"] = "standard"
}
fmt.Printf("🔀 Routing decision: %s -> %s\n", userType, conditionStatus)
bt, _ := json.Marshal(inputData)
return mq.Result{Payload: bt, Ctx: ctx, ConditionStatus: conditionStatus}
}
// Email sending nodes
type SendWelcomeEmailNode struct {
dag.Operation
}
func (s *SendWelcomeEmailNode) ProcessTask(ctx context.Context, task *mq.Task) mq.Result {
return s.sendEmail(ctx, task, "Welcome to our platform! 🎉")
}
type SendPremiumEmailNode struct {
dag.Operation
}
func (s *SendPremiumEmailNode) ProcessTask(ctx context.Context, task *mq.Task) mq.Result {
return s.sendEmail(ctx, task, "Premium Support Response 💎")
}
type SendStandardEmailNode struct {
dag.Operation
}
func (s *SendStandardEmailNode) ProcessTask(ctx context.Context, task *mq.Task) mq.Result {
return s.sendEmail(ctx, task, "Thank you for contacting us ⭐")
}
// Helper method for email sending
func (s *SendWelcomeEmailNode) sendEmail(ctx context.Context, task *mq.Task, emailType string) mq.Result {
var inputData map[string]any
if err := json.Unmarshal(task.Payload, &inputData); err != nil {
return mq.Result{Error: err, Ctx: ctx}
}
email, _ := inputData["email"].(string)
// Simulate email sending delay
time.Sleep(300 * time.Millisecond)
// Simulate occasional failures for demo purposes
timestamp := time.Now()
success := timestamp.Second()%15 != 0 // 93% success rate
if !success {
errorData := inputData
errorData["email_status"] = "failed"
errorData["error_message"] = "Email gateway temporarily unavailable. Please try again."
errorData["sent_at"] = timestamp.Format("2006-01-02 15:04:05")
errorData["retry_suggested"] = true
bt, _ := json.Marshal(errorData)
return mq.Result{
Payload: bt,
Ctx: ctx,
ConditionStatus: "failed",
}
}
// Generate mock email ID and response
emailID := fmt.Sprintf("EMAIL_%d_%s", timestamp.Unix(), email[0:3])
resultData := inputData
resultData["email_status"] = "sent"
resultData["email_id"] = emailID
resultData["email_type"] = emailType
resultData["sent_at"] = timestamp.Format("2006-01-02 15:04:05")
resultData["delivery_estimate"] = "Instant"
resultData["gateway"] = "MockEmail Gateway"
fmt.Printf("📧 Email sent successfully! Type: %s, ID: %s, To: %s\n", emailType, emailID, email)
bt, _ := json.Marshal(resultData)
return mq.Result{Payload: bt, Ctx: ctx, ConditionStatus: "sent"}
}
// Helper methods for other email nodes
func (s *SendPremiumEmailNode) sendEmail(ctx context.Context, task *mq.Task, emailType string) mq.Result {
node := &SendWelcomeEmailNode{}
return node.sendEmail(ctx, task, emailType)
}
func (s *SendStandardEmailNode) sendEmail(ctx context.Context, task *mq.Task, emailType string) mq.Result {
node := &SendWelcomeEmailNode{}
return node.sendEmail(ctx, task, emailType)
}
// SuccessPageNode - Shows successful email result
type SuccessPageNode struct {
dag.Operation
}
func (s *SuccessPageNode) ProcessTask(ctx context.Context, task *mq.Task) mq.Result {
var inputData map[string]any
if err := json.Unmarshal(task.Payload, &inputData); err != nil {
return mq.Result{Error: err, Ctx: ctx}
}
htmlTemplate, err := os.ReadFile("email/success.html")
if err != nil {
return mq.Result{Error: fmt.Errorf("failed to read success template: %v", err)}
}
parser := jet.NewWithMemory(jet.WithDelims("{{", "}}"))
rs, err := parser.ParseTemplate(string(htmlTemplate), inputData)
if err != nil {
return mq.Result{Error: err, Ctx: ctx}
}
ctx = context.WithValue(ctx, consts.ContentType, consts.TypeHtml)
finalData := map[string]any{
"html_content": rs,
"result": inputData,
"step": "success",
}
bt, _ := json.Marshal(finalData)
return mq.Result{Payload: bt, Ctx: ctx}
}
// EmailErrorPageNode - Shows validation or sending errors
type EmailErrorPageNode struct {
dag.Operation
}
func (e *EmailErrorPageNode) ProcessTask(ctx context.Context, task *mq.Task) mq.Result {
var inputData map[string]any
if err := json.Unmarshal(task.Payload, &inputData); err != nil {
return mq.Result{Error: err, Ctx: ctx}
}
// Determine error type and message
errorMessage, _ := inputData["validation_error"].(string)
errorField, _ := inputData["error_field"].(string)
emailError, _ := inputData["error_message"].(string)
if errorMessage == "" && emailError != "" {
errorMessage = emailError
errorField = "email_sending"
}
if errorMessage == "" {
errorMessage = "An unknown error occurred"
}
htmlTemplate, err := os.ReadFile("email/error.html")
if err != nil {
return mq.Result{Error: fmt.Errorf("failed to read error template: %v", err)}
}
parser := jet.NewWithMemory(jet.WithDelims("{{", "}}"))
templateData := map[string]any{
"error_message": errorMessage,
"error_field": errorField,
"retry_suggested": inputData["retry_suggested"],
}
rs, err := parser.ParseTemplate(string(htmlTemplate), templateData)
if err != nil {
return mq.Result{Error: err, Ctx: ctx}
}
ctx = context.WithValue(ctx, consts.ContentType, consts.TypeHtml)
finalData := map[string]any{
"html_content": rs,
"error_data": inputData,
"step": "error",
}
bt, _ := json.Marshal(finalData)
return mq.Result{Payload: bt, Ctx: ctx}
}