Files
mq/examples/email_notification_dag.go
2025-07-31 14:27:27 +05:45

994 lines
33 KiB
Go

package main
import (
"context"
"fmt"
"regexp"
"sort"
"strings"
"time"
"github.com/oarkflow/json"
"github.com/oarkflow/mq/dag"
"github.com/oarkflow/jet"
"github.com/oarkflow/mq"
"github.com/oarkflow/mq/consts"
)
func main() {
contactFormSchema := map[string]any{
"properties": map[string]any{
"first_name": map[string]any{
"type": "string",
"title": "👤 First Name",
"order": 1,
"ui": map[string]any{
"control": "input",
"class": "form-group",
"name": "first_name",
},
},
"last_name": map[string]any{
"type": "string",
"title": "👤 Last Name",
"order": 2,
"ui": map[string]any{
"control": "input",
"class": "form-group",
"name": "last_name",
},
},
"email": map[string]any{
"type": "email",
"title": "📧 Email Address",
"order": 3,
"ui": map[string]any{
"control": "input",
"class": "form-group",
"name": "email",
},
},
"user_type": map[string]any{
"type": "string",
"title": "👥 User Type",
"order": 4,
"ui": map[string]any{
"control": "select",
"class": "form-group",
"name": "user_type",
"options": []any{"new", "premium", "standard"},
},
},
"priority": map[string]any{
"type": "string",
"title": "🚨 Priority Level",
"order": 5,
"ui": map[string]any{
"control": "select",
"class": "form-group",
"name": "priority",
"options": []any{"low", "medium", "high", "urgent"},
},
},
"subject": map[string]any{
"type": "string",
"title": "📋 Subject",
"order": 6,
"ui": map[string]any{
"control": "input",
"class": "form-group",
"name": "subject",
},
},
"message": map[string]any{
"type": "textarea",
"title": "💬 Message",
"order": 7,
"ui": map[string]any{
"control": "textarea",
"class": "form-group",
"name": "message",
},
},
},
"required": []any{"first_name", "last_name", "email", "user_type", "priority", "subject", "message"},
}
contactFormLayout := `
<!DOCTYPE html>
<html>
<head>
<title>Contact Us - Email Notification System</title>
<style>
body { font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; max-width: 700px; margin: 50px auto; padding: 20px; background: linear-gradient(135deg, #1e3c72 0%, #2a5298 100%); color: white; min-height: 100vh; }
.form-container { background: rgba(255, 255, 255, 0.1); padding: 40px; border-radius: 20px; backdrop-filter: blur(15px); box-shadow: 0 12px 40px rgba(0, 0, 0, 0.4); border: 1px solid rgba(255, 255, 255, 0.2); }
h1 { text-align: center; margin-bottom: 10px; text-shadow: 2px 2px 4px rgba(0,0,0,0.3); font-size: 2.2em; }
.subtitle { text-align: center; margin-bottom: 30px; opacity: 0.9; font-size: 1.1em; }
.form-group { margin-bottom: 25px; }
label { display: block; margin-bottom: 8px; font-weight: 600; text-shadow: 1px 1px 2px rgba(0,0,0,0.3); font-size: 1.1em; }
input, textarea, select { width: 100%; padding: 15px; border: none; border-radius: 10px; font-size: 16px; background: rgba(255, 255, 255, 0.2); color: white; backdrop-filter: blur(5px); transition: all 0.3s ease; border: 1px solid rgba(255, 255, 255, 0.3); }
input:focus, textarea:focus, select:focus { outline: none; background: rgba(255, 255, 255, 0.3); border: 1px solid rgba(255, 255, 255, 0.6); transform: translateY(-2px); box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2); }
input::placeholder, textarea::placeholder { color: rgba(255, 255, 255, 0.7); }
textarea { height: 120px; resize: vertical; }
select { cursor: pointer; }
select option { background: #2a5298; color: white; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
@media (max-width: 600px) { .form-row { grid-template-columns: 1fr; } }
button { background: linear-gradient(45deg, #FF6B6B, #4ECDC4); color: white; padding: 18px 40px; border: none; border-radius: 30px; cursor: pointer; font-size: 18px; font-weight: bold; width: 100%; transition: all 0.3s ease; box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3); text-transform: uppercase; letter-spacing: 1px; }
button:hover { transform: translateY(-3px); box-shadow: 0 8px 25px rgba(0, 0, 0, 0.4); }
.info-box { background: rgba(255, 255, 255, 0.15); padding: 20px; border-radius: 12px; margin-bottom: 25px; text-align: center; border-left: 4px solid #4ECDC4; }
.feature-list { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 15px; margin: 20px 0; }
.feature-item { background: rgba(255, 255, 255, 0.1); padding: 15px; border-radius: 8px; text-align: center; font-size: 14px; }
</style>
</head>
<body>
<div class="form-container">
<h1>📧 Contact Us</h1>
<div class="subtitle">Advanced Email Notification System with DAG Workflow</div>
<div class="info-box">
<p><strong>🔄 Smart Routing:</strong> Our system automatically routes your message based on your user type and preferences.</p>
</div>
<div class="feature-list">
<div class="feature-item">
<strong>📱 Instant Notifications</strong><br>
Real-time email delivery
</div>
<div class="feature-item">
<strong>🎯 Smart Targeting</strong><br>
User-specific content
</div>
<div class="feature-item">
<strong>🔒 Secure Processing</strong><br>
Enterprise-grade security
</div>
</div>
<form method="post" action="/process?task_id={{task_id}}&next=true">
<div class="form-row">
{{form_fields}}
</div>
<button type="submit">🚀 Send Message</button>
</form>
</div>
</body>
</html>`
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(result.Payload))
}, mq.WithSyncMode(true))
// Add workflow nodes
// Note: Page nodes have no timeout by default, allowing users unlimited time for form input
flow.AddNode(dag.Page, "Contact Form", "ContactForm", &ConfigurableFormNode{Schema: contactFormSchema, HTMLLayout: contactFormLayout}, true)
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{})
// 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")
}
// ConfigurableFormNode - 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
type ConfigurableFormNode struct {
dag.Operation
Schema map[string]any // JSONSchema for fields and requirements
HTMLLayout string // HTML layout template with placeholders for fields
fieldsCache []fieldInfo // Cached field order and definitions
cacheInitialized bool // Whether cache is initialized
}
// fieldInfo caches field metadata for rendering
type fieldInfo struct {
name string
order int
def map[string]any
definedIndex int // fallback to definition order
}
func (c *ConfigurableFormNode) ProcessTask(ctx context.Context, task *mq.Task) mq.Result {
var inputData map[string]any
if task.Payload != nil && len(task.Payload) > 0 {
if err := json.Unmarshal(task.Payload, &inputData); err == nil {
// Validate input against schema requirements
validationErrors := validateAgainstSchema(inputData, c.Schema)
if len(validationErrors) > 0 {
inputData["validation_error"] = validationErrors[0] // Show first error
bt, _ := json.Marshal(inputData)
return mq.Result{Payload: bt, Ctx: ctx, ConditionStatus: "invalid"}
}
return mq.Result{Payload: task.Payload, Ctx: ctx}
}
}
// Initialize cache if not done
if !c.cacheInitialized {
c.fieldsCache = parseFieldsFromSchema(c.Schema)
c.cacheInitialized = true
}
// Render form fields from cached field order
formFieldsHTML := renderFieldsFromCache(c.fieldsCache)
parser := jet.NewWithMemory(jet.WithDelims("{{", "}}"))
layout := strings.Replace(c.HTMLLayout, "{{form_fields}}", formFieldsHTML, 1)
rs, err := parser.ParseTemplate(layout, map[string]any{
"task_id": ctx.Value("task_id"),
})
if err != nil {
return mq.Result{Error: err, Ctx: ctx}
}
ctx = context.WithValue(ctx, consts.ContentType, consts.TypeHtml)
data := map[string]any{
"html_content": rs,
"step": "form",
}
bt, _ := json.Marshal(data)
return mq.Result{Payload: bt, Ctx: ctx}
}
// validateAgainstSchema checks inputData against JSONSchema requirements
func validateAgainstSchema(inputData map[string]any, schema map[string]any) []string {
var errors []string
if _, ok := schema["properties"].(map[string]any); ok {
if required, ok := schema["required"].([]any); ok {
for _, field := range required {
fname := field.(string)
if val, exists := inputData[fname]; !exists || val == "" {
errors = append(errors, fname+" is required")
}
}
}
// Add more validation as needed (type, format, etc.)
}
return errors
}
// parseFieldsFromSchema extracts and sorts fields from schema, preserving order
func parseFieldsFromSchema(schema map[string]any) []fieldInfo {
var fields []fieldInfo
if props, ok := schema["properties"].(map[string]any); ok {
keyOrder := make([]string, 0, len(props))
for k := range props {
keyOrder = append(keyOrder, k)
}
for idx, name := range keyOrder {
field := props[name].(map[string]any)
order := -1
if o, ok := field["order"].(int); ok {
order = o
} else if o, ok := field["order"].(float64); ok {
order = int(o)
}
fields = append(fields, fieldInfo{name: name, order: order, def: field, definedIndex: idx})
}
if len(fields) > 1 {
sort.SliceStable(fields, func(i, j int) bool {
if fields[i].order != -1 && fields[j].order != -1 {
return fields[i].order < fields[j].order
} else if fields[i].order != -1 {
return true
} else if fields[j].order != -1 {
return false
}
return fields[i].definedIndex < fields[j].definedIndex
})
}
}
return fields
}
// renderFieldsFromCache generates HTML for form fields from cached field order
func renderFieldsFromCache(fields []fieldInfo) string {
var html strings.Builder
for _, f := range fields {
label := f.name
if l, ok := f.def["title"].(string); ok {
label = l
}
// UI config
ui := map[string]any{}
if uiRaw, ok := f.def["ui"].(map[string]any); ok {
ui = uiRaw
}
// Control type
controlType := "input"
if ct, ok := ui["control"].(string); ok {
controlType = ct
}
// CSS classes
classes := "form-group"
if cls, ok := ui["class"].(string); ok {
classes = cls
}
// Name attribute
nameAttr := f.name
if n, ok := ui["name"].(string); ok {
nameAttr = n
}
// Type
typeStr := "text"
if t, ok := f.def["type"].(string); ok {
switch t {
case "string":
typeStr = "text"
case "email":
typeStr = "email"
case "number":
typeStr = "number"
case "textarea":
typeStr = "textarea"
}
}
// Render control
if controlType == "textarea" || typeStr == "textarea" {
html.WriteString(fmt.Sprintf(`<div class="%s"><label for="%s">%s:</label><textarea id="%s" name="%s" placeholder="%s"></textarea></div>`, classes, nameAttr, label, nameAttr, nameAttr, label))
} else if controlType == "select" {
// Optionally support select with options in ui["options"]
optionsHTML := ""
if opts, ok := ui["options"].([]any); ok {
for _, opt := range opts {
optStr := fmt.Sprintf("%v", opt)
optionsHTML += fmt.Sprintf(`<option value="%s">%s</option>`, optStr, optStr)
}
}
html.WriteString(fmt.Sprintf(`<div class="%s"><label for="%s">%s:</label><select id="%s" name="%s">%s</select></div>`, classes, nameAttr, label, nameAttr, nameAttr, optionsHTML))
} else {
html.WriteString(fmt.Sprintf(`<div class="%s"><label for="%s">%s:</label><input type="%s" id="%s" name="%s" placeholder="%s"></div>`, classes, nameAttr, label, typeStr, nameAttr, nameAttr, label))
}
}
return html.String()
}
// 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 := `
<!DOCTYPE html>
<html>
<head>
<title>Message Sent Successfully</title>
<style>
body {
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
max-width: 700px;
margin: 50px auto;
padding: 20px;
background: linear-gradient(135deg, #4CAF50 0%, #45a049 100%);
color: white;
}
.result-container {
background: rgba(255, 255, 255, 0.1);
padding: 40px;
border-radius: 20px;
backdrop-filter: blur(15px);
box-shadow: 0 12px 40px rgba(0, 0, 0, 0.4);
text-align: center;
}
.success-icon {
font-size: 80px;
margin-bottom: 20px;
animation: bounce 2s infinite;
}
@keyframes bounce {
0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
40% { transform: translateY(-10px); }
60% { transform: translateY(-5px); }
}
h1 {
margin-bottom: 30px;
text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
font-size: 2.5em;
}
.info-grid {
display: grid;
grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
gap: 20px;
margin: 30px 0;
text-align: left;
}
.info-item {
background: rgba(255, 255, 255, 0.15);
padding: 20px;
border-radius: 12px;
border-left: 4px solid #4ECDC4;
}
.info-label {
font-weight: bold;
margin-bottom: 8px;
opacity: 0.9;
font-size: 14px;
text-transform: uppercase;
letter-spacing: 1px;
}
.info-value {
font-size: 16px;
word-break: break-word;
}
.message-preview {
background: rgba(255, 255, 255, 0.1);
padding: 25px;
border-radius: 12px;
margin: 30px 0;
text-align: left;
border: 1px solid rgba(255, 255, 255, 0.2);
}
.actions {
margin-top: 40px;
}
.btn {
background: linear-gradient(45deg, #FF6B6B, #4ECDC4);
color: white;
padding: 15px 30px;
border: none;
border-radius: 25px;
cursor: pointer;
font-size: 16px;
font-weight: bold;
margin: 0 15px;
text-decoration: none;
display: inline-block;
transition: all 0.3s ease;
text-transform: uppercase;
letter-spacing: 1px;
}
.btn:hover {
transform: translateY(-3px);
box-shadow: 0 8px 25px rgba(0, 0, 0, 0.3);
}
.status-badge {
background: #4CAF50;
color: white;
padding: 8px 20px;
border-radius: 25px;
font-size: 14px;
font-weight: bold;
display: inline-block;
margin: 10px 0;
text-transform: uppercase;
letter-spacing: 1px;
}
.workflow-info {
background: rgba(255, 255, 255, 0.1);
padding: 20px;
border-radius: 12px;
margin-top: 30px;
font-size: 14px;
opacity: 0.9;
}
</style>
</head>
<body>
<div class="result-container">
<div class="success-icon">✅</div>
<h1>Message Sent Successfully!</h1>
<div class="status-badge">{{email_status}}</div>
<div class="info-grid">
<div class="info-item">
<div class="info-label">👤 Recipient</div>
<div class="info-value">{{full_name}}</div>
</div>
<div class="info-item">
<div class="info-label">📧 Email Address</div>
<div class="info-value">{{email}}</div>
</div>
<div class="info-item">
<div class="info-label">🆔 Email ID</div>
<div class="info-value">{{email_id}}</div>
</div>
<div class="info-item">
<div class="info-label">⏰ Sent At</div>
<div class="info-value">{{sent_at}}</div>
</div>
<div class="info-item">
<div class="info-label">📨 Email Type</div>
<div class="info-value">{{email_type}}</div>
</div>
<div class="info-item">
<div class="info-label">👥 User Type</div>
<div class="info-value">{{user_type}}</div>
</div>
<div class="info-item">
<div class="info-label">🚨 Priority</div>
<div class="info-value">{{priority}}</div>
</div>
<div class="info-item">
<div class="info-label">🚚 Delivery</div>
<div class="info-value">{{delivery_estimate}}</div>
</div>
</div>
<div class="message-preview">
<div class="info-label">📋 Subject:</div>
<div class="info-value" style="margin: 10px 0; font-weight: bold; font-size: 18px;">
{{subject}}
</div>
<div class="info-label">💬 Message ({{message_length}} chars):</div>
<div class="info-value" style="margin-top: 15px; font-style: italic; line-height: 1.6;">
"{{message}}"
</div>
</div>
<div class="actions">
<a href="/" class="btn">📧 Send Another Message</a>
<a href="/api/metrics" class="btn">📊 View Metrics</a>
</div>
<div class="workflow-info">
<strong>🔄 Workflow Details:</strong><br>
Gateway: {{gateway}} | Template: {{email_template}} | Processed: {{processed_at}}<br>
This message was processed through our advanced DAG workflow system with conditional routing.
</div>
</div>
</body>
</html>`
parser := jet.NewWithMemory(jet.WithDelims("{{", "}}"))
rs, err := parser.ParseTemplate(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 := `
<!DOCTYPE html>
<html>
<head>
<title>Email Error</title>
<style>
body {
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
max-width: 700px;
margin: 50px auto;
padding: 20px;
background: linear-gradient(135deg, #FF6B6B 0%, #FF5722 100%);
color: white;
}
.error-container {
background: rgba(255, 255, 255, 0.1);
padding: 40px;
border-radius: 20px;
backdrop-filter: blur(15px);
box-shadow: 0 12px 40px rgba(0, 0, 0, 0.4);
text-align: center;
}
.error-icon {
font-size: 80px;
margin-bottom: 20px;
animation: shake 0.5s ease-in-out infinite alternate;
}
@keyframes shake {
0% { transform: translateX(0); }
100% { transform: translateX(5px); }
}
h1 {
margin-bottom: 30px;
text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
font-size: 2.5em;
}
.error-message {
background: rgba(255, 255, 255, 0.2);
padding: 25px;
border-radius: 12px;
margin: 25px 0;
font-size: 18px;
border-left: 6px solid #FFB6B6;
line-height: 1.6;
}
.error-details {
background: rgba(255, 255, 255, 0.15);
padding: 20px;
border-radius: 12px;
margin: 25px 0;
text-align: left;
}
.actions {
margin-top: 40px;
}
.btn {
background: linear-gradient(45deg, #4ECDC4, #44A08D);
color: white;
padding: 15px 30px;
border: none;
border-radius: 25px;
cursor: pointer;
font-size: 16px;
font-weight: bold;
margin: 0 15px;
text-decoration: none;
display: inline-block;
transition: all 0.3s ease;
text-transform: uppercase;
letter-spacing: 1px;
}
.btn:hover {
transform: translateY(-3px);
box-shadow: 0 8px 25px rgba(0, 0, 0, 0.3);
}
.retry-btn {
background: linear-gradient(45deg, #FFA726, #FF9800);
}
</style>
</head>
<body>
<div class="error-container">
<div class="error-icon">❌</div>
<h1>Email Processing Error</h1>
<div class="error-message">
{{error_message}}
</div>
{{if error_field}}
<div class="error-details">
<strong>🎯 Error Field:</strong> {{error_field}}<br>
<strong>⚡ Action Required:</strong> Please correct the highlighted field and try again.<br>
<strong>💡 Tip:</strong> Make sure all required fields are properly filled out.
</div>
{{end}}
{{if retry_suggested}}
<div class="error-details">
<strong>⚠️ Temporary Issue:</strong> This appears to be a temporary system issue.
Please try sending your message again in a few moments.<br>
<strong>🔄 Auto-Retry:</strong> Our system will automatically retry failed deliveries.
</div>
{{end}}
<div class="actions">
<a href="/" class="btn retry-btn">🔄 Try Again</a>
<a href="/api/status" class="btn">📊 Check Status</a>
</div>
<div style="margin-top: 30px; font-size: 14px; opacity: 0.8;">
🔄 DAG Error Handler | Email Notification Workflow Failed<br>
Our advanced routing system ensures reliable message delivery.
</div>
</div>
</body>
</html>`
parser := jet.NewWithMemory(jet.WithDelims("{{", "}}"))
templateData := map[string]any{
"error_message": errorMessage,
"error_field": errorField,
"retry_suggested": inputData["retry_suggested"],
}
rs, err := parser.ParseTemplate(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}
}