// Handler: POST /subscribe
// Demonstrates form data extraction and conditional response helpers
ctx = context()
req = ctx.request()
res = ctx.response()

// Extract form fields
email = req.form.email
frequency = req.form.frequency

// Validate
if email == nil or email == "" then
  res.error(400, "Email is required")
end

if frequency == nil or frequency == "" then
  res.error(400, "Please select a frequency")
end

// Validate email format (simple check)
if !contains(email, "@") then
  res.error(400, "Please enter a valid email address")
end

// Log subscription
print("Subscription submitted:")
print("  Email: " + email)
print("  Frequency: " + frequency)

// Send success response with custom status
res.json({
  status = "subscribed",
  email = email,
  frequency = frequency,
  message = "You have been subscribed to " + frequency + " updates"
}, 201)