package main

import (
	"testing"

	"github.com/stretchr/testify/assert"
)

func TestDomainValidation(t *testing.T) {
	tests := []struct {
		domain  string
		valid   bool
		reason  string
	}{
		{"example.com", true, "Valid domain"},
		{"sub.example.com", true, "Valid subdomain"},
		{"test.co.uk", true, "Valid domain with multiple TLDs"},
		{"", false, "Empty domain"},
		{"invalid", false, "No TLD"},
		{".com", false, "Starts with dot"},
		{"com.", false, "Ends with dot"},
		{"..double.com", false, "Double dots"},
		{"toolong" + string(make([]byte, 300)) + ".com", false, "Too long domain"},
		{"valid-domain.com", true, "Valid domain with hyphen"},
		{"-invalid.com", false, "Starts with hyphen"},
		{"invalid-.com", false, "Ends with hyphen"},
		{"valid123.com", true, "Valid domain with numbers"},
	}
	
	for _, test := range tests {
		t.Run(test.reason, func(t *testing.T) {
			// Simple domain validation logic
			valid := isValidDomain(test.domain)
			assert.Equal(t, test.valid, valid, "Domain: %s", test.domain)
		})
	}
}

func TestEmailValidation(t *testing.T) {
	tests := []struct {
		email   string
		valid   bool
		reason  string
	}{
		{"test@example.com", true, "Valid email"},
		{"user.name@domain.co.uk", true, "Valid email with subdomain"},
		{"user+tag@example.org", true, "Valid email with plus tag"},
		{"", false, "Empty email"},
		{"invalid", false, "No @ symbol"},
		{"@domain.com", false, "No local part"},
		{"user@", false, "No domain part"},
		{"user..name@example.com", false, "Double dots in local part"},
		{"user@.com", false, "Domain starts with dot"},
		{"user@com.", false, "Domain ends with dot"},
		{"user@toolong" + string(make([]byte, 300)) + ".com", false, "Too long email"},
	}
	
	for _, test := range tests {
		t.Run(test.reason, func(t *testing.T) {
			// Simple email validation logic
			valid := isValidEmail(test.email)
			assert.Equal(t, test.valid, valid, "Email: %s", test.email)
		})
	}
}

func TestCreditCardValidation(t *testing.T) {
	tests := []struct {
		cardNumber string
		valid      bool
		reason     string
	}{
		{"4242424242424242", true, "Valid Visa test card"},
		{"5555555555554444", true, "Valid Mastercard test card"},
		{"378282246310005", true, "Valid Amex test card"},
		{"", false, "Empty card number"},
		{"4111", false, "Too short"},
		{"42424242424242424242", false, "Too long"},
		{"abcdabcdabcdabcd", false, "Non-numeric"},
		{"4242-4242-4242-4242", false, "Contains dashes"},
		{"4242 4242 4242 4242", false, "Contains spaces"},
	}
	
	for _, test := range tests {
		t.Run(test.reason, func(t *testing.T) {
			// Simple credit card validation logic
			valid := isValidCreditCard(test.cardNumber)
			assert.Equal(t, test.valid, valid, "Card: %s", test.cardNumber)
		})
	}
}

func TestBusinessLogic(t *testing.T) {
	t.Run("Customer ID generation", func(t *testing.T) {
		// Test that customer IDs are unique
		id1 := generateCustomerID()
		id2 := generateCustomerID()
		
		assert.NotEmpty(t, id1)
		assert.NotEmpty(t, id2)
		assert.NotEqual(t, id1, id2)
	})
	
	t.Run("Pricing calculation", func(t *testing.T) {
		// Test pricing logic
		assert.Equal(t, 250.0, calculateMonthlyPrice())
		assert.Equal(t, 3000.0, calculateYearlyPrice())
	})
	
	t.Run("Provisioning steps", func(t *testing.T) {
		// Test provisioning workflow
		steps := getProvisioningSteps()
		
		expectedSteps := []string{
			"Domain Registration",
			"VPS Provisioning", 
			"Cloudron Installation",
			"DNS Configuration",
			"Business Setup",
		}
		
		assert.Equal(t, len(expectedSteps), len(steps))
		
		for i, expected := range expectedSteps {
			assert.Equal(t, expected, steps[i].Name)
		}
	})
}

func TestProvisioningProgress(t *testing.T) {
	t.Run("Initial progress", func(t *testing.T) {
		progress := calculateProgress(0) // No steps completed
		assert.Equal(t, 0, progress)
	})
	
	t.Run("Partial progress", func(t *testing.T) {
		progress := calculateProgress(2) // 2 of 5 steps completed
		assert.Equal(t, 40, progress)
	})
	
	t.Run("Complete progress", func(t *testing.T) {
		progress := calculateProgress(5) // All 5 steps completed
		assert.Equal(t, 100, progress)
	})
	
	t.Run("Invalid progress", func(t *testing.T) {
		progress := calculateProgress(10) // More than total steps
		assert.Equal(t, 100, progress) // Should cap at 100
	})
}

func TestErrorHandling(t *testing.T) {
	t.Run("Empty request validation", func(t *testing.T) {
		err := validateLaunchRequest("", "", "")
		assert.Error(t, err)
		assert.Contains(t, err.Error(), "required")
	})
	
	t.Run("Valid request", func(t *testing.T) {
		err := validateLaunchRequest("example.com", "test@example.com", "4242424242424242")
		assert.NoError(t, err)
	})
	
	t.Run("Invalid domain", func(t *testing.T) {
		err := validateLaunchRequest("invalid", "test@example.com", "4242424242424242")
		assert.Error(t, err)
	})
	
	t.Run("Invalid email", func(t *testing.T) {
		err := validateLaunchRequest("example.com", "invalid", "4242424242424242")
		assert.Error(t, err)
	})
	
	t.Run("Invalid card", func(t *testing.T) {
		err := validateLaunchRequest("example.com", "test@example.com", "invalid")
		assert.Error(t, err)
	})
}

// Helper functions for testing

func isValidDomain(domain string) bool {
	if domain == "" || len(domain) > 253 {
		return false
	}
	// Simple validation - in production, use more robust validation
	return len(domain) > 3 && contains(domain, ".")
}

func isValidEmail(email string) bool {
	if email == "" || len(email) > 254 {
		return false
	}
	// Simple validation - in production, use more robust validation
	return contains(email, "@") && contains(email, ".")
}

func isValidCreditCard(cardNumber string) bool {
	if cardNumber == "" {
		return false
	}
	// Simple validation - in production, use Luhn algorithm and proper card validation
	return len(cardNumber) >= 13 && len(cardNumber) <= 19 && isNumeric(cardNumber)
}

func contains(s, substr string) bool {
	return len(s) >= len(substr) && s[len(s)-len(substr):] == substr || 
		   (len(s) > len(substr) && s[:len(substr)] == substr) ||
		   (len(s) > len(substr) && findInString(s, substr))
}

func findInString(s, substr string) bool {
	for i := 0; i <= len(s)-len(substr); i++ {
		if s[i:i+len(substr)] == substr {
			return true
		}
	}
	return false
}

func isNumeric(s string) bool {
	for _, c := range s {
		if c < '0' || c > '9' {
			return false
		}
	}
	return true
}

func generateCustomerID() string {
	// Mock implementation
	return "cust_" + string(rune(len("test") * 1000))
}

func calculateMonthlyPrice() float64 {
	return 250.0
}

func calculateYearlyPrice() float64 {
	return calculateMonthlyPrice() * 12
}

type ProvisioningStep struct {
	Name   string
	Status string
}

func getProvisioningSteps() []ProvisioningStep {
	return []ProvisioningStep{
		{Name: "Domain Registration", Status: "pending"},
		{Name: "VPS Provisioning", Status: "pending"},
		{Name: "Cloudron Installation", Status: "pending"},
		{Name: "DNS Configuration", Status: "pending"},
		{Name: "Business Setup", Status: "pending"},
	}
}

func calculateProgress(completedSteps int) int {
	totalSteps := len(getProvisioningSteps())
	if completedSteps >= totalSteps {
		return 100
	}
	return (completedSteps * 100) / totalSteps
}

func validateLaunchRequest(domain, email, cardNumber string) error {
	if domain == "" {
		return &ValidationError{Message: "domain is required"}
	}
	if email == "" {
		return &ValidationError{Message: "email is required"}
	}
	if cardNumber == "" {
		return &ValidationError{Message: "card number is required"}
	}
	if !isValidDomain(domain) {
		return &ValidationError{Message: "invalid domain"}
	}
	if !isValidEmail(email) {
		return &ValidationError{Message: "invalid email"}
	}
	if !isValidCreditCard(cardNumber) {
		return &ValidationError{Message: "invalid credit card"}
	}
	return nil
}

type ValidationError struct {
	Message string
}

func (e *ValidationError) Error() string {
	return e.Message
}