package validation_test

import (
	"fmt"
	"time"

	"github.com/juanatsap/cv-site/internal/validation"
)

// Example_basicValidation demonstrates basic usage of the struct tag validator
func Example_basicValidation() {
	req := &validation.ContactFormRequest{
		Name:      "John Smith",
		Email:     "john@example.com",
		Company:   "Acme Corp",
		Subject:   "Inquiry about services",
		Message:   "I would like to know more about your services.",
		Honeypot:  "",
		Timestamp: time.Now().Unix() - 10, // 10 seconds ago
	}

	err := validation.ValidateContactFormV2(req)
	if err != nil {
		fmt.Println("Validation failed:", err)
		return
	}

	fmt.Println("Validation successful!")
	// Output: Validation successful!
}

// Example_validationErrors demonstrates error handling
func Example_validationErrors() {
	req := &validation.ContactFormRequest{
		Name:      "", // Empty - will fail required
		Email:     "invalid-email",
		Subject:   "Test",
		Message:   "Test message",
		Timestamp: time.Now().Unix() - 10, // Valid timestamp
	}

	err := validation.ValidateContactFormV2(req)
	if err != nil {
		if verrs, ok := err.(validation.ValidationErrors); ok {
			fmt.Printf("Found %d validation errors:\n", len(verrs))
			for _, e := range verrs {
				fmt.Printf("- %s: %s\n", e.Field, e.Message)
			}
		}
	}
	// Output:
	// Found 2 validation errors:
	// - name: name is required
	// - email: Invalid email address format
}

// Example_trimTransform demonstrates automatic trimming
func Example_trimTransform() {
	req := &validation.ContactFormRequest{
		Name:      "  John Smith  ",
		Email:     "  john@example.com  ",
		Subject:   "  Test  ",
		Message:   "  Test message  ",
		Timestamp: time.Now().Unix() - 10,
	}

	err := validation.ValidateContactFormV2(req)
	if err != nil {
		fmt.Println("Error:", err)
		return
	}

	fmt.Printf("Name: '%s'\n", req.Name)
	fmt.Printf("Email: '%s'\n", req.Email)
	fmt.Printf("Subject: '%s'\n", req.Subject)
	fmt.Printf("Message: '%s'\n", req.Message)
	// Output:
	// Name: 'John Smith'
	// Email: 'john@example.com'
	// Subject: 'Test'
	// Message: 'Test message'
}

// Example_securityValidation demonstrates security features
func Example_securityValidation() {
	// Email injection attempt via subject field
	req := &validation.ContactFormRequest{
		Name:      "John Smith",
		Email:     "test@example.com",
		Subject:   "Test\nBcc: attacker@evil.com",
		Message:   "Test",
		Timestamp: time.Now().Unix() - 10,
	}

	err := validation.ValidateContactFormV2(req)
	if err != nil {
		if verrs, ok := err.(validation.ValidationErrors); ok {
			for _, e := range verrs {
				if e.Tag == "no_injection" {
					fmt.Printf("Security violation detected: %s\n", e.Message)
					break
				}
			}
		}
	}
	// Output: Security violation detected: subject contains invalid characters (possible injection attempt)
}

// Example_botDetection demonstrates honeypot and timing validation
func Example_botDetection() {
	// Bot filled honeypot field
	req1 := &validation.ContactFormRequest{
		Name:     "Bot",
		Email:    "bot@example.com",
		Subject:  "Spam",
		Message:  "Spam message",
		Honeypot: "http://evil.com",
	}

	err1 := validation.ValidateContactFormV2(req1)
	if err1 != nil {
		if verrs, ok := err1.(validation.ValidationErrors); ok {
			if honeypotErr := verrs.GetFieldError("website"); honeypotErr != nil {
				fmt.Println("Bot detected via honeypot:", honeypotErr.Message)
			}
		}
	}

	// Bot submitted too quickly
	req2 := &validation.ContactFormRequest{
		Name:      "John",
		Email:     "john@example.com",
		Subject:   "Test",
		Message:   "Test",
		Timestamp: time.Now().Unix(), // Just now (< 2 seconds)
	}

	err2 := validation.ValidateContactFormV2(req2)
	if err2 != nil {
		if verrs, ok := err2.(validation.ValidationErrors); ok {
			if timingErr := verrs.GetFieldError("timestamp"); timingErr != nil {
				fmt.Println("Bot detected via timing:", timingErr.Message)
			}
		}
	}
	// Output:
	// Bot detected via honeypot: Bot detected
	// Bot detected via timing: Form submitted too quickly (bot detected)
}

// Example_internationalNames demonstrates UTF-8 support
func Example_internationalNames() {
	names := []struct {
		name  string
		valid bool
	}{
		{"José María", true},      // Spanish
		{"François Dubois", true}, // French
		{"Müller", true},          // German
		{"Anne-Marie", true},      // Hyphenated
		{"O'Connor", true},        // Apostrophe
		{"John123", false},        // Numbers (invalid)
		{"John@Smith", false},     // Special chars (invalid)
	}

	for _, tc := range names {
		req := &validation.ContactFormRequest{
			Name:      tc.name,
			Email:     "test@example.com",
			Subject:   "Test",
			Message:   "Test",
			Timestamp: time.Now().Unix() - 10,
		}

		err := validation.ValidateContactFormV2(req)
		isValid := err == nil || !containsPatternError(err, "name")

		if isValid == tc.valid {
			fmt.Printf("'%s': %v ✓\n", tc.name, tc.valid)
		} else {
			fmt.Printf("'%s': unexpected result\n", tc.name)
		}
	}
	// Output:
	// 'José María': true ✓
	// 'François Dubois': true ✓
	// 'Müller': true ✓
	// 'Anne-Marie': true ✓
	// 'O'Connor': true ✓
	// 'John123': false ✓
	// 'John@Smith': false ✓
}

// Example_multipleErrors demonstrates handling multiple validation errors
func Example_multipleErrors() {
	req := &validation.ContactFormRequest{
		Name:      "",        // Required
		Email:     "invalid", // Invalid format
		Subject:   "",        // Required
		Message:   "",        // Required
		Timestamp: time.Now().Unix() - 10,
	}

	err := validation.ValidateContactFormV2(req)
	if err != nil {
		if verrs, ok := err.(validation.ValidationErrors); ok {
			fmt.Printf("Total errors: %d\n", len(verrs))

			// Get errors by field
			fields := []string{"name", "email", "subject", "message"}
			for _, field := range fields {
				if fieldErr := verrs.GetFieldError(field); fieldErr != nil {
					fmt.Printf("- %s: %s (tag: %s)\n", fieldErr.Field, fieldErr.Message, fieldErr.Tag)
				}
			}
		}
	}
	// Output:
	// Total errors: 4
	// - name: name is required (tag: required)
	// - email: Invalid email address format (tag: email)
	// - subject: subject is required (tag: required)
	// - message: message is required (tag: required)
}

// Helper function for example
func containsPatternError(err error, field string) bool {
	if err == nil {
		return false
	}
	verrs, ok := err.(validation.ValidationErrors)
	if !ok {
		return false
	}
	for _, e := range verrs {
		if e.Field == field && e.Tag == "pattern" {
			return true
		}
	}
	return false
}