dance-lessons-coach/pkg/user/jwt_manager.go

package user

import (
	"time"
)

// JWTSecret represents a JWT secret with metadata
type JWTSecret struct {
	Secret    string
	IsPrimary bool
	CreatedAt time.Time
	ExpiresAt *time.Time // Optional expiration time
}

// JWTSecretManager manages multiple JWT secrets for rotation
type JWTSecretManager struct {
	secrets       []JWTSecret
	primarySecret string
}

// NewJWTSecretManager creates a new JWT secret manager
func NewJWTSecretManager(initialSecret string) *JWTSecretManager {
	return &JWTSecretManager{
		secrets: []JWTSecret{
			{
				Secret:    initialSecret,
				IsPrimary: true,
				CreatedAt: time.Now(),
			},
		},
		primarySecret: initialSecret,
	}
}

// AddSecret adds a new JWT secret
func (m *JWTSecretManager) AddSecret(secret string, isPrimary bool, expiresIn time.Duration) {
	var expiresAt *time.Time
	if expiresIn > 0 {
		expirationTime := time.Now().Add(expiresIn)
		expiresAt = &expirationTime
	}
	// If expiresIn is 0 or negative, expiresAt remains nil (no expiration)

	m.secrets = append(m.secrets, JWTSecret{
		Secret:    secret,
		IsPrimary: isPrimary,
		CreatedAt: time.Now(),
		ExpiresAt: expiresAt,
	})

	if isPrimary {
		m.primarySecret = secret
	}
}

// RotateToSecret rotates to a new primary secret
func (m *JWTSecretManager) RotateToSecret(newSecret string) {
	// Mark existing primary as non-primary
	for i, secret := range m.secrets {
		if secret.IsPrimary {
			m.secrets[i].IsPrimary = false
			break
		}
	}

	// Add new secret as primary
	m.AddSecret(newSecret, true, 0) // No expiration for primary
}

// GetPrimarySecret returns the current primary secret
func (m *JWTSecretManager) GetPrimarySecret() string {
	return m.primarySecret
}

// GetAllValidSecrets returns all valid (non-expired) secrets
func (m *JWTSecretManager) GetAllValidSecrets() []JWTSecret {
	var validSecrets []JWTSecret
	now := time.Now()

	for _, secret := range m.secrets {
		if secret.ExpiresAt == nil || secret.ExpiresAt.After(now) {
			validSecrets = append(validSecrets, secret)
		}
	}

	return validSecrets
}

// GetSecretByIndex returns a secret by index for testing
func (m *JWTSecretManager) GetSecretByIndex(index int) (string, bool) {
	if index < 0 || index >= len(m.secrets) {
		return "", false
	}
	return m.secrets[index].Secret, true
}

// Reset resets the secret manager to its initial state with only the primary secret
// This is useful for test cleanup to ensure tests don't interfere with each other
func (m *JWTSecretManager) Reset(initialSecret string) {
	m.secrets = []JWTSecret{
		{
			Secret:    initialSecret,
			IsPrimary: true,
			CreatedAt: time.Now(),
		},
	}
	m.primarySecret = initialSecret
}