driver

type Alias struct {
	FunctionName    string
	Name            string
	FunctionVersion string
	Description     string
	RoutingConfig   *AliasRoutingConfig
	AliasARN        string
	CreatedAt       string
}

type AliasConfig struct {
	FunctionName    string
	Name            string
	FunctionVersion string
	Description     string
	RoutingConfig   *AliasRoutingConfig // for weighted aliases
}

type AliasRoutingConfig struct {
	AdditionalVersion string
	Weight            float64 // 0.0-1.0, traffic percentage to additional version
}

type ConcurrencyConfig struct {
	FunctionName                 string
	ReservedConcurrentExecutions int
}

type FunctionConfig struct {
	Name        string
	Runtime     string
	Handler     string
	Memory      int // MB
	Timeout     int // seconds
	Environment map[string]string
	Tags        map[string]string
}

type FunctionInfo struct {
	Name         string
	ARN          string
	Runtime      string
	Handler      string
	Memory       int
	Timeout      int
	State        string
	Environment  map[string]string
	Tags         map[string]string
	LastModified string
}

type FunctionVersion struct {
	FunctionName string
	Version      string // "1", "2", etc. or "$LATEST"
	Description  string
	CodeSHA256   string
	CreatedAt    string
}

type HandlerFunc func(ctx context.Context, payload []byte) ([]byte, error)

type InvokeInput struct {
	FunctionName string
	Payload      []byte
	InvokeType   string // "RequestResponse" or "Event"
}

type InvokeOutput struct {
	StatusCode int
	Payload    []byte
	Error      string
}

type LayerConfig struct {
	Name               string
	Description        string
	Content            []byte
	CompatibleRuntimes []string
}

type LayerVersion struct {
	Name               string
	Version            int
	Description        string
	ContentSHA256      string
	ContentSize        int64
	CompatibleRuntimes []string
	CreatedAt          string
	ARN                string
}

type ProvisionedConcurrencyConfig struct {
	FunctionName string
	Qualifier    string // version or alias
	Provisioned  int
}

type Serverless interface {
	CreateFunction(ctx context.Context, config FunctionConfig) (*FunctionInfo, error)
	DeleteFunction(ctx context.Context, name string) error
	GetFunction(ctx context.Context, name string) (*FunctionInfo, error)
	ListFunctions(ctx context.Context) ([]FunctionInfo, error)
	UpdateFunction(ctx context.Context, name string, config FunctionConfig) (*FunctionInfo, error)
	Invoke(ctx context.Context, input InvokeInput) (*InvokeOutput, error)
	RegisterHandler(name string, handler HandlerFunc)

	// Versions
	PublishVersion(ctx context.Context, functionName, description string) (*FunctionVersion, error)
	ListVersions(ctx context.Context, functionName string) ([]FunctionVersion, error)

	// Aliases
	CreateAlias(ctx context.Context, config AliasConfig) (*Alias, error)
	UpdateAlias(ctx context.Context, config AliasConfig) (*Alias, error)
	DeleteAlias(ctx context.Context, functionName, aliasName string) error
	GetAlias(ctx context.Context, functionName, aliasName string) (*Alias, error)
	ListAliases(ctx context.Context, functionName string) ([]Alias, error)

	// Layers
	PublishLayerVersion(ctx context.Context, config LayerConfig) (*LayerVersion, error)
	GetLayerVersion(ctx context.Context, name string, version int) (*LayerVersion, error)
	ListLayerVersions(ctx context.Context, name string) ([]LayerVersion, error)
	DeleteLayerVersion(ctx context.Context, name string, version int) error
	ListLayers(ctx context.Context) ([]LayerVersion, error)

	// Concurrency
	PutFunctionConcurrency(ctx context.Context, config ConcurrencyConfig) error
	GetFunctionConcurrency(ctx context.Context, functionName string) (*ConcurrencyConfig, error)
	DeleteFunctionConcurrency(ctx context.Context, functionName string) error
}