package environment

import (
	"github.com/deis/tiller/pkg/hapi"
)

// EngineYard maps engine names to engine implementations.
type EngineYard map[string]Engine

func (y EngineYard) Get(k string) (Engine, bool) {
	e, ok := y[k]
	return e, ok
}

// Engine represents a template engine that can render templates.
//
// For some engines, "rendering" includes both compiling and executing. (Other
// engines do not distinguish between phases.)
//
// An Engine must be capable of executing multiple concurrent requests, but
// without tainting one request's environment with data from another request.
type Engine interface {
	Render(*hapi.Chart, *hapi.Values) ([]byte, error)
}

// ReleaseStorage represents a storage engine for a Release.
//
// Release storage must be concurrency safe.
type ReleaseStorage interface {
	Get(key string) (*hapi.Release, error)
	Set(key string, val *hapi.Release) error
}

// KubeClient represents a client capable of communicating with the Kubernetes API.
//
// A KubeClient must be concurrency safe.
type KubeClient interface {
	Install(manifest []byte) error
}

// Environment provides the context for executing a client request.
//
// All services in a context are concurrency safe.
type Environment struct {
	// EngineYard provides access to the known template engines.
	EngineYard EngineYard
	// Releases stores records of releases.
	Releases ReleaseStorage
	// KubeClient is a Kubernetes API client.
	KubeClient KubeClient
}

// New returns an environment initialized with the defaults.
func New() *Environment {
	return &Environment{}
}