package client

import (

	"fmt"

	"github.com/aws/aws-sdk-go/aws"

	"github.com/aws/aws-sdk-go/aws/client/metadata"

	"github.com/aws/aws-sdk-go/aws/request"

)

// A Config provides configuration to a service client instance.

type Config struct {

	Config        *aws.Config

	Handlers      request.Handlers

	PartitionID   string

	Endpoint      string

	SigningRegion string

	SigningName   string

	// States that the signing name did not come from a modeled source but

	// was derived based on other data. Used by service client constructors

	// to determine if the signin name can be overridden based on metadata the

	// service has.

	SigningNameDerived bool

}

// ConfigProvider provides a generic way for a service client to receive

// the ClientConfig without circular dependencies.

type ConfigProvider interface {

	ClientConfig(serviceName string, cfgs ...*aws.Config) Config

}

// ConfigNoResolveEndpointProvider same as ConfigProvider except it will not

// resolve the endpoint automatically. The service client's endpoint must be

// provided via the aws.Config.Endpoint field.

type ConfigNoResolveEndpointProvider interface {

	ClientConfigNoResolveEndpoint(cfgs ...*aws.Config) Config

}

// A Client implements the base client request and response handling

// used by all service clients.

type Client struct {

	request.Retryer

	metadata.ClientInfo

	Config   aws.Config

	Handlers request.Handlers

}

// New will return a pointer to a new initialized service client.

func New(cfg aws.Config, info metadata.ClientInfo, handlers request.Handlers, options ...func(*Client)) *Client {

	svc := &Client{

		Config:     cfg,

		ClientInfo: info,

		Handlers:   handlers.Copy(),

	}

	switch retryer, ok := cfg.Retryer.(request.Retryer); {

	case ok:

		svc.Retryer = retryer

	case cfg.Retryer != nil && cfg.Logger != nil:

		s := fmt.Sprintf("WARNING: %T does not implement request.Retryer; using DefaultRetryer instead", cfg.Retryer)

		cfg.Logger.Log(s)

		fallthrough

	default:

		maxRetries := aws.IntValue(cfg.MaxRetries)

		if cfg.MaxRetries == nil || maxRetries == aws.UseServiceDefaultRetries {

			maxRetries = DefaultRetryerMaxNumRetries

		}

		svc.Retryer = DefaultRetryer{NumMaxRetries: maxRetries}

	}

	svc.AddDebugHandlers()

	for _, option := range options {

		option(svc)

	}

	return svc

}

// NewRequest returns a new Request pointer for the service API

// operation and parameters.

func (c *Client) NewRequest(operation *request.Operation, params interface{}, data interface{}) *request.Request {

	return request.New(c.Config, c.ClientInfo, c.Handlers, c.Retryer, operation, params, data)

}

// AddDebugHandlers injects debug logging handlers into the service to log request

// debug information.

func (c *Client) AddDebugHandlers() {

	if !c.Config.LogLevel.AtLeast(aws.LogDebug) {

		return

	}

	c.Handlers.Send.PushFrontNamed(LogHTTPRequestHandler)

	c.Handlers.Send.PushBackNamed(LogHTTPResponseHandler)

}