// UnmarshalError unmarshals an error response for a JSON RPC service.
func UnmarshalError(req *aws.Request) {
	defer req.HTTPResponse.Body.Close()
	bodyBytes, err := ioutil.ReadAll(req.HTTPResponse.Body)
	if err != nil {
		req.Error = apierr.New("Unmarshal", "failed reading JSON RPC error response", err)
		return
	}
	if len(bodyBytes) == 0 {
		req.Error = apierr.NewRequestError(
			apierr.New("Unmarshal", req.HTTPResponse.Status, nil),
			req.HTTPResponse.StatusCode,
			"",
		)
		return
	}
	var jsonErr jsonErrorResponse
	if err := json.Unmarshal(bodyBytes, &jsonErr); err != nil {
		req.Error = apierr.New("Unmarshal", "failed decoding JSON RPC error response", err)
		return
	}

	codes := strings.SplitN(jsonErr.Code, "#", 2)
	req.Error = apierr.NewRequestError(
		apierr.New(codes[len(codes)-1], jsonErr.Message, nil),
		req.HTTPResponse.StatusCode,
		"",
	)
}

func unmarshalError(r *aws.Request) {
	defer r.HTTPResponse.Body.Close()

	if r.HTTPResponse.ContentLength == int64(0) {
		// No body, use status code to generate an awserr.Error
		r.Error = apierr.NewRequestError(
			apierr.New(strings.Replace(r.HTTPResponse.Status, " ", "", -1), r.HTTPResponse.Status, nil),
			r.HTTPResponse.StatusCode,
			"",
		)
		return
	}

	resp := &xmlErrorResponse{}
	err := xml.NewDecoder(r.HTTPResponse.Body).Decode(resp)
	if err != nil && err != io.EOF {
		r.Error = apierr.New("Unmarshal", "failed to decode S3 XML error response", nil)
	} else {
		r.Error = apierr.NewRequestError(
			apierr.New(resp.Code, resp.Message, nil),
			r.HTTPResponse.StatusCode,
			"",
		)
	}
}

func unmarshalError(req *Request) {
	bodyBytes, err := ioutil.ReadAll(req.HTTPResponse.Body)
	if err != nil {
		req.Error = apierr.New("UnmarshaleError", req.HTTPResponse.Status, err)
		return
	}
	if len(bodyBytes) == 0 {
		req.Error = apierr.NewRequestError(
			apierr.New("UnmarshaleError", req.HTTPResponse.Status, fmt.Errorf("empty body")),
			req.HTTPResponse.StatusCode,
			"",
		)
		return
	}
	var jsonErr jsonErrorResponse
	if err := json.Unmarshal(bodyBytes, &jsonErr); err != nil {
		req.Error = apierr.New("UnmarshaleError", "JSON unmarshal", err)
		return
	}
	req.Error = apierr.NewRequestError(
		apierr.New(jsonErr.Code, jsonErr.Message, nil),
		req.HTTPResponse.StatusCode,
		"",
	)
}

// loadProfiles loads from the file pointed to by shared credentials filename for profile.
// The credentials retrieved from the profile will be returned or error. Error will be
// returned if it fails to read from the file, or the data is invalid.
func loadProfile(filename, profile string) (Value, error) {
	config, err := ini.LoadFile(filename)
	if err != nil {
		return Value{}, apierr.New("SharedCredsLoad", "failed to load shared credentials file", err)
	}
	iniProfile := config.Section(profile)

	id, ok := iniProfile["aws_access_key_id"]
	if !ok {
		return Value{}, apierr.New("SharedCredsAccessKey",
			fmt.Sprintf("shared credentials %s in %s did not contain aws_access_key_id", profile, filename),
			nil)
	}

	secret, ok := iniProfile["aws_secret_access_key"]
	if !ok {
		return Value{}, apierr.New("SharedCredsSecret",
			fmt.Sprintf("shared credentials %s in %s did not contain aws_secret_access_key", profile, filename),
			nil)
	}

	token := iniProfile["aws_session_token"]

	return Value{
		AccessKeyID:     id,
		SecretAccessKey: secret,
		SessionToken:    token,
	}, nil
}

func TestAfterRetryRefreshCreds(t *testing.T) {
	os.Clearenv()
	credProvider := &mockCredsProvider{}
	svc := NewService(&Config{Credentials: credentials.NewCredentials(credProvider), MaxRetries: 1})

	svc.Handlers.Clear()
	svc.Handlers.ValidateResponse.PushBack(func(r *Request) {
		r.Error = apierr.New("UnknownError", "", nil)
		r.HTTPResponse = &http.Response{StatusCode: 400}
	})
	svc.Handlers.UnmarshalError.PushBack(func(r *Request) {
		r.Error = apierr.New("ExpiredTokenException", "", nil)
	})
	svc.Handlers.AfterRetry.PushBack(func(r *Request) {
		AfterRetryHandler(r)
	})

	assert.True(t, svc.Config.Credentials.IsExpired(), "Expect to start out expired")
	assert.False(t, credProvider.retreiveCalled)

	req := NewRequest(svc, &Operation{Name: "Operation"}, nil, nil)
	req.Send()

	assert.True(t, svc.Config.Credentials.IsExpired())
	assert.False(t, credProvider.retreiveCalled)

	_, err := svc.Config.Credentials.Get()
	assert.NoError(t, err)
	assert.True(t, credProvider.retreiveCalled)
}

func TestChainProviderWithNoValidProvider(t *testing.T) {
	p := &ChainProvider{
		Providers: []Provider{
			&stubProvider{err: apierr.New("FirstError", "first provider error", nil)},
			&stubProvider{err: apierr.New("SecondError", "second provider error", nil)},
		},
	}

	assert.True(t, p.IsExpired(), "Expect expired with no providers")
	_, err := p.Retrieve()
	assert.Equal(t, ErrNoValidProvidersFoundInChain, err, "Expect no providers error returned")
}

// UnmarshalError unmarshals a response error for the EC2 protocol.
func UnmarshalError(r *aws.Request) {
	defer r.HTTPResponse.Body.Close()

	resp := &xmlErrorResponse{}
	err := xml.NewDecoder(r.HTTPResponse.Body).Decode(resp)
	if err != nil && err != io.EOF {
		r.Error = apierr.New("Unmarshal", "failed decoding EC2 Query error response", err)
	} else {
		r.Error = apierr.NewRequestError(
			apierr.New(resp.Code, resp.Message, nil),
			r.HTTPResponse.StatusCode,
			resp.RequestID,
		)
	}
}

// Build builds a JSON payload for a JSON RPC request.
func Build(req *aws.Request) {
	var buf []byte
	var err error
	if req.ParamsFilled() {
		buf, err = jsonutil.BuildJSON(req.Params)
		if err != nil {
			req.Error = apierr.New("Marshal", "failed encoding JSON RPC request", err)
			return
		}
	} else {
		buf = emptyJSON
	}

	if req.Service.TargetPrefix != "" || string(buf) != "{}" {
		req.SetBufferBody(buf)
	}

	if req.Service.TargetPrefix != "" {
		target := req.Service.TargetPrefix + "." + req.Operation.Name
		req.HTTPRequest.Header.Add("X-Amz-Target", target)
	}
	if req.Service.JSONVersion != "" {
		jsonVersion := req.Service.JSONVersion
		req.HTTPRequest.Header.Add("Content-Type", "application/x-amz-json-"+jsonVersion)
	}
}

// Retrieve retrieves credentials from the EC2 service.
// Error will be returned if the request fails, or unable to extract
// the desired credentials.
func (m *EC2RoleProvider) Retrieve() (Value, error) {
	if m.Client == nil {
		m.Client = http.DefaultClient
	}
	if m.Endpoint == "" {
		m.Endpoint = metadataCredentialsEndpoint
	}

	credsList, err := requestCredList(m.Client, m.Endpoint)
	if err != nil {
		return Value{}, err
	}

	if len(credsList) == 0 {
		return Value{}, apierr.New("EmptyEC2RoleList", "empty EC2 Role list", nil)
	}
	credsName := credsList[0]

	roleCreds, err := requestCred(m.Client, m.Endpoint, credsName)
	if err != nil {
		return Value{}, err
	}

	m.expiresOn = roleCreds.Expiration
	if m.ExpiryWindow > 0 {
		// Offset based on expiry window if set.
		m.expiresOn = m.expiresOn.Add(-m.ExpiryWindow)
	}

	return Value{
		AccessKeyID:     roleCreds.AccessKeyID,
		SecretAccessKey: roleCreds.SecretAccessKey,
		SessionToken:    roleCreds.Token,
	}, nil
}

func buildHeader(r *aws.Request, v reflect.Value, name string) {
	str, err := convertType(v)
	if err != nil {
		r.Error = apierr.New("Marshal", "failed to encode REST request", err)
	} else if str != nil {
		r.HTTPRequest.Header.Add(name, *str)
	}
}

func buildQueryString(r *aws.Request, v reflect.Value, name string, query url.Values) {
	str, err := convertType(v)
	if err != nil {
		r.Error = apierr.New("Marshal", "failed to encode REST request", err)
	} else if str != nil {
		query.Set(name, *str)
	}
}

// requestCred requests the credentials for a specific credentials from the EC2 service.
//
// If the credentials cannot be found, or there is an error reading the response
// and error will be returned.
func requestCred(client *http.Client, endpoint, credsName string) (*ec2RoleCredRespBody, error) {
	resp, err := client.Get(endpoint + credsName)
	if err != nil {
		return nil, apierr.New("GetEC2RoleCredentials",
			fmt.Sprintf("failed to get %s EC2 Role credentials", credsName),
			err)
	}
	defer resp.Body.Close()

	respCreds := &ec2RoleCredRespBody{}
	if err := json.NewDecoder(resp.Body).Decode(respCreds); err != nil {
		return nil, apierr.New("DecodeEC2RoleCredentials",
			fmt.Sprintf("failed to decode %s EC2 Role credentials", credsName),
			err)
	}

	return respCreds, nil
}

func buildHeaderMap(r *aws.Request, v reflect.Value, prefix string) {
	for _, key := range v.MapKeys() {
		str, err := convertType(v.MapIndex(key))
		if err != nil {
			r.Error = apierr.New("Marshal", "failed to encode REST request", err)
		} else if str != nil {
			r.HTTPRequest.Header.Add(prefix+key.String(), *str)
		}
	}
}

// Unmarshal unmarshals a response for a JSON RPC service.
func Unmarshal(req *aws.Request) {
	defer req.HTTPResponse.Body.Close()
	if req.DataFilled() {
		err := jsonutil.UnmarshalJSON(req.Data, req.HTTPResponse.Body)
		if err != nil {
			req.Error = apierr.New("Unmarshal", "failed decoding JSON RPC response", err)
		}
	}
	return
}

// requestCredList requests a list of credentials from the EC2 service.
// If there are no credentials, or there is an error making or receiving the request
func requestCredList(client *http.Client, endpoint string) ([]string, error) {
	resp, err := client.Get(endpoint)
	if err != nil {
		return nil, apierr.New("ListEC2Role", "failed to list EC2 Roles", err)
	}
	defer resp.Body.Close()

	credsList := []string{}
	s := bufio.NewScanner(resp.Body)
	for s.Scan() {
		credsList = append(credsList, s.Text())
	}

	if err := s.Err(); err != nil {
		return nil, apierr.New("ReadEC2Role", "failed to read list of EC2 Roles", err)
	}

	return credsList, nil
}

// internal logic for deciding whether to upload a single part or use a
// multipart upload.
func (u *uploader) upload() (*UploadOutput, error) {
	u.init()

	if u.opts.PartSize < MinUploadPartSize {
		msg := fmt.Sprintf("part size must be at least %d bytes", MinUploadPartSize)
		return nil, apierr.New("ConfigError", msg, nil)
	}

	// Do one read to determine if we have more than one part
	buf, err := u.nextReader()
	if err == io.EOF || err == io.ErrUnexpectedEOF { // single part
		return u.singlePart(buf)
	} else if err != nil {
		return nil, apierr.New("ReadRequestBody", "read upload data failed", err)
	}

	mu := multiuploader{uploader: u}
	return mu.upload(buf)
}

// Unmarshal unmarshals a response for an AWS Query service.
func Unmarshal(r *aws.Request) {
	defer r.HTTPResponse.Body.Close()
	if r.DataFilled() {
		decoder := xml.NewDecoder(r.HTTPResponse.Body)
		err := xmlutil.UnmarshalXML(r.Data, decoder, r.Operation.Name+"Result")
		if err != nil {
			r.Error = apierr.New("Unmarshal", "failed decoding Query response", err)
			return
		}
	}
}

// Unmarshal unmarshals a payload response for the REST XML protocol.
func Unmarshal(r *aws.Request) {
	if t := rest.PayloadType(r.Data); t == "structure" || t == "" {
		defer r.HTTPResponse.Body.Close()
		decoder := xml.NewDecoder(r.HTTPResponse.Body)
		err := xmlutil.UnmarshalXML(r.Data, decoder, "")
		if err != nil {
			r.Error = apierr.New("Unmarshal", "failed to decode REST XML response", err)
			return
		}
	}
}

func buildURI(r *aws.Request, v reflect.Value, name string) {
	value, err := convertType(v)
	if err != nil {
		r.Error = apierr.New("Marshal", "failed to encode REST request", err)
	} else if value != nil {
		uri := r.HTTPRequest.URL.Path
		uri = strings.Replace(uri, "{"+name+"}", EscapePath(*value, true), -1)
		uri = strings.Replace(uri, "{"+name+"+}", EscapePath(*value, false), -1)
		r.HTTPRequest.URL.Path = uri
	}
}

func TestChainProviderGet(t *testing.T) {
	p := &ChainProvider{
		Providers: []Provider{
			&stubProvider{err: apierr.New("FirstError", "first provider error", nil)},
			&stubProvider{err: apierr.New("SecondError", "second provider error", nil)},
			&stubProvider{
				creds: Value{
					AccessKeyID:     "AKID",
					SecretAccessKey: "SECRET",
					SessionToken:    "",
				},
			},
		},
	}

	creds, err := p.Retrieve()
	assert.Nil(t, err, "Expect no error")
	assert.Equal(t, "AKID", creds.AccessKeyID, "Expect access key ID to match")
	assert.Equal(t, "SECRET", creds.SecretAccessKey, "Expect secret access key to match")
	assert.Empty(t, creds.SessionToken, "Expect session token to be empty")
}