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

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

// 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{}, awserr.New("SharedCredsLoad", "failed to load shared credentials file", err)
	}
	iniProfile := config.Section(profile)

	id, ok := iniProfile["aws_access_key_id"]
	if !ok {
		return Value{}, awserr.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{}, awserr.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
}

// UnmarshalError unmarshals a response error for the REST JSON protocol.
func UnmarshalError(r *request.Request) {
	code := r.HTTPResponse.Header.Get("X-Amzn-Errortype")
	bodyBytes, err := ioutil.ReadAll(r.HTTPResponse.Body)
	if err != nil {
		r.Error = awserr.New("SerializationError", "failed reading REST JSON error response", err)
		return
	}
	if len(bodyBytes) == 0 {
		r.Error = awserr.NewRequestFailure(
			awserr.New("SerializationError", r.HTTPResponse.Status, nil),
			r.HTTPResponse.StatusCode,
			"",
		)
		return
	}
	var jsonErr jsonErrorResponse
	if err := json.Unmarshal(bodyBytes, &jsonErr); err != nil {
		r.Error = awserr.New("SerializationError", "failed decoding REST JSON error response", err)
		return
	}

	if code == "" {
		code = jsonErr.Code
	}

	codes := strings.SplitN(code, ":", 2)
	r.Error = awserr.NewRequestFailure(
		awserr.New(codes[0], jsonErr.Message, nil),
		r.HTTPResponse.StatusCode,
		r.RequestID,
	)
}

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

	if r.HTTPResponse.StatusCode == http.StatusMovedPermanently {
		r.Error = awserr.New("BucketRegionError",
			fmt.Sprintf("incorrect region, the bucket is not in '%s' region", aws.StringValue(r.Service.Config.Region)), nil)
		return
	}

	if r.HTTPResponse.ContentLength == int64(0) {
		// No body, use status code to generate an awserr.Error
		r.Error = awserr.NewRequestFailure(
			awserr.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 = awserr.New("SerializationError", "failed to decode S3 XML error response", nil)
	} else {
		r.Error = awserr.NewRequestFailure(
			awserr.New(resp.Code, resp.Message, nil),
			r.HTTPResponse.StatusCode,
			"",
		)
	}
}

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

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

// Build builds a JSON payload for a JSON RPC request.
func Build(req *request.Request) {
	var buf []byte
	var err error
	if req.ParamsFilled() {
		buf, err = jsonutil.BuildJSON(req.Params)
		if err != nil {
			req.Error = awserr.New("SerializationError", "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() (credentials.Value, error) {
	if m.Client == nil {
		m.Client = ec2metadata.New(nil)
	}

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

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

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

	m.SetExpiration(roleCreds.Expiration, m.ExpiryWindow)

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

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

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

// 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 *ec2metadata.Client) ([]string, error) {
	resp, err := client.GetMetadata(iamSecurityCredsPath)
	if err != nil {
		return nil, awserr.New("EC2RoleRequestError", "failed to list EC2 Roles", err)
	}

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

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

	return credsList, nil
}

func unmarshalError(r *request.Request) {
	defer r.HTTPResponse.Body.Close()
	_, err := ioutil.ReadAll(r.HTTPResponse.Body)
	if err != nil {
		r.Error = awserr.New("SerializationError", "unable to unmarshal EC2 metadata error respose", err)
	}

	// TODO extract the error...
}

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

func unmarshalHandler(r *request.Request) {
	defer r.HTTPResponse.Body.Close()
	b, err := ioutil.ReadAll(r.HTTPResponse.Body)
	if err != nil {
		r.Error = awserr.New("SerializationError", "unable to unmarshal EC2 metadata respose", err)
	}

	data := r.Data.(*metadataOutput)
	data.Content = string(b)
}

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

// 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, awserr.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, awserr.New("ReadRequestBody", "read upload data failed", err)
	}

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

// Unmarshal unmarshals a response body for the EC2 protocol.
func Unmarshal(r *request.Request) {
	defer r.HTTPResponse.Body.Close()
	if r.DataFilled() {
		decoder := xml.NewDecoder(r.HTTPResponse.Body)
		err := xmlutil.UnmarshalXML(r.Data, decoder, "")
		if err != nil {
			r.Error = awserr.New("SerializationError", "failed decoding EC2 Query response", err)
			return
		}
	}
}

func buildURI(r *request.Request, v reflect.Value, name string) {
	value, err := convertType(v)
	if err != nil {
		r.Error = awserr.New("SerializationError", "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
	}
}

// ConvertFromList accepts a []*dynamodb.AttributeValue and converts it to an array or
// slice.
//
// If v contains any structs, the result is first converted it to a
// []interface{}, then JSON encoded/decoded it to convert to a typed array or
// slice, so `json` struct tags are respected.
func ConvertFromList(item []*dynamodb.AttributeValue, v interface{}) (err error) {
	defer func() {
		if r := recover(); r != nil {
			if e, ok := r.(runtime.Error); ok {
				err = e
			} else if s, ok := r.(string); ok {
				err = fmt.Errorf(s)
			} else {
				err = r.(error)
			}
			item = nil
		}
	}()

	rv := reflect.ValueOf(v)
	if rv.Kind() != reflect.Ptr || rv.IsNil() {
		return awserr.New("SerializationError",
			fmt.Sprintf("v must be a non-nil pointer to an array or slice, got %s",
				rv.Type()),
			nil)
	}
	if rv.Elem().Kind() != reflect.Array && rv.Elem().Kind() != reflect.Slice {
		return awserr.New("SerializationError",
			fmt.Sprintf("v must be a non-nil pointer to an array or slice, got %s",
				rv.Type()),
			nil)
	}

	l := make([]interface{}, 0, len(item))
	for _, v := range item {
		l = append(l, convertFrom(v))
	}

	if isTyped(reflect.TypeOf(v)) {
		err = convertToTyped(l, v)
	} else {
		rv.Elem().Set(reflect.ValueOf(l))
	}

	return err
}

// ConvertFromMap accepts a map[string]*dynamodb.AttributeValue and converts it to a
// map[string]interface{} or struct.
//
// If v points to a struct, the result is first converted it to a
// map[string]interface{}, then JSON encoded/decoded it to convert to a struct,
// so `json` struct tags are respected.
func ConvertFromMap(item map[string]*dynamodb.AttributeValue, v interface{}) (err error) {
	defer func() {
		if r := recover(); r != nil {
			if e, ok := r.(runtime.Error); ok {
				err = e
			} else if s, ok := r.(string); ok {
				err = fmt.Errorf(s)
			} else {
				err = r.(error)
			}
			item = nil
		}
	}()

	rv := reflect.ValueOf(v)
	if rv.Kind() != reflect.Ptr || rv.IsNil() {
		return awserr.New("SerializationError",
			fmt.Sprintf("v must be a non-nil pointer to a map[string]interface{} or struct, got %s",
				rv.Type()),
			nil)
	}
	if rv.Elem().Kind() != reflect.Struct && !(rv.Elem().Kind() == reflect.Map && rv.Elem().Type().Key().Kind() == reflect.String) {
		return awserr.New("SerializationError",
			fmt.Sprintf("v must be a non-nil pointer to a map[string]interface{} or struct, got %s",
				rv.Type()),
			nil)
	}

	m := make(map[string]interface{})
	for k, v := range item {
		m[k] = convertFrom(v)
	}

	if isTyped(reflect.TypeOf(v)) {
		err = convertToTyped(m, v)
	} else {
		rv.Elem().Set(reflect.ValueOf(m))
	}

	return err
}

func unmarshalBody(r *request.Request, v reflect.Value) {
	if field, ok := v.Type().FieldByName("SDKShapeTraits"); ok {
		if payloadName := field.Tag.Get("payload"); payloadName != "" {
			pfield, _ := v.Type().FieldByName(payloadName)
			if ptag := pfield.Tag.Get("type"); ptag != "" && ptag != "structure" {
				payload := v.FieldByName(payloadName)
				if payload.IsValid() {
					switch payload.Interface().(type) {
					case []byte:
						b, err := ioutil.ReadAll(r.HTTPResponse.Body)
						if err != nil {
							r.Error = awserr.New("SerializationError", "failed to decode REST response", err)
						} else {
							payload.Set(reflect.ValueOf(b))
						}
					case *string:
						b, err := ioutil.ReadAll(r.HTTPResponse.Body)
						if err != nil {
							r.Error = awserr.New("SerializationError", "failed to decode REST response", err)
						} else {
							str := string(b)
							payload.Set(reflect.ValueOf(&str))
						}
					default:
						switch payload.Type().String() {
						case "io.ReadSeeker":
							payload.Set(reflect.ValueOf(aws.ReadSeekCloser(r.HTTPResponse.Body)))
						case "aws.ReadSeekCloser", "io.ReadCloser":
							payload.Set(reflect.ValueOf(r.HTTPResponse.Body))
						default:
							r.Error = awserr.New("SerializationError",
								"failed to decode REST response",
								fmt.Errorf("unknown payload type %s", payload.Type()))
						}
					}
				}
			}
		}
	}
}