package json

import (
	"encoding/json"

	crp "git.loafle.net/commons/rpc-go/protocol"
	cuej "git.loafle.net/commons/util-go/encoding/json"
)

// ----------------------------------------------------------------------------
// ClientNotificationCodec
// ----------------------------------------------------------------------------
// clientRequest represents a JSON-RPC notification sent to a client.
type clientNotification struct {
	// A String containing the name of the method to be invoked.
	Method string `json:"method"`
	// Object to pass as request parameter to the method.
	Params *json.RawMessage `json:"params,omitempty"`
}

// ClientNotificationCodec decodes and encodes a single notification.
type ClientNotificationCodec struct {
	noti *clientNotification
	err  error
}

func (cnc *ClientNotificationCodec) HasResponse() bool {
	return false
}

func (cnc *ClientNotificationCodec) Method() string {
	return cnc.noti.Method
}

func (cnc *ClientNotificationCodec) ReadParams(args []interface{}) error {
	if cnc.err == nil && cnc.noti.Params != nil {
		// Note: if scr.request.Params is nil it's not an error, it's an optional member.
		// JSON params structured object. Unmarshal to the args object.
		if err := cuej.SetValueWithJSONStringArray(*cnc.noti.Params, args); nil != err {
			cnc.err = &crp.Error{
				Code:    crp.E_INVALID_REQ,
				Message: err.Error(),
				Data:    cnc.noti.Params,
			}
			return cnc.err
		}
		return nil
	}
	return cnc.err
}

func (cnc *ClientNotificationCodec) Params() ([]string, error) {
	if cnc.err == nil && cnc.noti.Params != nil {
		var values []string

		if err := json.Unmarshal(*cnc.noti.Params, &values); err != nil {
			cnc.err = &crp.Error{
				Code:    crp.E_INVALID_REQ,
				Message: err.Error(),
				Data:    cnc.noti.Params,
			}
			return nil, cnc.err
		}

		return values, nil
	}
	return nil, cnc.err
}