package json

import (
	"encoding/json"

	"git.loafle.net/commons_go/rpc/codec"
)

// ----------------------------------------------------------------------------
// 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
	codec codec.Codec
}

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.
		raws := make([]json.RawMessage, len(args))
		if err := json.Unmarshal(*cnc.noti.Params, &raws); err != nil {
			cnc.err = &Error{
				Code:    E_INVALID_REQ,
				Message: err.Error(),
				Data:    cnc.noti.Params,
			}
			return cnc.err
		}

		for indexI := 0; indexI < len(args); indexI++ {
			raw := raws[indexI]
			arg := args[indexI]
			if err := json.Unmarshal(raw, &arg); err != nil {
				cnc.err = &Error{
					Code:    E_INVALID_REQ,
					Message: err.Error(),
					Data:    cnc.noti.Params,
				}
				return cnc.err
			}
		}
	}
	return cnc.err
}

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

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

		return results, nil
	}
	return nil, cnc.err
}