nikoksr/notify

package line

import (
    "context"
    "fmt"

    "github.com/line/line-bot-sdk-go/linebot"
)

// Line struct holds info about client and destination ID for communicating with line API.
type Line struct {
    client      *linebot.Client
    receiverIDs []string
}

// New creates a new instance of Line notifier service
// For more info about line api credential:
// -> https://github.com/line/line-bot-sdk-go
func New(channelSecret, channelAccessToken string) (*Line, error) {
    bot, err := linebot.New(channelSecret, channelAccessToken)
    if err != nil {
        return nil, err
    }

    l := &Line{
        client: bot,
    }

    return l, nil
}

// AddReceivers receives user, group or room IDs then add them to internal receivers list.
func (l *Line) AddReceivers(receiverIDs ...string) {
    l.receiverIDs = append(l.receiverIDs, receiverIDs...)
}

// Send receives message subject and body then sends it to all receivers set previously
// Subject will be on the first line followed by message on the next line.
func (l *Line) Send(ctx context.Context, subject, message string) error {
    lineMessage := &linebot.TextMessage{
        Text: subject + "\n" + message,
    }

    for _, receiverID := range l.receiverIDs {
        select {
        case <-ctx.Done():
            return ctx.Err()
        default:
            _, err := l.client.PushMessage(receiverID, lineMessage).WithContext(ctx).Do()
            if err != nil {
                return fmt.Errorf("push message to %q: %w", receiverID, err)
            }
        }
    }

    return nil
}