2021/6/5 Amazon Lex はじめてのLINEチャットボット

amazonlex-linebot

const Line = require('@line/bot-sdk')
const Aws = require('aws-sdk')

const channelAccessToken = process.env.CHANNEL_ACCESS_TOKEN
const channelSecret = process.env.CHANNEL_SECRET
const lex = new Aws.LexRuntime()
const line = new Line.Client({ channelAccessToken, channelSecret })

exports.handler = async (event) => {
	console.log(JSON.stringify(event))

	// Signature validation LINEから来たデータかをbot-sdkで検証
	if (!Line.validateSignature(event.body, channelSecret, event.headers['x-line-signature'])) {
		return {
			//不正だった場合400を返す
			statusCode: 400,
			body: 'Bad Request',
		}
	}
	//LINEからきたメッセージをJSON形式に変換
	const body = JSON.parse(event.body)
	const events = body.events

	// webhookのendpoint検証すると0件のイベントが送信されるので0件の時はステータスコード200を返す
	if (events.length === 0) {
		return {
			statusCode: 200,
			body: 'Test OK',
		}
	}

	for (let i = 0; i < events.length; i++) {
		if ('replyToken' in events[i]) {
			const event = events[i]
			const replyToken = event.replyToken

			if ('message' in event) {
				const messageEvent = event
				//テキストメッセージ送信時の処理
				if (messageEvent.message.type === 'text') {
					const inputText = messageEvent.message.text
					const param = {
						botAlias: 'prod',
						botName: 'BookTrip_jaJP',
						userId: messageEvent.source.userId,
						inputText
					}

					const result = await lex.postText(param).promise()

					const messages = []
					if (result.dialogState === 'ReadyForFulfillment') {
						messages.push({
							type: 'text',
							text: '予約が完了しました！'
						})
					} else {
						messages.push({
							type: 'text',
							text: result.message
						})
					}
					await line.replyMessage(replyToken, messages)
				}
			}
		}
	}

	return { 
		statusCode: 200,
		body: 'OK'
	}
}