LINE Bot 開發入門 - 以呷爸點餐系統為例

import os
from flask import Flask, request, abort
from linebot.v3 import WebhookHandler
from linebot.v3.messaging import (
    Configuration,
    ApiClient,
    MessagingApi,
    ReplyMessageRequest,
    TextMessage,
)
from linebot.v3.webhooks import MessageEvent, TextMessageContent
from linebot.v3.exceptions import InvalidSignatureError

app = Flask(__name__)

# 從環境變數讀取憑證
channel_secret = os.environ.get("LINE_CHANNEL_SECRET")
channel_access_token = os.environ.get("LINE_CHANNEL_ACCESS_TOKEN")

configuration = Configuration(access_token=channel_access_token)
handler = WebhookHandler(channel_secret)


@app.route("/callback", methods=["POST"])
def callback():
    """LINE Webhook endpoint"""
    signature = request.headers.get("X-Line-Signature", "")
    body = request.get_data(as_text=True)

    try:
        handler.handle(body, signature)
    except InvalidSignatureError:
        abort(400)

    return "OK"


@handler.add(MessageEvent, message=TextMessageContent)
def handle_message(event):
    """處理文字訊息"""
    user_message = event.message.text

    # 在這裡處理訊息邏輯
    reply_text = f"你說：{user_message}"

    with ApiClient(configuration) as api_client:
        messaging_api = MessagingApi(api_client)
        messaging_api.reply_message(
            ReplyMessageRequest(
                reply_token=event.reply_token,
                messages=[TextMessage(text=reply_text)]
            )
        )


@app.route("/", methods=["GET"])
def index():
    """首頁 - 顯示服務狀態"""
    return "LINE Bot is running!"


if __name__ == "__main__":
    app.run(host="0.0.0.0", port=5000)

@handler.add(MessageEvent, message=TextMessageContent)
def handle_message(event):
    source_type = event.source.type

    if source_type == "user":
        # 1對1 聊天 - 用於設定個人偏好
        user_id = event.source.user_id
    elif source_type == "group":
        # 群組 - 用於群組點餐
        group_id = event.source.group_id
        user_id = event.source.user_id

def get_user_display_name(event):
    """取得發訊者名稱"""
    user_id = event.source.user_id

    with ApiClient(configuration) as api_client:
        messaging_api = MessagingApi(api_client)

        if event.source.type == "group":
            # 群組中要用不同 API
            profile = messaging_api.get_group_member_profile(
                event.source.group_id, user_id
            )
        else:
            profile = messaging_api.get_profile(user_id)

        return profile.display_name

from linebot.v3.webhooks import LeaveEvent, UnfollowEvent

@handler.add(LeaveEvent)
def handle_leave(event):
    """Bot 被踢出群組"""
    if event.source.type == "group":
        group_id = event.source.group_id
        # 從白名單移除
        unregister_from_whitelist(group_id)

@handler.add(UnfollowEvent)
def handle_unfollow(event):
    """使用者封鎖 Bot"""
    user_id = event.source.user_id
    # 從白名單移除
    unregister_from_whitelist(user_id)

def should_respond(event, user_text):
    # 1對1 聊天：永遠回應
    if event.source.type == "user":
        return True, user_text

    # 群組：使用 Session 機制
    group_id = event.source.group_id
    text_stripped = user_text.strip()

    # 檢查群組是否在點餐中
    is_ordering = check_group_session(group_id)

    if is_ordering:
        # 點餐中：所有訊息都轉發（AI 過濾非訂餐訊息）
        return True, user_text
    else:
        # 非點餐中：只回應特定指令
        if text_stripped in ["開單", "菜單"]:
            return True, user_text
        # 還會檢查：啟用密碼、@呷爸/@jaba 等（簡化省略）
        return False, user_text

# v3 寫法
from linebot.v3 import WebhookHandler
from linebot.v3.messaging import Configuration, ApiClient, MessagingApi
from linebot.v3.webhooks import MessageEvent, TextMessageContent

# 舊版寫法（已不建議）
from linebot import LineBotApi, WebhookHandler

# v3 需要用 Context Manager
with ApiClient(configuration) as api_client:
    messaging_api = MessagingApi(api_client)
    messaging_api.reply_message(...)

# 舊版直接呼叫
line_bot_api.reply_message(...)