import csv
import os
from pathlib import Path

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

load_dotenv()

BASE_DIR = Path(__file__).resolve().parents[1]
DATA_PATH = BASE_DIR / "Line_Bot_datasets" / "jiashuo_questions.csv"

app = Flask(__name__)

configuration = Configuration(
    access_token=os.environ["LINE_CHANNEL_ACCESS_TOKEN"]
)

handler = WebhookHandler(
    os.environ["LINE_CHANNEL_SECRET"]
)


def load_questions():
    with DATA_PATH.open("r", encoding="utf-8-sig", newline="") as file:
        return list(csv.DictReader(file))


QUESTIONS = load_questions()


def search_answer(user_text):
    user_text = user_text.strip().lower()

    for row in QUESTIONS:
        keywords = [
            keyword.strip().lower()
            for keyword in row["keywords"].split("|")
        ]

        if any(keyword and keyword in user_text for keyword in keywords):
            return (
                f"【{row['category']}】\n"
                f"{row['answer']}"
            )

    return (
        "我目前找不到對應答案。\n\n"
        "你可以試著問：\n"
        "課程、報名、AI、Python、咖啡、水電、PLC、上課地點、補助、甄試、聯絡方式。"
    )


@app.post("/callback")
def callback():
    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_text_message(event):
    user_text = event.message.text
    reply_text = search_answer(user_text)

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


if __name__ == "__main__":
    app.run(
        host="0.0.0.0",
        port=int(os.getenv("PORT", "5000")),
        debug=True
    )