main.py

from fastapi.middleware.cors import CORSMiddleware
from fastapi import FastAPI, Request,  Header, BackgroundTasks, HTTPException, status

import google.generativeai as genai_gen

from linebot import LineBotApi, WebhookHandler
from linebot.exceptions import InvalidSignatureError
from linebot.models import MessageEvent, TextMessage, TextSendMessage, ImageSendMessage, AudioMessage, ImageMessage

import json, os
import io
import PIL.Image

from imgurpython import ImgurClient
from Image_text_generation import Image_text_Generator
from Uploading_images import get_image_url, store_user_message, analyze_with_gemini, get_previous_message

#==========================
#  API 金鑰
#==========================

# 設定 Google AI API 金鑰
google_api = os.environ["GOOGLE_API_KEY"]
genai_gen.configure(api_key=google_api)

# 設定生成文字的參數
generation_config = genai_gen.types.GenerationConfig(max_output_tokens=1000, temperature=0.2, top_p=0.5, top_k=16) #2048

# 使用 gemini-2.0-flash-exp 模型
model = genai_gen.GenerativeModel('gemini-2.0-flash-exp', system_instruction="主要用繁體中文回答，但如果用戶使用詢問英文問題，就用英文回應。你現在是個專業助理，職稱為OPEN小助理，個性活潑、樂觀，願意回答所有問題", generation_config=generation_config)

# 設定 Line Bot 的 API 金鑰和秘密金鑰
line_bot_api = LineBotApi(os.environ["CHANNEL_ACCESS_TOKEN"])
line_handler = WebhookHandler(os.environ["CHANNEL_SECRET"])

# 設定 Imgur 的 API
client_id = os.environ.get("IMGUR_CLIENT_ID")
client_secret = os.environ.get("IMGUR_CLIENT_SECRET")
access_token = os.environ.get("IMGUR_ACCESS_TOKEN")
refresh_token = os.environ.get("IMGUR_REFRESH_TOKEN")

# 設定是否正在與使用者交談
working_status = os.getenv("DEFALUT_TALKING", default = "true").lower() == "true"

# 建立 FastAPI 應用程式
app = FastAPI()

# 設定 CORS，允許跨域請求
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# 處理根路徑請求
@app.get("/")
def root():
    return {"title": "Line Bot"}

# 處理 Line Webhook 請求
@app.post("/webhook")
async def webhook(
    request: Request,
    background_tasks: BackgroundTasks,
    x_line_signature=Header(None),
):
    # 取得請求內容
    body = await request.body()
    try:
        # 將處理 Line 事件的任務加入背景工作
        background_tasks.add_task(
            line_handler.handle, body.decode("utf-8"), x_line_signature
        )
    except InvalidSignatureError:
        # 處理無效的簽章錯誤
        raise HTTPException(status_code=400, detail="Invalid signature")
    return "ok"
    

#==========================
# 主程式(圖片與文字)
#==========================
# 建立 chat_sessions 字典
chat_sessions = {}
@line_handler.add(MessageEvent, message=(ImageMessage, TextMessage))
def handle_image_message(event):
    user_id = event.source.user_id
    chat = chat_sessions.get(user_id) or model.start_chat(history=[])
    chat_sessions[user_id] = chat

    # ========
    # 生成圖片
    # ========
    user_text = event.message.text if event.message.type == "text" else None
    image_url = None
    if user_text and user_text.startswith("生成圖片"):
        prompt = user_text.replace("生成圖片", "").strip()

         # 先立即回覆避免token過期
        line_bot_api.reply_message(event.reply_token, TextSendMessage(text="圖片生成中～ 請稍候.....✨"))
        imgur = ImgurClient(client_id, client_secret, access_token, refresh_token)
        image_generator = Image_text_Generator(imgur)
        # 生成圖片
        image_binary = image_generator.generate_image_with_gemini(prompt)

        if image_binary:
            album = "nvsYwgq"
            image_url = image_generator.upload_image_to_imgur(image_binary,album)

            if image_url:
                # 使用 push message 發送圖片，避免 reply token 超時
                line_bot_api.push_message(
                    event.source.user_id,
                    [
                        TextSendMessage(text="✨ 這是我為你生成的圖片喔～"),
                        ImageSendMessage(original_content_url=image_url, preview_image_url=image_url)
                    ]
                )
            else:
                line_bot_api.push_message(
                    event.source.user_id,
                    TextSendMessage(text="⚠️ 圖片上傳失敗，請稍後再試~")
                )
        else:
            line_bot_api.push_message(
                event.source.user_id,
                TextSendMessage(text="⚠️ 圖片生成失敗，請稍後再試~")
            )
        return


    # ========
    # 上傳圖片
    # ========
    if event.message.type == "image":
        image_path = get_image_url(event.message.id)
        if image_path:
            store_user_message(user_id, "image", image_path)
            line_bot_api.reply_message(event.reply_token, TextSendMessage(text="圖片已接收成功囉，幫我輸入你想詢問的問題喔~"))
        else:
            line_bot_api.reply_message(event.reply_token, TextSendMessage(text="沒有接收到圖片~"))
        return

    previous_message = get_previous_message(user_id)
    if previous_message and previous_message["type"] == "image" and event.message.type == "text":
        image_path = previous_message["content"]
        user_text = event.message.text
        store_user_message(user_id, "text", user_text)
        try:
            if not os.path.exists(image_path):
                raise FileNotFoundError(f"圖片路徑無效：{image_path}")
            organ = PIL.Image.open(image_path)
            completion = chat.send_message([user_text, organ])
            out = completion.text
        except Exception as e:
            out = f"發生錯誤: {e}"

    # ========
    # 純文字
    # ========
    else:
        if event.message.type != "text":
            line_bot_api.reply_message(event.reply_token, TextSendMessage(text="請輸入文字或圖片~"))
            return
        if event.message.text == "再見":
            line_bot_api.reply_message(event.reply_token, TextSendMessage(text="Bye!"))
            return
        if working_status:
            try:
                prompt = event.message.text
                store_user_message(user_id, "text", prompt)
                completion = chat.send_message(prompt)
                out = completion.text if completion.text else "我不太懂什麼意思也~"
            except:
                out = "執行出錯!請換個說法！"

    line_bot_api.reply_message(event.reply_token, TextSendMessage(text=out))


if __name__ == "__main__":
    # 啟動 FastAPI 應用程式
    uvicorn.run("main:app", host="0.0.0.0", port=7860, reload=True)