app.py

import gradio as gr
import uuid
import os
import csv
import datetime
from datetime import timezone, timedelta
import re
from openai import OpenAI
import sys

# --- JST（日本時間）の定義 ---
JST = timezone(timedelta(hours=9), 'JST')

# --- API Key and Client Initialization ---
OPENROUTER_API_KEY = os.environ.get("OPENROUTER_API_KEY")

if not OPENROUTER_API_KEY:
    print("Warning: OpenRouter API Key not found.", file=sys.stderr)

try:
    client = OpenAI(
        base_url="https://openrouter.ai/api/v1",
        api_key=OPENROUTER_API_KEY,
    )
    print("OpenAI client initialized.")
except Exception as e:
    print(f"Failed to initialize OpenAI client: {e}", file=sys.stderr)

# --- Helper Functions ---
def generate_user_id():
    return str(uuid.uuid4())

def load_prompt(level):
    try:
        filename = f"{level.lower()}_prompt.txt"
        if os.path.exists(filename):
            with open(filename, "r", encoding="utf-8") as f:
                return f.read()
        return "You are a helpful AI assistant."
    except Exception:
        return "You are a helpful AI assistant."

# --- Core Logic Functions ---

def chat_process(message, display_history, full_logs, prompt_level):
    """
    チャット処理を行う関数
    """
    if display_history is None: display_history = []
    if full_logs is None: full_logs = []

    # 1. ユーザーメッセージの作成
    current_time_user = datetime.datetime.now(JST).strftime("%Y-%m-%d %H:%M:%S")
    user_msg_data = {
        "role": "user", 
        "content": message, 
        "timestamp": current_time_user
    }
    
    temp_display = display_history + [user_msg_data]
    temp_logs = full_logs + [user_msg_data]

    # APIリクエスト用のメッセージ作成
    system_prompt = load_prompt(prompt_level)
    messages_for_api = [{"role": "system", "content": system_prompt}]
    
    for msg in temp_display:
        messages_for_api.append({"role": msg["role"], "content": msg["content"]})

    ai_response = ""
    try:
        model_name = "google/gemini-2.5-flash"

        response = client.chat.completions.create(
            model=model_name,
            messages=messages_for_api,
            temperature=0.7,
            max_tokens=500,
        )
        content = response.choices[0].message.content
        ai_response = content if content is not None else ""
        if not ai_response:
            ai_response = "(応答が空でした)"

    except Exception as e:
        error_msg = f"API Error: {e}"
        print(error_msg, file=sys.stderr)
        ai_response = f"システムエラーが発生しました: {e}"

    # 2. AIメッセージの作成
    current_time_ai = datetime.datetime.now(JST).strftime("%Y-%m-%d %H:%M:%S")
    ai_msg_data = {
        "role": "assistant", 
        "content": ai_response, 
        "timestamp": current_time_ai
    }

    new_display = temp_display + [ai_msg_data]
    new_logs = temp_logs + [ai_msg_data]

    return "", new_display, new_display, new_logs

def change_difficulty_logic(new_level, full_logs):
    """
    難易度変更時の処理
    """
    if full_logs is None: full_logs = []

    notification_msg = (
        f"**[システム通知]**\n"
        f"難易度を **{new_level}** に変更しました。\n"
        f"解答開始と入力すれば指導が始まります。"
    )
    current_time = datetime.datetime.now(JST).strftime("%Y-%m-%d %H:%M:%S")
    
    msg_data = {
        "role": "assistant",
        "content": notification_msg,
        "timestamp": current_time
    }

    new_display_history = [msg_data]
    new_full_logs = full_logs + [msg_data]
    
    return new_display_history, new_display_history, new_full_logs, new_level

def export_csv_logic(user_id, user_name, full_logs):
    print(f"Exporting CSV for UserID: {user_id}, Name: '{user_name}'")

    if not user_name or not user_name.strip():
        gr.Warning("名前が正しく取得できませんでした")
        return None

    if not full_logs:
        gr.Warning("保存する履歴がまだありません。")
        return None

    timestamp_str = datetime.datetime.now(JST).strftime("%Y%m%d_%H%M%S")
    
    safe_name = re.sub(r'[\\/*?:"<>|]', "", user_name)
    safe_name = safe_name.strip().replace(" ", "_")
    filename = f"chat_history_{safe_name}_{timestamp_str}.csv"
    
    try:
        with open(filename, "w", newline="", encoding="utf-8-sig") as f:
            writer = csv.writer(f)
            writer.writerow(["Timestamp", "Role", "Content"])
            
            for msg in full_logs:
                ts = msg.get("timestamp", "")
                role = msg.get("role", "")
                content = msg.get("content", "")
                writer.writerow([ts, role, content])
        
        print(f"Successfully saved to {filename}")
        return filename
    except Exception as e:
        print(f"CSV Export Error: {e}", file=sys.stderr)
        gr.Warning(f"CSV保存エラー: {e}")
        return None

def start_app_logic(user_name):
    """
    名前が入力されているか確認し、画面表示を切り替える
    """
    if not user_name or not user_name.strip():
        raise gr.Error("お名前を入力してください。")
    
    # Start画面を隠し(False)、Main画面を表示(True)
    return gr.update(visible=False), gr.update(visible=True)


# --- UI Definition ---
with gr.Blocks() as demo:
    # ステート定義
    user_id_state = gr.State(generate_user_id)
    display_history_state = gr.State([]) # 画面用
    full_logs_state = gr.State([])       # 保存用
    prompt_level_state = gr.State("Beginner")
    
    start_msg_constant = gr.State("解答開始")

    # =========================================
    # 1. スタート画面
    # =========================================
    with gr.Column(visible=True) as start_screen:
        gr.Markdown("# AI Chatbot System")
        gr.Markdown("学習を始めるには、お名前を入力して「解答開始」を押してください。")
        
        user_name_input = gr.Textbox(
            label="お名前", 
            placeholder="山田 太郎", 
            scale=2
        )
        
        start_btn = gr.Button("解答開始", variant="primary", size="lg")

    # =========================================
    # 2. メインチャット画面
    # =========================================
    with gr.Column(visible=False) as main_screen:
        gr.Markdown("# Multi-Level AI Chatbot")
        
        with gr.Row():
            export_btn = gr.DownloadButton("📥 会話をCSVで保存", scale=1)

        with gr.Row():
            gr.Markdown("## 問題の難易度を選択してください（初級から順番に取り組んでください）")
            
        with gr.Row():
            level_radio = gr.Radio(
                ["Beginner", "Intermediate", "Advanced"],
                label="Difficulty Level",
                value="Beginner",
                interactive=True
            )

        # 【修正箇所】Chatbotの定義にlatex_delimitersを追加
        chatbot = gr.Chatbot(
            type="messages", 
            height=500,
            latex_delimiters=[
                {"left": "$$", "right": "$$", "display": True},   # 行全体（ディスプレイ数式）
                {"left": "$", "right": "$", "display": False},    # インライン数式
                {"left": "\\(", "right": "\\)", "display": False},
                {"left": "\\[", "right": "\\]", "display": True},
            ]
        )
        
        msg_input = gr.Textbox(
            placeholder="メッセージを入力してください... (Enterで送信)", 
            label="Chat Input",
            lines=1
        )
        send_btn = gr.Button("送信", variant="primary")

    # --- Event Handling ---

    # A. スタートボタンの処理
    start_btn.click(
        fn=start_app_logic,
        inputs=[user_name_input],
        outputs=[start_screen, main_screen]
    ).then(
        fn=chat_process,
        inputs=[start_msg_constant, display_history_state, full_logs_state, prompt_level_state],
        outputs=[msg_input, chatbot, display_history_state, full_logs_state]
    )

    # B. メッセージ送信時の処理
    chat_event_args = {
        "fn": chat_process,
        "inputs": [msg_input, display_history_state, full_logs_state, prompt_level_state],
        "outputs": [msg_input, chatbot, display_history_state, full_logs_state]
    }

    msg_input.submit(**chat_event_args)
    send_btn.click(**chat_event_args)

    # C. 難易度変更時の処理
    level_radio.change(
        fn=change_difficulty_logic,
        inputs=[level_radio, full_logs_state],
        outputs=[chatbot, display_history_state, full_logs_state, prompt_level_state]
    )

    # D. CSV保存処理
    export_btn.click(
        fn=export_csv_logic,
        inputs=[user_id_state, user_name_input, full_logs_state],
        outputs=[export_btn]
    )

if __name__ == "__main__":
    demo.launch(debug=True, share=False)