import sqlite3
import os


def init_db():
    conn = sqlite3.connect(os.getenv("SQLITE_DB_PATH"))

    # 业务表：会话
    conn.execute("""
    CREATE TABLE IF NOT EXISTS session (
        id INTEGER PRIMARY KEY AUTOINCREMENT,
        thread_id TEXT NOT NULL UNIQUE,
        username TEXT NOT NULL,
        title TEXT NOT NULL,
        created_time DATETIME DEFAULT CURRENT_TIMESTAMP
    );
    """)

    conn.commit()
    conn.close()


def exists_session(thread_id: str, username: str) -> bool:
    conn = sqlite3.connect(os.getenv("SQLITE_DB_PATH"))
    cursor = conn.cursor()

    cursor.execute(
        """
        SELECT 1
        FROM session
        WHERE thread_id = ? AND username = ?
        LIMIT 1
        """,
        (thread_id, username)
    )

    result = cursor.fetchone()
    conn.close()

    return result is not None


def save_session(thread_id: str, username: str, title: str):
    conn = sqlite3.connect(os.getenv("SQLITE_DB_PATH"))
    conn.execute(
        """
        INSERT OR REPLACE INTO session
        (thread_id, username, title)
        VALUES (?, ?, ?)
        """,
        (thread_id, username, title)
    )
    conn.commit()
    conn.close()