import sqlite3
import pandas as pd
import os
from datetime import datetime
import json

def process_following_data(source_db_path, target_db_path, min_followers=20, max_followers=50):
    """
    处理关注者数据，筛选出符合条件的用户并保存到新数据库
    """
    if not os.path.exists(source_db_path):
        raise FileNotFoundError(f"找不到数据库文件: {source_db_path}")
    
    conn = sqlite3.connect(source_db_path)
    
    print("正在读取关注关系数据...")
    df_relationships = pd.read_sql_query("""
        SELECT user_id, following_of
        FROM following_relationships
    """, conn)
    
    print("正在统计关注者数量...")
    grouped = (
        df_relationships
        .groupby('user_id')['following_of']
        .agg(lambda x: list(set(x)))
        .reset_index()
    )
    grouped['follower_count'] = grouped['following_of'].apply(len)
    
    filtered = grouped[
        (grouped['follower_count'] >= min_followers) & 
        (grouped['follower_count'] <= max_followers)
    ]
    
    print("正在获取用户详细信息...")
    target_users = tuple(filtered['user_id'].tolist())
    
    if not target_users:
        print("没有找到符合条件的用户")
        conn.close()
        return 0
    
    # 将列表转换为字符串
    filtered['following_of'] = filtered['following_of'].apply(json.dumps)
    
    users_df = pd.read_sql_query("""
        SELECT *
        FROM users
        WHERE user_id IN ({})
    """.format(','.join(['?' for _ in target_users])), conn, params=target_users)
    
    # 合并数据，只保留需要的列
    result_df = pd.merge(
        users_df,
        filtered[['user_id', 'follower_count']],
        on='user_id',
        how='inner'
    )
    
    print(f"正在保存符合条件的 {len(result_df)} 个用户信息到新数据库...")
    
    # 保存到新数据库
    target_conn = sqlite3.connect(target_db_path)
    
    # 确保删除following_of列（如果存在），因为我们会在单独的表中存储它
    if 'following_of' in result_df.columns:
        result_df = result_df.drop('following_of', axis=1)
    
    # 创建主表
    result_df.to_sql('users', target_conn, index=False, if_exists='replace')
    
    # 创建索引
    target_conn.execute("CREATE INDEX IF NOT EXISTS idx_user_id ON users(user_id)")
    target_conn.execute("CREATE INDEX IF NOT EXISTS idx_followers_count ON users(followers_count)")
    
    # 创建并填充关注者表
    target_conn.execute("""
        CREATE TABLE IF NOT EXISTS user_followers (
            user_id TEXT PRIMARY KEY,
            followers TEXT,
            follower_count INTEGER,
            FOREIGN KEY(user_id) REFERENCES users(user_id)
        )
    """)
    
    # 准备关注者数据
    followers_data = filtered[['user_id', 'following_of', 'follower_count']]
    followers_data.to_sql('user_followers', target_conn, index=False, if_exists='replace')
    
    # 打印预览
    print("\n符合条件的用户数据预览：")
    preview_df = result_df[['user_id', 'name', 'followers_count', 'friends_count']].head()
    print(preview_df)
    
    conn.close()
    target_conn.close()
    
    return len(result_df)

if __name__ == "__main__":
    # 设置数据库路径
    source_db = "following_expanded.db"
    target_db = f"filtered_users_{datetime.now().strftime('%Y%m%d_%H%M%S')}.db"
    
    try:
        result_count = process_following_data(source_db, target_db)
        print(f"\n处理完成！已将 {result_count} 个用户的信息保存到 {target_db}")
    except Exception as e:
        print(f"处理过程中出现错误: {str(e)}")
        # 打印详细的错误跟踪信息
        import traceback
        print("\n详细错误信息:")
        print(traceback.format_exc())