import psycopg2
import csv
from psycopg2 import sql
from datetime import datetime

def format_datetime(value):
    if isinstance(value, datetime):
        return value.strftime('%Y-%m-%d %H:%M:%S')
    return value

def export_table_to_csv(host, port, database, user, password, main_table, related_table, related_column, csv_file_path):
    try:
        # データベースに接続
        conn = psycopg2.connect(
            host=host,
            port=port,
            database=database,
            user=user,
            password=password
        )
        
        cur = conn.cursor()
        
        # メインテーブルの列情報を取得（user_idを除く）
        cur.execute(sql.SQL("SELECT * FROM {} LIMIT 0").format(sql.Identifier(main_table)))
        main_columns = [desc[0] for desc in cur.description if desc[0] != 'member_id']
        
        # クエリを作成（列名を明確に指定）
        query = sql.SQL("""
            SELECT {main_columns}, {related_table}.name
            FROM {main_table}
            LEFT JOIN {related_table} ON {main_table}.member_id = {related_table}.id
        """).format(
            main_columns=sql.SQL(', ').join([sql.SQL("{}.{}").format(sql.Identifier(main_table), sql.Identifier(col)) for col in main_columns]),
            main_table=sql.Identifier(main_table),
            related_table=sql.Identifier(related_table)
        )
        
        cur.execute(query)
        
        # 列名を再構成（nameを2番目に配置）
        column_names = [main_columns[0], 'name'] + main_columns[1:]
        
        rows = cur.fetchall()
        
        with open(csv_file_path, 'w', newline='', encoding='utf-8-sig') as csvfile:
            csvwriter = csv.writer(csvfile)
            csvwriter.writerow(column_names)
            
            for row in rows:
                # nameを2番目に移動
                formatted_row = [format_datetime(row[0])] + [row[-1]] + [format_datetime(field) if field is not None else '' for field in row[1:-1]]
                csvwriter.writerow(formatted_row)
        
        print(f"テーブル '{main_table}' の内容を '{csv_file_path}' に出力しました。")
        
    except (Exception, psycopg2.Error) as error:
        print("エラーが発生しました:", error)
    
    finally:
        if conn:
            cur.close()
            conn.close()
            print("データベース接続を閉じました。")

# 使用例
host = "192.168.1.220"
port = "12245"
database = "dislocker"
user = "suti7"
password = "Testing1234"
main_table = "pc_usage_history"
related_table = "club_member"
related_column = "name"  # 例: 登録者の名前を表示したい場合
csv_file_path = "output.csv"

export_table_to_csv(host, port, database, user, password, main_table, related_table, related_column, csv_file_path)