# init_full_sync.py
import pyodbc
import config
import db_utils
import time
import os

def run_full_sync():
    print("=== 开始全量初始化同步 ===")
    print("注意：将基于 config.SYNC_MAPPING 中的文件路径进行处理")
    
    sql_conn = db_utils.get_sql_conn()
    sql_cursor = sql_conn.cursor()
    sql_cursor.fast_executemany = True

    # 第一层循环：遍历配置文件中的所有文件路径
    for acc_path, tables_map in config.SYNC_MAPPING.items():
        if not os.path.exists(acc_path):
            print(f"⚠️  [跳过] 文件不存在: {acc_path}")
            continue

        print(f"\n📂 正在处理文件: {acc_path}")
        
        try:
            acc_conn = db_utils.get_access_conn(acc_path)
            acc_cursor = acc_conn.cursor()

            # 第二层循环：遍历该文件下的所有表映射
            for acc_table, target_config in tables_map.items():
                target_schema = target_config['target_schema']
                target_table = target_config['target_table']
                full_target_name = db_utils.fmt_table(target_schema, target_table)

                print(f"  👉 同步表: [{acc_table}] -> {full_target_name}")

                try:
                    # 1. 检查 Access 表是否存在
                    acc_cursor.execute(f"SELECT TOP 1 * FROM [{acc_table}]")
                    
                    # 2. 获取列结构
                    columns = [col[0] for col in acc_cursor.description]
                    insert_sql = db_utils.generate_insert_sql(target_schema, target_table, columns)

                    # 3. TRUNCATE 目标表
                    sql_cursor.execute(f"TRUNCATE TABLE {full_target_name}")
                    
                    # 4. 开启 IDENTITY_INSERT (尝试)
                    try: sql_cursor.execute(f"SET IDENTITY_INSERT {full_target_name} ON")
                    except: pass

                    # 5. 传输数据
                    print(f"     正在读取并写入数据...")
                    acc_cursor.execute(f"SELECT * FROM [{acc_table}]")
                    
                    total_rows = 0
                    while True:
                        rows = acc_cursor.fetchmany(config.BATCH_SIZE)
                        if not rows: break
                        sql_cursor.executemany(insert_sql, rows)
                        total_rows += len(rows)
                        print(f"     已写入 {total_rows} 行...", end='\r')
                    
                    # 6. 关闭 IDENTITY_INSERT
                    try: sql_cursor.execute(f"SET IDENTITY_INSERT {full_target_name} OFF")
                    except: pass
                    
                    sql_conn.commit()
                    print(f"\n     ✅ 完成。")

                except Exception as tbl_err:
                    print(f"     ❌ 表级错误: {tbl_err}")
                    sql_conn.rollback()

            acc_conn.close()

        except Exception as file_err:
            print(f"  ❌ 文件级错误: {file_err}")

    sql_conn.close()
    print("\n=== 全量同步结束 ===")

if __name__ == "__main__":
    run_full_sync()