from typing import List, Any
from datetime import datetime
from psycopg import AsyncConnection, sql

class ScadaRepository:
    
    @staticmethod
    async def insert_batch(conn: AsyncConnection, data: List[dict]):
        if not data:
            return

        async with conn.cursor() as cur:
            async with cur.copy(
                "COPY scada.scada_data (time, device_id, monitored_value, cleaned_value) FROM STDIN"
            ) as copy:
                for item in data:
                    await copy.write_row((
                        item['time'], item['device_id'], item.get('monitored_value'), item.get('cleaned_value')
                    ))

    @staticmethod
    async def get_data_by_time(conn: AsyncConnection, device_id: str, start_time: datetime, end_time: datetime) -> List[dict]:
        async with conn.cursor() as cur:
            await cur.execute(
                "SELECT * FROM scada.scada_data WHERE device_id = %s AND time >= %s AND time <= %s",
                (device_id, start_time, end_time)
            )
            return await cur.fetchall()

    @staticmethod
    async def update_field(conn: AsyncConnection, time: datetime, device_id: str, field: str, value: Any):
        valid_fields = {"monitored_value", "cleaned_value"}
        if field not in valid_fields:
            raise ValueError(f"Invalid field: {field}")

        query = sql.SQL("UPDATE scada.scada_data SET {} = %s WHERE time = %s AND device_id = %s").format(sql.Identifier(field))
        
        async with conn.cursor() as cur:
            await cur.execute(query, (value, time, device_id))