from utils.s7data import S7Client
from utils.statepoint import Statepoint
import snap7.util, threading, time

class S7Writer:
    def __init__(self, s7c: S7Client):
        self.client = s7c
        self.bool_dict = {}
        self.write_dict = {}
        self.sleep_time = 1000
        self.run = threading.Event()
        self.type_dict = {"int": (2, snap7.util.set_int),
                          "dint": (4, snap7.util.set_dint),
                          "real": (4, snap7.util.set_real)}

    def add_task_bool(self, db: int, start: int, offset: int, point: Statepoint):
        self.bool_dict[(db, start, offset)] = point

    def add_task(self, dtype: str, db: int, start: int, point: Statepoint):
        if dtype not in self.type_dict.keys():
            raise ValueError(f"type {dtype} is not supported.")
        self.write_dict[(dtype, db, start)] = point

    def do_task_bool(self):
        for addr, point in self.bool_dict.items():
            tmp = self.client.db_read(addr[0], addr[1], 1)
            snap7.util.set_bool(tmp, 0, addr[2], point.data)
            self.client.db_write(addr[0], addr[1], tmp)

    def do_task(self):
        for addr, point in self.write_dict.items():
            type_length, type_func = self.type_dict[addr[0]]
            tmp = bytearray(type_length)
            type_func(tmp, 0, point.data)
            self.client.db_write(addr[1], addr[2], tmp)

    def write_forever(self):
        self.run.set()
        while self.run.is_set():
            try:
                self.do_task_bool()
                self.do_task()
            except Exception as e:
                print("PLC写入线程异常:", e)
                self.run.clear()
                return
            time.sleep(self.sleep_time/1000)

    def loop_start(self):
        if hasattr(self, "thread"):
            raise ValueError("It can only be started once.")
        self.thread = threading.Thread(target=self.write_forever)
        self.thread.start()