import threading
import time
import logging
from snap7.util import *

class CacheManager:
    """PLC数据缓存管理器"""
    
    def __init__(self, config, plc_manager, app=None):
        """
        初始化缓存管理器
        
        Args:
            config: 配置对象
            plc_manager: PLC管理器实例
            app: 主应用程序引用（用于配置重载）
        """
        self.plc_manager = plc_manager
        self.config = config
        self.app = app
        self.cache = {}
        self.refresh_interval = 1  # 1秒刷新一次
        self.running = False
        self.lock = threading.Lock()
        self.thread = None
        self.last_update = {}  # 区域级最后更新时间
        self.plc_last_connected = {}  # PLC级最后连接时间
        self.plc_connection_status = {}  # PLC连接状态
        self.logger = logging.getLogger("CacheManager")
        self.init_cache()
    
    def init_cache(self):
        """初始化缓存结构"""
        for plc in self.config["plcs"]:
            plc_name = plc["name"]
            self.cache[plc_name] = {}
            self.last_update[plc_name] = {}
            self.plc_last_connected[plc_name] = 0  # 初始化为0（未连接）
            self.plc_connection_status[plc_name] = "never_connected"
            
            for area in plc["areas"]:
                name = area["name"]
                # 确保初始状态为断开
                self.cache[plc_name][name] = {
                    "data": bytearray(area["size"]),
                    "db_number": area["db_number"],
                    "offset": area["offset"],
                    "size": area["size"],
                    "type": area["type"],
                    "structure": area.get("structure", []),
                    "status": "disconnected"  # 初始状态为断开
                }
                self.last_update[plc_name][name] = 0
    
    def refresh_cache(self):
        """后台线程：定期刷新缓存"""
        while self.running:
            start_time = time.time()

            try:
                for plc in self.config["plcs"]:
                    plc_name = plc["name"]
                    refresh_interval = plc.get("refresh_interval", 0.5)
                    client = self.plc_manager.get_plc(plc_name)
                    
                    # 检查PLC连接状态
                    plc_connected = client.connected
                    
                    # 更新PLC连接状态
                    with self.lock:
                        if plc_connected:
                            self.plc_last_connected[plc_name] = time.time()
                            self.plc_connection_status[plc_name] = "connected"
                        else:
                            if self.plc_last_connected[plc_name] == 0:
                                self.plc_connection_status[plc_name] = "never_connected"
                            else:
                                self.plc_connection_status[plc_name] = "disconnected"
                    
                    # 刷新所有可读区域
                    for area in plc["areas"]:
                        if area["type"] in ["read", "read_write"]:
                            name = area["name"]
                            try:
                                data = client.read_db(area["db_number"], area["offset"], area["size"])
                                
                                # 更新区域状态基于PLC连接状态和读取结果
                                with self.lock:
                                    if plc_connected and data and len(data) == area["size"]:
                                        self.cache[plc_name][name]["data"] = bytearray(data)
                                        self.cache[plc_name][name]["status"] = "connected"
                                        self.last_update[plc_name][name] = time.time()
                                    else:
                                        self.cache[plc_name][name]["status"] = self.plc_connection_status[plc_name]
                                        # 如果之前有数据，保留旧数据但标记状态
                                        if self.last_update[plc_name][name] > 0:
                                            self.logger.info(f"PLC {plc_name} area {name} disconnected but keeping last valid data")
                            except Exception as e:
                                with self.lock:
                                    self.cache[plc_name][name]["status"] = self.plc_connection_status[plc_name]
                                self.logger.warning(f"Error updating status for {plc_name}/{name}: {e}")

                    """计算刷新一个PLC的时间"""
                    # 计算实际执行时间
                    execution_time = time.time() - start_time
                    #计算需要睡眠的时间，确保总等于refresh_time
                    sleep_time = max(0, refresh_interval - execution_time)
                    time.sleep(sleep_time)
                    print(f"plc_name: {plc_name},"
                          f"Cache refresh completed.Execution time: {execution_time:.3f}s,"
                          f"Sleep time: {sleep_time:.3f}s,"
                          f"Total interval: {execution_time + sleep_time:.3f}s")

                    # 记录实际刷新间隔
                    self.logger.debug(f"plc_name: {plc_name},"
                                      f"Cache refresh completed.Execution time: {execution_time:.3f}s,"
                                      f"Sleep time: {sleep_time:.3f}s,"
                                      f"Total interval: {execution_time + sleep_time:.3f}s")
                
                time.sleep(self.refresh_interval)
            except Exception as e:
                self.logger.error(f"Error in refresh_cache: {e}")
                time.sleep(self.refresh_interval)
    
    def start(self):
        """启动缓存刷新线程"""
        if self.running:
            return
            
        self.running = True
        self.thread = threading.Thread(
            target=self.refresh_cache,
            name="CacheRefreshThread",
            daemon=True
        )
        self.thread.start()
        self.logger.info("Cache manager started")
    
    def stop(self):
        """停止缓存刷新线程"""
        if not self.running:
            return
            
        self.running = False
        if self.thread:
            # 等待线程结束，但设置超时防止卡死
            self.thread.join(timeout=2.0)
            if self.thread.is_alive():
                self.logger.warning("Cache refresh thread did not terminate gracefully")
            self.thread = None
        self.logger.info("Cache manager stopped")
    
    def get_plc_connection_status(self, plc_name):
        """获取PLC连接状态"""
        with self.lock:
            return self.plc_connection_status.get(plc_name, "unknown")
    
    def get_last_update_time(self, plc_name, area_name):
        """获取区域数据最后更新时间"""
        with self.lock:
            return self.last_update.get(plc_name, {}).get(area_name, 0)
    
    def get_summary(self):
        """获取缓存摘要信息"""
        summary = {}
        with self.lock:
            for plc_name, areas in self.cache.items():
                summary[plc_name] = {}
                for area_name, area in areas.items():
                    last_update = self.last_update[plc_name][area_name]
                    plc_status = self.plc_connection_status.get(plc_name, "unknown")
                    
                    # 区域状态应与PLC连接状态一致，除非有有效数据
                    area_status = area["status"]
                    if plc_status == "never_connected":
                        area_status = "never_connected"
                    elif plc_status == "disconnected" and self.last_update[plc_name][area_name] == 0:
                        area_status = "disconnected"
                    
                    summary[plc_name][area_name] = {
                        "status": area_status,
                        "plc_connection_status": plc_status,
                        "last_update": time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(last_update)) if last_update > 0 else "Never",
                        "size": area["size"],
                        "type": area["type"]
                    }
        return summary
    
    def get_area_status(self, plc_name, area_name):
        """获取区域状态"""
        with self.lock:
            area = self.cache.get(plc_name, {}).get(area_name)
            if not area:
                return {"status": "not_found", "message": "PLC or area not found"}
            
            plc_status = self.plc_connection_status.get(plc_name, "unknown")
            last_update = self.last_update.get(plc_name, {}).get(area_name, 0)
            
            # 区域状态应与PLC连接状态一致，除非有有效数据
            area_status = area["status"]
            if plc_status == "never_connected":
                area_status = "never_connected"
            elif plc_status == "disconnected" and last_update == 0:
                area_status = "disconnected"
            
            return {
                "status": area_status,
                "plc_connection_status": plc_status,
                "last_update": last_update,
                "last_update_formatted": time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(last_update)) if last_update > 0 else "Never",
                "size": area["size"],
                "type": area["type"]
            }
    
    def read_area(self, plc_name, area_name, offset, length):
        """单个区域读取"""
        with self.lock:
            area = self.cache.get(plc_name, {}).get(area_name)
            if not area:
                return None, "Area not found", "unknown", 0

            if offset + length > area["size"]:
                return None, "Offset out of bounds", "unknown", 0
                
            client = self.plc_manager.get_plc(plc_name)
            plc_status = self.plc_connection_status.get(plc_name, "unknown")
            
            # 如果PLC未连接，直接返回错误
            if plc_status != "connected":
                return None, f"PLC not connected (status: {plc_status})", plc_status, 0
                
            try:
                data = client.read_db(area["db_number"], area["offset"] + offset, length)
                # 验证数据有效性
                if data and len(data) == length:
                    # 更新缓存中的这部分数据
                    for i in range(length):
                        area["data"][offset + i] = data[i]
                    update_time = time.time()
                    self.last_update[plc_name][area_name] = update_time
                    area["status"] = "connected"
                    
                    return data, None, plc_status, update_time
                else:
                    area["status"] = plc_status
                    return None, "Invalid data returned", plc_status, 0
            except Exception as e:
                area["status"] = plc_status
                self.logger.error(f"Read failed for {plc_name}/{area_name}: {e}")
                return None, f"Read failed: {str(e)}", plc_status, 0

    def read_area_bool(self, plc_name, area_name, offset, length):
        """单个区域读取"""
        with self.lock:
            area = self.cache.get(plc_name, {}).get(area_name)
            if not area:
                return None, "Area not found", "unknown", 0

            if offset + length > area["size"]:
                return None, "Offset out of bounds", "unknown", 0

            client = self.plc_manager.get_plc(plc_name)
            plc_status = self.plc_connection_status.get(plc_name, "unknown")

            # 如果PLC未连接，直接返回错误
            if plc_status != "connected":
                return None, f"PLC not connected (status: {plc_status})", plc_status, 0

            try:
                data = client.read_db_bool(area["db_number"], area["offset"] + offset, length)
                # 验证数据有效性
                if all(isinstance(val, bool) for val in data.values()):
                    # 按字典键顺序更新多个值
                    for i, val in data.items():
                        area["data"][offset + i] = val  # 确保offset+i不越界

                    # area["data"][offset] = data.values
                    update_time = time.time()
                    self.last_update[plc_name][area_name] = update_time
                    area["status"] = "connected"

                    return data, None, plc_status, update_time
                else:
                    area["status"] = plc_status
                    return None, "Invalid data returned", plc_status, 0
            except Exception as e:
                area["status"] = plc_status
                self.logger.error(f"Read failed for {plc_name}/{area_name}: {e}")
                return None, f"Read failed: {str(e)}", plc_status, 0
    
    def write_area(self, plc_name, area_name, offset, data):
        """单个区域写入"""
        with self.lock:
            area = self.cache.get(plc_name, {}).get(area_name)
            if not area:
                return False, "Area not found", "unknown", 0
                
            if area["type"] not in ["write", "read_write"]:
                plc_status = self.plc_connection_status.get(plc_name, "unknown")
                return False, "Area is read-only", plc_status, 0
                
            if offset + len(data) > area["size"]:
                plc_status = self.plc_connection_status.get(plc_name, "unknown")
                return False, "Offset out of bounds", plc_status, 0
                
            client = self.plc_manager.get_plc(plc_name)
            plc_status = self.plc_connection_status.get(plc_name, "unknown")
            
            # 如果PLC未连接，直接返回错误
            if plc_status != "connected":
                return False, f"PLC not connected (status: {plc_status})", plc_status, 0
                
            try:
                success = client.write_db(area["db_number"], area["offset"] + offset, data)
                if success:
                    # 更新缓存中的这部分数据
                    for i in range(len(data)):
                        area["data"][offset + i] = data[i]
                    update_time = time.time()
                    self.last_update[plc_name][area_name] = update_time
                    area["status"] = "connected (last write)"
                    
                    return True, None, plc_status, update_time
                else:
                    area["status"] = plc_status
                    return False, "Write failed", plc_status, 0
            except Exception as e:
                area["status"] = plc_status
                self.logger.error(f"Write failed for {plc_name}/{area_name}: {e}")
                return False, f"Write failed: {str(e)}", plc_status, 0

    def batch_write_area(self, plc_name, area_name, offset, data):
        """单个区域写入"""
        with self.lock:
            area = self.cache.get(plc_name, {}).get(area_name)
            if not area:
                return False, "Area not found", "unknown", 0

            if area["type"] not in ["write", "read_write"]:
                plc_status = self.plc_connection_status.get(plc_name, "unknown")
                return False, "Area is read-only", plc_status, 0

            if offset + len(data) > area["size"]:
                plc_status = self.plc_connection_status.get(plc_name, "unknown")
                return False, "Offset out of bounds", plc_status, 0

            client = self.plc_manager.get_plc(plc_name)
            plc_status = self.plc_connection_status.get(plc_name, "unknown")

            # 如果PLC未连接，直接返回错误
            if plc_status != "connected":
                return False, f"PLC not connected (status: {plc_status})", plc_status, 0

            try:
                for i, byte in enumerate(data):
                    byte_data = bytes([byte])
                    current_offset = offset + (i * 2)
                    byte_value = byte_data[0]

                    value = bytearray(2)
                    if isinstance(byte_value, int):
                        set_int(value, 0, byte_value)
                    data = value

                    success = client.batch_write_db(area["db_number"], current_offset, data)
                    if success:
                        # 更新缓存中的这部分数据
                        for j in range(len(data)):
                            area["data"][offset + j] = data[j]
                        update_time = time.time()
                        self.last_update[plc_name][area_name] = update_time
                        area["status"] = "connected (last write)"
                    else:
                        area["status"] = plc_status
                        return False, "Write failed", plc_status, 0
                return True, None, plc_status, update_time
            except Exception as e:
                area["status"] = plc_status
                self.logger.error(f"Write failed for {plc_name}/{area_name}: {e}")
                return False, f"Write failed: {str(e)}", plc_status, 0

    def batch_write_bool_area(self, plc_name, area_name, offset, data):
        """单个区域写入"""
        with self.lock:
            area = self.cache.get(plc_name, {}).get(area_name)
            if not area:
                return False, "Area not found", "unknown", 0

            if area["type"] not in ["write", "read_write"]:
                plc_status = self.plc_connection_status.get(plc_name, "unknown")
                return False, "Area is read-only", plc_status, 0

            if offset + len(data) > area["size"]:
                plc_status = self.plc_connection_status.get(plc_name, "unknown")
                return False, "Offset out of bounds", plc_status, 0

            client = self.plc_manager.get_plc(plc_name)
            plc_status = self.plc_connection_status.get(plc_name, "unknown")

            # 如果PLC未连接，直接返回错误
            if plc_status != "connected":
                return False, f"PLC not connected (status: {plc_status})", plc_status, 0

            try:
                value = bytearray(offset + 1)
                for bit, bit_value in enumerate(data):
                    set_bool(value, offset, bit, bit_value)
                    data = value

                    success = client.batch_write_db_bool(area["db_number"], offset, data)
                    if success:
                        # 更新缓存中的这部分数据
                        for j in range(len(data)):
                            area["data"][offset + j] = data[j]
                        update_time = time.time()
                        self.last_update[plc_name][area_name] = update_time
                        area["status"] = "connected (last write)"
                    else:
                        area["status"] = plc_status
                        return False, "Write failed", plc_status, 0
                return True, None, plc_status, update_time
            except Exception as e:
                area["status"] = plc_status
                self.logger.error(f"Write failed for {plc_name}/{area_name}: {e}")
                return False, f"Write failed: {str(e)}", plc_status, 0

    def write_area_bool(self, plc_name, area_name, offset, data):
        """单个区域写入"""
        with self.lock:
            area = self.cache.get(plc_name, {}).get(area_name)
            if not area:
                return False, "Area not found", "unknown", 0

            if area["type"] not in ["write", "read_write"]:
                plc_status = self.plc_connection_status.get(plc_name, "unknown")
                return False, "Area is read-only", plc_status, 0

            if offset + len(data) > area["size"]:
                plc_status = self.plc_connection_status.get(plc_name, "unknown")
                return False, "Offset out of bounds", plc_status, 0

            client = self.plc_manager.get_plc(plc_name)
            plc_status = self.plc_connection_status.get(plc_name, "unknown")

            # 如果PLC未连接，直接返回错误
            if plc_status != "connected":
                return False, f"PLC not connected (status: {plc_status})", plc_status, 0

            try:
                success = client.write_db_bool(area["db_number"], area["offset"] + offset, data)
                if success:
                    # 更新缓存中的这部分数据
                    for i in range(len(data)):
                        area["data"][offset + i] = data[i]
                    update_time = time.time()
                    self.last_update[plc_name][area_name] = update_time
                    area["status"] = "connected (last write)"

                    return True, None, plc_status, update_time
                else:
                    area["status"] = plc_status
                    return False, "Write failed", plc_status, 0
            except Exception as e:
                area["status"] = plc_status
                self.logger.error(f"Write failed for {plc_name}/{area_name}: {e}")
                return False, f"Write failed: {str(e)}", plc_status, 0
    
    def batch_read(self, requests):
        """批量读取"""
        results = []

        for req in requests:
            plc_name = req["plc_name"]
            area_name = req["area_name"]
            offset = req.get("offset", 0)
            length = req.get("length", None)

            # 获取PLC连接状态
            plc_status = self.plc_connection_status.get(plc_name, "unknown")

            # 如果PLC未连接，直接返回错误
            if plc_status != "connected":
                results.append({
                    "plc_name": plc_name,
                    "area_name": area_name,
                    "status": "error",
                    "plc_connection_status": plc_status,
                    "last_update": 0,
                    "last_update_formatted": "N/A",
                    "message": f"PLC not connected (status: {plc_status})"
                })
                continue

            area = self.cache.get(plc_name, {}).get(area_name)
            if not area:
                results.append({
                    "plc_name": plc_name,
                    "area_name": area_name,
                    "status": "error",
                    "plc_connection_status": plc_status,
                    "last_update": 0,
                    "last_update_formatted": "N/A",
                    "message": "Area not found"
                })
                continue

            # 如果未指定length，读取整个区域
            if length is None:
                length = area["size"] - offset

            data, error, _, update_time = self.read_area(plc_name, area_name, offset, length)
            if error:
                results.append({
                    "plc_name": plc_name,
                    "area_name": area_name,
                    "status": "error",
                    "plc_connection_status": plc_status,
                    "last_update": update_time,
                    "last_update_formatted": time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(update_time)) if update_time > 0 else "Never",
                    "message": error
                })
            else:
                results.append({
                    "plc_name": plc_name,
                    "area_name": area_name,
                    "status": "success",
                    "plc_connection_status": plc_status,
                    "last_update": update_time,
                    "last_update_formatted": time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(update_time)),
                    "offset": offset,
                    "length": length,
                    "data": list(data)
                })
        return results

    def batch_write(self, requests):
        """批量写入"""
        results = []
        for req in requests:
            plc_name = req["plc_name"]
            area_name = req["area_name"]
            offset = req["offset"]
            data = bytes(req["data"])

            # 获取PLC连接状态
            plc_status = self.plc_connection_status.get(plc_name, "unknown")

            # 如果PLC未连接，直接返回错误
            if plc_status != "connected":
                results.append({
                    "plc_name": plc_name,
                    "area_name": area_name,
                    "status": "error",
                    "plc_connection_status": plc_status,
                    "last_update": 0,
                    "last_update_formatted": "N/A",
                    "message": f"PLC not connected (status: {plc_status})",
                    "offset": offset
                })
                continue
            success, error, _, update_time = self.batch_write_area(plc_name, area_name, offset, data)
            if error:
                results.append({
                    "plc_name": plc_name,
                    "area_name": area_name,
                    "status": "error",
                    "plc_connection_status": plc_status,
                    "last_update": update_time,
                    "last_update_formatted": time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(update_time)) if update_time > 0 else "Never",
                    "message": error,
                    "offset": offset
                })
            else:
                results.append({
                    "plc_name": plc_name,
                    "area_name": area_name,
                    "status": "success",
                    "plc_connection_status": plc_status,
                    "last_update": update_time,
                    "last_update_formatted": time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(update_time)),
                    "offset": offset,
                    "length": len(data)
                })
        return results

    def batch_write_bool(self, requests):
        """批量写入"""
        results = []
        for req in requests:
            plc_name = req["plc_name"]
            area_name = req["area_name"]
            offset = req["offset"]
            data = bytes(req["data"])

            # 获取PLC连接状态
            plc_status = self.plc_connection_status.get(plc_name, "unknown")

            # 如果PLC未连接，直接返回错误
            if plc_status != "connected":
                results.append({
                    "plc_name": plc_name,
                    "area_name": area_name,
                    "status": "error",
                    "plc_connection_status": plc_status,
                    "last_update": 0,
                    "last_update_formatted": "N/A",
                    "message": f"PLC not connected (status: {plc_status})",
                    "offset": offset
                })
                continue

            success, error, _, update_time = self.batch_write_bool_area(plc_name, area_name, offset, data)
            if error:
                results.append({
                    "plc_name": plc_name,
                    "area_name": area_name,
                    "status": "error",
                    "plc_connection_status": plc_status,
                    "last_update": update_time,
                    "last_update_formatted": time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(update_time)) if update_time > 0 else "Never",
                    "message": error,
                    "offset": offset
                })
            else:
                results.append({
                    "plc_name": plc_name,
                    "area_name": area_name,
                    "status": "success",
                    "plc_connection_status": plc_status,
                    "last_update": update_time,
                    "last_update_formatted": time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(update_time)),
                    "offset": offset,
                    "length": len(data)
                })
        return results
    
    def get_parsed_data(self, plc_name, area_name):
        """获取解析后的数据"""
        from data_parser import parse_data
        
        with self.lock:
            area = self.cache.get(plc_name, {}).get(area_name)
            if not area:
                return {"error": "Area not found"}
                
            plc_status = self.plc_connection_status.get(plc_name, "unknown")
            last_update = self.last_update.get(plc_name, {}).get(area_name, 0)
            
            # 区域状态应与PLC连接状态一致，除非有有效数据
            area_status = area["status"]
            if plc_status == "never_connected":
                area_status = "never_connected"
            elif plc_status == "disconnected" and last_update == 0:
                area_status = "disconnected"
            
            structure = area.get("structure", [])
            if structure:
                parsed = parse_data(area["data"], structure)
                parsed["status"] = area_status
                parsed["plc_connection_status"] = plc_status
                parsed["last_update"] = last_update
                parsed["last_update_formatted"] = time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(last_update)) if last_update > 0 else "Never"
                return parsed
            else:
                return {
                    "raw_data": list(area["data"]),
                    "status": area_status,
                    "plc_connection_status": plc_status,
                    "last_update": last_update,
                    "last_update_formatted": time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(last_update)) if last_update > 0 else "Never"
                }