# -*- coding: utf-8 -*-
import time
import socket
import serial
import serial.tools.list_ports
import traceback
import sys

try:
    from .guitastrotools import GuitastroException
except:
    from guitastrotools import GuitastroException

# #####################################################################
# #####################################################################
# #####################################################################
# Class communication
# #####################################################################
# #####################################################################
# #####################################################################

class CommunicationException(GuitastroException):

    ERR_FILE_NOT_EXISTS = 0
    ERR_CHAN_OPEN = 1
    ERR_CHAN_UNKNOWN = 2
    ERR_CHAN_PORT_NOT_FOUND = 3
    ERR_CHAN_CLOSE = 4
    ERR_CHAN_NOT_OPENED = 5
    ERR_CHAN_PORT_NOT_DEFINED = 6
    ERR_CHAN_EVER_OPENED = 7
    ERR_CHAN_HOSTNAME_NOT_DEFINED = 8
    ERR_CHAN_TCP_RECV_TIMEOUT = 9
    ERR_CHAN_PUTREAD_LOCKED = 10

    errors = [""]*11
    errors[ERR_FILE_NOT_EXISTS] = "The named file was not found"
    errors[ERR_CHAN_OPEN] = ""
    errors[ERR_CHAN_UNKNOWN] = ""
    errors[ERR_CHAN_PORT_NOT_FOUND] = ""
    errors[ERR_CHAN_CLOSE] = ""
    errors[ERR_CHAN_PORT_NOT_DEFINED] = ""
    errors[ERR_CHAN_EVER_OPENED] = "Channel already opened"
    errors[ERR_CHAN_HOSTNAME_NOT_DEFINED] = ""
    errors[ERR_CHAN_TCP_RECV_TIMEOUT] = ""
    errors[ERR_CHAN_PUTREAD_LOCKED] = "Channel is locked. See "

class Communication(CommunicationException):
    """Communication channel manager

    This class allows to open and close TCP or SERIAL communications.
    There are methods to put and read messages.

    :Example:

    To get only informations on communication channels SERIAL and TCP:
    ::

        >>> chan = Communication("INFOS")
        >>> available_serial_ports = chan.get_available_serial_ports()
        >>> my_ip_address = chan.get_ip()

    To open a SERIAL port:
    ::

        >>> chan = Communication("SERIAL", port="//./COM1", baud_rate=9600)

    To open a TCP port:
    ::

        >>> chan = Communication("TCP", hostname="192.168.0.4", port="8080")

    To close an opened port:
    ::

        >>> chan.close()

    To send a message through an opened port:
    ::

        >>> chan.put("Hello")

    To read a message through an opened port:
    ::

        >>> result = chan.read()

    Very often protocols need to add suffix characters to the messages.
    The following optional keys can be added to Communication:

        * END_OF_COMMAND_TO_SEND (str): Suffix systematically added at the end of messages sent.
        * END_OF_COMMAND_TO_RECEIVE (str): Suffix systematically suppressed at the end of messages received.
        * DELAY_INIT_CHAN (float): Delay (seconds) executed just after the communication opening because some devices cannot be joined before.
        * DELAY_PUT_READ (float): Delay (seconds) between put and read commands.

    :Example:

    Open a serial port with many parameters, send a message a wait for a response:

    ::

        chan = Communication("SERIAL", port="//./COM1", baud_rate=9600, end_of_command_to_send="\\n", delay_ini_chan=1.8, delay_put_read=0.2)
        result = chan.putread("Hello")

    It is possible to open a simulation of the communication channel .
    To do that the following optional keys can be added to Communication:

        * REAL (bool): Default value is True

    """

    # === Constant for error codes
    NO_ERROR = 0

    # --- main communication
    _fid_chan   = None
    _port_chan  = None
    _delay_put_read = 0.05 ; # seconds between put-get communication
    _delay_init_chan = 1.5 ; # seconds to wait after open communication
    _end_of_message = ""
    _verbose_chan = False
    _lock_putread = False
    _real = True

    # =====================================================================
    # methods
    # =====================================================================

    def _set_last_error_msg(self):
        self._error_msg = sys.exc_info()[1]
        #traceback.print_exc(file=sys.stdout)

    def get_last_error_msg(self):
        return self._error_msg

    def set_channel_params(self, *args, **kwargs):
        #argc = len(args)
        #kwargc = len(kwargs)
        #self.log.print("3.*args={} argc={}".format(args,argc))
        #self.log.print("3.**kwargs={} kwargc={}".format(kwargs,kwargc))
        # --- Dico of optional parameters for all axis_types
        param_optionals = {}
        param_optionals["END_OF_COMMAND_TO_SEND"] = (str, "")
        param_optionals["END_OF_COMMAND_TO_RECEIVE"] = (str, "")
        param_optionals["DELAY_INIT_CHAN"] = (float, 0.0)
        param_optionals["END_OF_MESSAGE"] = (str, "")
        param_optionals["DELAY_PUT_READ"] = (float, 0.05)
        param_optionals["REAL"] = (bool, True)
        # --- Dico of axis_types and their parameters
        channel_types = {}
        channel_types["SERIAL"]= {"MANDATORY" : {"PORT":[str,"//./COM1"]}, "OPTIONAL" : {"BAUD_RATE":[int,9600]} }
        channel_types["TCP"]= {"MANDATORY" : {"PORT":[int,"5000"], "HOSTNAME":[str,"127.0.0.1"]}, "OPTIONAL" : {} }
        channel_types["INFOS"]= {"MANDATORY" : {}, "OPTIONAL" : {} }
        # ---
        argc = len(args)
        # kwargc = len(kwargs)
        # ========= valid *args
        valid = 1
        if (argc==0):
            valid = 0
            msg = "No channel type specified ({})".format(channel_types.keys())
        else:
            # --- Identify the selected type
            selected_channel_type = args[0].upper()
            if selected_channel_type in channel_types:
                parameters = channel_types[selected_channel_type]
            else:
                valid = 0
                msg = "{} not found amongst channel types ({})".format(selected_channel_type,channel_types.keys())
        if valid==0:
            raise CommunicationException(CommunicationException.ERR_CHAN_PORT_NOT_FOUND, msg)
        # ========= valid **kwargs
        valid = 0
        # ====== change keys into upper strings
        dics = dict()
        for k,v in kwargs.items():
            ku = str(k).upper()
            if (type(v) is str):
                v = v.strip()
            dic = { ku : v }
            dics.update(dic)
        selected_parameters = dics
        #self.log.print("dics={}".format(dics))
        # ====== decode **kwargs
        valid = 0
        self._channel_params = {}
        # --- input values of mandatory parameters
        params = parameters["MANDATORY"]
        for param_key in params:
            if param_key in selected_parameters:
                raw_value = selected_parameters[param_key]
                type_conv = params[param_key][0]
                if type_conv==float:
                    value = float(raw_value)
                elif type_conv==int:
                    value = int(raw_value)
                else:
                    value = raw_value
                self._channel_params[param_key] = value
            else:
                msg = "{} not found amongst mandatory parameters ({})".format(param_key,params.keys())
                raise Exception(msg)
        # --- input or default values of optional parameters
        params = param_optionals
        for parameter_key in parameters["OPTIONAL"]:
            params[parameter_key] = parameters["OPTIONAL"][parameter_key]
        for param_key in params:
            if param_key in selected_parameters:
                raw_value = selected_parameters[param_key]
                type_conv = params[param_key][0]
            else:
                raw_value = params[param_key][1]
                type_conv = params[param_key][0]
            if type_conv==float:
                value = float(raw_value)
            elif type_conv==int:
                value = int(raw_value)
            else:
                value = raw_value
            self._channel_params[param_key] = value
        # ===
        self._channel_type = selected_channel_type
        self._end_of_command_to_send    = self._channel_params["END_OF_COMMAND_TO_SEND"]
        if type(self._end_of_command_to_send)==bytes:
            self._end_of_command_to_send = self._end_of_command_to_send.decode()
        self._end_of_command_to_receive = self._channel_params["END_OF_COMMAND_TO_RECEIVE"]
        if type(self._end_of_command_to_receive)==bytes:
            self._end_of_command_to_receive = self._end_of_command_to_receive.decode()
        self._delay_init_chan           = self._channel_params["DELAY_INIT_CHAN"]
        self._delay_put_read            = self._channel_params["DELAY_PUT_READ"]
        if self._channel_type=="SERIAL":
            self._port_chan = self._channel_params["PORT"]
            self._baud_rate = self._channel_params["BAUD_RATE"]
        if self._channel_type=="TCP":
            self._port_chan = self._channel_params["PORT"]
            self._hostname_chan = self._channel_params["HOSTNAME"]
        self._real = self._channel_params["REAL"]
        self._method_before_put = None
        self._method_after_read = None

    def get_ip(self)->str:
        """Tool to return the IP of this computer

        Returns:

            The IP addresse of the local machine.

        :Example:

        To get the IP of the computer:

        ::

            >>> chan = Communication("INFOS")
            >>> my_ip_address = chan.get_ip()

        """
        ip = '127.0.0.1'
        s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        try:
            # doesn't even have to be reachable
            valid = False
            try:
                s.connect(('10.255.255.255', 1))
                valid = True
            except:
                try:
                    s.connect(('255.255.255.255', 1))
                    valid = True
                except:
                    pass
            if valid==True:
                ip = s.getsockname()[0]
        except Exception:
            pass
        finally:
            s.close()
        return ip


    def get_available_serial_ports(self):
        """Return a list of available serial ports of the local computer

        Returns:

            The list of serial port names of the local machine

        :Example:

        To get the IP of the computer:

        ::

            >>> chan = Communication("INFOS")
            >>> available_serial_ports = chan.get_available_serial_ports()

        """
        # --
        prefix_myserial_ports = ""
        if sys.platform.startswith('win'):
            prefix_myserial_ports = "//./"
        elif sys.platform.startswith('linux') or sys.platform.startswith('cygwin'):
            prefix_myserial_ports = ""
        elif sys.platform.startswith('darwin'):
            prefix_myserial_ports = ""
        # --
        serial_ports = serial.tools.list_ports.comports(include_links=False)
        # --
        available_serial_ports = []
        for serial_port in serial_ports:
            available_serial_port = prefix_myserial_ports + serial_port.device
            available_serial_ports.append(available_serial_port)
        return available_serial_ports

    def _set_port_chan(self, port:str):
        self._port_chan = port
        return self._port_chan

    def _get_port_chan(self):
        return self._port_chan

    def _set_hostname_chan(self, hostname:str):
        self._hostname_chan = hostname
        return self._hostname_chan

    def _get_hostname_chan(self):
        return self._hostname_chan

    def _my_open_chan(self):
        # --- abstract method
        # --- Please overload it according your language protocol
        return self.NO_ERROR

    def open_chan(self):
        """Open the channel
        """
        err = self.NO_ERROR
        if self._real == False:
            fid = "simulation"
            self._fid_chan = fid
            return err, fid
        if self._channel_type=="SERIAL":
            fid = self._fid_chan
            port  = self._port_chan
            if self._port_chan == None:
                raise CommunicationException(CommunicationException.ERR_CHAN_PORT_NOT_DEFINED)
            if self._fid_chan != None:
                raise CommunicationException(CommunicationException.ERR_CHAN_EVER_OPENED)
            # --- pass here only if the port was closed
            try:
               fid = serial.Serial(
                  port=port,
                  baudrate = self._baud_rate,
                  parity = serial.PARITY_NONE,
                  stopbits = serial.STOPBITS_ONE,
                  bytesize = serial.EIGHTBITS,
                  timeout = 0
               )
               if fid.isOpen():
                  err = self.NO_ERROR
               else:
                  err = self.ERR_CHAN_OPEN
            except:
                self._set_last_error_msg()
                msg = str(self._error_msg)
                msg += f". List of available ports {self.get_available_serial_ports()}"
                raise CommunicationException(CommunicationException.ERR_CHAN_UNKNOWN, msg)
            # --- some inits
            if err == self.NO_ERROR:
                self._fid_chan = fid
                time.sleep(self._delay_init_chan)
                fid.flush()
                self._lock_putread = False
        elif self._channel_type=="TCP":
            fid = self._fid_chan
            port  = self._port_chan
            if self._port_chan == None:
                raise CommunicationException(CommunicationException.ERR_CHAN_PORT_NOT_DEFINED)
            hostname  = self._hostname_chan
            if self._hostname_chan == None:
                raise CommunicationException(CommunicationException.ERR_CHAN_HOSTNAME_NOT_DEFINED)
            if self._fid_chan != None:
                raise CommunicationException(CommunicationException.ERR_CHAN_EVER_OPENED)
            # --- pass here only if the port was closed
            try:
                fid = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
                fid.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
                # Connect to server and send data
                fid.connect((hostname, port))
                fid.settimeout(1)
            except:
                self._set_last_error_msg()
                msg = self._error_msg
                raise CommunicationException(CommunicationException.ERR_CHAN_UNKNOWN, msg)
            # --- some inits
            if err == self.NO_ERROR:
                self._fid_chan = fid
                self._lock_putread = False
        err = self._my_open_chan()
        return err, fid

    def _my_close_chan(self):
        # --- abstract method
        # --- Please overload it according your language protocol
        return self.NO_ERROR

    def close_chan(self):
        """Close the channel
        """
        err = self.NO_ERROR
        fid = self._fid_chan
        if self._fid_chan == None:
            raise CommunicationException(CommunicationException.ERR_CHAN_NOT_OPENED)
        if self._real == False:
            self._fid_chan = None
        else:
            try:
                err = self._my_close_chan()
                fid.close()
                self._fid_chan = None
            except:
                self._set_last_error_msg()
                msg = self._error_msg
                raise CommunicationException(CommunicationException.ERR_CHAN_CLOSE, msg)
        return (err, fid)

    def check_chan(self):
        """Check if the channel is opened. If not, try to open it.
        """
        err = self.NO_ERROR
        fid = self._fid_chan
        if fid == None:
            err, fid = self.open_chan()
        return (err, fid)

    def put_chan(self, cmd: str):
        """ Send a message into the opened channel

        Args:

            cmd: Message to send. Suffix defined by the option key END_OF_COMMAND_TO_SEND is added inside the method.

        """
        # --- check the opening of the serial port
        err, fid = self.check_chan()
        if self._method_before_put != None:
            cmd = self._method_before_put(cmd)
        if self._real == False:
            pass
        elif self._channel_type=="SERIAL":
            # --- serial port buffer reset for the next read
            fid.reset_input_buffer()
            # --- serial port is ready to put message
            cmd = cmd + self._end_of_command_to_send
            #print(f"cmd={cmd}")
            fid.write(cmd.encode())
            fid.flush()
        elif self._channel_type=="TCP":
            cmd = cmd + self._end_of_command_to_send
            fid.sendall(cmd.encode())
        return (err, cmd)

    def read_chan(self):
        """ Receive a message from the opened channel

        Returns:

            The string of the message read.

        """
        # --- check the opening of the serial port
        err, fid = self.check_chan()
        lignes = "" ; # fid.readlines()
        t0 = time.time()
        dt = 0
        nn = 0
        if self._real == False:
            lignes = ""
        elif self._channel_type=="SERIAL":
            while True:
                n = 0
                for car in fid.read():
                    n += 1
                    car = chr(car)
                    lignes += car
                    nn = 0
                    t0 = time.time()
                    #self.log.print("car={} n={} nn={}".format(car,n,nn))
                if n==0:
                    nn += 1
                    if nn==2:
                        #self.log.print("n={} nn={} Time out".format(n,nn))
                        break
                    time.sleep(0.05)
                dt = time.time()-t0
                if dt>10.0:
                    break
        elif self._channel_type=="TCP":
            try:
                lignes = fid.recv(1024)
            except:
                err = self.ERR_CHAN_TCP_RECV_TIMEOUT
        #print("dt={} lignes={} type={}".format(dt,lignes,type(lignes)))
        # --- format la sortie
        if type(lignes)==bytes:
            # --- TCP case (the try is useful for a pickle data)
            try:
                lignes = lignes.decode("utf-8")
            except:
                pass
        if self._end_of_command_to_receive!="":
            res = lignes.split(self._end_of_command_to_receive)
        else:
            res = lignes
        # print("READ {} = {}".format(self._port_chan,res))
        if self._method_after_read != None:
            res = self._method_after_read(res)
        return (err, res)

    def _set_delay_chan(self, delay_s:float):
        if delay_s<=0:
            raise Exception("delay must be strictly positive")
        self._delay_chan = delay_s
        return self.NO_ERROR

    def _get_delay_chan(self):
        return self._delay_chan

    def _set_delay_init_chan(self, delay_s:float):
        if delay_s<=0:
            raise Exception("delay must be strictly positive")
        self._delay_init_chan = delay_s
        return self.NO_ERROR

    def _get_delay_init_chan(self):
        return self._delay_init_chan

    def _set_verbose_chan(self, verbose:bool):
        if type(verbose) is not bool:
            raise Exception("verbose must be boolean")
        self._verbose_chan = verbose
        return self.NO_ERROR

    def _get_verbose_chan(self):
        return self._verbose_chan

    def _get_method_before_put(self):
        return self._method_before_put

    def _set_method_before_put(self, method:object):
        self._method_before_put = method

    def _del_method_before_put(self):
        self._method_before_put = None

    def _get_method_after_read(self):
        return self._method_after_read

    def _set_method_after_read(self, method:object):
        self._method_after_read = method

    def _del_method_after_read(self):
        self._method_after_read = None

# =====================================================================
# =====================================================================
# Methods for users
# =====================================================================
# =====================================================================

    port_chan        = property(_get_port_chan,        _set_port_chan)
    delay_chan       = property(_get_delay_chan,       _set_delay_chan)
    delay_init_chan  = property(_get_delay_init_chan,  _set_delay_init_chan)
    verbose_chan     = property(_get_verbose_chan,     _set_verbose_chan)
    method_before_put = property(_get_method_before_put, _set_method_before_put, _del_method_before_put)
    method_after_read = property(_get_method_after_read, _set_method_after_read, _del_method_after_read)

    def putread_chan(self, cmd:str, index:int=-1):
        """ Send and Receive a message from the opened channel

        Args:

            cmd: The message to send
            index: >0 to extract only the word returned at the index position

        Returns:

            A string containing the response received.
        """
        return self.putread_chan_check(cmd, index)

    def putread_chan_nocheck(self, cmd:str, index:int=-1):
        """ Send and Receive a message from the opened channel

        No lock version. See comments of the putread_chan_check

        Args:

            cmd: The message to send
            index: >0 to extract only the word returned at the index position

        Returns:

            A string containing the response received.
        """
        if self.verbose_chan==True:
            #self.log.self.log.print("Putread: "+cmd)
            pass
        self._lock_putread = True
        self.put_chan(cmd)
        time.sleep(self._delay_put_read)
        err, res = self.read_chan()
        if err != self.NO_ERROR:
            self._lock_putread = False
            return (err, res)
        if index>=0:
            n = len(res)
            if index>n-1:
                index = n-1
            self._lock_putread = False
            return (err, res[index])
        self._lock_putread = False
        return (err, res)

    #def putread_chan_lock_verify(self, cmd, index=-1):
    def putread_chan_check(self, cmd, index=-1):
        """ Send and Receive a message from the opened channel

        Same as putread_chan but a lock is added to avoid multiple calls to the controller.

        Args:

            cmd: The message to send
            index: >0 to extract only the word returned at the index position

        Returns:

            A string containing the response received.
        """
        if self.verbose_chan==True:
            #print("Putread: "+cmd)
            pass
        err = self.NO_ERROR
        res = ""
        # --- verify the lock state
        if self._lock_putread == True:
            # --- Case the lock state = True, the com is occupied
            t0 = time.time()
            while self._lock_putread == True:
                # --- Loop until the com is freed
                time.sleep(0.05)
                dt = time.time() - t0
                if dt>3.0:
                    print("Serial port locked timeout for {}".format(cmd))
                    break
        # --- verify the lock state
        if self._lock_putread == False:
            # --- Case the lock state = False, the com is free
            # --- lock during com operations
            self._lock_putread = True
            #print("Serial port is locked 0 normaly by {}".format(cmd))
            self.put_chan(cmd)
            time.sleep(self._delay_put_read)
            err, res = self.read_chan()
            if err != self.NO_ERROR:
                self._lock_putread = False
                #print("Serial port is unlocked 1 err={} res={} by {}".format(err,res,cmd))
                return (err, res)
            if index>=0:
                n = len(res)
                if index>n-1:
                    index = n-1
                self._lock_putread = False
                #print("Serial port is unlocked 2 err={} res={} by {}".format(err,res,cmd))
                return (err, res[index])
            self._lock_putread = False
            #print("Serial port is unlocked 3 err={} res={} by {}".format(err,res,cmd))
        else:
            #print("Pb serial port is locked for {}".format(cmd))
            err = self.ERR_CHAN_PUTREAD_LOCKED
        return (err, res)

# =====================================================================
# =====================================================================
# Special methods
# =====================================================================
# =====================================================================

    def __init__(self, *args, **kwargs):
        self._error_msg = ""
        self.set_channel_params(*args, **kwargs)
        self.verbose_chan = False
        self._lock_putread = False

    def __del__(self):
        """
        Clean procedure when a channel is closed
        """
        try:
            fid = self._fid_chan
            #self.log.print(f"CHAN Just before close the serial channel: fid={fid}")
            err, fid = self.close_chan()
            #self.log.print(f"CHAN Just after close the serial channel: err={err} fid={fid}")
        except:
            pass

    def __repr__(self):
        msg = ""
        # ------------------------
        msg += f"=== Communication channel of type {self._channel_type} ==="
        msg += "\n--- Channel parameters:"
        for key, val in self._channel_params.items():
            msg += f"\n * {key} = {val}"
        return msg

# #####################################################################
# #####################################################################
# #####################################################################
# Main
# #####################################################################
# #####################################################################
# #####################################################################

if __name__ == "__main__":

    default = 2
    example = input(f"Select the example (0 to 2) ({default}) ")
    try:
        example = int(example)
    except:
        example = default

    print("Example       = {}".format(example))

    if example == 0:
        chan = Communication("INFOS")
        # --- serial ports
        available_serial_ports = chan.get_available_serial_ports()
        print("Available com ports:")
        k = 0
        for available_serial_port in available_serial_ports:
            print("Available com port [{}]: {}".format(k,available_serial_port))
            k+=1
        # --- IP of this computer
        print(f"IP = {chan.get_ip()}")

    if example == 1:
        host = '192.168.20.30'
        port = 1025
        real = False
        chan = Communication("TCP", HOSTNAME = host, PORT = port, DELAY_PUT_READ = 0.1, REAL = real)

    if example == 2:
        """
        Example Esatto
        """
        import ast
        import shlex
        def esatto_decode_serial(result:str) -> list:
            dico = ast.literal_eval(result[:-2])
            return dico
        param = {}
        param["PORT"] = "//./COM5"
        param["BAUD_RATE"] = 115200
        param["DELAY_INIT_CHAN"] = 0.1
        param["DELAY_PUT_READ"] = 0.5
        param["END_OF_COMMAND_TO_SEND"] = "".encode('utf8')
        param["END_OF_COMMAND_TO_RECEIVE"] = "".encode('utf8')
        param["REAL"] = True
        chan = Communication("SERIAL", **param)
        chan.method_after_read = esatto_decode_serial
        print(chan)
        cmd = shlex.quote('{"req":{"get": ""}}}')
        err, res = chan.putread_chan(cmd)
        del chan