# Stolen from https://github.com/ksheumaker/homeassistant-apsystems_ecur
# cheers to ksheumaker and HAEdwin

import socket
import binascii
import logging

class APSystemsInvalidData(Exception):
    pass

class APSystemsECUR:
    def __init__(self, ipaddr, port=8899, raw_ecu=None, raw_inverter=None):
        self.ipaddr = ipaddr
        self.port = port

        # what do we expect socket data to end in
        self.recv_suffix = b'END\n'

        # how long to wait on socket commands until we get our recv_suffix
        self.timeout = 5

        # how many times do we try the same command in a single update before failing
        self.cmd_attempts = 3

        # how big of a buffer to read at a time from the socket
        self.recv_size = 4096*16

        self.qs1_ids = [ '802', '801' ]
        self.yc600_ids = [ '406', '407', '408', '409' ]
        self.yc1000_ids = [ '501', '502', '503', '504' ]

        self.cmd_suffix = 'END\n'
        self.ecu_query = 'APS1100160001' + self.cmd_suffix
        self.inverter_query_prefix = 'APS1100280002'
        self.inverter_query_suffix = self.cmd_suffix

        self.inverter_signal_prefix = 'APS1100280030'
        self.inverter_signal_suffix = self.cmd_suffix

        self.inverter_byte_start = 26

        self.ecu_id = None
        self.qty_of_inverters = 0
        self.lifetime_energy = 0
        self.current_power = 0
        self.today_energy = 0
        self.inverters = []
        self.firmware = None
        self.timezone = None
        self.last_update = None

        self.ecu_raw_data = raw_ecu
        self.inverter_raw_data = raw_inverter
        self.inverter_raw_signal = None

        self.read_buffer = b''

        self.reader = None
        self.writer = None

    def query_ecu(self):
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.connect((self.ipaddr,self.port))

        logging.debug('ecu query: %s', self.ecu_query)
        sock.sendall(self.ecu_query.encode('utf-8'))
        self.ecu_raw_data = sock.recv(self.recv_size)

        logging.debug('raw ecu data: %s', self.ecu_raw_data)
        logging.debug('ecu id: %s', self.ecu_raw_data[13:25])
        power = self.ecu_raw_data[31:35]
        logging.debug('current power: %s', int.from_bytes(power, byteorder='big'))

        self.process_ecu_data()

        sock.shutdown(socket.SHUT_RDWR)
        sock.close()
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.connect((self.ipaddr,self.port))

        cmd = self.inverter_query_prefix + self.ecu_id + self.inverter_query_suffix
        logging.debug('inverter data cmd: %s', cmd)
        sock.sendall(cmd.encode('utf-8'))
        self.inverter_raw_data = sock.recv(self.recv_size)

        logging.debug('raw inverter data: %s', self.inverter_raw_data)

        sock.shutdown(socket.SHUT_RDWR)
        sock.close()
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.connect((self.ipaddr,self.port))

        cmd = self.inverter_signal_prefix + self.ecu_id + self.inverter_signal_suffix
        logging.debug('inverter signal cmd: %s', cmd)
        sock.sendall(cmd.encode('utf-8'))
        self.inverter_raw_signal = sock.recv(self.recv_size)

        logging.debug('raw signal data: %s', self.inverter_raw_signal)

        sock.shutdown(socket.SHUT_RDWR)
        sock.close()

        data = self.process_inverter_data()

        data['ecu_id'] = self.ecu_id
        data['today_energy'] = self.today_energy
        data['lifetime_energy'] = self.lifetime_energy
        data['current_power'] = self.current_power

        return(data)
 
    def aps_int(self, codec, start):
        try:
            return int(binascii.b2a_hex(codec[(start):(start+2)]), 16)
        except ValueError as err:
            debugdata = binascii.b2a_hex(codec)
            raise APSystemsInvalidData(f'Unable to convert binary to int location={start} data={debugdata}')
 
    def aps_short(self, codec, start):
        try:
            return int(binascii.b2a_hex(codec[(start):(start+1)]), 8)
        except ValueError as err:
            debugdata = binascii.b2a_hex(codec)
            raise APSystemsInvalidData(f'Unable to convert binary to short int location={start} data={debugdata}')

    def aps_double(self, codec, start):
        try:
            return int (binascii.b2a_hex(codec[(start):(start+4)]), 16)
        except ValueError as err:
            debugdata = binascii.b2a_hex(codec)
            raise APSystemsInvalidData(f'Unable to convert binary to double location={start} data={debugdata}')
    
    def aps_bool(self, codec, start):
        return bool(binascii.b2a_hex(codec[(start):(start+2)]))
    
    def aps_uid(self, codec, start):
        return str(binascii.b2a_hex(codec[(start):(start+12)]))[2:14]
    
    def aps_str(self, codec, start, amount):
        return str(codec[start:(start+amount)])[2:(amount+2)]
    
    def aps_timestamp(self, codec, start, amount):
        timestr=str(binascii.b2a_hex(codec[start:(start+amount)]))[2:(amount+2)]
        return timestr[0:4]+'-'+timestr[4:6]+'-'+timestr[6:8]+' '+timestr[8:10]+':'+timestr[10:12]+':'+timestr[12:14]

    def check_ecu_checksum(self, data, cmd):
        datalen = len(data) - 1
        logging.debug('datalen: %s', datalen)
        try:
            checksum = int(data[5:9])
            logging.debug('checksum: %s', checksum)
        except ValueError as err:
            debugdata = binascii.b2a_hex(data)
            raise APSystemsInvalidData(f'Error getting checksum int from {cmd} data={debugdata}')

        if datalen != checksum:
            debugdata = binascii.b2a_hex(data)
            raise APSystemsInvalidData(f'Checksum on {cmd} failed checksum={checksum} datalen={datalen} data={debugdata}')

        start_str = self.aps_str(data, 0, 3)
        end_str = self.aps_str(data, len(data) - 4, 3)

        if start_str != 'APS':
            debugdata = binascii.b2a_hex(data)
            raise APSystemsInvalidData(f'Result on {cmd} incorrect start signature {start_str} != APS data={debugdata}')

        if end_str != 'END':
            debugdata = binascii.b2a_hex(data)
            raise APSystemsInvalidData(f'Result on {cmd} incorrect end signature {end_str} != END data={debugdata}')

        return True

    def process_ecu_data(self, data=None):
        logging.debug('Processing ECU data...')
        if not data:
            data = self.ecu_raw_data

        self.check_ecu_checksum(data, 'ECU Query')

        self.ecu_id = self.aps_str(data, 13, 12)
        self.qty_of_inverters = self.aps_int(data, 46)
        self.firmware = self.aps_str(data, 55, 15)
        self.timezone = self.aps_str(data, 70, 9)
        self.lifetime_energy = self.aps_double(data, 27) / 10
        self.today_energy = self.aps_double(data, 35) / 100
        self.current_power = self.aps_double(data, 31)


    def process_signal_data(self, data=None):
        logging.debug('Processing signal data...')
        signal_data = {}

        if not data:
            data = self.inverter_raw_signal

        self.check_ecu_checksum(data, 'Signal Query')

        if not self.qty_of_inverters:
            return signal_data

        location = 15
        for i in range(0, self.qty_of_inverters):
            uid = self.aps_uid(data, location)
            location += 6

            strength = data[location]
            location += 1

            strength = int((strength / 255) * 100)
            signal_data[uid] = strength

        return signal_data

    def process_inverter_data(self, data=None):
        logging.debug('Processing inverter data...')
        if not data:
            data = self.inverter_raw_data

        self.check_ecu_checksum(data, 'Inverter data')

        output = {}

        timestamp = self.aps_timestamp(data, 19, 14)
        inverter_qty = self.aps_int(data, 17)

        self.last_update = timestamp
        output['timestamp'] = timestamp
        output['inverter_qty'] = inverter_qty
        output['inverters'] = {}

        # this is the start of the loop of inverters
        location = self.inverter_byte_start

        signal = self.process_signal_data()

        inverters = {}
        for i in range(0, inverter_qty):

            inv={}

            inverter_uid = self.aps_uid(data, location)
            inv['uid'] = inverter_uid
            location += 6

            inv['online'] = self.aps_bool(data, location)
            location += 1

            inv['unknown'] = self.aps_str(data, location, 2)
            location += 2

            inv['frequency'] = self.aps_int(data, location) / 10
            location += 2

            inv['temperature'] = self.aps_int(data, location) - 100
            location += 2

            inv['signal'] = signal.get(inverter_uid, 0)

            # the first 3 digits determine the type of inverter
            inverter_type = inverter_uid[0:3]
            if inverter_type in self.yc600_ids:
                (channel_data, location) = self.process_yc600(data, location)
                inv.update(channel_data)    

            elif inverter_type in self.qs1_ids:
                (channel_data, location) = self.process_qs1(data, location)
                inv.update(channel_data)
            
            elif inverter_type in self.yc1000_ids:
                (channel_data, location) = self.process_yc1000(data, location)
                inv.update(channel_data)

            else:
                raise APSystemsInvalidData(f'Unsupported inverter type {inverter_type}')

            inverters[inverter_uid] = inv

        output['inverters'] = inverters
        return (output)
    
    def process_yc1000(self, data, location):

        power = []
        voltages = []

        power.append(self.aps_int(data, location))
        location += 2

        voltage = self.aps_int(data, location)
        location += 2

        power.append(self.aps_int(data, location))
        location += 2
        
        voltage = self.aps_int(data, location)
        location += 2

        power.append(self.aps_int(data, location))
        location += 2
        
        voltage = self.aps_int(data, location)
        location += 2

        power.append(self.aps_int(data, location))
        location += 2

        voltages.append(voltage)

        output = {
            'model' : 'YC1000',
            'channel_qty' : 4,
            'power' : power,
            'voltage' : voltages
        }

        return (output, location)

    
    def process_qs1(self, data, location):

        power = []
        voltages = []

        power.append(self.aps_int(data, location))
        location += 2

        voltage = self.aps_int(data, location)
        location += 2

        power.append(self.aps_int(data, location))
        location += 2

        power.append(self.aps_int(data, location))
        location += 2

        power.append(self.aps_int(data, location))
        location += 2

        voltages.append(voltage)

        output = {
            'model' : 'QS1',
            'channel_qty' : 4,
            'power' : power,
            'voltage' : voltages
        }

        return (output, location)


    def process_yc600(self, data, location):
        power = []
        voltages = []

        for i in range(0, 2):
            power.append(self.aps_int(data, location))
            location += 2

            voltages.append(self.aps_int(data, location))
            location += 2

        output = {
            'model' : 'YC600',
            'channel_qty' : 2,
            'power' : power,
            'voltage' : voltages,
        }

        return (output, location)