""""
ModBus control routines
Copyright (C) 2023-2025 M.T. Konstapel

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <https://www.gnu.org/licenses/>.
"""

import minimalmodbus
import serial

class ModBusController(minimalmodbus.Instrument):
    """Instrument class for Epever Charge Controllers.

    Args:
        * portname (str): port name
        * slaveaddress (int): slave address in the range 1 to 247

    """

    def __init__(self, portname, slaveaddress):
        minimalmodbus.Instrument.__init__(self, portname, slaveaddress)
        self.serial.baudrate = 9600
        self.serial.bytesize = 8
        self.serial.parity = serial.PARITY_NONE
        self.serial.stopbits = 1
        self.serial.timeout = 0.3
        self.mode = minimalmodbus.MODE_RTU
        self.clear_buffers_before_each_transaction = True
        self.close_port_after_each_call  = False

    #Address range 0x3000
    def get_id(self):
        device_id = [None]*4
        device_id[0] = self.read_register(0, 0, 4, False)
        device_id[1] = self.read_register(1, 0, 4, False)
        device_id[2] = self.read_register(2, 0, 4, False)
        device_id[3] = self.read_register(3, 0, 4, False)

        return device_id

    def get_type(self):
        device_type = self.read_register(4, 0, 4, False)

        return device_type

    # Get the 60 character long description string from ModBus device
    def get_type_string(self):
        register_offset = 6                     # ModBus register for text string starts at 6
        device_type_register = [None]*30        # ModBus register for text string is 30 integers long
        device_type_string = ""                 # Store the decoded string here

        for index, entry in enumerate(device_type_register):
            # Read Type string registers
            device_type_register[index] = self.read_register(index + register_offset, 0, 4, False)
            # Convert to ASCII string
            device_type_string += chr((device_type_register[index] & 0xFF00) >> 8)
            device_type_string += chr(device_type_register[index] & 0xFF)

        return device_type_string.strip()

    def get_number_of_input_registers(self):
        device_number_of_input_registers = self.read_register(36, 0, 4, False)

        return device_number_of_input_registers

    def read_all_input_registers(self):

        number_of_input_registers = self.get_number_of_input_registers()
        offset = 40
        input_register = [None]*number_of_input_registers

        for index in range(number_of_input_registers):
            input_register[index] = self.read_register(index + offset, 0, 4, False)

        return input_register

    def enable_heater(self):
        self.write_bit(0, 1, 5)

    def disable_heater(self):
        self.write_bit(0, 0, 5)