import os
import re

from scripts.base.base import Base, SWUpdateTargets
from scripts.update_package_script.utilities import Utilities, SWUpdateCommands, CanCommStatus


class SoftwareUpdateScript(Base):

    _DECODED_BYTES_KEY_NAME = 'decoded_bytes'
    _CUR_DATA_INDEX_KEY_NAME = 'cur_data_index'
    _CUR_INSERT_DATA_INDEX_KEY_NAME = 'cur_insert_index'
    _TOTAL_BYTES_TX_KEY_NAME = 'total_bytes_tx'
    _RESIDUAL_BYTES_KEY_NAME = 'residual_bytes'
    _BINARY_SEND_COMPLETE_KEY_NAME = 'is_binary_done'
    _SIG_MSG_SEND_COMPLETE_KEY_NAME = 'is_sig_msg_done'

    _XML_REPORT_FILE_TYPE_KEY_NAME = 'filetype'
    _XML_REPORT_BIN_SIZE_KEY_NAME = 'size'

    _DECODE_LIST_MAX_SIZE_BYTES = 4096
    _SHIFT_BITS_BY_8 = 8
    _DECODE_COPRIME_1 = 19
    _DECODE_COPRIME_2 = 23
    _DECODE_VALUE = 256
    _DECODE_ADD_VALUE = 211
    _XML_REPORT_END_TAG = "</root>"
    _XML_REPORT_HEADER_SIZE = 2

    def __init__(self):

        super().__init__()
        self._signature_start_in_bytes = bytes(self.SIGNATURE_START, 'utf-8')
        self._signature_end_in_bytes = bytes(self.SIGNATURE_END, 'utf-8')
        self._decode_data_status = dict()
        self._xml_report_values = dict()
        self._utilities = Utilities()

    def _reset_variables(self):

        # TODO #define for the dictionary keys
        self._decode_data_status['decode_values_found'] = False
        self._decode_data_status['end_tag_found'] = False
        self._decode_data_status['decode_found_index'] = 0
        self._decode_data_status['converted_xml'] = ''
        self._decode_data_status['is_first_line'] = False
        self._decode_data_status['num_of_bytes_sent'] = 0 #TODO remove?
        self._decode_data_status[self._RESIDUAL_BYTES_KEY_NAME] = list()
        self._decode_data_status[self._DECODED_BYTES_KEY_NAME] = list()
        self._decode_data_status[self._CUR_DATA_INDEX_KEY_NAME] = 0
        self._decode_data_status[self._CUR_INSERT_DATA_INDEX_KEY_NAME] = 0
        self._decode_data_status[self._TOTAL_BYTES_TX_KEY_NAME] = 0
        self._decode_data_status[self._BINARY_SEND_COMPLETE_KEY_NAME] = False
        self._decode_data_status[self._SIG_MSG_SEND_COMPLETE_KEY_NAME] = False

        self._xml_report_values['name'] = ''
        self._xml_report_values['version'] = ''
        self._xml_report_values[self._XML_REPORT_FILE_TYPE_KEY_NAME] = ''
        self._xml_report_values['security'] = ''
        self._xml_report_values['version'] = ''
        self._xml_report_values[self._XML_REPORT_BIN_SIZE_KEY_NAME] = 0
        self._xml_report_values['raw'] = ''

        self._utilities.clear_msg_ack_nack_status(self._utilities.SEND_MSG_ACK_STATUS_KEY_NAME)
        self._utilities.clear_msg_ack_nack_status(self._utilities.UPDATE_MSG_ACK_STATUS_KEY_NAME)

    def _verify_signature(self, signature: bytes):
        # TODO fill up
        pass

    def _verify_key(self):
        pass

    def _get_decode_variables(self, line_bytes: bytes):

        if len(self._decode_data_status[self._RESIDUAL_BYTES_KEY_NAME]) != 0:
            line_bytes = self._decode_data_status[self._RESIDUAL_BYTES_KEY_NAME] + line_bytes

        if len(line_bytes) > 2:
            a = int(line_bytes[0])
            b = int(line_bytes[1])
            if a is not None and b is not None:
                code = (a << self._SHIFT_BITS_BY_8) + b
                for s in range(0, 0xFF):
                    convert = ((s % self._DECODE_COPRIME_1) << self._SHIFT_BITS_BY_8) + (s % self._DECODE_COPRIME_2)

                    if code == convert:
                        self._decode_data_status['decode_found_index'] = s
                        self._decode_data_status['decode_values_found'] = True
                        print("Breaking {} {} {} {} {}".format(code, convert, s, a, b))
                        break

    def _decode_line(self, line_bytes: bytes):

        start_index = 0

        if len(self._decode_data_status[self._RESIDUAL_BYTES_KEY_NAME]) != 0:
            line_bytes = self._decode_data_status[self._RESIDUAL_BYTES_KEY_NAME] + line_bytes
            self._decode_data_status[self._RESIDUAL_BYTES_KEY_NAME] = list()

        if self._decode_data_status['is_first_line'] is False:
            start_index = self._XML_REPORT_HEADER_SIZE
            self._decode_data_status['is_first_line'] = True

        for d in range(start_index, len(line_bytes)):
            if self._decode_data_status['end_tag_found'] is False:
                decoded_value_bytes = (line_bytes[d] - self._decode_data_status[
                    'decode_found_index']) % self._DECODE_VALUE
                self._decode_data_status['decode_found_index'] += self._DECODE_ADD_VALUE
                self._decode_data_status['converted_xml'] += ''.join(chr(decoded_value_bytes)).replace('\n', '')

                if self._XML_REPORT_END_TAG in self._decode_data_status['converted_xml']:

                    converted_xml = self._decode_data_status['converted_xml']
                    self._decode_data_status['end_tag_found'] = True
                    self._xml_report_values[self._XML_REPORT_FILE_TYPE_KEY_NAME] = \
                        re.search('<filetype>(.*)</filetype>', converted_xml).group(1)
                    binary_size_int = re.search('<size>(.*)</size>', converted_xml).group(1)
                    self._xml_report_values[self._XML_REPORT_BIN_SIZE_KEY_NAME] = int(binary_size_int)

                    print(self._xml_report_values['filetype'], self._xml_report_values['size'],
                          len(converted_xml), converted_xml, self._decode_data_status['decode_found_index'], 'H') # TODO remove
            else:
                self._decode_data_status[self._DECODED_BYTES_KEY_NAME].append(line_bytes[d])
                self._decode_data_status[self._CUR_DATA_INDEX_KEY_NAME] += 1

    def _process_read_line(self, line: bytes):

        if self._signature_start_in_bytes in line:
            if self._signature_end_in_bytes:
                signature = line[len(self._signature_start_in_bytes):line.find(self._signature_end_in_bytes)]
                self._verify_signature(signature)
                end_of_signature_mark = line.find(self._signature_end_in_bytes) + len(self._signature_end_in_bytes)
                xml_report_start = line[end_of_signature_mark:]
                if (len(line) - end_of_signature_mark) > 2 and self._decode_data_status['decode_values_found'] is False:
                    self._get_decode_variables(xml_report_start)
                else:
                    print(xml_report_start, 'D')
                    self._decode_data_status[self._RESIDUAL_BYTES_KEY_NAME] = xml_report_start

                if self._decode_data_status['decode_values_found'] is True:
                    self._decode_line(xml_report_start)
            else:
                # TODO fill up
                pass
        else:
            self._get_decode_variables(line) if self._decode_data_status['decode_values_found'] is False else None
            self._decode_line(line)

    def _handle_processed_data(self):

        send_ack_status = self._utilities.get_msg_ack_nack_status(self._utilities.SEND_MSG_ACK_STATUS_KEY_NAME)
        update_ack_status = self._utilities.get_msg_ack_nack_status(self._utilities.UPDATE_MSG_ACK_STATUS_KEY_NAME)
        #print(send_ack_status, update_ack_status)

        # TODO change the target right now they do not match because they are written for Leahi
        # TODO for instance, it should be self._xml_report_values[self._XML_REPORT_FILE_TYPE_KEY_NAME] as the second parameter
        target = 'TARGET_TD_FPGA'  #'TARGET_TD'  # self._xml_report_values[self._XML_REPORT_FILE_TYPE_KEY_NAME]
        target = SWUpdateTargets[target].value
        #print(self._decode_data_status[self._DECODED_BYTES_KEY_NAME])
        if send_ack_status == CanCommStatus.CAN_COMM_NOT_STARTED.value:
            if self._xml_report_values[self._XML_REPORT_FILE_TYPE_KEY_NAME] != '':
                self._utilities.send_command_msg(SWUpdateCommands.SW_UPDATE_START.value, target)
                # TODO change the target right now they do not match because they are written for Leahi
        # CanCommStatus.CAN_COMM_SUCCESSFUL.value: # TODO this should be changed to successful but the ack is not received now yet
        elif send_ack_status == 2 and self._decode_data_status[self._BINARY_SEND_COMPLETE_KEY_NAME] is False:
            if update_ack_status == CanCommStatus.CAN_COMM_NOT_STARTED.value or \
                update_ack_status == 2: #CanCommStatus.CAN_COMM_SUCCESSFUL.value):
                    current_write_index = self._decode_data_status[self._TOTAL_BYTES_TX_KEY_NAME]
                    current_insert_index = self._decode_data_status[self._CUR_DATA_INDEX_KEY_NAME]
                    binary_size = self._xml_report_values[self._XML_REPORT_BIN_SIZE_KEY_NAME]
                    var = ''
                    data_2_write = ''
                    if current_write_index == binary_size:
                        self._decode_data_status[self._BINARY_SEND_COMPLETE_KEY_NAME] = True

                    if current_insert_index - current_write_index >= self.SW_UPDATE_FLASH_BUFFER_SIZE:
                        data_2_write = self._decode_data_status[self._DECODED_BYTES_KEY_NAME] \
                            [current_write_index: current_write_index + self.SW_UPDATE_FLASH_BUFFER_SIZE]
                        self._decode_data_status[self._TOTAL_BYTES_TX_KEY_NAME] += self.SW_UPDATE_FLASH_BUFFER_SIZE
                        self._utilities.send_software_update_msg(target, data_2_write, self.SW_UPDATE_FLASH_BUFFER_SIZE)
                        var = 'A'
                    elif current_insert_index == binary_size and \
                        self._decode_data_status[self._BINARY_SEND_COMPLETE_KEY_NAME] is False:
                        remaining_bytes = current_insert_index - current_write_index
                        data_2_write = self._decode_data_status[self._DECODED_BYTES_KEY_NAME] \
                            [current_write_index: current_insert_index]
                        data_2_write += [0] * (self.SW_UPDATE_FLASH_BUFFER_SIZE - remaining_bytes)
                        self._decode_data_status[self._TOTAL_BYTES_TX_KEY_NAME] += remaining_bytes
                        self._utilities.send_software_update_msg(target, data_2_write, remaining_bytes)
                        var = 'B'
                    print(current_write_index, self._decode_data_status[self._CUR_DATA_INDEX_KEY_NAME],
                          current_insert_index - current_write_index, var, len(data_2_write))

        elif update_ack_status == 2 and self._decode_data_status[self._BINARY_SEND_COMPLETE_KEY_NAME] is True: #CanCommStatus.CAN_COMM_SUCCESSFUL.value: # TODO this should be changed to successful but the ack is not received now yet
            # TODO do we need the electronic signature from xml?
            data_2_write = [0] * self.SW_UPDATE_FLASH_BUFFER_SIZE
            self._utilities.send_software_update_msg(target, data_2_write, self.SW_UPDATE_FLASH_BUFFER_SIZE, signature_msg=True)

            if self._utilities.get_msg_ack_nack_status(self._utilities.UPDATE_MSG_ACK_STATUS_KEY_NAME) == 2:  #TODO change to successful
                self._decode_data_status[self._SIG_MSG_SEND_COMPLETE_KEY_NAME] = True

    def _process_remaining_data(self):

        while True:
            self._handle_processed_data()

            if self._decode_data_status[self._SIG_MSG_SEND_COMPLETE_KEY_NAME] is True:
                break

        # TODO change the target right now they do not match because they are written for Leahi
        # TODO for instance, it should be self._xml_report_values[self._XML_REPORT_FILE_TYPE_KEY_NAME] as the second parameter
        target = 'TARGET_TD_FPGA'  #'TARGET_TD'  # self._xml_report_values[self._XML_REPORT_FILE_TYPE_KEY_NAME]
        target = SWUpdateTargets[target].value
        self._utilities.send_command_msg(SWUpdateCommands.SW_UPDATE_VERIFY.value, target)
        # TODO change the target right now they do not match because they are written for Leahi


    def update_software_packages(self, packages_dir: str, stack_to_update: str = None):
        # 1. Verify signature
        # 2. Verify key
        # 3. Read XML file for to find the packages to update
        # 4. Decrypt the content
        # 5. Send the data to bootloader
        # 6. Wait for the bootloader to ack/nack or timeout after 3000 ms
        # 7. Send the entire file
        # 8. Show progress

        for file in os.listdir(packages_dir):
            if file.endswith(".bin"):
                with open(os.path.join(packages_dir, file), 'rb') as f:
                    # Get ready for the next binary file
                    self._reset_variables()
                    for line in f:
                        self._process_read_line(line)
                        self._handle_processed_data()

                    self._process_remaining_data()

                f.close()

        # TODO for testing remove
        print(self._decode_data_status[self._CUR_DATA_INDEX_KEY_NAME],
              self._decode_data_status[self._DECODED_BYTES_KEY_NAME][0],
              self._decode_data_status[self._DECODED_BYTES_KEY_NAME][-4],
              self._decode_data_status[self._DECODED_BYTES_KEY_NAME][-3],
              self._decode_data_status[self._DECODED_BYTES_KEY_NAME][-2],
              self._decode_data_status[self._DECODED_BYTES_KEY_NAME][-1],
              len(self._decode_data_status[self._DECODED_BYTES_KEY_NAME]))
        # TODO remove