#!/usr/bin/env python

import argparse
import os
import struct


class CrcCCITT:
    msb_table = (
        0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50A5, 0x60C6, 0x70E7,
        0x8108, 0x9129, 0xA14A, 0xB16B, 0xC18C, 0xD1AD, 0xE1CE, 0xF1EF,
        0x1231, 0x0210, 0x3273, 0x2252, 0x52B5, 0x4294, 0x72F7, 0x62D6,
        0x9339, 0x8318, 0xB37B, 0xA35A, 0xD3BD, 0xC39C, 0xF3FF, 0xE3DE,
        0x2462, 0x3443, 0x0420, 0x1401, 0x64E6, 0x74C7, 0x44A4, 0x5485,
        0xA56A, 0xB54B, 0x8528, 0x9509, 0xE5EE, 0xF5CF, 0xC5AC, 0xD58D,
        0x3653, 0x2672, 0x1611, 0x0630, 0x76D7, 0x66F6, 0x5695, 0x46B4,
        0xB75B, 0xA77A, 0x9719, 0x8738, 0xF7DF, 0xE7FE, 0xD79D, 0xC7BC,
        0x48C4, 0x58E5, 0x6886, 0x78A7, 0x0840, 0x1861, 0x2802, 0x3823,
        0xC9CC, 0xD9ED, 0xE98E, 0xF9AF, 0x8948, 0x9969, 0xA90A, 0xB92B,
        0x5AF5, 0x4AD4, 0x7AB7, 0x6A96, 0x1A71, 0x0A50, 0x3A33, 0x2A12,
        0xDBFD, 0xCBDC, 0xFBBF, 0xEB9E, 0x9B79, 0x8B58, 0xBB3B, 0xAB1A,
        0x6CA6, 0x7C87, 0x4CE4, 0x5CC5, 0x2C22, 0x3C03, 0x0C60, 0x1C41,
        0xEDAE, 0xFD8F, 0xCDEC, 0xDDCD, 0xAD2A, 0xBD0B, 0x8D68, 0x9D49,
        0x7E97, 0x6EB6, 0x5ED5, 0x4EF4, 0x3E13, 0x2E32, 0x1E51, 0x0E70,
        0xFF9F, 0xEFBE, 0xDFDD, 0xCFFC, 0xBF1B, 0xAF3A, 0x9F59, 0x8F78,
        0x9188, 0x81A9, 0xB1CA, 0xA1EB, 0xD10C, 0xC12D, 0xF14E, 0xE16F,
        0x1080, 0x00A1, 0x30C2, 0x20E3, 0x5004, 0x4025, 0x7046, 0x6067,
        0x83B9, 0x9398, 0xA3FB, 0xB3DA, 0xC33D, 0xD31C, 0xE37F, 0xF35E,
        0x02B1, 0x1290, 0x22F3, 0x32D2, 0x4235, 0x5214, 0x6277, 0x7256,
        0xB5EA, 0xA5CB, 0x95A8, 0x8589, 0xF56E, 0xE54F, 0xD52C, 0xC50D,
        0x34E2, 0x24C3, 0x14A0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
        0xA7DB, 0xB7FA, 0x8799, 0x97B8, 0xE75F, 0xF77E, 0xC71D, 0xD73C,
        0x26D3, 0x36F2, 0x0691, 0x16B0, 0x6657, 0x7676, 0x4615, 0x5634,
        0xD94C, 0xC96D, 0xF90E, 0xE92F, 0x99C8, 0x89E9, 0xB98A, 0xA9AB,
        0x5844, 0x4865, 0x7806, 0x6827, 0x18C0, 0x08E1, 0x3882, 0x28A3,
        0xCB7D, 0xDB5C, 0xEB3F, 0xFB1E, 0x8BF9, 0x9BD8, 0xABBB, 0xBB9A,
        0x4A75, 0x5A54, 0x6A37, 0x7A16, 0x0AF1, 0x1AD0, 0x2AB3, 0x3A92,
        0xFD2E, 0xED0F, 0xDD6C, 0xCD4D, 0xBDAA, 0xAD8B, 0x9DE8, 0x8DC9,
        0x7C26, 0x6C07, 0x5C64, 0x4C45, 0x3CA2, 0x2C83, 0x1CE0, 0x0CC1,
        0xEF1F, 0xFF3E, 0xCF5D, 0xDF7C, 0xAF9B, 0xBFBA, 0x8FD9, 0x9FF8,
        0x6E17, 0x7E36, 0x4E55, 0x5E74, 0x2E93, 0x3EB2, 0x0ED1, 0x1EF0)

    @classmethod
    def calc_crc(cls, msg):
        crc = 0x00

        for byte in msg:
            crc = cls.msb_table[(crc >> 8 ^ byte) & 0xff] ^ ((crc << 8) & 0xFF00)

        return crc


class FrSkyFirmwareInformation:
    fourcc = "FRSK"
    header_version = 1

    product_family_list = {
        "INTERNAL_MODULE": 0,
        "EXTERNAL_MODULE": 1,
        "RECEIVER": 2,
        "SENSOR": 3,
        "BLUETOOTH_CHIP": 4,
        "POWER_CONTROL_CHIP": 5
    }

    product_id_list = {
        # None
        "None": 0x00,

        # Modules
        "XJT": 0x01,
        "ISRM": 0x02,
        # TODO missing modules

        # Receivers
        "X8R": 0x01,
        "RX8R": 0x02,
        "RX8R-PRO": 0x03,
        "RX6R": 0x04,
        "RX4R": 0x05,
        "G-RX8": 0x06,
        'G-RX6': 0x07,
        "X6R": 0x08,
        "X4R": 0x09,
        "X4R-SB": 0x0A,
        "XSR": 0x0B,
        "XSR-M": 0x0C,
        "RXSR": 0x0D,
        "S6R": 0x0E,
        "S8R": 0x0F,
        "XM": 0x10,
        "XM+": 0x11,
        "XMR": 0x12,
        "R9": 0x13,
        "R9-SLIM": 0x14,
        "R9-SLIM+": 0x15,
        "R9MINI": 0x16,
        "R9MM": 0x17,
        "R9-STAB": 0x18
    }

    def __init__(self, data, args):
        self.data = data
        self.args = args

    @staticmethod
    def parse_version(s):
        try:
            return [int(part) for part in s.split(".")]
        except Exception:
            raise argparse.ArgumentTypeError("%r is not a valid version" % s)

    def write(self, filename):
        with open(filename, "wb") as f:
            f.write(self.fourcc.encode())
            f.write(struct.pack('B', self.header_version))
            for i in range(3):
                f.write(struct.pack('B', self.args.version[i]))
            f.write(struct.pack('I', len(self.data)))
            f.write(struct.pack('B', self.product_family_list[self.args.family]))
            f.write(struct.pack('B', self.product_id_list[self.args.product]))
            f.write(struct.pack('H', CrcCCITT.calc_crc(self.data)))
            f.write(self.data)


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('-f', '--family', help="Product family", choices=FrSkyFirmwareInformation.product_family_list.keys(), required=True)
    parser.add_argument('-p', '--product', help="Product ID", choices=FrSkyFirmwareInformation.product_id_list.keys(), required=True)
    parser.add_argument('-v', '--version', help="Firmware version", type=FrSkyFirmwareInformation.parse_version, required=True)
    parser.add_argument("input", type=argparse.FileType("rb"))

    args = parser.parse_args()

    print("Product family:", args.family)
    print("Product ID:", args.product)
    print("Product version:", ".".join(str(part) for part in args.version))
    s = input("Do you confirm?")
    if s.upper() == 'Y':
        frsk = FrSkyFirmwareInformation(args.input.read(), args)
        output = os.path.splitext(args.input.name)[0] + ".frsk"
        frsk.write(output)
        print("File %s created!" % output)


if __name__ == '__main__':
    main()