'''
Created on Jul 6, 2012

@author: sbolduc
'''
from struct import pack, unpack

HEADING_FACTOR = 360.0 / 1024.0
DEPTH_FACTOR = 10.0 / 16.0

def create_kill():
    return pack(">1B1B1B1B", 42, 42, 42, 42)

def encodeCrc8(heading, depth, light):
    header = 0
    
    message_id = 1
    scaled_heading = int(float(heading) / HEADING_FACTOR)
    scaled_depth = int(float(depth) / DEPTH_FACTOR)
    
    first_byte = (message_id << 7) | ((scaled_heading & 0x03F8) >> 3)
    second_byte = ((scaled_heading & 0x07) << 5) | (scaled_depth << 1) | light
    
    data = first_byte << 8
    data |= second_byte & 0xFF
    
    crc = crc8().crc([chr(first_byte), chr(second_byte)])

    message_bytes = header << 24
    message_bytes |= data << 16
    message_bytes |= crc
    
    message_bytes = pack(">1H1H", data, crc)
    
    return (message_bytes, heading, depth, light, crc, first_byte, second_byte, crc, 0)

def encodeCrc16(heading, depth, light):
    message_id = 1
    scaled_heading = int(float(heading) / HEADING_FACTOR)
    scaled_depth = int(float(depth) / DEPTH_FACTOR)
    
    first_byte = (message_id << 7) | ((scaled_heading & 0x03F8) >> 3)
    second_byte = ((scaled_heading & 0x07) << 5) | (scaled_depth << 1) | light
    
    data = first_byte << 8
    data |= second_byte & 0xFF
    
    crc = crc16().crc([first_byte, second_byte])

    first_crc = crc >> 8
    second_crc = crc & 0xFF
    
    message_bytes = data << 16
    message_bytes |= crc
    
    message_bytes = pack(">1H1H", data, crc)
    
    return (message_bytes, heading, depth, light, crc, first_byte, second_byte, first_crc, second_crc)

def decodeCrc16(message_bytes):
    data = unpack(">1H1H", message_bytes)
    
    first_byte = data[0] >> 8
    second_byte = data[0] & 0xFF
    
    first_crc = data[1] >> 8
    second_crc = data[1] & 0xFF
    
    calculated_crc = crc16().crc([first_byte, second_byte])
    
    message_id = (int(first_byte) & 0xFF) >> 7
    heading = ((int(first_byte) & 0x7F) << 3 | ((int(second_byte) & 0xE0) >> 5)) * HEADING_FACTOR
    depth = (int(second_byte & 0x1E) >> 1) * DEPTH_FACTOR
    light = (int(second_byte) & 0x01) == 1
    
    return (message_id, heading, depth, light, data[1], calculated_crc, first_byte, second_byte, first_crc, second_crc)

def decodeCrc8(message_bytes):
    data = unpack(">1H1H", message_bytes)
    
    header = data[0] >> 8
    
    first_byte = data[0] & 0xFF
    second_byte = data[1] >> 8
    
    crc = data[1] & 0xFF
    
    calculated_crc = crc8().crc([chr(first_byte), chr(second_byte)])
    
    message_id = (int(first_byte) & 0xFF) >> 7
    heading = ((int(first_byte) & 0x7F) << 3 | ((int(second_byte) & 0xE0) >> 5)) * HEADING_FACTOR
    depth = (int(second_byte & 0x1E) >> 1) * DEPTH_FACTOR
    light = (int(second_byte) & 0x01) == 1
    
    return (message_id, heading, depth, light, data[1], calculated_crc, first_byte, second_byte, crc, 0)
    
class crc8:
    
    def __init__(self):
        self.crcTable = (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)

    def crc(self, msg):
        runningCRC = 0
        for c in msg:
            c = ord(c)
            runningCRC = self.crcByte(runningCRC, c)
        return runningCRC
    
    def crcByte(self, oldCrc, byte):
        magic = self.crcTable[(oldCrc >> 8 ^ byte) % 256] % 256
        magic2 = self.crcTable[(oldCrc >> 8 ^ byte) % 256] >> 8
        res = magic | ((oldCrc % 256) ^ magic2) << 8
        return res 

class crc16:
    
    def __init__(self):
        self.crcTable = [0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280, 0xC241,
                         0xC601, 0x06C0, 0x0780, 0xC741, 0x0500, 0xC5C1, 0xC481, 0x0440,
                         0xCC01, 0x0CC0, 0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81, 0x0E40,
                         0x0A00, 0xCAC1, 0xCB81, 0x0B40, 0xC901, 0x09C0, 0x0880, 0xC841,
                         0xD801, 0x18C0, 0x1980, 0xD941, 0x1B00, 0xDBC1, 0xDA81, 0x1A40,
                         0x1E00, 0xDEC1, 0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80, 0xDC41,
                         0x1400, 0xD4C1, 0xD581, 0x1540, 0xD701, 0x17C0, 0x1680, 0xD641,
                         0xD201, 0x12C0, 0x1380, 0xD341, 0x1100, 0xD1C1, 0xD081, 0x1040,
                         0xF001, 0x30C0, 0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281, 0x3240,
                         0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0, 0x3480, 0xF441,
                         0x3C00, 0xFCC1, 0xFD81, 0x3D40, 0xFF01, 0x3FC0, 0x3E80, 0xFE41,
                         0xFA01, 0x3AC0, 0x3B80, 0xFB41, 0x3900, 0xF9C1, 0xF881, 0x3840,
                         0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0, 0x2A80, 0xEA41,
                         0xEE01, 0x2EC0, 0x2F80, 0xEF41, 0x2D00, 0xEDC1, 0xEC81, 0x2C40,
                         0xE401, 0x24C0, 0x2580, 0xE541, 0x2700, 0xE7C1, 0xE681, 0x2640,
                         0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0, 0x2080, 0xE041,
                         0xA001, 0x60C0, 0x6180, 0xA141, 0x6300, 0xA3C1, 0xA281, 0x6240,
                         0x6600, 0xA6C1, 0xA781, 0x6740, 0xA501, 0x65C0, 0x6480, 0xA441,
                         0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0, 0x6E80, 0xAE41,
                         0xAA01, 0x6AC0, 0x6B80, 0xAB41, 0x6900, 0xA9C1, 0xA881, 0x6840,
                         0x7800, 0xB8C1, 0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80, 0xBA41,
                         0xBE01, 0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1, 0xBC81, 0x7C40,
                         0xB401, 0x74C0, 0x7580, 0xB541, 0x7700, 0xB7C1, 0xB681, 0x7640,
                         0x7200, 0xB2C1, 0xB381, 0x7340, 0xB101, 0x71C0, 0x7080, 0xB041,
                         0x5000, 0x90C1, 0x9181, 0x5140, 0x9301, 0x53C0, 0x5280, 0x9241,
                         0x9601, 0x56C0, 0x5780, 0x9741, 0x5500, 0x95C1, 0x9481, 0x5440,
                         0x9C01, 0x5CC0, 0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81, 0x5E40,
                         0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901, 0x59C0, 0x5880, 0x9841,
                         0x8801, 0x48C0, 0x4980, 0x8941, 0x4B00, 0x8BC1, 0x8A81, 0x4A40,
                         0x4E00, 0x8EC1, 0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80, 0x8C41,
                         0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0, 0x4680, 0x8641,
                         0x8201, 0x42C0, 0x4380, 0x8341, 0x4100, 0x81C1, 0x8081, 0x4040]
        
    def crc(self, data):
        crc = 0x0000
        for b in data:
            crc = (crc >> 8) ^ self.crcTable[(crc ^ int(b)) & 0xff]
        return crc;
