import pic24

NoOperands = [
    0xD5, 0xD6, 0xD7, 0xD8,
    0xEF, # comment on this one: Read & toss 2 response words
    0xF4, 0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB
]

ScriptCommandTable = {
    0xB4: 'SCMD_JT2_WAIT_PE_RESP',
    0xB5: 'SCMD_JT2_GET_PE_RESP',
    0xB6: 'SCMD_JT2_XFERINST_BUF',
    0xB7: 'SCMD_JT2_XFRFASTDAT_BUF',
    0xB8: 'SCMD_JT2_XFRFASTDAT_LIT',
    0xB9: 'SCMD_JT2_XFERDATA32_LIT',
    0xBA: 'SCMD_JT2_XFERDATA8_LIT',
    0xBB: 'SCMD_JT2_SENDCMD',
    0xBC: 'SCMD_JT2_SETMODE',
    0xBD: 'SCMD_UNIO_TX_RX',
    0xBE: 'SCMD_UNIO_TX',
    0xBF: 'SCMD_MEASURE_PULSE',
    0xC0: 'SCMD_ICDSLAVE_TX_BUF_BL',
    0xC1: 'SCMD_ICDSLAVE_TX_LIT_BL',
    0xC2: 'SCMD_ICDSLAVE_RX_BL',
    0xC3: 'SCMD_SPI_RDWR_BYTE_BUF',
    0xC4: 'SCMD_SPI_RDWR_BYTE_LIT',
    0xC5: 'SCMD_SPI_RD_BYTE_BUF',
    0xC6: 'SCMD_SPI_WR_BYTE_BUF',
    0xC7: 'SCMD_SPI_WR_BYTE_LIT',
    0xC8: 'SCMD_I2C_RD_BYTE_NACK',
    0xC9: 'SCMD_I2C_RD_BYTE_ACK',
    0xCA: 'SCMD_I2C_WR_BYTE_BUF',
    0xCB: 'SCMD_I2C_WR_BYTE_LIT',
    0xCC: 'SCMD_I2C_STOP',
    0xCD: 'SCMD_I2C_START',
    0xCE: 'SCMD_AUX_STATE_BUFFER',
    0xCF: 'SCMD_SET_AUX',
    0xD0: 'SCMD_WRITE_BITS_BUF_HLD',
    0xD1: 'SCMD_WRITE_BITS_LIT_HLD',
    0xD2: 'SCMD_CONST_WRITE_DL',
    0xD3: 'SCMD_WRITE_BUFBYTE_W',
    0xD4: 'SCMD_WRITE_BUFWORD_W',
    0xD5: 'SCMD_RD2_BITS_BUFFER',
    0xD6: 'SCMD_RD2_BYTE_BUFFER',
    0xD7: 'SCMD_VISI24',
    0xD8: 'SCMD_NOP24',
    0xD9: 'SCMD_COREINST24',
    0xDA: 'SCMD_COREINST18',
    0xDB: 'SCMD_POP_DOWNLOAD',
    0xDC: 'SCMD_ICSP_STATES_BUFFER',
    0xDD: 'SCMD_LOOP_BUFFER',
    0xDE: 'SCMD_ICDSLAVE_TX_BUF',
    0xDF: 'SCMD_ICDSLAVE_TX_LIT',
    0xE0: 'SCMD_ICDSLAVE_RX',
    0xE1: 'SCMD_POKE_SFR',
    0xE2: 'SCMD_PEEK_SFR',
    0xE3: 'SCMD_EXIT_SCRIPT',
    0xE4: 'SCMD_GOTO_INDEX',
    0xE5: 'SCMD_IF_GT_GOTO',
    0xE6: 'SCMD_IF_EQ_GOTO',
    0xE7: 'SCMD_DELAY_SHORT',
    0xE8: 'SCMD_DELAY_LONG',
    0xE9: 'SCMD_LOOP',
    0xEA: 'SCMD_SET_ICSP_SPEED',
    0xEB: 'SCMD_READ_BITS',
    0xEC: 'SCMD_READ_BITS_BUFFER',
    0xED: 'SCMD_WRITE_BITS_BUFFER',
    0xEE: 'SCMD_WRITE_BITS_LITERAL',
    0xEF: 'SCMD_READ_BYTE',
    0xF0: 'SCMD_READ_BYTE_BUFFER',
    0xF1: 'SCMD_WRITE_BYTE_BUFFER',
    0xF2: 'SCMD_WRITE_BYTE_LITERAL',
    0xF3: 'SCMD_SET_ICSP_PINS',
    0xF4: 'SCMD_BUSY_LED_OFF',
    0xF5: 'SCMD_BUSY_LED_ON',
    0xF6: 'SCMD_MCLR_GND_OFF',
    0xF7: 'SCMD_MCLR_GND_ON',
    0xF8: 'SCMD_VPP_PWM_OFF',
    0xF9: 'SCMD_VPP_PWM_ON',
    0xFA: 'SCMD_VPP_OFF',
    0xFB: 'SCMD_VPP_ON',
    0xFC: 'SCMD_VDD_GND_OFF',
    0xFD: 'SCMD_VDD_GND_ON',
    0xFE: 'SCMD_VDD_OFF',
    0xFF: 'SCMD_VDD_ON'
}

def disassemble(blob, offset):
    code = blob[offset]
    length = 1
    command = ScriptCommandTable[code]
    result = {}
    result['mnemonic'] = command
    if code == 0xCF:
        length += 1
        result['op'] = hex(blob[offset + 1])
    elif code == 0xD3 or code == 0xD4:
        length += 1
        immediate = blob[offset + 1]
    elif code == 0xD9:
        if blob[offset + 1 + 2] == 0x04:
            # it's a goto, and there's a second instruction. this OUGHT to be
            # followed by a SCMD_NOP24...
            if blob[offset + 1 + 3] == 0xD8:
                # it is! whew
                instrbytes = blob[offset + 1:offset + 1 + 3]
                instrbytes.append(0)
                instrbytes.append(0)
                instrbytes.append(0)

                (postinstr_offset, instr) = pic24.disassemble(instrbytes, 0)
                length = 1 + 3 + 1 # the command, three real bytes + the nop
                result['op'] = instr #pic24.render(instr)
            else:
                (postinstr_offset, instr) = pic24.disassemble(blob, offset + 1)
#                length = postinstr_offset - offset
                length = 4
                result['op'] = instr #pic24.render(instr)
                print("Goto not followed by nop, uhh what's " + hex(blob[offset + 3 + 1]))
        else:
            (postinstr_offset, instr) = pic24.disassemble(blob, offset + 1)
            length = postinstr_offset - offset
            result['op'] = instr #pic24.render(instr)
    elif code in NoOperands:
        pass
    elif code == 0xE7 or code == 0xE8:
        length += 1
        result['op'] = hex(blob[offset + 1])
    elif code == 0xEE:
        length += 2
# not sure if this is really two operands
        result['op'] = hex(blob[offset + 1]) + ", " + hex(blob[offset + 2])
    elif code == 0xE9:
        length += 2
        result['op'] = hex((blob[offset + 2] << 8) + blob[offset + 1])
    elif code == 0xF2:
        length += 1
        result['op'] = hex(blob[offset + 1])
    elif code == 0xF3:
        length += 1
        result['op'] = hex(blob[offset + 1])
    else:
        print("Unknown: " + command)
        return None

    return (offset + length, result)