import usb.core
import usb.util
import array

from ccid_raw import SmartcardConnection
from smartcard_emulator import SmartCardEmulator

from contextlib import closing

from util import HEX
from constants import *
from apdu_split import Apdu_splitter, apdu_states

def find_dev():
    dev = usb.core.find(idVendor=0x03eb, idProduct=0x6004)
    if dev is None:
        raise ValueError("Device not found")
    else:
        print("Found device")
    return dev

def pattern_match(inpt):
    print("Matching inpt", inpt)
    if (inpt == ATR_SYSMOCOM1) or (inpt == ATR_STRANGE_SIM):
        print("ATR: ", inpt)
        return NEW_ATR
    elif (inpt == CMD_SEL_FILE):
        print("CMD_SEL_FILE:", inpt)
        return CMD_SEL_ROOT
    elif (inpt == CMD_GET_DATA):
        print("CMD_DATA:", inpt)
        return CMD_SEL_ROOT
    else:
        return inpt

def poll_ep(dev, ep):
    try:
        return dev.read(ep, 64, 10)
    except usb.core.USBError as e:
        if e.errno != ERR_TIMEOUT:
            raise
        return None

def write_phone(dev, resp):
    print("WR: ", HEX(resp))
    dev.write(PHONE_WR, resp, 10)

def replace(data):
    if data is None:
        raise MITMReplaceError
    else:
        try:
            if data[0] == 0x3B:
                print("*** Replace ATR")
#                return array('B', ATR_SYSMOCOM2)
            elif data[0] == 0x9F:
                print("*** Replace return val")
#                return array('B', [0x60, 0x00])
        except ValueError:
            print("*** Value error! ")
    return data

def do_mitm(sim_emul=True):
    dev = find_dev()
    if sim_emul == True:
        my_class = SmartCardEmulator
    else:
        my_class = SmartcardConnection
    with closing(my_class()) as sm_con:
        atr = sm_con.getATR()

        apdus = []
        apdu = Apdu_splitter()

        while True:
            cmd = poll_ep(dev, PHONE_INT)
            if cmd is not None:
                print("Int line ", HEX(cmd))
                assert cmd[0] == ord('R')
# FIXME: restart card anyways?
#               sm_con.reset_card()
                print("Write atr: ", HEX(atr))
                write_phone(dev, replace(atr))
                apdus = []
                apdu = Apdu_splitter()

            cmd = poll_ep(dev, PHONE_RD)
            if cmd is not None:
                print("RD: ", HEX(cmd))
                for c in cmd:
                    if apdu.state == apdu_states.APDU_S_FIN:
                        apdus.append(apdu)
                        apdu = Apdu_splitter()

                    apdu.split(c)
                    if apdu.state == apdu_states.APDU_S_FIN and apdu.pts_buf == [0xff, 0x00, 0xff]:
                        sim_data = sm_con.send_receive_cmd(apdu.pts_buf)
                        write_phone(dev,  replace(array('B', sim_data)))
                        continue;

                    if apdu.state == apdu_states.APDU_S_SW1:
                        if apdu.data is not None and len(apdu.data) == 0:
                            # FIXME: implement other ACK types
                            write_phone(dev,  replace(array('B', [apdu.ins])))
                            apdu.split(apdu.ins)
                        else:
                            sim_data = sm_con.send_receive_cmd(apdu.buf)
                            write_phone(dev, replace(sim_data))
                            for c in sim_data:
                                apdu.split(c)
                    elif apdu.state == apdu_states.APDU_S_SEND_DATA:
                            sim_data = sm_con.send_receive_cmd(replace(apdu.buf))
                            sim_data.insert(0, apdu.ins)
                            write_phone(dev, replace(sim_data))
                            apdu.state = apdu_states.APDU_S_SW1
                            for c in sim_data:
                                apdu.split(c)