import struct
import asyncio
from unittest.mock import AsyncMock
from pm3py.core.protocol import Cmd
from pm3py.core.transport import PM3Response
from pm3py.core.hf_iso14a import HF14ACommands

def test_14a_scan():
    t = AsyncMock()
    hf14a = HF14ACommands(t)
    # Build iso14a_card_select_t response
    uid = b"\x04\x01\x02\x03\x04\x05\x06"
    card = uid + b"\x00" * 3  # uid[10]
    card += bytes([7])  # uidlen
    card += b"\x44\x00"  # atqa
    card += bytes([0x08])  # sak
    card += bytes([0])  # ats_len
    card += b"\x00" * 256  # ats
    resp = PM3Response(cmd=Cmd.ACK, status=0, reason=0, ng=False,
                       data=card, oldarg=[1, 0, 0])
    t.send_mix.return_value = resp
    result = asyncio.get_event_loop().run_until_complete(hf14a.scan())
    assert result["uid"] == "04010203040506"
    assert result["uid_len"] == 7
    assert result["sak"] == 0x08


def test_14a_raw_trims_to_received_length():
    t = AsyncMock()
    hf14a = HF14ACommands(t)
    # firmware replies with its whole (padded) buffer; oldarg[0] = bytes actually received
    version = bytes.fromhex("0004040201000f03") + b"\x80\x91"   # 8-byte version + 2-byte CRC
    t.send_mix.return_value = PM3Response(cmd=Cmd.ACK, status=0, reason=0, ng=False,
                                          data=version + b"\x00" * 30, oldarg=[10, 0, 0])
    result = asyncio.get_event_loop().run_until_complete(hf14a.raw(b"\x60"))
    assert result["received"] == 10
    assert result["raw"] == version            # trimmed to the received length, not the padding
    assert result["data"] == version.hex()


def test_14a_raw_no_response_is_empty():
    t = AsyncMock()
    hf14a = HF14ACommands(t)
    # tag didn't answer: received length 0, buffer full of zeros -> must come back empty
    t.send_mix.return_value = PM3Response(cmd=Cmd.ACK, status=0, reason=0, ng=False,
                                          data=b"\x00" * 40, oldarg=[0, 0, 0])
    result = asyncio.get_event_loop().run_until_complete(hf14a.raw(b"\x30\x99"))
    assert result["received"] == 0
    assert result["raw"] == b""                # not 40 bytes of zeros
    assert result["data"] is None


def test_14a_sim_packs_ng_struct():
    t = AsyncMock()
    hf14a = HF14ACommands(t)
    t.send_ng.return_value = PM3Response(cmd=Cmd.HF_ISO14443A_SIMULATE, status=0,
                                         reason=0, ng=True, data=b"", oldarg=[])
    uid = b"\x04\x01\x02\x03"
    result = asyncio.get_event_loop().run_until_complete(
        hf14a.sim(tagtype=7, uid=uid, exit_after=3))
    assert result["status"] == 0
    args, kwargs = t.send_ng.call_args
    assert args[0] == Cmd.HF_ISO14443A_SIMULATE
    payload = kwargs["payload"]
    assert len(payload) == 69  # PACKED firmware struct size
    tagtype, flags = struct.unpack_from("<BH", payload, 0)
    assert tagtype == 7
    assert flags & 0x0030 == 0x0010  # FLAG_4B_UID_IN_DATA
    assert payload[3:7] == uid      # uid[10] field, first 4 bytes
    assert payload[13] == 3         # exitAfter


def test_14a_sim_no_uid_uses_emul_flag():
    t = AsyncMock()
    hf14a = HF14ACommands(t)
    t.send_ng.return_value = PM3Response(cmd=Cmd.HF_ISO14443A_SIMULATE, status=0,
                                         reason=0, ng=True, data=b"", oldarg=[])
    asyncio.get_event_loop().run_until_complete(hf14a.sim(tagtype=1))
    payload = t.send_ng.call_args.kwargs["payload"]
    _, flags = struct.unpack_from("<BH", payload, 0)
    assert flags & 0x0030 == 0x0000  # FLAG_UID_IN_EMUL


def test_14a_sniff_sends_ng_param_byte():
    t = AsyncMock()
    hf14a = HF14ACommands(t)
    t.send_ng.return_value = PM3Response(cmd=Cmd.HF_ISO14443A_SNIFF, status=0,
                                         reason=0, ng=True, data=b"", oldarg=[])
    result = asyncio.get_event_loop().run_until_complete(hf14a.sniff(2))
    assert result["status"] == 0
    args, kwargs = t.send_ng.call_args
    assert args[0] == Cmd.HF_ISO14443A_SNIFF
    assert kwargs["payload"] == bytes([2])