import os
import struct

import pytest
from fido2.ctap import CtapError
from fido2.hid import CAPABILITY, CTAPHID


def test_init_assigns_channel(device):
    assert device._channel_id not in (0, 0xFFFFFFFF)
    assert device.capabilities & CAPABILITY.CBOR
    assert device.capabilities & CAPABILITY.WINK


def test_ping_single_packet(device):
    assert device.ping(b"hello") == b"hello"


def test_ping_multi_packet(device):
    # 57 bytes in the first packet, then 59 per continuation packet.
    payload = os.urandom(3000)
    assert device.ping(payload) == payload


def test_ping_largest_message(device):
    payload = os.urandom(57 + 128 * 59)
    assert device.ping(payload) == payload


def test_wink(device):
    device.wink()


def test_unknown_command(device):
    with pytest.raises(CtapError) as e:
        device.call(0x40)
    assert e.value.code == CtapError.ERR.INVALID_COMMAND


def test_out_of_order_continuation(device):
    conn = device._connection
    cid = device._channel_id
    conn.write_packet(struct.pack(">IBH", cid, 0x80 | CTAPHID.PING, 100).ljust(64, b"\0"))
    conn.write_packet(struct.pack(">IB", cid, 1).ljust(64, b"\0"))  # expected seq 0
    response = conn.read_packet()
    assert response[:7] == struct.pack(">IBH", cid, 0x80 | CTAPHID.ERROR, 1)
    assert response[7] == CtapError.ERR.INVALID_SEQ
    assert device.ping(b"still alive") == b"still alive"


def test_other_channel_busy_while_receiving(device):
    conn = device._connection
    cid = device._channel_id
    conn.write_packet(struct.pack(">IBH", cid, 0x80 | CTAPHID.PING, 100).ljust(64, b"\0"))
    conn.write_packet(struct.pack(">IBH", cid + 1, 0x80 | CTAPHID.PING, 1).ljust(64, b"\0"))
    response = conn.read_packet()
    assert response[:8] == struct.pack(">IBHB", cid + 1, 0x80 | CTAPHID.ERROR, 1, CtapError.ERR.CHANNEL_BUSY)
    # Finish the original message.
    conn.write_packet(struct.pack(">IB", cid, 0).ljust(64, b"\0"))
    response = conn.read_packet()
    assert response[:7] == struct.pack(">IBH", cid, 0x80 | CTAPHID.PING, 100)
    conn.read_packet()  # continuation packet with the rest of the echo