import sys

sys.path.append('../src')
sys.path.append('../src/lib')

from utest import *
from ustruct import pack, unpack
from ubinascii import hexlify, unhexlify

from trezor import msg
from trezor.loop import Select, Syscall, READ, WRITE
from trezor.utils import chunks
from trezor.wire import codec_v2


def test_reader():
    rep_len = 64
    interface = 0xdeadbeef
    session_id = 0x12345678
    message_type = 0x87654321
    message_len = 250
    reader = codec_v2.Reader(interface, session_id)

    message = bytearray(range(message_len))
    report_header = bytearray(unhexlify('011234567887654321000000fa'))

    # open, expected one read
    first_report = report_header + message[:rep_len - len(report_header)]
    assert_async(reader.open(), [(None, Select(READ | interface)), (first_report, StopIteration()),])
    assert_eq(reader.type, message_type)
    assert_eq(reader.size, message_len)

    # empty read
    empty_buffer = bytearray()
    assert_async(reader.readinto(empty_buffer), [(None, StopIteration()),])
    assert_eq(len(empty_buffer), 0)
    assert_eq(reader.size, message_len)

    # short read, expected no read
    short_buffer = bytearray(32)
    assert_async(reader.readinto(short_buffer), [(None, StopIteration()),])
    assert_eq(len(short_buffer), 32)
    assert_eq(short_buffer, message[:len(short_buffer)])
    assert_eq(reader.size, message_len - len(short_buffer))

    # aligned read, expected no read
    aligned_buffer = bytearray(rep_len - len(report_header) - len(short_buffer))
    assert_async(reader.readinto(aligned_buffer), [(None, StopIteration()),])
    assert_eq(aligned_buffer, message[len(short_buffer):][:len(aligned_buffer)])
    assert_eq(reader.size, message_len - len(short_buffer) - len(aligned_buffer))

    # one byte read, expected one read
    next_report_header = bytearray(unhexlify('021234567800000000'))
    next_report = next_report_header + message[rep_len - len(report_header):][:rep_len - len(next_report_header)]
    onebyte_buffer = bytearray(1)
    assert_async(reader.readinto(onebyte_buffer), [(None, Select(READ | interface)), (next_report, StopIteration()),])
    assert_eq(onebyte_buffer, message[len(short_buffer):][len(aligned_buffer):][:len(onebyte_buffer)])
    assert_eq(reader.size, message_len - len(short_buffer) - len(aligned_buffer) - len(onebyte_buffer))

    # too long read, raises eof
    assert_async(reader.readinto(bytearray(reader.size + 1)), [(None, EOFError()),])

    # long read, expect multiple reads
    start_size = reader.size
    long_buffer = bytearray(start_size)
    report_payload = message[rep_len - len(report_header) + rep_len - len(next_report_header):]
    report_payload_head = report_payload[:rep_len - len(next_report_header) - len(onebyte_buffer)]
    report_payload_rest = report_payload[len(report_payload_head):]
    report_payload_rest = list(chunks(report_payload_rest, rep_len - len(next_report_header)))
    report_payloads = [report_payload_head] + report_payload_rest
    next_reports = [bytearray(unhexlify('0212345678') + pack('>L', i + 1)) + r for i, r in enumerate(report_payloads)]
    expected_syscalls = []
    for i, _ in enumerate(next_reports):
        prev_report = next_reports[i - 1] if i > 0 else None
        expected_syscalls.append((prev_report, Select(READ | interface)))
    expected_syscalls.append((next_reports[-1], StopIteration()))
    assert_async(reader.readinto(long_buffer), expected_syscalls)
    assert_eq(long_buffer, message[-start_size:])
    assert_eq(reader.size, 0)

    # one byte read, raises eof
    assert_async(reader.readinto(onebyte_buffer), [(None, EOFError()),])


def test_writer():
    rep_len = 64
    interface = 0xdeadbeef
    session_id = 0x12345678
    message_type = 0x87654321
    message_len = 1024
    writer = codec_v2.Writer(interface, session_id, message_type, message_len)

    # init header corresponding to the data above
    report_header = bytearray(unhexlify('01123456788765432100000400'))

    assert_eq(writer.data, report_header + bytearray(64 - len(report_header)))

    # empty write
    start_size = writer.size
    assert_async(writer.write(bytearray()), [(None, StopIteration()),])
    assert_eq(writer.data, report_header + bytearray(rep_len - len(report_header)))
    assert_eq(writer.size, start_size)

    # short write, expected no report
    start_size = writer.size
    short_payload = bytearray(range(4))
    assert_async(writer.write(short_payload), [(None, StopIteration()),])
    assert_eq(writer.size, start_size - len(short_payload))
    assert_eq(writer.data,
              report_header
              + short_payload
              + bytearray(rep_len - len(report_header) - len(short_payload)))

    # aligned write, expected one report
    start_size = writer.size
    aligned_payload = bytearray(range(rep_len - len(report_header) - len(short_payload)))
    msg.send = mock_call(msg.send, [
        (interface, report_header
         + short_payload
         + aligned_payload
         + bytearray(rep_len - len(report_header) - len(short_payload) - len(aligned_payload))), ])
    assert_async(writer.write(aligned_payload), [(None, Select(WRITE | interface)), (None, StopIteration()),])
    assert_eq(writer.size, start_size - len(aligned_payload))
    msg.send.assert_called_n_times(1)
    msg.send = msg.send.original

    # short write, expected no report, but data starts with correct seq and cont marker
    report_header = bytearray(unhexlify('021234567800000000'))
    start_size = writer.size
    assert_async(writer.write(short_payload), [(None, StopIteration()),])
    assert_eq(writer.size, start_size - len(short_payload))
    assert_eq(writer.data[:len(report_header) + len(short_payload)],
              report_header + short_payload)

    # long write, expected multiple reports
    start_size = writer.size
    long_payload_head = bytearray(range(rep_len - len(report_header) - len(short_payload)))
    long_payload_rest = bytearray(range(start_size - len(long_payload_head)))
    long_payload = long_payload_head + long_payload_rest
    expected_payloads = [short_payload + long_payload_head] + list(chunks(long_payload_rest, rep_len - len(report_header)))
    expected_reports = [
        bytearray(unhexlify('0212345678') + pack('>L', seq)) + rep
        for seq, rep in enumerate(expected_payloads)]
    expected_reports[-1] += bytearray(bytes(1) * (rep_len - len(expected_reports[-1])))
    # test write
    expected_write_reports = expected_reports[:-1]
    msg.send = mock_call(msg.send, [(interface, rep) for rep in expected_write_reports])
    assert_async(writer.write(long_payload), len(expected_write_reports) * [(None, Select(WRITE | interface))] + [(None, StopIteration())])
    assert_eq(writer.size, start_size - len(long_payload))
    msg.send.assert_called_n_times(len(expected_write_reports))
    msg.send = msg.send.original
    # test write raises eof
    msg.send = mock_call(msg.send, [])
    assert_async(writer.write(bytearray(1)), [(None, EOFError())])
    msg.send.assert_called_n_times(0)
    msg.send = msg.send.original
    # test close
    expected_close_reports = expected_reports[-1:]
    msg.send = mock_call(msg.send, [(interface, rep) for rep in expected_close_reports])
    assert_async(writer.close(), len(expected_close_reports) * [(None, Select(WRITE | interface))] + [(None, StopIteration())])
    assert_eq(writer.size, 0)
    msg.send.assert_called_n_times(len(expected_close_reports))
    msg.send = msg.send.original


if __name__ == '__main__':
    run_tests()