import pytest
from target_simulator.utils.tftp_client import TFTPClient, TFTPError
import io


def test_tftp_client_init():
    client = TFTPClient(server_ip="127.0.0.1", server_port=69)
    assert client.server_ip == "127.0.0.1"
    assert client.server_port == 69


def test_tftp_client_validate_params():
    client = TFTPClient(server_ip="127.0.0.1")
    # filename valido
    client._validate_params("file.txt", "octet")
    # filename non valido
    with pytest.raises(ValueError):
        client._validate_params("", "octet")
    # mode non valido
    with pytest.raises(ValueError):
        client._validate_params("file.txt", "invalid_mode")


def test_tftp_error():
    err = TFTPError(1, "fail")
    assert str(err) == "TFTP Error 1: fail"
    assert err.code == 1
    assert err.message == "fail"


def test_tftp_client_upload_mock(monkeypatch):
    client = TFTPClient(server_ip="127.0.0.1")

    # Mock socket and fileobj
    class DummySocket:
        def __init__(self):
            self.calls = 0

        def settimeout(self, t):
            pass

        def sendto(self, data, addr):
            pass

        def recvfrom(self, bufsize):
            self.calls += 1
            if self.calls == 1:
                return (b"\x00\x04", ("127.0.0.1", 69))  # ACK(0) corto
            else:
                # ACK valido per blocchi successivi
                return (b"\x00\x04\x00\x01", ("127.0.0.1", 69))

        def close(self):
            pass

    monkeypatch.setattr("socket.socket", lambda *a, **kw: DummySocket())
    fileobj = io.BytesIO(b"testdata")
    # Should not raise
    client.upload("file.txt", fileobj, mode="octet")