import pytest
from ecu_framework.flashing.hex_flasher import HexFlasher
from ecu_framework.lin.base import LinFrame


class _StubLin:
    def __init__(self):
        self.sent = []
    def connect(self):
        pass
    def disconnect(self):
        pass
    def send(self, frame: LinFrame):
        self.sent.append(frame)
    def receive(self, id=None, timeout=1.0):
        return None


@pytest.mark.unit
def test_hex_flasher_sends_basic_sequence(tmp_path):
    # Minimal valid Intel HEX file (EOF record)
    hex_path = tmp_path / "fw.hex"
    hex_path.write_text(":00000001FF\n")

    lin = _StubLin()
    flasher = HexFlasher(lin)
    flasher.flash_hex(str(hex_path))

    # Placeholder assertion; refine as the flasher gains functionality
    assert isinstance(lin.sent, list)