"""DTC parsing correctness (CAN multi-ECU, ISO-TP frame indices, single-frame)."""
import os
import sys

sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

from obdcore.link import parse_dtcs, _line_bytes, decode_dtc


def test_single_frame_can():
    # 43 02 <P0133> <P0420>
    lines = ["43 02 01 33 04 20"]
    assert parse_dtcs(lines, 0x43, True) == ["P0133", "P0420"]
    print("  single-frame CAN: OK")


def test_multi_ecu_no_phantom_codes():
    # Two ECUs each reply "43 <count> ...". The old flatten-and-strip-once code
    # ate the second header (43 01) as a DTC pair -> phantom code. Each header
    # must be stripped per-message.
    lines = ["43 01 01 33", "43 01 04 20"]
    got = parse_dtcs(lines, 0x43, True)
    assert got == ["P0133", "P0420"], got
    assert not any(d.startswith("C0301") or "4301" in d for d in got)
    print(f"  multi-ECU CAN, no phantom codes: {got}: OK")


def test_iso_tp_numbered_frames_hex_index():
    # Multiframe with numbered continuations, including hex indices A:..F:.
    # First frame "0:" starts with 43 08; continuations carry raw pairs. A
    # continuation starting with 0x43 (a real C03xx code) must NOT be mistaken
    # for a new header because it is a numbered continuation.
    lines = [
        "0: 43 08 01 33 04 20",
        "1: 05 67 07 E4 43 45",     # ...last pair 43 45 == C0345 (real code, starts 0x43)
        "2: 09 96 00 00 00 00",
    ]
    got = parse_dtcs(lines, 0x43, True)
    assert got == ["P0133", "P0420", "P0567", "P07E4", "C0345", "P0996"], got
    print(f"  numbered multiframe + C03xx continuation not misread: {got}: OK")


def test_hex_frame_index_stripped():
    assert _line_bytes("A: 11 22") == [0x11, 0x22]      # hex index A: now stripped
    assert _line_bytes("F:1122") == [0x11, 0x22]
    print("  _line_bytes strips hex ISO-TP frame indices A:-F:: OK")


def test_legacy_non_can_still_works():
    # 43 header per line (non-CAN)
    lines = ["43 01 33 00 00", "43 04 20 00 00"]
    got = parse_dtcs(lines, 0x43, False)
    assert "P0133" in got and "P0420" in got, got
    print(f"  non-CAN legacy parse intact: {got}: OK")


if __name__ == "__main__":
    test_single_frame_can()
    test_multi_ecu_no_phantom_codes()
    test_iso_tp_numbered_frames_hex_index()
    test_hex_frame_index_stripped()
    test_legacy_non_can_still_works()
    print("\nALL DTC PARSE TESTS PASS")