"""Tests for cli._prepend_note_to_message.

Regression coverage for the TypeError raised when a queued /model or
/reload-skills note was prepended to a multimodal (image-attached) message:
``can only concatenate str (not "list") to str``.
"""

from cli import _prepend_note_to_message


def test_string_message_gets_note_prepended():
    assert _prepend_note_to_message("hello", "NOTE") == "NOTE\n\nhello"


def test_empty_note_returns_message_unchanged():
    assert _prepend_note_to_message("hello", "") == "hello"
    assert _prepend_note_to_message("hello", "   ") == "hello"
    parts = [{"type": "text", "text": "hi"}]
    assert _prepend_note_to_message(parts, "") == parts


def test_note_is_stripped():
    assert _prepend_note_to_message("hello", "  NOTE  ") == "NOTE\n\nhello"


def test_empty_string_message_yields_just_note():
    # No trailing blank lines when the user message is empty.
    assert _prepend_note_to_message("", "NOTE") == "NOTE"


def test_empty_text_part_yields_just_note():
    message = [
        {"type": "text", "text": ""},
        {"type": "image_url", "image_url": {"url": "x"}},
    ]
    result = _prepend_note_to_message(message, "NOTE")
    assert result[0]["text"] == "NOTE"
    assert result[1]["type"] == "image_url"


def test_list_message_folds_note_into_first_text_part():
    message = [
        {"type": "text", "text": "describe this"},
        {"type": "image_url", "image_url": {"url": "data:..."}},
    ]
    result = _prepend_note_to_message(message, "NOTE")

    assert result[0]["type"] == "text"
    assert result[0]["text"] == "NOTE\n\ndescribe this"
    # Image part is preserved untouched.
    assert result[1] == {"type": "image_url", "image_url": {"url": "data:..."}}
    # Original message is not mutated.
    assert message[0]["text"] == "describe this"


def test_image_only_list_gets_leading_text_part():
    message = [{"type": "image_url", "image_url": {"url": "data:..."}}]
    result = _prepend_note_to_message(message, "NOTE")

    assert result[0] == {"type": "text", "text": "NOTE"}
    assert result[1]["type"] == "image_url"


def test_list_message_does_not_raise_typeerror():
    # The exact #repro shape: multimodal list + queued note must not raise
    # "can only concatenate str (not 'list') to str".
    message = [
        {"type": "text", "text": "look"},
        {"type": "image_url", "image_url": {"url": "x"}},
    ]
    result = _prepend_note_to_message(
        message, "Model switched to gpt-5.5 (provider: openai-codex)."
    )
    assert isinstance(result, list)
    assert result[0]["text"].startswith("Model switched to gpt-5.5")


def test_unknown_shape_returned_unchanged():
    assert _prepend_note_to_message(123, "NOTE") == 123
    assert _prepend_note_to_message(None, "NOTE") is None