from textual.widgets.text_area import Document

TEXT = """I must not fear.
Fear is the mind-killer."""


def test_insert_no_newlines():
    document = Document(TEXT)
    document.replace_range((0, 1), (0, 1), " really")
    assert document.lines == [
        "I really must not fear.",
        "Fear is the mind-killer.",
    ]


def test_insert_empty_string():
    document = Document(TEXT)
    document.replace_range((0, 1), (0, 1), "")
    assert document.lines == ["I must not fear.", "Fear is the mind-killer."]


def test_insert_invalid_column():
    document = Document(TEXT)
    document.replace_range((0, 999), (0, 999), " really")
    assert document.lines == ["I must not fear. really", "Fear is the mind-killer."]


def test_insert_invalid_row_and_column():
    document = Document(TEXT)
    document.replace_range((999, 0), (999, 0), " really")
    assert document.lines == ["I must not fear.", "Fear is the mind-killer.", " really"]


def test_insert_range_newline_file_start():
    document = Document(TEXT)
    document.replace_range((0, 0), (0, 0), "\n")
    assert document.lines == ["", "I must not fear.", "Fear is the mind-killer."]


def test_insert_newline_splits_line():
    document = Document(TEXT)
    document.replace_range((0, 1), (0, 1), "\n")
    assert document.lines == ["I", " must not fear.", "Fear is the mind-killer."]


def test_insert_newline_splits_line_selection():
    document = Document(TEXT)
    document.replace_range((0, 1), (0, 6), "\n")
    assert document.lines == ["I", " not fear.", "Fear is the mind-killer."]


def test_insert_multiple_lines_ends_with_newline():
    document = Document(TEXT)
    document.replace_range((0, 1), (0, 1), "Hello,\nworld!\n")
    assert document.lines == [
        "IHello,",
        "world!",
        " must not fear.",
        "Fear is the mind-killer.",
    ]


def test_insert_multiple_lines_ends_with_no_newline():
    document = Document(TEXT)
    document.replace_range((0, 1), (0, 1), "Hello,\nworld!")
    assert document.lines == [
        "IHello,",
        "world! must not fear.",
        "Fear is the mind-killer.",
    ]


def test_insert_multiple_lines_starts_with_newline():
    document = Document(TEXT)
    document.replace_range((0, 1), (0, 1), "\nHello,\nworld!\n")
    assert document.lines == [
        "I",
        "Hello,",
        "world!",
        " must not fear.",
        "Fear is the mind-killer.",
    ]


def test_insert_range_text_no_newlines():
    """Ensuring we can do a simple replacement of text."""
    document = Document(TEXT)
    document.replace_range((0, 2), (0, 6), "MUST")
    assert document.lines == [
        "I MUST not fear.",
        "Fear is the mind-killer.",
    ]


TEXT_NEWLINE_EOF = """\
I must not fear.
Fear is the mind-killer.
"""


def test_newline_eof():
    document = Document(TEXT_NEWLINE_EOF)
    assert document.lines == [
        "I must not fear.",
        "Fear is the mind-killer.",
        "",
    ]