from pathlib import Path

import pytest

from app.navigator import Navigator, VisibleEntry
from app.ui import (
    RenderLine,
    build_render_lines,
    format_entry,
    move_selection,
    open_terminal_streams,
)


def test_move_selection_stays_within_bounds() -> None:
    assert move_selection(current_index=0, step=-1, entry_count=3) == 0
    assert move_selection(current_index=1, step=1, entry_count=3) == 2
    assert move_selection(current_index=2, step=1, entry_count=3) == 2


def test_format_entry_supports_parent_and_tree_indicators(tmp_path: Path) -> None:
    parent_entry = VisibleEntry(
        name="..",
        path=tmp_path,
        depth=0,
        has_children=True,
        is_expanded=False,
        is_parent=True,
    )
    collapsed_entry = VisibleEntry(
        name="scripts",
        path=tmp_path / "scripts",
        depth=0,
        has_children=True,
        is_expanded=False,
    )
    expanded_child = VisibleEntry(
        name="build",
        path=tmp_path / "scripts" / "build",
        depth=1,
        has_children=False,
        is_expanded=False,
    )

    assert format_entry(parent_entry) == ".."
    assert format_entry(collapsed_entry) == "▶ scripts"
    assert format_entry(expanded_child) == "      build"


def test_build_render_lines_marks_selected_entry(tmp_path: Path) -> None:
    workspace = tmp_path / "workspace"
    workspace.mkdir()
    alpha = workspace / "alpha"
    beta = workspace / "beta"
    alpha.mkdir()
    beta.mkdir()

    navigator = Navigator(workspace)
    navigator.set_selected_index(2)

    assert build_render_lines(navigator) == [
        RenderLine(text="..", is_selected=False),
        RenderLine(text="  alpha", is_selected=False),
        RenderLine(text="  beta", is_selected=True),
    ]


def test_open_terminal_streams_raises_without_terminal(
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    def raise_os_error(*args: object, **kwargs: object) -> object:
        raise OSError

    monkeypatch.setattr("builtins.open", raise_os_error)
    monkeypatch.setattr("sys.stdin.isatty", lambda: False)
    monkeypatch.setattr("sys.stderr.isatty", lambda: False)

    with pytest.raises(RuntimeError, match="Interactive terminal is required"):
        with open_terminal_streams():
            pass