"""Tests for InputHistory."""

from tuimble.app import InputHistory


def test_empty_history_up_returns_none():
    h = InputHistory()
    assert h.up("current") is None


def test_empty_history_down_returns_none():
    h = InputHistory()
    assert h.down() is None


def test_push_then_up_returns_last():
    h = InputHistory()
    h.push("hello")
    assert h.up("draft") == "hello"


def test_up_twice_with_single_entry_stays():
    h = InputHistory()
    h.push("one")
    assert h.up("draft") == "one"
    assert h.up("draft") == "one"  # no older entry, stays put


def test_up_navigates_backwards():
    h = InputHistory()
    h.push("first")
    h.push("second")
    h.push("third")
    assert h.up("draft") == "third"
    assert h.up("draft") == "second"
    assert h.up("draft") == "first"
    assert h.up("draft") == "first"  # clamped at oldest


def test_down_navigates_forward():
    h = InputHistory()
    h.push("first")
    h.push("second")
    h.push("third")
    h.up("draft")  # -> third
    h.up("draft")  # -> second
    assert h.down() == "third"


def test_down_past_end_restores_draft():
    h = InputHistory()
    h.push("one")
    h.up("my draft")  # -> one
    result = h.down()  # -> back to draft
    assert result == "my draft"


def test_down_without_prior_up_returns_none():
    h = InputHistory()
    h.push("one")
    assert h.down() is None


def test_push_resets_navigation():
    h = InputHistory()
    h.push("first")
    h.up("draft")  # -> first
    h.push("second")
    # After push, navigation resets -- up should go to newest
    assert h.up("new draft") == "second"


def test_up_preserves_current_as_draft():
    """First up() saves current input; down past end restores it."""
    h = InputHistory()
    h.push("old")
    h.up("typing in progress")
    assert h.down() == "typing in progress"


def test_full_cycle():
    """Push several, navigate to oldest, then back to draft."""
    h = InputHistory()
    h.push("a")
    h.push("b")
    h.push("c")

    assert h.up("draft") == "c"
    assert h.up("draft") == "b"
    assert h.up("draft") == "a"
    assert h.down() == "b"
    assert h.down() == "c"
    assert h.down() == "draft"
    assert h.down() is None  # already at draft