"""Unit-Tests Project-State-Store (PLAN.md §6.4 State Sync, §24.2, §18.1)."""

from __future__ import annotations

import pytest
from hms_domain import PresetScene
from hms_persistence.state_store import ProjectStateStore


def test_revisions_start_at_zero() -> None:
    store = ProjectStateStore()
    assert store.state_revision == 0
    assert store.project_revision == 0
    assert store.snapshot()["values"] == {}


def test_activate_project_resets_live_state() -> None:
    """Kein Mischzustand: Projektwechsel leert den Livezustand (§24.2)."""
    from hms_domain import Project

    store = ProjectStateStore()
    store.set_value("master/intensity", 0.5)
    store.activate_project(Project(name="Show A"))
    assert store.project_revision == 1
    assert store.project is not None and store.project.name == "Show A"
    assert store.get_value("master/intensity") is None  # Live geleert
    assert store.state_revision == 2  # set_value (1) + Projektwechsel (2)


def test_set_and_clear_value_increase_state_revision() -> None:
    store = ProjectStateStore()
    r1 = store.set_value("master/intensity", 0.7)
    assert r1 == 1
    r2 = store.set_value("master/intensity", 0.9)
    assert r2 == 2
    r3 = store.clear_value("master/intensity")
    assert r3 == 3
    assert store.get_value("master/intensity") is None
    # Löschen eines nicht existierenden Pfades erhöht trotzdem deterministisch
    r4 = store.clear_value("master/intensity")
    assert r4 == 4


def test_snapshot_contains_revisions_and_values() -> None:
    store = ProjectStateStore()
    store.set_value("master/intensity", 1.0)
    snap = store.snapshot()
    assert snap["state_revision"] == 1
    assert snap["project_revision"] == 0
    assert snap["values"] == {"master/intensity": 1.0}
    assert snap["monotonic_ns"] > 0


def test_delta_since_reports_changes_and_deletions() -> None:
    """Delta überträgt Änderungen; gelöschte Pfade als None (§6.4)."""
    store = ProjectStateStore()
    store.set_value("a", 1.0)
    seen = store.state_revision
    # nach „Disconnect": neue Änderungen
    store.set_value("a", 2.0)
    store.set_value("b", 3.0)
    store.clear_value("c")  # c war nie gesetzt – bleibt neutral
    delta = store.delta_since(seen, pending={"a": 1.0, "c": 0.0})
    assert delta is not None
    assert delta.state_revision == store.state_revision
    assert delta.changes["a"] == 2.0  # geändert
    assert "b" in delta.changes and delta.changes["b"] == 3.0  # neu
    assert delta.changes.get("c") is None  # gelöscht


def test_delta_none_when_up_to_date() -> None:
    store = ProjectStateStore()
    store.set_value("a", 1.0)
    assert store.delta_since(store.state_revision, pending={}) is None


def test_delta_rejects_future_revision() -> None:
    store = ProjectStateStore()
    with pytest.raises(ValueError, match="Zukunft"):
        store.delta_since(99, pending={})


def test_apply_scene_overwrites_live_as_target_state() -> None:
    """Szenenabruf erzeugt Zielzustand; Übergänge macht der Renderer (§18.1)."""
    store = ProjectStateStore()
    store.set_value("layer/x/opacity", 0.2)
    scene = PresetScene(
        name="Look",
        composition_snapshot={
            "values": {"layer/x/opacity": 0.8, "master/intensity": 1.0}
        },
    )
    rev = store.apply_scene(scene)
    assert rev == 2  # set + scene
    assert store.get_value("layer/x/opacity") == pytest.approx(0.8)
    assert store.get_value("master/intensity") == pytest.approx(1.0)


def test_apply_scene_rejects_scene_without_values() -> None:
    scene = PresetScene(name="Kaputt", composition_snapshot={"values": "kein dict"})
    store = ProjectStateStore()
    with pytest.raises(ValueError, match="Werte"):
        store.apply_scene(scene)


def test_bump_project_revision_independent_of_state() -> None:
    """Projektinhalt (Medien/Szenen) und Livezustand getrennt (§24.2)."""
    store = ProjectStateStore()
    state_before = store.state_revision
    store.bump_project_revision()
    assert store.project_revision == 1
    assert store.state_revision == state_before  # Live unverändert