"""Tests for the overlay model + draft (SHARD-WP-0008 T2)."""

from shard_wiki.coordination import DecisionLog, EventType, OverlayEngine
from shard_wiki.model import Identity
from shard_wiki.provenance import OverlayState


def test_draft_records_event_and_is_retrievable():
    log = DecisionLog()
    eng = OverlayEngine("space", log)
    ov = eng.draft(Identity("shardA", "Home"), "new body", base_rev="r1")

    assert ov.state is OverlayState.DRAFT
    assert ov.body == "new body"
    # recorded in the log (coordination-canonical)
    events = log.events("space")
    assert len(events) == 1 and events[0].type is EventType.OVERLAY_CREATED
    # retrievable through the fold by its id
    got = eng.get(ov.overlay_id)
    assert got is not None
    assert got.target == Identity("shardA", "Home")
    assert got.base_rev == "r1"
    assert got.body == "new body"


def test_open_overlays_lists_drafts():
    log = DecisionLog()
    eng = OverlayEngine("space", log)
    eng.draft(Identity("s", "A"), "a", base_rev=None)
    eng.draft(Identity("s", "B"), "b", base_rev=None)
    assert {o.target.key for o in eng.open_overlays()} == {"A", "B"}


def test_unknown_overlay_is_none():
    assert OverlayEngine("space", DecisionLog()).get("nope") is None


def test_overlay_payload_round_trips():
    log = DecisionLog()
    eng = OverlayEngine("space", log)
    ov = eng.draft(Identity("shardA", "sub/Page"), "x", base_rev="r9")
    assert eng.get(ov.overlay_id) == ov  # payload reconstructs an equal Overlay