"""
test_canvas_service.py — Unit tests for CanvasService (demo mode in-memory store).
"""
import asyncio
import pytest
import sys
import os

# Ensure backend is on path
sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", ".."))

from oracle.canvas_service import CanvasService

TENANT = "tenant_test_001"
ACTOR = "user_test_001"


def run(coro):
    return asyncio.get_event_loop().run_until_complete(coro)


@pytest.fixture
def svc():
    """Fresh CanvasService instance with empty demo store per test."""
    from oracle import canvas_service as _mod
    _mod._DEMO_PAGES.clear()
    _mod._DEMO_REVISIONS.clear()
    _mod._DEMO_COMPONENTS.clear()
    return CanvasService()


def test_create_page(svc):
    page = run(svc.create_page(tenant_id=TENANT, owner_id=ACTOR, title="Test Canvas"))
    assert page["tenantId"] == TENANT
    assert page["ownerId"] == ACTOR
    assert page["title"] == "Test Canvas"
    assert page["headRevision"] == 0
    assert page["pageType"] == "main"
    assert page["branchName"] == "main"


def test_get_page_not_found(svc):
    result = run(svc.get_page("nonexistent_id", TENANT))
    assert result is None


def test_get_page_returns_page(svc):
    page = run(svc.create_page(tenant_id=TENANT, owner_id=ACTOR))
    retrieved = run(svc.get_page(page["pageId"], TENANT))
    assert retrieved is not None
    assert retrieved["pageId"] == page["pageId"]


def test_commit_revision_advances_head(svc):
    page = run(svc.create_page(tenant_id=TENANT, owner_id=ACTOR))
    comps = [{"componentId": "cmp_001", "type": "barChart", "title": "Test"}]
    rev = run(svc.commit_revision(
        page_id=page["pageId"],
        tenant_id=TENANT,
        actor_id=ACTOR,
        commit_kind="prompt",
        commit_summary="Test prompt",
        components=comps,
        idempotency_key="ikey_001",
    ))
    assert rev["revisionNumber"] == 1
    updated = run(svc.get_page(page["pageId"], TENANT))
    assert updated["headRevision"] == 1
    assert len(updated["components"]) == 1


def test_idempotency_key_prevents_double_commit(svc):
    page = run(svc.create_page(tenant_id=TENANT, owner_id=ACTOR))
    comps = [{"componentId": "cmp_001", "type": "barChart", "title": "Test"}]
    rev1 = run(svc.commit_revision(
        page_id=page["pageId"], tenant_id=TENANT, actor_id=ACTOR,
        commit_kind="prompt", commit_summary="First", components=comps,
        idempotency_key="ikey_idempotent",
    ))
    rev2 = run(svc.commit_revision(
        page_id=page["pageId"], tenant_id=TENANT, actor_id=ACTOR,
        commit_kind="prompt", commit_summary="Duplicate", components=comps,
        idempotency_key="ikey_idempotent",
    ))
    assert rev1["revisionId"] == rev2["revisionId"]
    # Head should still be 1
    updated = run(svc.get_page(page["pageId"], TENANT))
    assert updated["headRevision"] == 1


def test_rollback_creates_new_revision(svc):
    page = run(svc.create_page(tenant_id=TENANT, owner_id=ACTOR))
    comps_v1 = [{"componentId": "cmp_v1", "type": "barChart", "title": "V1"}]
    comps_v2 = [{"componentId": "cmp_v2", "type": "lineChart", "title": "V2"}]

    run(svc.commit_revision(
        page_id=page["pageId"], tenant_id=TENANT, actor_id=ACTOR,
        commit_kind="prompt", commit_summary="V1", components=comps_v1, idempotency_key="key_v1",
    ))
    run(svc.commit_revision(
        page_id=page["pageId"], tenant_id=TENANT, actor_id=ACTOR,
        commit_kind="prompt", commit_summary="V2", components=comps_v2, idempotency_key="key_v2",
    ))

    # Rollback to revision 1
    rollback_rev = run(svc.rollback(
        page_id=page["pageId"], tenant_id=TENANT, actor_id=ACTOR,
        target_revision=1, idempotency_key="key_rollback",
    ))
    assert rollback_rev["revisionNumber"] == 3
    assert rollback_rev["commitKind"] == "rollback"

    revisions = run(svc.list_revisions(page["pageId"], TENANT))
    assert len(revisions) == 3  # 3 revisions total


def test_list_revisions_returns_newest_first(svc):
    page = run(svc.create_page(tenant_id=TENANT, owner_id=ACTOR))
    for i in range(3):
        run(svc.commit_revision(
            page_id=page["pageId"], tenant_id=TENANT, actor_id=ACTOR,
            commit_kind="prompt", commit_summary=f"Rev {i+1}",
            components=[], idempotency_key=f"key_{i}",
        ))
    revisions = run(svc.list_revisions(page["pageId"], TENANT))
    assert revisions[0]["revisionNumber"] > revisions[-1]["revisionNumber"]


def test_tenant_isolation(svc):
    page = run(svc.create_page(tenant_id=TENANT, owner_id=ACTOR))
    # Different tenant cannot access the page
    result = run(svc.get_page(page["pageId"], "tenant_different_999"))
    assert result is None