"""Regression tests for API response contracts.

These tests lock down the shape of API responses to prevent
accidental breaking changes.
"""

import json
import pytest
from httpx import ASGITransport, AsyncClient
from unittest.mock import MagicMock, patch, AsyncMock


pytestmark = pytest.mark.regression


@pytest.fixture(autouse=True)
def disable_rate_limiting(monkeypatch):
    """Disable rate limiting for all regression tests."""
    import api.rate_limiter
    monkeypatch.setattr(api.rate_limiter, "_match_endpoint", lambda path, config: None)


@pytest.fixture
async def unauthenticated_client(in_memory_engine):
    """Client without mock auth — requests should be rejected."""
    from api.app import app
    import database

    original_engine = database.engine
    database.engine = in_memory_engine
    transport = ASGITransport(app=app)
    async with AsyncClient(transport=transport, base_url="http://test") as client:
        yield client
    database.engine = original_engine
    app.dependency_overrides.clear()


class TestStatusEndpoint:
    @pytest.mark.asyncio
    async def test_status_returns_ok(self, async_client):
        response = await async_client.get("/api/status")
        assert response.status_code == 200
        data = response.json()
        assert data["status"] == "OK"


class TestListingEndpoint:
    @pytest.mark.asyncio
    async def test_listing_has_listings_key(self, async_client):
        response = await async_client.get("/api/listing?limit=5")
        assert response.status_code == 200
        data = response.json()
        assert "listings" in data


class TestListingGeojsonEndpoint:
    @pytest.mark.asyncio
    async def test_listing_geojson_has_feature_collection_shape(self, async_client):
        response = await async_client.get("/api/listing_geojson?listing_type=RENT")
        assert response.status_code == 200
        data = response.json()
        assert data.get("type") == "FeatureCollection"
        assert "features" in data


class TestStreamEndpoint:
    @pytest.mark.asyncio
    async def test_stream_first_line_is_metadata(self, async_client):
        response = await async_client.get("/api/listing_geojson/stream?listing_type=RENT")
        assert response.status_code == 200
        lines = [line for line in response.text.strip().split("\n") if line.strip()]
        assert len(lines) >= 1
        first = json.loads(lines[0])
        assert first.get("type") == "metadata"
        assert "batch_size" in first
        assert "total_expected" in first
        assert "cached" in first

    @pytest.mark.asyncio
    async def test_stream_last_line_is_complete(self, async_client):
        response = await async_client.get("/api/listing_geojson/stream?listing_type=RENT")
        assert response.status_code == 200
        lines = [line for line in response.text.strip().split("\n") if line.strip()]
        assert len(lines) >= 1
        last = json.loads(lines[-1])
        assert last.get("type") == "complete"
        assert "total" in last


class TestTaskStatusEndpoint:
    @pytest.mark.asyncio
    async def test_task_status_response_shape(self, async_client):
        from services.task_service import TaskStatus
        mock_status = TaskStatus(
            task_id="test-123",
            status="SUCCESS",
            result=None,
            progress=1.0,
            processed=10,
            total=10,
            message="Done",
            error=None,
            traceback=None,
        )
        with patch("services.task_service.get_task_status", return_value=mock_status), \
             patch("services.task_service.get_user_tasks", return_value=["test-123"]):
            response = await async_client.get("/api/task_status?task_id=test-123")
        assert response.status_code == 200
        data = response.json()
        for key in ["task_id", "status", "result", "progress", "processed", "total", "message", "error", "traceback"]:
            assert key in data, f"Missing key: {key}"


class TestUnauthenticatedAccess:
    @pytest.mark.asyncio
    @pytest.mark.parametrize("method,path", [
        ("GET", "/api/listing"),
        ("GET", "/api/listing_geojson?listing_type=RENT"),
        ("GET", "/api/listing_geojson/stream?listing_type=RENT"),
        ("GET", "/api/task_status?task_id=test"),
        ("GET", "/api/tasks_for_user"),
        ("POST", "/api/refresh_listings?listing_type=RENT"),
        ("POST", "/api/cancel_task?task_id=test"),
        ("POST", "/api/clear_all_tasks"),
    ])
    async def test_unauthenticated_endpoints_return_error(
        self, unauthenticated_client, method, path
    ):
        if method == "GET":
            response = await unauthenticated_client.get(path)
        else:
            response = await unauthenticated_client.post(path)
        assert response.status_code in (401, 403), (
            f"{method} {path} returned {response.status_code}, expected 401 or 403"
        )