# ABOUTME: Tests for health and metrics endpoints.
# ABOUTME: Covers /healthz DB check and /metrics Prometheus format.

import os
from unittest.mock import MagicMock

import pytest


def make_test_settings(
    csrf_secret: str = "test-secret",
    trusted_proxy_ips: str = "127.0.0.1",
    metrics_enabled: bool = True,
):
    """Create Settings for testing by setting env vars temporarily."""
    from animaltrack.config import Settings

    old_env = os.environ.copy()
    try:
        os.environ["CSRF_SECRET"] = csrf_secret
        os.environ["TRUSTED_PROXY_IPS"] = trusted_proxy_ips
        os.environ["METRICS_ENABLED"] = str(metrics_enabled).lower()
        return Settings()
    finally:
        os.environ.clear()
        os.environ.update(old_env)


class TestHealthzEndpoint:
    """Tests for /healthz endpoint."""

    @pytest.fixture
    def client(self, seeded_db):
        """Create a test client for the app."""
        from starlette.testclient import TestClient

        from animaltrack.web.app import create_app

        settings = make_test_settings(trusted_proxy_ips="testclient")
        app, rt = create_app(settings=settings, db=seeded_db)
        return TestClient(app, raise_server_exceptions=False)

    def test_healthz_returns_200_when_db_healthy(self, client):
        """GET /healthz returns 200 OK when database is healthy."""
        resp = client.get("/healthz")
        assert resp.status_code == 200
        assert resp.text == "OK"

    def test_healthz_returns_503_when_db_fails(self, seeded_db):
        """GET /healthz returns 503 when database query fails."""
        from starlette.testclient import TestClient

        from animaltrack.web.app import create_app

        # Create a mock db that raises on execute
        mock_db = MagicMock()
        mock_db.execute.side_effect = Exception("Database connection lost")

        settings = make_test_settings(trusted_proxy_ips="testclient")
        app, rt = create_app(settings=settings, db=mock_db)
        client = TestClient(app, raise_server_exceptions=False)

        resp = client.get("/healthz")
        assert resp.status_code == 503
        assert "Database error" in resp.text


class TestMetricsEndpoint:
    """Tests for /metrics Prometheus endpoint."""

    @pytest.fixture
    def client_metrics_enabled(self, seeded_db):
        """Create a test client with metrics enabled."""
        from starlette.testclient import TestClient

        from animaltrack.web.app import create_app

        settings = make_test_settings(
            trusted_proxy_ips="testclient",
            metrics_enabled=True,
        )
        app, rt = create_app(settings=settings, db=seeded_db)
        return TestClient(app, raise_server_exceptions=False)

    @pytest.fixture
    def client_metrics_disabled(self, seeded_db):
        """Create a test client with metrics disabled."""
        from starlette.testclient import TestClient

        from animaltrack.web.app import create_app

        settings = make_test_settings(
            trusted_proxy_ips="testclient",
            metrics_enabled=False,
        )
        app, rt = create_app(settings=settings, db=seeded_db)
        return TestClient(app, raise_server_exceptions=False)

    def test_metrics_returns_200_when_enabled(self, client_metrics_enabled):
        """GET /metrics returns 200 when metrics_enabled=True."""
        resp = client_metrics_enabled.get("/metrics")
        assert resp.status_code == 200

    def test_metrics_returns_404_when_disabled(self, client_metrics_disabled):
        """GET /metrics returns 404 when metrics_enabled=False."""
        resp = client_metrics_disabled.get("/metrics")
        assert resp.status_code == 404

    def test_metrics_returns_prometheus_format(self, client_metrics_enabled):
        """GET /metrics returns valid Prometheus text format."""
        resp = client_metrics_enabled.get("/metrics")

        # Check Content-Type
        content_type = resp.headers.get("content-type", "")
        assert "text/plain" in content_type

        # Check body contains Prometheus format elements
        body = resp.text
        assert "# HELP" in body
        assert "# TYPE" in body
        assert "animaltrack_up" in body

    def test_metrics_includes_db_health_metric(self, client_metrics_enabled):
        """GET /metrics includes database health gauge."""
        resp = client_metrics_enabled.get("/metrics")
        body = resp.text

        assert "animaltrack_db_healthy" in body
        assert "# TYPE animaltrack_db_healthy gauge" in body