"""Tests for API routes."""

import pytest
from fastapi.testclient import TestClient
from app.main import app


@pytest.fixture
def client():
    """Create test client."""
    return TestClient(app)


@pytest.fixture
def sample_initial_state():
    """Sample initial state string."""
    return "5;5;2;1;2,2,4,4;;0,0"


@pytest.fixture
def sample_traffic():
    """Sample traffic string for 5x5 grid."""
    segments = []
    # Horizontal segments
    for x in range(4):
        for y in range(5):
            segments.append(f"{x},{y},{x+1},{y},1")
    # Vertical segments
    for x in range(5):
        for y in range(4):
            segments.append(f"{x},{y},{x},{y+1},1")
    return ";".join(segments)


class TestHealthEndpoint:
    """Tests for health check endpoint."""

    def test_health_check(self, client):
        """Test health check returns ok."""
        response = client.get("/api/health")
        assert response.status_code == 200
        assert response.json()["status"] == "ok"


class TestAlgorithmsEndpoint:
    """Tests for algorithms endpoint."""

    def test_list_algorithms(self, client):
        """Test listing available algorithms."""
        response = client.get("/api/algorithms")
        assert response.status_code == 200

        data = response.json()
        assert "algorithms" in data
        assert len(data["algorithms"]) == 8  # 8 algorithms

        # Check algorithm structure
        algo = data["algorithms"][0]
        assert "code" in algo
        assert "name" in algo
        assert "description" in algo

    def test_algorithms_codes(self, client):
        """Test all expected algorithm codes are present."""
        response = client.get("/api/algorithms")
        data = response.json()

        codes = [a["code"] for a in data["algorithms"]]
        expected = ["BF", "DF", "ID", "UC", "GR1", "GR2", "AS1", "AS2"]
        assert set(codes) == set(expected)


class TestGenerateGridEndpoint:
    """Tests for grid generation endpoint."""

    def test_generate_default_grid(self, client):
        """Test generating grid with default config."""
        response = client.post("/api/grid/generate", json={})
        assert response.status_code == 200

        data = response.json()
        assert "initial_state" in data
        assert "traffic" in data
        assert "parsed" in data

    def test_generate_custom_grid(self, client):
        """Test generating grid with custom config."""
        response = client.post(
            "/api/grid/generate",
            json={
                "width": 8,
                "height": 8,
                "num_stores": 2,
                "num_destinations": 3,
                "num_tunnels": 1,
                "obstacle_density": 0.1,
            },
        )
        assert response.status_code == 200

        data = response.json()
        parsed = data["parsed"]
        assert parsed["width"] == 8
        assert parsed["height"] == 8
        assert len(parsed["stores"]) == 2
        assert len(parsed["destinations"]) == 3

    def test_generate_grid_parsed_structure(self, client):
        """Test parsed grid structure."""
        response = client.post("/api/grid/generate", json={"width": 5, "height": 5})
        data = response.json()
        parsed = data["parsed"]

        assert "width" in parsed
        assert "height" in parsed
        assert "stores" in parsed
        assert "destinations" in parsed
        assert "tunnels" in parsed
        assert "segments" in parsed

    def test_generate_grid_stores_structure(self, client):
        """Test store structure in response."""
        response = client.post(
            "/api/grid/generate",
            json={"width": 5, "height": 5, "num_stores": 1},
        )
        data = response.json()
        store = data["parsed"]["stores"][0]

        assert "id" in store
        assert "position" in store
        assert "x" in store["position"]
        assert "y" in store["position"]


class TestPathEndpoint:
    """Tests for path finding endpoint."""

    def test_find_path(self, client):
        """Test finding path between two points."""
        # First generate a grid
        gen_response = client.post(
            "/api/grid/generate",
            json={"width": 5, "height": 5, "num_stores": 1, "num_destinations": 1},
        )
        grid_data = gen_response.json()["parsed"]

        # Find path from store to destination
        store = grid_data["stores"][0]
        dest = grid_data["destinations"][0]

        response = client.post(
            "/api/search/path",
            json={
                "grid_width": 5,
                "grid_height": 5,
                "start": store["position"],
                "goal": dest["position"],
                "segments": grid_data["segments"],
                "tunnels": grid_data["tunnels"],
                "strategy": "BF",
            },
        )
        assert response.status_code == 200

        data = response.json()
        assert "plan" in data
        assert "cost" in data
        assert "nodes_expanded" in data
        assert "path" in data
        assert "runtime_ms" in data
        assert "memory_kb" in data

    def test_find_path_all_strategies(self, client):
        """Test path finding with all strategies."""
        gen_response = client.post(
            "/api/grid/generate",
            json={"width": 5, "height": 5, "num_stores": 1, "num_destinations": 1},
        )
        grid_data = gen_response.json()["parsed"]
        store = grid_data["stores"][0]
        dest = grid_data["destinations"][0]

        strategies = ["BF", "DF", "ID", "UC", "GR1", "GR2", "AS1", "AS2"]
        for strategy in strategies:
            response = client.post(
                "/api/search/path",
                json={
                    "grid_width": 5,
                    "grid_height": 5,
                    "start": store["position"],
                    "goal": dest["position"],
                    "segments": grid_data["segments"],
                    "tunnels": grid_data["tunnels"],
                    "strategy": strategy,
                },
            )
            assert response.status_code == 200, f"Strategy {strategy} failed"

    def test_find_path_with_visualization(self, client):
        """Test path finding returns visualization steps."""
        gen_response = client.post(
            "/api/grid/generate",
            json={"width": 5, "height": 5, "num_stores": 1, "num_destinations": 1},
        )
        grid_data = gen_response.json()["parsed"]
        store = grid_data["stores"][0]
        dest = grid_data["destinations"][0]

        response = client.post(
            "/api/search/path",
            json={
                "grid_width": 5,
                "grid_height": 5,
                "start": store["position"],
                "goal": dest["position"],
                "segments": grid_data["segments"],
                "tunnels": grid_data["tunnels"],
                "strategy": "BF",
            },
        )
        data = response.json()

        # Steps should be included
        assert "steps" in data
        assert data["steps"] is not None
        assert len(data["steps"]) > 0


class TestPlanEndpoint:
    """Tests for delivery planning endpoint."""

    def test_create_plan(self, client, sample_initial_state, sample_traffic):
        """Test creating delivery plan."""
        response = client.post(
            "/api/search/plan",
            json={
                "initial_state": sample_initial_state,
                "traffic": sample_traffic,
                "strategy": "BF",
                "visualize": False,
            },
        )
        assert response.status_code == 200

        data = response.json()
        assert "output" in data
        assert "assignments" in data
        assert "total_cost" in data
        assert "total_nodes_expanded" in data
        assert "runtime_ms" in data
        assert "memory_kb" in data

    def test_create_plan_all_strategies(self, client, sample_initial_state, sample_traffic):
        """Test planning with all strategies."""
        strategies = ["BF", "DF", "ID", "UC", "GR1", "GR2", "AS1", "AS2"]
        for strategy in strategies:
            response = client.post(
                "/api/search/plan",
                json={
                    "initial_state": sample_initial_state,
                    "traffic": sample_traffic,
                    "strategy": strategy,
                    "visualize": False,
                },
            )
            assert response.status_code == 200, f"Strategy {strategy} failed"

    def test_plan_assignments_structure(self, client, sample_initial_state, sample_traffic):
        """Test plan assignments structure."""
        response = client.post(
            "/api/search/plan",
            json={
                "initial_state": sample_initial_state,
                "traffic": sample_traffic,
                "strategy": "BF",
                "visualize": False,
            },
        )
        data = response.json()

        # Should have 2 assignments (2 destinations in sample)
        assert len(data["assignments"]) == 2

        assignment = data["assignments"][0]
        assert "store_id" in assignment
        assert "destination_id" in assignment
        assert "path" in assignment


class TestCompareEndpoint:
    """Tests for algorithm comparison endpoint."""

    def test_compare_algorithms(self, client, sample_initial_state, sample_traffic):
        """Test comparing all algorithms."""
        response = client.post(
            "/api/search/compare",
            json={
                "initial_state": sample_initial_state,
                "traffic": sample_traffic,
            },
        )
        assert response.status_code == 200

        data = response.json()
        assert "comparisons" in data
        assert "optimal_cost" in data
        assert len(data["comparisons"]) == 8  # 8 algorithms

    def test_compare_result_structure(self, client, sample_initial_state, sample_traffic):
        """Test comparison result structure."""
        response = client.post(
            "/api/search/compare",
            json={
                "initial_state": sample_initial_state,
                "traffic": sample_traffic,
            },
        )
        data = response.json()
        result = data["comparisons"][0]

        assert "algorithm" in result
        assert "name" in result
        assert "plan" in result
        assert "cost" in result
        assert "nodes_expanded" in result
        assert "runtime_ms" in result
        assert "memory_kb" in result
        assert "is_optimal" in result

    def test_compare_marks_optimal(self, client, sample_initial_state, sample_traffic):
        """Test that optimal solutions are marked."""
        response = client.post(
            "/api/search/compare",
            json={
                "initial_state": sample_initial_state,
                "traffic": sample_traffic,
            },
        )
        data = response.json()

        # At least one should be marked optimal
        optimal_count = sum(1 for r in data["comparisons"] if r["is_optimal"])
        assert optimal_count >= 1

        # Optimal results should have cost equal to optimal_cost
        for result in data["comparisons"]:
            if result["is_optimal"]:
                assert result["cost"] == data["optimal_cost"]

    def test_compare_ucs_astar_optimal(self, client, sample_initial_state, sample_traffic):
        """Test UCS and A* find optimal solutions."""
        response = client.post(
            "/api/search/compare",
            json={
                "initial_state": sample_initial_state,
                "traffic": sample_traffic,
            },
        )
        data = response.json()

        ucs = next(r for r in data["comparisons"] if r["algorithm"] == "UC")
        astar = next(r for r in data["comparisons"] if r["algorithm"] == "AS1")

        # Both should find optimal cost
        assert ucs["cost"] == data["optimal_cost"]
        assert astar["cost"] == data["optimal_cost"]


class TestErrorHandling:
    """Tests for API error handling."""

    def test_invalid_strategy(self, client, sample_initial_state, sample_traffic):
        """Test error on invalid strategy."""
        response = client.post(
            "/api/search/plan",
            json={
                "initial_state": sample_initial_state,
                "traffic": sample_traffic,
                "strategy": "INVALID",
                "visualize": False,
            },
        )
        # Should return validation error or internal error
        assert response.status_code in [400, 422, 500]

    def test_invalid_grid_dimensions(self, client):
        """Test error on invalid grid dimensions."""
        response = client.post(
            "/api/grid/generate",
            json={"width": -1, "height": 5},
        )
        # Should return validation error
        assert response.status_code in [400, 422, 500]