"""Tests for OpenAPI endpoint parser module.

RED phase: written before implementation.
"""

from __future__ import annotations

import pytest

pytestmark = pytest.mark.unit

_MINIMAL_SPEC = {
    "openapi": "3.0.0",
    "info": {"title": "Test API", "version": "1.0.0"},
    "paths": {},
}

_GET_SPEC = {
    "openapi": "3.0.0",
    "info": {"title": "Orders API", "version": "1.0.0"},
    "paths": {
        "/orders/{order_id}": {
            "get": {
                "operationId": "get_order",
                "summary": "Get an order",
                "description": "Retrieves a single order by ID",
                "parameters": [
                    {
                        "name": "order_id",
                        "in": "path",
                        "required": True,
                        "schema": {"type": "string"},
                        "description": "The order identifier",
                    }
                ],
                "responses": {
                    "200": {
                        "description": "Order found",
                        "content": {
                            "application/json": {
                                "schema": {
                                    "type": "object",
                                    "properties": {"id": {"type": "string"}},
                                }
                            }
                        },
                    }
                },
            }
        }
    },
}

_POST_SPEC = {
    "openapi": "3.0.0",
    "info": {"title": "Orders API", "version": "1.0.0"},
    "paths": {
        "/orders": {
            "post": {
                "operationId": "create_order",
                "summary": "Create an order",
                "description": "Creates a new order",
                "requestBody": {
                    "required": True,
                    "content": {
                        "application/json": {
                            "schema": {
                                "type": "object",
                                "properties": {
                                    "item": {"type": "string"},
                                    "quantity": {"type": "integer"},
                                },
                            }
                        }
                    },
                },
                "responses": {"201": {"description": "Created"}},
            }
        }
    },
}

_MULTI_PARAM_SPEC = {
    "openapi": "3.0.0",
    "info": {"title": "Items API", "version": "1.0.0"},
    "paths": {
        "/items/{item_id}": {
            "get": {
                "operationId": "get_item",
                "summary": "Get item",
                "description": "",
                "parameters": [
                    {
                        "name": "item_id",
                        "in": "path",
                        "required": True,
                        "schema": {"type": "integer"},
                    },
                    {
                        "name": "include_details",
                        "in": "query",
                        "required": False,
                        "schema": {"type": "boolean"},
                    },
                ],
                "responses": {"200": {"description": "OK"}},
            }
        }
    },
}

_REF_SPEC = {
    "openapi": "3.0.0",
    "info": {"title": "Ref API", "version": "1.0.0"},
    "components": {
        "schemas": {
            "Item": {
                "type": "object",
                "properties": {"id": {"type": "string"}},
            }
        }
    },
    "paths": {
        "/items": {
            "get": {
                "operationId": "list_items",
                "summary": "List items",
                "description": "",
                "responses": {
                    "200": {
                        "description": "OK",
                        "content": {
                            "application/json": {
                                "schema": {"$ref": "#/components/schemas/Item"}
                            }
                        },
                    }
                },
            }
        }
    },
}

_MULTI_ENDPOINT_SPEC = {
    "openapi": "3.0.0",
    "info": {"title": "Multi API", "version": "1.0.0"},
    "paths": {
        "/users": {
            "get": {
                "operationId": "list_users",
                "summary": "List users",
                "description": "",
                "responses": {"200": {"description": "OK"}},
            },
            "post": {
                "operationId": "create_user",
                "summary": "Create user",
                "description": "",
                "responses": {"201": {"description": "Created"}},
            },
        },
        "/users/{id}": {
            "delete": {
                "operationId": "delete_user",
                "summary": "Delete user",
                "description": "",
                "parameters": [
                    {"name": "id", "in": "path", "required": True, "schema": {"type": "string"}}
                ],
                "responses": {"204": {"description": "Deleted"}},
            }
        },
    },
}


class TestParseEndpoints:
    """Tests for parse_endpoints function."""

    def test_empty_paths_returns_empty_tuple(self) -> None:
        """Spec with no paths yields no endpoints."""
        from app.openapi.parser import parse_endpoints

        result = parse_endpoints(_MINIMAL_SPEC)
        assert result == ()

    def test_parse_get_endpoint(self) -> None:
        """Parse a GET endpoint with path parameter."""
        from app.openapi.parser import parse_endpoints

        result = parse_endpoints(_GET_SPEC)
        assert len(result) == 1
        ep = result[0]
        assert ep.path == "/orders/{order_id}"
        assert ep.method == "GET"
        assert ep.operation_id == "get_order"
        assert ep.summary == "Get an order"

    def test_parse_get_endpoint_parameters(self) -> None:
        """Path parameters are extracted correctly."""
        from app.openapi.parser import parse_endpoints

        result = parse_endpoints(_GET_SPEC)
        ep = result[0]
        assert len(ep.parameters) == 1
        param = ep.parameters[0]
        assert param.name == "order_id"
        assert param.location == "path"
        assert param.required is True
        assert param.schema_type == "string"

    def test_parse_post_with_request_body(self) -> None:
        """POST endpoint with request body is extracted."""
        from app.openapi.parser import parse_endpoints

        result = parse_endpoints(_POST_SPEC)
        assert len(result) == 1
        ep = result[0]
        assert ep.method == "POST"
        assert ep.request_body_schema is not None
        assert ep.request_body_schema["type"] == "object"

    def test_parse_path_and_query_params(self) -> None:
        """Both path and query parameters are extracted."""
        from app.openapi.parser import parse_endpoints

        result = parse_endpoints(_MULTI_PARAM_SPEC)
        ep = result[0]
        locations = {p.location for p in ep.parameters}
        assert "path" in locations
        assert "query" in locations

    def test_autogenerate_operation_id_when_missing(self) -> None:
        """Auto-generate operation_id when not provided in spec."""
        from app.openapi.parser import parse_endpoints

        spec = {
            "openapi": "3.0.0",
            "info": {"title": "Test", "version": "1.0"},
            "paths": {
                "/things/{id}": {
                    "get": {
                        "summary": "Get thing",
                        "description": "",
                        "responses": {"200": {"description": "OK"}},
                    }
                }
            },
        }
        result = parse_endpoints(spec)
        ep = result[0]
        assert ep.operation_id != ""
        assert len(ep.operation_id) > 0

    def test_multiple_endpoints_extracted(self) -> None:
        """Multiple path+method combinations are all extracted."""
        from app.openapi.parser import parse_endpoints

        result = parse_endpoints(_MULTI_ENDPOINT_SPEC)
        assert len(result) == 3
        methods = {ep.method for ep in result}
        assert "GET" in methods
        assert "POST" in methods
        assert "DELETE" in methods

    def test_ref_in_response_schema_resolved(self) -> None:
        """$ref in response schema is resolved to the target schema."""
        from app.openapi.parser import parse_endpoints

        result = parse_endpoints(_REF_SPEC)
        ep = result[0]
        assert ep.response_schema is not None
        # Resolved ref should contain the properties
        assert "properties" in ep.response_schema or "$ref" not in ep.response_schema

    def test_result_is_tuple(self) -> None:
        """parse_endpoints returns a tuple (immutable)."""
        from app.openapi.parser import parse_endpoints

        result = parse_endpoints(_GET_SPEC)
        assert isinstance(result, tuple)

    def test_endpoint_info_is_frozen(self) -> None:
        """EndpointInfo instances are frozen/immutable."""
        from app.openapi.parser import parse_endpoints

        result = parse_endpoints(_GET_SPEC)
        ep = result[0]
        with pytest.raises((AttributeError, TypeError)):
            ep.method = "POST"  # type: ignore[misc]