from __future__ import annotations

from contextlib import contextmanager
from uuid import uuid4

import pytest
from fastapi import Request, status

from dependencies import get_auth_session
from models import MiningOperationType, Project, User
from services.session import AuthSession, SessionTokens
from tests.utils.security import random_password, random_token


@pytest.fixture()
def auth_session_context(client):
    """Allow tests to swap the current auth session for the test app."""

    original_override = client.app.dependency_overrides[get_auth_session]

    @contextmanager
    def _use(user: User | None):
        def _override(request: Request) -> AuthSession:
            if user is None:
                session = AuthSession.anonymous()
            else:
                session = AuthSession(
                    tokens=SessionTokens(
                        access_token=random_token(),
                        refresh_token=random_token(),
                    )
                )
                session.user = user
            request.state.auth_session = session
            return session

        client.app.dependency_overrides[get_auth_session] = _override
        try:
            yield
        finally:
            client.app.dependency_overrides[get_auth_session] = original_override

    return _use


def _unique(name: str) -> str:
    return f"{name}-{uuid4().hex}"


def _create_user(uow, *, roles: tuple[str, ...] = (), is_superuser: bool = False) -> User:
    assert uow.users and uow.roles
    uow.ensure_default_roles()
    user = User(
        email=f"{_unique('user')}@example.com",
        username=_unique('user'),
        password_hash=User.hash_password(random_password()),
        is_active=True,
        is_superuser=is_superuser,
    )
    uow.users.create(user)
    uow.flush()

    for role_name in roles:
        role = uow.roles.get_by_name(role_name)
        if role is None:  # pragma: no cover - defensive guard
            raise AssertionError(f"Role {role_name} not found")
        uow.users.assign_role(user_id=user.id, role_id=role.id)
    return uow.users.get(user.id, with_roles=True)


def _create_project(uow) -> Project:
    assert uow.projects
    project = Project(
        name=_unique('project'),
        location="Integration Site",
        operation_type=MiningOperationType.OPEN_PIT,
    )
    uow.projects.create(project)
    uow.flush()
    return project


class TestAuthenticationRequirements:
    def test_api_projects_list_requires_login(self, client, auth_session_context):
        with auth_session_context(None):
            response = client.get("/projects")

        assert response.status_code == status.HTTP_401_UNAUTHORIZED
        assert response.json()["detail"] == "Authentication required."

    def test_ui_project_list_requires_login(self, client, auth_session_context):
        with auth_session_context(None):
            response = client.get("/projects/ui")

        assert response.status_code == status.HTTP_401_UNAUTHORIZED


class TestRoleRestrictions:
    def test_api_projects_create_forbidden_for_viewer(
        self,
        client,
        auth_session_context,
        unit_of_work_factory,
    ) -> None:
        with unit_of_work_factory() as uow:
            viewer = _create_user(uow, roles=("viewer",))

        payload = {
            "name": _unique("project"),
            "location": "Restricted",
            "operation_type": MiningOperationType.OPEN_PIT.value,
            "description": "Test restriction",
        }
        with auth_session_context(viewer):
            response = client.post("/projects", json=payload)

        assert response.status_code == status.HTTP_403_FORBIDDEN
        assert response.json()[
            "detail"] == "Insufficient permissions for this action."

    def test_api_projects_create_allows_project_manager(
        self,
        client,
        auth_session_context,
        unit_of_work_factory,
    ) -> None:
        with unit_of_work_factory() as uow:
            manager = _create_user(uow, roles=("project_manager",))

        payload = {
            "name": _unique("managed-project"),
            "location": "Permitted",
            "operation_type": MiningOperationType.OPEN_PIT.value,
            "description": "Authorized creation",
        }
        with auth_session_context(manager):
            response = client.post("/projects", json=payload)

        assert response.status_code == status.HTTP_201_CREATED
        assert response.json()["name"] == payload["name"]

    def test_api_projects_update_forbidden_for_viewer(
        self,
        client,
        auth_session_context,
        unit_of_work_factory,
    ) -> None:
        with unit_of_work_factory() as uow:
            project = _create_project(uow)
            viewer = _create_user(uow, roles=("viewer",))

        with auth_session_context(viewer):
            response = client.put(
                f"/projects/{project.id}",
                json={"description": "Updated"},
            )

        assert response.status_code == status.HTTP_403_FORBIDDEN
        assert response.json()[
            "detail"] == "Insufficient role permissions for this action."

    def test_api_projects_update_allows_manager(
        self,
        client,
        auth_session_context,
        unit_of_work_factory,
    ) -> None:
        with unit_of_work_factory() as uow:
            project = _create_project(uow)
            manager = _create_user(uow, roles=("project_manager",))

        updated_description = "Manager updated description"
        with auth_session_context(manager):
            response = client.put(
                f"/projects/{project.id}",
                json={"description": updated_description},
            )

        assert response.status_code == status.HTTP_200_OK
        assert response.json()["description"] == updated_description

    def test_ui_project_edit_forbidden_for_viewer(
        self,
        client,
        auth_session_context,
        unit_of_work_factory,
    ) -> None:
        with unit_of_work_factory() as uow:
            project = _create_project(uow)
            viewer = _create_user(uow, roles=("viewer",))

        with auth_session_context(viewer):
            response = client.get(f"/projects/{project.id}/edit")

        assert response.status_code == status.HTTP_403_FORBIDDEN
        assert response.json()[
            "detail"] == "Insufficient role permissions for this action."

    def test_ui_project_edit_accessible_to_manager(
        self,
        client,
        auth_session_context,
        unit_of_work_factory,
    ) -> None:
        with unit_of_work_factory() as uow:
            project = _create_project(uow)
            manager = _create_user(uow, roles=("project_manager",))

        with auth_session_context(manager):
            response = client.get(f"/projects/{project.id}/edit")

        assert response.status_code == status.HTTP_200_OK
        assert response.template.name == "projects/form.html"