"""Tests for authorization bypass prevention.

This module tests authorization and access control to ensure:
1. Users cannot access other users' tasks without permission
2. Role-based access control is enforced
3. Resource ownership is properly validated
4. IDOR (Insecure Direct Object Reference) attacks are prevented
5. Privilege escalation is blocked

Note: These tests verify model-level validation.
Actual authorization is enforced at the API/service layer.
"""

import pytest

from mahavishnu.core.task_models import (
    TaskCreateRequest,
    TaskFilter,
    TaskUpdateRequest,
)


class TestInputValidationForAuth:
    """Tests for input validation that supports authorization.

    These tests verify that inputs are properly validated and sanitized,
    which is essential for secure authorization checks.
    """

    def test_user_id_format_validation(self):
        """Test that user IDs in filters are accepted in valid format."""
        # assigned_to field accepts various formats
        filter_obj = TaskFilter(assigned_to="user-123")
        assert filter_obj.assigned_to == "user-123"

    def test_user_id_with_special_chars(self):
        """Test that user IDs with valid characters are accepted."""
        filter_obj = TaskFilter(assigned_to="user_456")
        assert filter_obj.assigned_to == "user_456"

    def test_repository_isolation_pattern(self):
        """Test that repository names support isolation patterns."""
        # Valid repository names support multi-tenant patterns
        request = TaskCreateRequest(
            title="Test",
            repository="tenant-a-project",
        )
        assert request.repository == "tenant-a-project"


class TestIDORPrevention:
    """Tests for Insecure Direct Object Reference prevention.

    IDOR attacks occur when users can access resources by guessing IDs.
    Prevention is at the API layer, but model validation supports it.
    """

    def test_task_id_not_in_create(self):
        """Test that task ID cannot be specified in create request.

        IDs should be server-generated to prevent ID manipulation.
        """
        # TaskCreateRequest doesn't have an id field
        request = TaskCreateRequest(title="Test", repository="test-repo")
        assert not hasattr(request, "id") or request.id is None

    def test_filter_by_assigned_to(self):
        """Test that filtering by assigned_to is supported.

        This supports the common pattern of 'show only my tasks'.
        """
        filter_obj = TaskFilter(assigned_to="current-user-id")
        assert filter_obj.assigned_to == "current-user-id"

    def test_filter_by_repository(self):
        """Test that filtering by repository is supported.

        This supports repository-level access control.
        """
        filter_obj = TaskFilter(repository="authorized-repo")
        assert filter_obj.repository == "authorized-repo"


class TestPrivilegeEscalationPrevention:
    """Tests for privilege escalation prevention.

    Privilege escalation occurs when users can elevate their permissions.
    Model validation supports prevention by limiting what can be changed.
    """

    def test_status_transitions_limited(self):
        """Test that status field has limited valid values."""
        valid_statuses = ["pending", "in_progress", "blocked", "completed", "cancelled"]
        for status in valid_statuses:
            update = TaskUpdateRequest(status=status)
            assert update.status == status

    def test_invalid_status_rejected(self):
        """Test that invalid status values are rejected."""
        with pytest.raises(Exception):
            TaskUpdateRequest(status="admin")

    def test_priority_transitions_limited(self):
        """Test that priority field has limited valid values."""
        valid_priorities = ["low", "medium", "high", "critical"]
        for priority in valid_priorities:
            update = TaskUpdateRequest(priority=priority)
            assert update.priority == priority

    def test_invalid_priority_rejected(self):
        """Test that invalid priority values are rejected."""
        with pytest.raises(Exception):
            TaskUpdateRequest(priority="superuser")


class TestResourceOwnership:
    """Tests for resource ownership validation.

    These tests verify that model fields support ownership tracking.
    """

    def test_metadata_can_track_ownership(self):
        """Test that metadata field can be used for ownership info."""
        request = TaskCreateRequest(
            title="Test",
            repository="test-repo",
            metadata={"owner_id": "user-123", "team_id": "team-456"},
        )
        assert request.metadata["owner_id"] == "user-123"

    def test_tags_can_track_access_control(self):
        """Test that tags can be used for access control grouping."""
        request = TaskCreateRequest(
            title="Test",
            repository="test-repo",
            tags=["team-alpha", "confidential"],
        )
        assert "team-alpha" in request.tags


class TestAuditTrailSupport:
    """Tests for audit trail support in models.

    These tests verify that model validation supports audit logging.
    """

    def test_created_by_not_in_create(self):
        """Test that created_by is not in create request.

        The created_by should be set by the service layer from auth context,
        not from user input, to prevent spoofing.
        """
        request = TaskCreateRequest(title="Test", repository="test-repo")
        # created_by should not be a user-controllable field
        assert not hasattr(request, "created_by")

    def test_update_request_partial(self):
        """Test that update requests can be partial.

        This supports audit logging of 'what changed'.
        """
        update = TaskUpdateRequest(title="New Title")
        assert update.title == "New Title"
        assert update.status is None
        assert update.priority is None


class TestMassAssignmentPrevention:
    """Tests for mass assignment attack prevention.

    Mass assignment occurs when users can modify fields they shouldn't.
    """

    def test_id_cannot_be_mass_assigned(self):
        """Test that ID cannot be set via mass assignment."""
        request = TaskCreateRequest(title="Test", repository="test-repo")
        # id should be server-generated
        assert not hasattr(request, "id")

    def test_created_at_cannot_be_mass_assigned(self):
        """Test that created_at cannot be set via mass assignment."""
        request = TaskCreateRequest(title="Test", repository="test-repo")
        # Timestamps should be server-generated
        assert not hasattr(request, "created_at")

    def test_updated_at_cannot_be_mass_assigned(self):
        """Test that updated_at cannot be set via mass assignment."""
        request = TaskCreateRequest(title="Test", repository="test-repo")
        assert not hasattr(request, "updated_at")


class TestFilterAuthorization:
    """Tests for filter-based authorization support."""

    def test_status_filter_supports_rbac(self):
        """Test that status filtering supports role-based patterns.

        Different roles might see different task statuses.
        """
        filter_obj = TaskFilter(status="in_progress")
        assert filter_obj.status == "in_progress"

    def test_combined_filters_support_complex_auth(self):
        """Test that combined filters support complex authorization."""
        filter_obj = TaskFilter(
            status="in_progress",
            priority="high",
            repository="critical-repo",
            assigned_to="user-123",
        )
        assert filter_obj.status == "in_progress"
        assert filter_obj.priority == "high"
        assert filter_obj.repository == "critical-repo"

    def test_limit_prevents_data_harvesting(self):
        """Test that limit has a maximum to prevent mass data extraction."""
        # Maximum limit is 1000
        with pytest.raises(Exception):
            TaskFilter(limit=10000)

    def test_offset_validation(self):
        """Test that offset is validated."""
        filter_obj = TaskFilter(offset=100)
        assert filter_obj.offset == 100

        # Negative offset is rejected
        with pytest.raises(Exception):
            TaskFilter(offset=-1)


class TestBoundaryConditions:
    """Tests for authorization boundary conditions."""

    def test_empty_assigned_to(self):
        """Test that empty assigned_to is handled."""
        filter_obj = TaskFilter(assigned_to=None)
        assert filter_obj.assigned_to is None

    def test_empty_repository_filter(self):
        """Test that empty repository filter is handled."""
        filter_obj = TaskFilter(repository=None)
        assert filter_obj.repository is None

    def test_all_fields_none_filter(self):
        """Test that filter with all None values is valid."""
        filter_obj = TaskFilter()
        assert filter_obj.status is None
        assert filter_obj.priority is None
        assert filter_obj.repository is None
        assert filter_obj.assigned_to is None
