import pytest

from netbox_services.engine.allocators import (
    CreateAllocator,
    FirstFreeIPAddressAllocator,
    SpecificAllocator,
)


@pytest.mark.django_db
class TestFirstFreeIPAddressAllocator:
    def test_allocate_creates_ip(self, db):
        from ipam.models import IPAddress, Prefix
        from netbox_services.engine.context import Context

        Prefix.objects.create(prefix="10.99.0.0/24")
        allocator = FirstFreeIPAddressAllocator({
            "strategy": "first_free",
            "prefix": {"type": "prefix", "filters": {}},
        })
        ip = allocator.allocate(Context(service=None))
        assert ip is not None
        assert "10.99.0." in str(ip.address)

    def test_no_prefix_raises(self, db):
        from netbox_services.engine.context import Context
        allocator = FirstFreeIPAddressAllocator({
            "strategy": "first_free",
            "prefix": {"type": "prefix", "filters": {"description": "no-such-prefix"}},
        })
        with pytest.raises(ValueError):
            allocator.allocate(Context(service=None))


@pytest.mark.django_db
class TestSpecificAllocator:
    def test_specific_address(self, db):
        from netbox_services.engine.context import Context
        allocator = SpecificAllocator({"strategy": "specific", "address": "10.50.0.1/24"})
        ip = allocator.allocate(Context(service=None))
        assert str(ip.address) == "10.50.0.1/24"

    def test_specific_requires_address_or_path(self, db):
        from netbox_services.engine.context import Context
        allocator = SpecificAllocator({"strategy": "specific"})
        with pytest.raises(ValueError):
            allocator.allocate(Context(service=None))


@pytest.mark.django_db
class TestCreateAllocator:
    def test_create_returns_unsaved_instance(self, db):
        from dcim.models import Device, DeviceRole, DeviceType, Manufacturer, Site
        from netbox_services.engine.context import Context

        mfr = Manufacturer.objects.create(name="alloc-mfr", slug="alloc-mfr")
        dt = DeviceType.objects.create(manufacturer=mfr, model="alloc-model", slug="alloc-model")
        role = DeviceRole.objects.create(name="alloc-role", slug="alloc-role")
        site = Site.objects.create(name="alloc-site", slug="alloc-site")

        allocator = CreateAllocator({
            "strategy": "create",
            "attrs": {
                "name": "test-device",
                "device_type": dt.pk,
                "role": role.pk,
                "site": site.pk,
                "status": "active",
            },
        })
        ctx = Context(service=None)
        obj = allocator.allocate(ctx, model=Device)
        assert obj.pk is None
        assert obj.name == "test-device"
        assert obj.device_type == dt
        assert obj.role == role
        assert obj.site == site
        assert obj.status == "active"

    def test_create_with_jinja2_attrs(self, db):
        from dcim.models import Device, DeviceRole, DeviceType, Manufacturer, Site
        from tenancy.models import Tenant
        from netbox_services.engine.context import Context

        mfr = Manufacturer.objects.create(name="jinja-mfr", slug="jinja-mfr")
        dt = DeviceType.objects.create(manufacturer=mfr, model="jinja-model", slug="jinja-model")
        role = DeviceRole.objects.create(name="jinja-role", slug="jinja-role")
        site = Site.objects.create(name="jinja-site", slug="jinja-site")
        tenant = Tenant.objects.create(name="jinja-tenant", slug="jinja-tenant")

        service = type("FakeService", (), {"tenant": tenant})()
        parent = Device(name="parent-dev", device_type=dt, role=role, site=site)

        allocator = CreateAllocator({
            "strategy": "create",
            "attrs": {
                "name": "rtr-{{ service.tenant.slug }}-{{ index + 1 }}",
                "device_type": dt.pk,
                "role": role.pk,
                "site": "{{ ..site.pk }}",
                "status": "active",
            },
        })
        ctx = Context(service=service, parent_object=parent)
        obj = allocator.allocate(ctx, model=Device, index=0, ancestors=[parent])
        assert obj.name == "rtr-jinja-tenant-1"
        assert obj.site == site

    def test_create_requires_model(self, db):
        from netbox_services.engine.context import Context
        allocator = CreateAllocator({"strategy": "create", "attrs": {}})
        with pytest.raises(ValueError):
            allocator.allocate(Context(service=None))