from django.test import TestCase
from modules.task_management.serializers import TaskSerializer
from rest_framework.exceptions import ValidationError
from django.contrib.auth import get_user_model
from modules.task_management.models import Task, TaskWorkHoursTable
from modules.fleet.models import Vehicle, WorkOrder
from modules.crm.models import Client


class TaskSerializerTests(TestCase):
    def setUp(self):
        User = get_user_model()
        self.user = User.objects.create_user(username="task-user-base", email="task-user-base@example.test", password="pass")
        self.client = Client.objects.create(name="Klijent zadatka")
        self.vehicle = Vehicle.objects.create(
            registration_number="ZG-TSK-01",
            asset_type='crane',
            make='Liebherr',
            model='LTM',
            crane_serial_number='123456',
            client=self.client,
            is_company_vehicle=False,
        )

    def test_validate_title_too_short_raises(self):
        serializer = TaskSerializer(data={"title": "ab", "description": "", "status": "aktivan", "vehicle": str(self.vehicle.id)})
        with self.assertRaises(ValidationError):
            serializer.is_valid(raise_exception=True)

    def test_validate_title_ok(self):
        serializer = TaskSerializer(data={"title": "Valid title", "description": "", "status": "aktivan", "vehicle": str(self.vehicle.id)})
        assert serializer.is_valid(), serializer.errors

    def test_cannot_close_without_work_order(self):
        serializer = TaskSerializer(data={"title": "Task 1", "description": "", "status": "neaktivan", "vehicle": str(self.vehicle.id)})
        with self.assertRaises(ValidationError):
            serializer.is_valid(raise_exception=True)

    def test_can_close_with_work_order(self):
        work_order = WorkOrder.objects.create(vehicle=self.vehicle, creator=self.user, purpose='defektaza')
        task = Task.objects.create(title="Task 2", description="", status="servis", assigned_to=self.user, vehicle=self.vehicle)

        serializer = TaskSerializer(instance=task, data={"status": "neaktivan", "work_order": str(work_order.id)}, partial=True)
        assert serializer.is_valid(), serializer.errors

    def test_cannot_mark_finished_without_work_order(self):
        serializer = TaskSerializer(data={"title": "Task 3", "description": "", "status": "zavrsen", "vehicle": str(self.vehicle.id)})
        with self.assertRaises(ValidationError):
            serializer.is_valid(raise_exception=True)

    def test_can_mark_finished_with_work_order(self):
        work_order = WorkOrder.objects.create(vehicle=self.vehicle, creator=self.user, purpose='kontrola')
        task = Task.objects.create(title="Task 4", description="", status="servis", assigned_to=self.user, vehicle=self.vehicle)

        serializer = TaskSerializer(instance=task, data={"status": "zavrsen", "work_order": str(work_order.id)}, partial=True)
        assert serializer.is_valid(), serializer.errors

    def test_scheduled_date_is_optional_on_create(self):
        serializer = TaskSerializer(data={"title": "Task planned", "status": "aktivan", "vehicle": str(self.vehicle.id)})
        assert serializer.is_valid(), serializer.errors
        assert 'scheduled_date' not in serializer.errors

    def test_scheduled_date_is_included_in_serialized_output(self):
        import datetime
        task = Task.objects.create(
            title="Task with date",
            assigned_to=self.user,
            vehicle=self.vehicle,
            scheduled_date=datetime.date(2026, 9, 1),
        )
        serializer = TaskSerializer(instance=task)
        assert 'scheduled_date' in serializer.data
        assert str(serializer.data['scheduled_date']) == '2026-09-01'

    def test_scheduled_date_can_be_null_in_serialized_output(self):
        task = Task.objects.create(title="Task no date", assigned_to=self.user, vehicle=self.vehicle)
        serializer = TaskSerializer(instance=task)
        assert serializer.data['scheduled_date'] is None

    def test_vehicle_details_are_included_in_serialized_output(self):
        task = Task.objects.create(title="Task crane details", assigned_to=self.user, vehicle=self.vehicle)
        serializer = TaskSerializer(instance=task)
        assert serializer.data['vehicle_make'] == 'Liebherr'
        assert serializer.data['vehicle_model'] == 'LTM'
        assert serializer.data['crane_serial_number'] == '123456'
        assert serializer.data['vehicle_owner_name'] == 'Klijent zadatka'
        assert serializer.data['vehicle_asset_type'] == 'crane'

    def test_work_hours_table_is_included_in_serialized_output(self):
        task = Task.objects.create(title="Task work hours", assigned_to=self.user, vehicle=self.vehicle)
        TaskWorkHoursTable.objects.create(
            task=task,
            data={
                'rows': [
                    {'date': '12.07.2026', 'work_hours': '8', 'travel_hours': '2'},
                ]
            },
        )

        serializer = TaskSerializer(instance=task)
        assert serializer.data['work_hours_table']['data']['rows'][0]['date'] == '12.07.2026'
        assert serializer.data['work_hours_table']['data']['rows'][0]['work_hours'] == '8'
        assert serializer.data['work_hours_table']['data']['rows'][0]['travel_hours'] == '2'

    def test_scheduled_date_accepts_valid_date(self):
        serializer = TaskSerializer(
            data={"title": "Task mit datum", "status": "aktivan",
                  "vehicle": str(self.vehicle.id), "scheduled_date": "2026-12-25"}
        )
        assert serializer.is_valid(), serializer.errors

    def test_scheduled_date_rejects_invalid_date_string(self):
        serializer = TaskSerializer(
            data={"title": "Task bad date", "status": "aktivan",
                  "vehicle": str(self.vehicle.id), "scheduled_date": "not-a-date"}
        )
        assert not serializer.is_valid()
        assert 'scheduled_date' in serializer.errors

    def test_can_assign_work_order_from_different_crane(self):
        """Task može dobiti putni nalog koji pripada drugoj dizalici (cross-crane dijeljenje naloga)."""
        other_vehicle = Vehicle.objects.create(
            registration_number="ZG-TSK-02",
            asset_type='crane',
            make='Manitowoc',
            model='Grove',
            client=self.client,
            is_company_vehicle=False,
        )
        work_order = WorkOrder.objects.create(vehicle=other_vehicle, creator=self.user, purpose='kontrola')
        task = Task.objects.create(title="Cross-crane task", status="servis", assigned_to=self.user, vehicle=self.vehicle)

        serializer = TaskSerializer(instance=task, data={"work_order": str(work_order.id)}, partial=True)
        assert serializer.is_valid(), serializer.errors
        updated_task = serializer.save()
        assert updated_task.work_order_id == work_order.id
        assert updated_task.vehicle_id == self.vehicle.id  # task zadržava svoju dizalicu

    def test_can_close_task_with_cross_crane_work_order(self):
        """Task se može zatvoriti putnim nalogom koji pripada drugoj dizalici."""
        other_vehicle = Vehicle.objects.create(
            registration_number="ZG-TSK-03",
            asset_type='crane',
            make='Tadano',
            model='GR',
            client=self.client,
            is_company_vehicle=False,
        )
        work_order = WorkOrder.objects.create(vehicle=other_vehicle, creator=self.user, purpose='popravak')
        task = Task.objects.create(title="Task for close", status="servis", assigned_to=self.user, vehicle=self.vehicle)

        serializer = TaskSerializer(
            instance=task,
            data={"status": "zavrsen", "work_order": str(work_order.id)},
            partial=True
        )
        assert serializer.is_valid(), serializer.errors
        updated_task = serializer.save()
        assert updated_task.status == 'zavrsen'
        assert updated_task.work_order_id == work_order.id

    def test_work_order_auto_derives_vehicle_when_task_has_none(self):
        """Ako task nema dizalicu a dobiva WO, dizalica se preuzima iz WO (backward compat)."""
        work_order = WorkOrder.objects.create(vehicle=self.vehicle, creator=self.user, purpose='defektaza')
        serializer = TaskSerializer(
            data={"title": "Auto-vehicle task", "status": "aktivan", "work_order": str(work_order.id)},
        )
        # vehicle je obavezan pri kreiranju, ali ako task nije instanca ovo bi trebalo failati
        # Provjeri da vehicle derivation iz WO radi samo ako task već postoji (partial update)
        task = Task.objects.create(title="Temp task", status="aktivan", assigned_to=self.user, vehicle=self.vehicle)
        serializer2 = TaskSerializer(instance=task, data={"work_order": str(work_order.id)}, partial=True)
        assert serializer2.is_valid(), serializer2.errors