from django.test import TestCase
from django.contrib.auth import get_user_model
from rest_framework.exceptions import ValidationError
from modules.task_management.services import TaskService
from modules.task_management.models import Task, TaskTemplate, TaskTemplateEntry, TaskWorkEntry
from modules.fleet.models import Vehicle, WorkOrder, VehicleServiceRecord


class TaskServiceTests(TestCase):
    def setUp(self):
        User = get_user_model()
        self.user = User.objects.create_user(username="user1", email="u1@example.test", password="pass")
        self.other_user = User.objects.create_user(username="user2", email="u2@example.test", password="pass")
        self.staff = User.objects.create_user(username="admin", email="admin@example.test", password="pass", is_staff=True)

    def test_create_task_entry_creates_task_and_assigns_user(self):
        data = {"title": "Do work", "description": "Something", "status": "aktivan"}
        entry = TaskService.create_task_entry(data=data, user=self.user)
        assert isinstance(entry, Task)
        assert entry.assigned_to == self.user
        assert entry.title == "Do work"

    def test_create_task_entry_short_title_raises(self):
        data = {"title": "x", "description": "", "status": "aktivan"}
        with self.assertRaises(ValidationError):
            TaskService.create_task_entry(data=data, user=self.user)

    def test_update_task_entry_permission_denied_for_non_owner(self):
        task = Task.objects.create(title="T", description="", assigned_to=self.other_user)
        with self.assertRaises(ValidationError):
            TaskService.update_task_entry(instance=task, data={"title": "New"}, user=self.user)

    def test_update_task_entry_allowed_for_owner(self):
        task = Task.objects.create(title="Old", description="", assigned_to=self.user)
        updated = TaskService.update_task_entry(instance=task, data={"title": "New"}, user=self.user)
        assert updated.title == "New"

    def test_update_task_entry_rejects_closing_without_work_order(self):
        task = Task.objects.create(title="Za zatvaranje", description="", assigned_to=self.user, status='servis')
        with self.assertRaises(ValidationError):
            TaskService.update_task_entry(instance=task, data={"status": "neaktivan"}, user=self.user)

    def test_update_task_entry_allows_closing_with_work_order(self):
        vehicle = Vehicle.objects.create(registration_number="ZG-TASK-01", asset_type='crane')
        work_order = WorkOrder.objects.create(vehicle=vehicle, creator=self.user, purpose='defektaza')
        task = Task.objects.create(title="Za zatvaranje", description="", assigned_to=self.user, status='servis')
        updated = TaskService.update_task_entry(
            instance=task,
            data={"status": "neaktivan", "work_order": work_order},
            user=self.user,
        )
        assert updated.status == "neaktivan"
        assert updated.work_order == work_order

    def test_update_task_entry_rejects_finished_without_work_order(self):
        task = Task.objects.create(title="Za završetak", description="", assigned_to=self.user, status='servis')
        with self.assertRaises(ValidationError):
            TaskService.update_task_entry(instance=task, data={"status": "zavrsen"}, user=self.user)

    def test_update_task_entry_allows_finished_with_work_order(self):
        vehicle = Vehicle.objects.create(registration_number="ZG-TASK-01A", asset_type='crane')
        work_order = WorkOrder.objects.create(vehicle=vehicle, creator=self.user, purpose='kontrola')
        task = Task.objects.create(title="Za završetak", description="", assigned_to=self.user, status='servis', vehicle=vehicle)
        updated = TaskService.update_task_entry(
            instance=task,
            data={"status": "zavrsen", "work_order": work_order},
            user=self.user,
        )
        assert updated.status == "zavrsen"
        assert updated.work_order == work_order

    def test_create_task_entry_from_template_creates_service_records(self):
        vehicle = Vehicle.objects.create(registration_number="ZG-TASK-02", asset_type='crane')
        template = TaskTemplate.objects.create(
            code='template-servis-zapisi',
            title='Template servis',
            description='Opis templatea',
            status='aktivan',
        )
        TaskTemplateEntry.objects.create(
            task_template=template,
            sort_order=1,
            title='Pregled sustava',
            work_description='Provjera hidraulike',
            active_faults='Greška E101',
            explanation_hr='Prevedeno i objašnjeno.',
        )
        TaskTemplateEntry.objects.create(
            task_template=template,
            sort_order=2,
            title='Zamjena senzora',
            work_description='Zamijenjen senzor kuta',
            active_faults='',
            explanation_hr='Senzor kalibriran.',
        )

        created = TaskService.create_task_entry(
            data={'template_id': template.id, 'vehicle': vehicle},
            user=self.user,
        )

        self.assertEqual(created.vehicle_id, vehicle.id)
        self.assertEqual(TaskWorkEntry.objects.filter(task=created).count(), 2)
        records = VehicleServiceRecord.objects.filter(task=created).order_by('created_at')
        self.assertEqual(records.count(), 2)
        self.assertEqual(records.first().service_title, 'Pregled sustava')
        self.assertIn('Obrazloženje (HR): Prevedeno i objašnjeno.', records.first().description)
        self.assertIn('Aktivne greške: Greška E101', records.first().description)
        self.assertEqual(records.first().performed_by_id, self.user.id)

    def test_create_task_entry_from_template_limits_service_records_to_ten(self):
        vehicle = Vehicle.objects.create(registration_number="ZG-TASK-03", asset_type='crane')
        template = TaskTemplate.objects.create(
            code='template-limit-10',
            title='Template limit',
            description='Opis',
            status='aktivan',
        )
        for index in range(1, 13):
            TaskTemplateEntry.objects.create(
                task_template=template,
                sort_order=index,
                title=f'Korak {index}',
                work_description=f'Opis {index}',
            )

        created = TaskService.create_task_entry(
            data={'template_id': template.id, 'vehicle': vehicle},
            user=self.user,
        )

        self.assertEqual(TaskWorkEntry.objects.filter(task=created).count(), 10)
        self.assertEqual(VehicleServiceRecord.objects.filter(task=created).count(), 10)