from django.contrib.auth import get_user_model
from django.test import TestCase
from rest_framework.test import APIRequestFactory, force_authenticate

from apps.fields.models import Field
from .models import Crop, Plan, PlanVarietyChange, Variety
from .serializers import PlanSerializer
from .views import PlanViewSet


class PlanVarietyChangeTests(TestCase):
    def setUp(self):
        self.factory = APIRequestFactory()
        self.user = get_user_model().objects.create_user(
            username='tester',
            password='secret12345',
        )
        self.crop = Crop.objects.create(name='水稲')
        self.old_variety = Variety.objects.create(crop=self.crop, name='にこまる')
        self.new_variety = Variety.objects.create(crop=self.crop, name='たちはるか特栽')
        self.field = Field.objects.create(
            name='足川北上',
            address='高知県高岡郡',
            area_tan='1.2000',
            area_m2=1200,
            owner_name='吉田',
            group_name='北',
            display_order=1,
        )
        self.plan = Plan.objects.create(
            field=self.field,
            year=2026,
            crop=self.crop,
            variety=self.old_variety,
            notes='',
        )

    def test_serializer_update_creates_history_when_variety_changes(self):
        serializer = PlanSerializer(
            instance=self.plan,
            data={'variety': self.new_variety.id},
            partial=True,
        )
        self.assertTrue(serializer.is_valid(), serializer.errors)
        serializer.save()

        self.plan.refresh_from_db()
        self.assertEqual(self.plan.variety_id, self.new_variety.id)

        change = PlanVarietyChange.objects.get(plan=self.plan)
        self.assertEqual(change.field_id, self.field.id)
        self.assertEqual(change.year, 2026)
        self.assertEqual(change.old_variety_id, self.old_variety.id)
        self.assertEqual(change.new_variety_id, self.new_variety.id)
        self.assertEqual(change.moved_entry_count, 0)

    def test_serializer_update_does_not_create_history_without_variety_change(self):
        serializer = PlanSerializer(
            instance=self.plan,
            data={'notes': 'メモ更新'},
            partial=True,
        )
        self.assertTrue(serializer.is_valid(), serializer.errors)
        serializer.save()

        self.plan.refresh_from_db()
        self.assertEqual(self.plan.notes, 'メモ更新')
        self.assertFalse(PlanVarietyChange.objects.exists())

    def test_bulk_update_creates_history_for_existing_plan(self):
        view = PlanViewSet.as_view({'post': 'bulk_update'})
        request = self.factory.post(
            '/api/plans/bulk_update/',
            {
                'field_ids': [self.field.id],
                'year': 2026,
                'crop': self.crop.id,
                'variety': self.new_variety.id,
            },
            format='json',
        )
        force_authenticate(request, user=self.user)

        response = view(request)

        self.assertEqual(response.status_code, 200)
        self.plan.refresh_from_db()
        self.assertEqual(self.plan.variety_id, self.new_variety.id)

        change = PlanVarietyChange.objects.get(plan=self.plan)
        self.assertEqual(change.old_variety_id, self.old_variety.id)
        self.assertEqual(change.new_variety_id, self.new_variety.id)