"""C-04 图片放大最小闭环用例：成功链路/余额不足/坏图回滚/流水/并发。"""
import io

from django.core.files.uploadedfile import SimpleUploadedFile
from django.test import TestCase
from PIL import Image
from rest_framework.test import APIClient

from aitool.models import AIToolRecord
from aitool.views.upscale_view import UPSCALE_COST
from user.models import FUser, PointTransaction


def _resp_bytes(response):
    return b''.join(response.streaming_content)


def _img(color='red', size=(32, 32)):
    img = Image.new('RGB', size, color=color)
    buf = io.BytesIO()
    img.save(buf, format='PNG')
    buf.seek(0)
    return SimpleUploadedFile('t.png', buf.getvalue(), content_type='image/png')


class UpscaleTest(TestCase):
    def setUp(self):
        self.client = APIClient()
        self.u = FUser.objects.create_user(username='c04u', password='x12345678')
        self.u.points = 100
        self.u.save(update_fields=['points'])
        self.client.force_authenticate(user=self.u)

    def test_success_chain(self):
        r = self.client.post('/api/aitool/upscale/', {'file': _img(), 'scale': 2}, format='multipart')
        self.assertEqual(r.status_code, 200)
        self.assertEqual(r['X-AITool-Cost'], str(UPSCALE_COST))
        self.assertTrue(r['X-AITool-File'].startswith('/media/aitool/upscale/'))
        out = Image.open(io.BytesIO(_resp_bytes(r)))
        self.assertEqual(out.size, (64, 64))
        self.u.refresh_from_db()
        self.assertEqual(self.u.points, 100 - UPSCALE_COST)
        rec = AIToolRecord.objects.filter(user=self.u, status='success').order_by('-id').first()
        self.assertIsNotNone(rec)
        self.assertEqual(rec.scale, 2)
        tx = PointTransaction.objects.filter(user=self.u, transaction_type='spend').order_by('-id').first()
        self.assertEqual(tx.amount, UPSCALE_COST)

    def test_scale_4x(self):
        r = self.client.post('/api/aitool/upscale/', {'file': _img(), 'scale': 4}, format='multipart')
        self.assertEqual(r.status_code, 200)
        out = Image.open(io.BytesIO(_resp_bytes(r)))
        self.assertEqual(out.size, (128, 128))

    def test_insufficient_points(self):
        self.u.points = 0
        self.u.save(update_fields=['points'])
        r = self.client.post('/api/aitool/upscale/', {'file': _img(), 'scale': 2}, format='multipart')
        self.assertEqual(r.status_code, 402)
        self.assertEqual(r.json().get('code'), 'INSUFFICIENT_POINTS')
        self.assertFalse(AIToolRecord.objects.filter(user=self.u).exists())

    def test_invalid_scale(self):
        r = self.client.post('/api/aitool/upscale/', {'file': _img(), 'scale': 8}, format='multipart')
        self.assertEqual(r.status_code, 400)

    def test_bad_image_refunds(self):
        bad = SimpleUploadedFile('t.png', b'not-an-image', content_type='image/png')
        before = self.u.points
        r = self.client.post('/api/aitool/upscale/', {'file': bad, 'scale': 2}, format='multipart')
        self.assertIn(r.status_code, (400, 500))
        self.u.refresh_from_db()
        self.assertEqual(self.u.points, before)
        statuses = set(AIToolRecord.objects.filter(user=self.u).values_list('status', flat=True))
        self.assertTrue(statuses <= {'failed', 'refunded', 'success'})
        # 坏图应有回滚流水
        self.assertTrue(PointTransaction.objects.filter(
            user=self.u, transaction_type='earn', description__contains='回滚').exists())

    def test_records_endpoint(self):
        self.client.post('/api/aitool/upscale/', {'file': _img(), 'scale': 2}, format='multipart')
        r = self.client.get('/api/aitool/records/')
        self.assertEqual(r.status_code, 200)
        self.assertTrue(len(r.json()['data']) >= 1)

    def test_requires_login(self):
        anon = APIClient()
        r = anon.post('/api/aitool/upscale/', {'file': _img()}, format='multipart')
        self.assertIn(r.status_code, (401, 403))