import json
from datetime import datetime, timezone as dt_timezone
from io import StringIO

from django.core.management import call_command
from django.test import TestCase
from django.utils import timezone

from basic_info import models as basic_models
from printing import models as printing_models


class BackfillPrintingOrderKdRiQiCommandTest(TestCase):
    def setUp(self):
        self.merchant = basic_models.Merchant.objects.create(
            name='测试印染厂',
            type=basic_models.MerchantTypeEnum.FACTORY,
        )
        self.customer = basic_models.Customer.objects.create(
            merchant=self.merchant,
            name='测试客户',
        )

    def _create_order(self, *, external_order_id, external_raw, kd_riqi=None, merchant=None):
        return printing_models.PrintingOrder.objects.create(
            merchant=merchant or self.merchant,
            customer=self.customer,
            fabric='测试面料',
            width='160cm',
            external_order_id=external_order_id,
            external_raw=external_raw,
            kd_riqi=kd_riqi,
        )

    def test_dry_run_reports_without_writing(self):
        order = self._create_order(
            external_order_id='KD001',
            external_raw={'first_record': {'KdRiQi': '2026-01-26T20:00:52Z'}},
        )
        output = StringIO()

        call_command('backfill_printing_order_kd_riqi', '--dry-run', stdout=output)

        order.refresh_from_db()
        payload = json.loads(output.getvalue())
        self.assertIsNone(order.kd_riqi)
        self.assertEqual(payload['would_update'], 1)
        self.assertEqual(payload['updated'], 0)

    def test_backfills_missing_kd_riqi_from_external_raw(self):
        order = self._create_order(
            external_order_id='KD001',
            external_raw={'first_record': {'KdRiQi': '2026-01-26T20:00:52Z'}},
        )
        output = StringIO()

        call_command('backfill_printing_order_kd_riqi', stdout=output)

        order.refresh_from_db()
        payload = json.loads(output.getvalue())
        self.assertEqual(timezone.localtime(order.kd_riqi).isoformat(), '2026-01-26T20:00:52+08:00')
        self.assertEqual(payload['updated'], 1)

    def test_skips_missing_and_invalid_values(self):
        missing = self._create_order(
            external_order_id='KD001',
            external_raw={'first_record': {}},
        )
        invalid = self._create_order(
            external_order_id='KD002',
            external_raw={'first_record': {'KdRiQi': 'invalid'}},
        )
        output = StringIO()

        call_command('backfill_printing_order_kd_riqi', stdout=output)

        missing.refresh_from_db()
        invalid.refresh_from_db()
        payload = json.loads(output.getvalue())
        self.assertIsNone(missing.kd_riqi)
        self.assertIsNone(invalid.kd_riqi)
        self.assertEqual(payload['skipped_missing'], 1)
        self.assertEqual(payload['skipped_invalid'], 1)

    def test_filters_by_external_order_id(self):
        target = self._create_order(
            external_order_id='KD001',
            external_raw={'first_record': {'KdRiQi': '2026-01-26T20:00:52Z'}},
        )
        other = self._create_order(
            external_order_id='KD002',
            external_raw={'first_record': {'KdRiQi': '2026-01-27T20:00:52Z'}},
        )

        call_command('backfill_printing_order_kd_riqi', '--external-order-id', 'KD001', stdout=StringIO())

        target.refresh_from_db()
        other.refresh_from_db()
        self.assertIsNotNone(target.kd_riqi)
        self.assertIsNone(other.kd_riqi)

    def test_overwrite_can_update_kd_riqi_and_outgoing_date(self):
        order = self._create_order(
            external_order_id='KD001',
            external_raw={'first_record': {'KdRiQi': '2026-01-26T20:00:52Z'}},
            kd_riqi=datetime(2026, 1, 26, 20, 0, 52, tzinfo=dt_timezone.utc),
        )
        order.outgoing_date = datetime(2026, 1, 26, 20, 0, 52, tzinfo=dt_timezone.utc)
        order.save(update_fields=['outgoing_date'])
        output = StringIO()

        call_command(
            'backfill_printing_order_kd_riqi',
            '--overwrite',
            '--update-outgoing-date',
            stdout=output,
        )

        order.refresh_from_db()
        payload = json.loads(output.getvalue())
        self.assertEqual(timezone.localtime(order.kd_riqi).isoformat(), '2026-01-26T20:00:52+08:00')
        self.assertEqual(timezone.localtime(order.outgoing_date).isoformat(), '2026-01-26T20:00:52+08:00')
        self.assertEqual(payload['updated'], 1)
        self.assertTrue(payload['overwrite'])
        self.assertTrue(payload['update_outgoing_date'])