import json
import unittest
from unittest.mock import patch
from routes import purchase


class DomesticPrePackagingSnapshotTest(unittest.TestCase):
    def test_reads_exact_order_snapshot_including_zero(self):
        items = [{'material_code': 'M1', 'pre_pack_qty': 0},
                 {'material_code': 'M2', 'pre_pack_qty': 120},
                 {'material_code': 'M3'}]
        with patch.object(purchase, 'query', side_effect=[
            [{'货品编号': 'SKU', '计划下单时间': '2026-10-22 09:30:00'}],
            [{'bom_items': json.dumps(items)}]
        ]) as query:
            self.assertEqual(purchase._domestic_order_pre_packaging(23), {'M1': 0, 'M2': 120})
        self.assertEqual(query.call_args_list[0].args[1], (23,))
        self.assertEqual(query.call_args_list[1].args[1], ('SKU', '2026-10-22 09:30:00'))
        self.assertIn('ordered_at=%s', query.call_args_list[1].args[0])

    def test_missing_or_ambiguous_snapshot_is_not_replaced_with_current_balance(self):
        for snapshots in ([], [{'bom_items': '[]'}, {'bom_items': '[]'}],
                          [{'bom_items': 'invalid'}], [{'bom_items': None}]):
            with self.subTest(snapshots=snapshots), patch.object(purchase, 'query', side_effect=[
                [{'货品编号': 'SKU', '计划下单时间': '2026-10-22 09:30:00'}], snapshots
            ]):
                self.assertEqual(purchase._domestic_order_pre_packaging(23), {})

    def test_manual_order_without_confirmation_time_has_no_snapshot(self):
        with patch.object(purchase, 'query', return_value=[{'货品编号': 'SKU', '计划下单时间': None}]) as query:
            self.assertEqual(purchase._domestic_order_pre_packaging(23), {})
            self.assertEqual(query.call_count, 1)