import os
import sys
import types
import unittest
from unittest.mock import patch

from models.ai_client import AIClient


class _LegacySchemaError(Exception):
    pass


class _Result:
    def __init__(self, data):
        self.data = data


class _LegacyQuery:
    def __init__(self, rows):
        self.rows = rows
        self.selects = []

    def select(self, columns):
        self.selects.append(columns)
        if "default_model" in columns:
            raise _LegacySchemaError("column ai_providers.default_model does not exist")
        return self

    def eq(self, *_args, **_kwargs):
        return self

    def order(self, *_args, **_kwargs):
        return self

    def execute(self):
        return _Result(self.rows)


class _LegacySupabase:
    def __init__(self, rows):
        self.query = _LegacyQuery(rows)

    def table(self, name):
        assert name == "ai_providers"
        return self.query


class LegacySchemaCompatibilityTests(unittest.TestCase):
    def test_detects_only_known_legacy_missing_columns(self):
        self.assertTrue(
            AIClient._is_legacy_schema_error(
                _LegacySchemaError("column ai_providers.default_model does not exist")
            )
        )
        self.assertFalse(
            AIClient._is_legacy_schema_error(
                _LegacySchemaError("column ai_providers.api_key does not exist")
            )
        )

    def test_legacy_schema_returns_empty_so_current_environment_fallback_stays_authoritative(self):
        legacy_supabase = _LegacySupabase([])
        fake_supabase = types.SimpleNamespace(
            create_client=lambda _url, _key: legacy_supabase,
        )
        client = AIClient.__new__(AIClient)

        with patch.dict(
            os.environ,
            {"SUPABASE_URL": "https://example.supabase.co", "SUPABASE_SERVICE_ROLE_KEY": "test"},
            clear=True,
        ), patch.dict(sys.modules, {"supabase": fake_supabase}):
            providers = client._try_load_from_supabase()

        self.assertEqual(legacy_supabase.query.selects, [
            "id,name,api_key,base_url,default_model,tier,purpose",
        ])
        self.assertEqual(providers, [])


if __name__ == "__main__":
    unittest.main()