import json
from pathlib import Path
import tempfile
import unittest
from unittest.mock import patch

from engine import static_files, prompt_builder


class StaticFilesTests(unittest.TestCase):
    def setUp(self):
        self.directory = tempfile.TemporaryDirectory()
        self.addCleanup(self.directory.cleanup)
        self.path = Path(self.directory.name) / 'character.json'
        static_files._CACHE.clear()
        self.addCleanup(static_files._CACHE.clear)

    def test_character_reads_once_and_returns_independent_nested_data(self):
        self.path.write_text('{"personality": ["curious"]}')
        original = Path.read_text
        with patch.object(prompt_builder, 'CHARACTERS_DIR', self.path.parent), patch.object(
            Path, 'read_text', autospec=True, side_effect=original
        ) as read:
            first = prompt_builder.load_character('character')
            first['personality'].append('changed')
            self.assertEqual(prompt_builder.load_character('character')['personality'], ['curious'])
            self.assertEqual(read.call_count, 1)

    def test_edit_replace_delete_and_invalid_json_do_not_return_stale_data(self):
        self.path.write_text('{"name":"a"}')
        self.assertEqual(static_files.load_static_json(self.path), {'name': 'a'})
        self.path.write_text('{"name":"updated"}')
        self.assertEqual(static_files.load_static_json(self.path), {'name': 'updated'})
        replacement = self.path.with_suffix('.new')
        replacement.write_text('{"name":"replacement"}')
        replacement.replace(self.path)
        self.assertEqual(static_files.load_static_json(self.path), {'name': 'replacement'})
        self.path.write_text('{invalid')
        with self.assertRaises(json.JSONDecodeError):
            static_files.load_static_json(self.path)
        self.path.unlink()
        with self.assertRaises(FileNotFoundError):
            static_files.load_static_json(self.path)
        self.path.write_text('{}')
        self.assertEqual(static_files.load_static_json(self.path), {})

    def test_prompt_text_is_cached_and_refreshes(self):
        self.path.write_text('  Türkçe\n')
        original = Path.read_text
        with patch.object(Path, 'read_text', autospec=True, side_effect=original) as read:
            for _ in range(2):
                self.assertEqual(static_files.load_static_text(self.path), '  Türkçe\n')
            self.assertEqual(read.call_count, 1)
            self.path.write_text('New prompt')
            self.assertEqual(static_files.load_static_text(self.path), 'New prompt')
            self.assertEqual(read.call_count, 2)

    def test_cache_evicts_least_recently_used_file(self):
        with patch.object(static_files, '_MAX_ENTRIES', 2):
            paths = [self.path.with_name(str(i)) for i in range(3)]
            for path in paths:
                path.write_text(path.name)
            for path in paths[:2]:
                static_files.load_static_text(path)
            static_files.load_static_text(paths[0])
            static_files.load_static_text(paths[2])
            self.assertEqual(len(static_files._CACHE), 2)
            self.assertNotIn((paths[1].resolve(), False), static_files._CACHE)