import unittest
import json
import subprocess
from unittest.mock import patch, MagicMock
from src.gemini_cli_adapter import GeminiCliAdapter

class TestGeminiCliAdapterParity(unittest.TestCase):
    def setUp(self) -> None:
        """Set up a fresh adapter instance and reset session state for each test."""
        self.adapter = GeminiCliAdapter(binary_path="gemini")

    def tearDown(self) -> None:
        pass

    def test_count_tokens_fallback(self) -> None:
        """Test the character-based token estimation fallback."""
        contents = ["Hello", "world!"]
        estimated = self.adapter.count_tokens(contents)
        # "Hello\nworld!" is 12 chars. 12 // 4 = 3
        self.assertEqual(estimated, 3)

    @patch('subprocess.Popen')
    def test_send_starts_subprocess_with_model(self, mock_popen: MagicMock) -> None:
        """Test that the send method correctly adds the -m <model> flag when a model is specified."""
        mock_process = MagicMock()
        mock_process.stdout = [b'{"kind": "message", "payload": "hi"}']
        mock_process.stderr = []
        mock_process.returncode = 0
        mock_popen.return_value = mock_process
        
        self.adapter.send("test", model="gemini-2.0-flash")
        
        args, _ = mock_popen.call_args
        cmd_list = args[0]
        self.assertIn("-m", cmd_list)
        self.assertIn("gemini-2.0-flash", cmd_list)

    @patch('subprocess.Popen')
    def test_send_parses_tool_calls_from_streaming_json(self, mock_popen: MagicMock) -> None:
        """Test that tool_use messages in the streaming JSON are correctly parsed."""
        tool_call_json = {
            "kind": "tool_use",
            "payload": {
                "id": "call_abc",
                "name": "list_directory",
                "input": {"path": "."}
            }
        }
        
        mock_process = MagicMock()
        mock_process.stdout = [
            (json.dumps(tool_call_json) + "\n").encode('utf-8'),
            b'{"kind": "message", "payload": "I listed the files."}'
        ]
        mock_process.stderr = []
        mock_process.returncode = 0
        mock_popen.return_value = mock_process
        
        result = self.adapter.send("msg")
        self.assertEqual(len(result["tool_calls"]), 1)
        self.assertEqual(result["tool_calls"][0]["name"], "list_directory")
        self.assertEqual(result["text"], "I listed the files.")