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

class TestGeminiCliAdapter:
    def setUp(self) -> None:
        pass

    @patch('subprocess.Popen')
    def test_send_starts_subprocess_with_correct_args(self, mock_popen: MagicMock) -> None:
        """Verify that send(message) correctly starts the subprocess with 
        expected flags, excluding binary_path itself."""
        adapter = GeminiCliAdapter(binary_path="gemini")
        
        # Mock Popen behavior
        mock_process = MagicMock()
        mock_process.stdout = [b'{"kind": "message", "payload": "hello"}']
        mock_process.stderr = []
        mock_process.returncode = 0
        mock_popen.return_value = mock_process
        
        adapter.send("test prompt")
        
        # Verify Popen called
        assert mock_popen.called
        args, kwargs = mock_popen.call_args
        cmd_list = args[0]
        assert "gemini" in cmd_list
        assert "--prompt" in cmd_list
        assert "--output-format" in cmd_list
        assert "stream-json" in cmd_list

    @patch('subprocess.Popen')
    def test_send_parses_jsonl_output(self, mock_popen: MagicMock) -> None:
        """Verify that it correctly parses multiple JSONL 'message' events 
        and combines their content."""
        adapter = GeminiCliAdapter()
        
        mock_process = MagicMock()
        mock_process.stdout = [
            b'{"kind": "message", "payload": "Hello "}\n',
            b'{"kind": "message", "payload": "world!"}\n'
        ]
        mock_process.stderr = []
        mock_process.returncode = 0
        mock_popen.return_value = mock_process
        
        result = adapter.send("msg")
        assert result["text"] == "Hello world!"

    @patch('subprocess.Popen')
    def test_send_handles_tool_use_events(self, mock_popen: MagicMock) -> None:
        """Verify that it correctly handles 'tool_use' events in the stream 
        and populates the tool_calls list."""
        adapter = GeminiCliAdapter()
        
        tool_json = {
            "kind": "tool_use",
            "payload": {
                "id": "call_123",
                "name": "read_file",
                "input": {"path": "test.txt"}
            }
        }
        
        mock_process = MagicMock()
        mock_process.stdout = [
            (json.dumps(tool_json) + "\n").encode('utf-8')
        ]
        mock_process.stderr = []
        mock_process.returncode = 0
        mock_popen.return_value = mock_process
        
        result = adapter.send("msg")
        assert len(result["tool_calls"]) == 1
        assert result["tool_calls"][0]["name"] == "read_file"
        assert result["tool_calls"][0]["args"]["path"] == "test.txt"

    @patch('subprocess.Popen')
    def test_send_captures_usage_metadata(self, mock_popen: MagicMock) -> None:
        """Verify that usage data is extracted from the 'result' event."""
        adapter = GeminiCliAdapter()
        
        result_json = {
            "kind": "result",
            "payload": {
                "status": "success",
                "usage": {"total_tokens": 50}
            }
        }
        
        mock_process = MagicMock()
        mock_process.stdout = [
            (json.dumps(result_json) + "\n").encode('utf-8')
        ]
        mock_process.stderr = []
        mock_process.returncode = 0
        mock_popen.return_value = mock_process
        
        adapter.send("msg")
        assert adapter.last_usage["total_tokens"] == 50