import pytest
from unittest.mock import MagicMock, patch
import ai_client

class MockUsage:
    def __init__(self):
        self.prompt_token_count = 10
        self.candidates_token_count = 5
        self.total_token_count = 15
        self.cached_content_token_count = 0

class MockPart:
    def __init__(self, text, function_call):
        self.text = text
        self.function_call = function_call

class MockContent:
    def __init__(self, parts):
        self.parts = parts

class MockCandidate:
    def __init__(self, parts):
        self.content = MockContent(parts)
        self.finish_reason = MagicMock()
        self.finish_reason.name = "STOP"

def test_ai_client_event_emitter_exists():
    # This should fail initially because 'events' won't exist on ai_client
    assert hasattr(ai_client, 'events')

def test_event_emission():
    callback = MagicMock()
    ai_client.events.on("test_event", callback)
    ai_client.events.emit("test_event", payload={"data": 123})
    callback.assert_called_once_with(payload={"data": 123})

def test_send_emits_events():
    with patch("ai_client._send_gemini") as mock_send_gemini, \
         patch("ai_client._send_anthropic") as mock_send_anthropic:
        
        mock_send_gemini.return_value = "gemini response"
        
        start_callback = MagicMock()
        response_callback = MagicMock()
        
        ai_client.events.on("request_start", start_callback)
        ai_client.events.on("response_received", response_callback)
        
        ai_client.set_provider("gemini", "gemini-2.5-flash-lite")
        ai_client.send("context", "message")
        
        # We mocked _send_gemini so it doesn't emit events inside. 
        # But wait, ai_client.send itself emits request_start and response_received?
        # Actually, ai_client.send delegates to _send_gemini. 
        # Let's mock _gemini_client instead to let _send_gemini run and emit events.
        pass

def test_send_emits_events_proper():
    with patch("ai_client._ensure_gemini_client"), \
         patch("ai_client._gemini_client") as mock_client:
         
        mock_chat = MagicMock()
        mock_client.chats.create.return_value = mock_chat
        
        mock_response = MagicMock()
        mock_response.candidates = [MockCandidate([MockPart("gemini response", None)])]
        mock_response.usage_metadata = MockUsage()
        mock_chat.send_message.return_value = mock_response
        
        start_callback = MagicMock()
        response_callback = MagicMock()
        
        ai_client.events.on("request_start", start_callback)
        ai_client.events.on("response_received", response_callback)
        
        ai_client.set_provider("gemini", "gemini-2.5-flash-lite")
        ai_client.send("context", "message")
        
        assert start_callback.called
        assert response_callback.called
        
        args, kwargs = start_callback.call_args
        assert kwargs['payload']['provider'] == 'gemini'

def test_send_emits_tool_events():
    import mcp_client
    with patch("ai_client._ensure_gemini_client"), \
         patch("ai_client._gemini_client") as mock_client, \
         patch("mcp_client.dispatch") as mock_dispatch:
        
        mock_chat = MagicMock()
        mock_client.chats.create.return_value = mock_chat
        
        # 1. Setup mock response with a tool call
        mock_fc = MagicMock()
        mock_fc.name = "read_file"
        mock_fc.args = {"path": "test.txt"}
        
        mock_response_with_tool = MagicMock()
        mock_response_with_tool.candidates = [MockCandidate([MockPart("tool call text", mock_fc)])]
        mock_response_with_tool.usage_metadata = MockUsage()
        
        # 2. Setup second mock response (final answer)
        mock_response_final = MagicMock()
        mock_response_final.candidates = [MockCandidate([MockPart("final answer", None)])]
        mock_response_final.usage_metadata = MockUsage()
        
        mock_chat.send_message.side_effect = [mock_response_with_tool, mock_response_final]
        mock_dispatch.return_value = "file content"
        
        ai_client.set_provider("gemini", "gemini-2.5-flash-lite")
        
        tool_callback = MagicMock()
        ai_client.events.on("tool_execution", tool_callback)
        
        ai_client.send("context", "message")
        
        # Should be called twice: once for 'started', once for 'completed'
        assert tool_callback.call_count == 2
        
        # Check 'started' call
        args, kwargs = tool_callback.call_args_list[0]
        assert kwargs['payload']['status'] == 'started'
        assert kwargs['payload']['tool'] == 'read_file'
        
        # Check 'completed' call
        args, kwargs = tool_callback.call_args_list[1]
        assert kwargs['payload']['status'] == 'completed'
        assert kwargs['payload']['result'] == 'file content'