tests/test_cli/test_mcp.py

"""Integration tests for MCP CLI commands.

These are real tests that:
- Actually write/read config files
- Test actual CLI behavior
- Test MCP server initialization (when MCP SDK is available)
"""

import json
import sys
from unittest.mock import MagicMock, patch

import pytest
from click.testing import CliRunner

from headroom.cli.main import main
from headroom.cli.mcp import (
    get_headroom_command,
    load_mcp_config,
    save_mcp_config,
)

# Check if MCP SDK is available
try:
    import mcp  # noqa: F401

    MCP_AVAILABLE = True
except ImportError:
    MCP_AVAILABLE = False


@pytest.fixture
def temp_claude_dir(tmp_path):
    """Create a temporary .claude directory for testing."""
    claude_dir = tmp_path / ".claude"
    claude_dir.mkdir()
    return claude_dir


@pytest.fixture
def mock_claude_config_path(temp_claude_dir):
    """Patch the MCP config path to use temp directory.

    Also mocks the claude CLI as absent so tests exercise the mcp.json
    fallback path rather than the `claude mcp add` path.
    """
    import shutil as _shutil

    config_path = temp_claude_dir / "mcp.json"
    # Capture the original function reference before patching so we don't recurse.
    _real_which = _shutil.which

    def which_no_claude(cmd):
        if cmd == "claude":
            return None
        return _real_which(cmd)

    with patch("headroom.cli.mcp.MCP_CONFIG_PATH", config_path):
        with patch("headroom.cli.mcp.CLAUDE_CONFIG_DIR", temp_claude_dir):
            with patch("headroom.cli.mcp.shutil.which", side_effect=which_no_claude):
                yield config_path


@pytest.fixture
def mock_mcp_available():
    """Mock MCP SDK as available for testing install/uninstall commands."""
    mock_mcp = MagicMock()
    with patch.dict(sys.modules, {"mcp": mock_mcp}):
        yield mock_mcp


class TestMCPConfigFunctions:
    """Test config file handling functions."""

    def test_get_headroom_command_returns_list(self):
        """Command should be a list suitable for subprocess."""
        cmd = get_headroom_command()
        assert isinstance(cmd, list)
        assert len(cmd) >= 1
        # Should end with mcp serve args
        assert "mcp" in cmd or "-m" in cmd

    def test_load_mcp_config_empty_when_no_file(self, mock_claude_config_path):
        """Loading non-existent config returns empty structure."""
        config = load_mcp_config()
        assert config == {"mcpServers": {}}

    def test_save_and_load_config(self, mock_claude_config_path):
        """Config can be saved and loaded back."""
        test_config = {
            "mcpServers": {
                "headroom": {
                    "command": "headroom",
                    "args": ["mcp", "serve"],
                }
            }
        }
        save_mcp_config(test_config)

        # File should exist
        assert mock_claude_config_path.exists()

        # Load it back
        loaded = load_mcp_config()
        assert loaded == test_config

    def test_save_config_creates_directory(self, tmp_path):
        """save_mcp_config creates parent directory if needed."""
        claude_dir = tmp_path / "new_dir" / ".claude"
        config_path = claude_dir / "mcp.json"

        with patch("headroom.cli.mcp.MCP_CONFIG_PATH", config_path):
            with patch("headroom.cli.mcp.CLAUDE_CONFIG_DIR", claude_dir):
                save_mcp_config({"mcpServers": {}})

        assert config_path.exists()

    def test_load_config_preserves_other_servers(self, mock_claude_config_path):
        """Loading preserves other MCP servers in config."""
        # Write config with another server
        existing_config = {
            "mcpServers": {
                "other-server": {"command": "other", "args": []},
            }
        }
        mock_claude_config_path.write_text(json.dumps(existing_config))

        loaded = load_mcp_config()
        assert "other-server" in loaded["mcpServers"]


class TestMCPInstallCommand:
    """Test 'headroom mcp install' command."""

    def test_install_creates_config(self, mock_claude_config_path, mock_mcp_available):
        """Install creates MCP config file."""
        runner = CliRunner()
        result = runner.invoke(main, ["mcp", "install"])

        assert result.exit_code == 0, f"Failed with output: {result.output}"
        assert "installed" in result.output.lower()
        assert mock_claude_config_path.exists()

        # Verify config content
        config = json.loads(mock_claude_config_path.read_text())
        assert "headroom" in config["mcpServers"]
        assert config["mcpServers"]["headroom"]["command"] == "headroom"
        assert "mcp" in config["mcpServers"]["headroom"]["args"]
        assert "serve" in config["mcpServers"]["headroom"]["args"]

    def test_install_preserves_other_servers(self, mock_claude_config_path, mock_mcp_available):
        """Install preserves existing MCP servers."""
        # Create config with another server
        existing_config = {
            "mcpServers": {
                "github": {"command": "github-mcp", "args": []},
            }
        }
        mock_claude_config_path.write_text(json.dumps(existing_config))

        runner = CliRunner()
        result = runner.invoke(main, ["mcp", "install"])

        assert result.exit_code == 0, f"Failed with output: {result.output}"

        # Both servers should exist
        config = json.loads(mock_claude_config_path.read_text())
        assert "github" in config["mcpServers"]
        assert "headroom" in config["mcpServers"]

    def test_install_with_custom_proxy_url(self, mock_claude_config_path, mock_mcp_available):
        """Install with custom proxy URL sets env var."""
        runner = CliRunner()
        result = runner.invoke(main, ["mcp", "install", "--proxy-url", "http://localhost:9000"])

        assert result.exit_code == 0, f"Failed with output: {result.output}"

        config = json.loads(mock_claude_config_path.read_text())
        assert (
            config["mcpServers"]["headroom"]["env"]["HEADROOM_PROXY_URL"] == "http://localhost:9000"
        )

    def test_install_default_proxy_url_no_env(self, mock_claude_config_path, mock_mcp_available):
        """Install with default proxy URL doesn't set env var."""
        runner = CliRunner()
        result = runner.invoke(main, ["mcp", "install"])

        assert result.exit_code == 0, f"Failed with output: {result.output}"

        config = json.loads(mock_claude_config_path.read_text())
        # No env section for default URL
        assert "env" not in config["mcpServers"]["headroom"]

    def test_install_already_configured_no_force(self, mock_claude_config_path, mock_mcp_available):
        """Install without --force when already configured exits cleanly."""
        # First install
        runner = CliRunner()
        runner.invoke(main, ["mcp", "install"])

        # Second install without force
        result = runner.invoke(main, ["mcp", "install"])

        assert result.exit_code == 0
        assert "already configured" in result.output.lower()

    def test_install_force_overwrites(self, mock_claude_config_path, mock_mcp_available):
        """Install with --force overwrites existing config."""
        runner = CliRunner()
        runner.invoke(main, ["mcp", "install", "--proxy-url", "http://old:8787"])

        # Force install with new URL
        result = runner.invoke(
            main, ["mcp", "install", "--force", "--proxy-url", "http://new:9000"]
        )

        assert result.exit_code == 0, f"Failed with output: {result.output}"
        assert "installed" in result.output.lower()

        config = json.loads(mock_claude_config_path.read_text())
        assert config["mcpServers"]["headroom"]["env"]["HEADROOM_PROXY_URL"] == "http://new:9000"

    @pytest.mark.skipif(MCP_AVAILABLE, reason="Test only runs when MCP SDK is NOT installed")
    def test_install_without_mcp_sdk_fails(self, mock_claude_config_path):
        """Install fails gracefully when MCP SDK is not installed."""
        runner = CliRunner()
        result = runner.invoke(main, ["mcp", "install"])

        # Should fail with helpful message
        assert result.exit_code == 1
        assert "mcp" in result.output.lower() or "not installed" in result.output.lower()


class TestMCPUninstallCommand:
    """Test 'headroom mcp uninstall' command."""

    def test_uninstall_removes_headroom(self, mock_claude_config_path, mock_mcp_available):
        """Uninstall removes headroom from config."""
        # First install
        runner = CliRunner()
        runner.invoke(main, ["mcp", "install"])

        # Then uninstall
        result = runner.invoke(main, ["mcp", "uninstall"])

        assert result.exit_code == 0
        assert "removed" in result.output.lower()

        config = json.loads(mock_claude_config_path.read_text())
        assert "headroom" not in config["mcpServers"]

    def test_uninstall_preserves_other_servers(self, mock_claude_config_path):
        """Uninstall preserves other MCP servers."""
        # Create config with headroom and another server
        config = {
            "mcpServers": {
                "headroom": {"command": "headroom", "args": ["mcp", "serve"]},
                "github": {"command": "github-mcp", "args": []},
            }
        }
        mock_claude_config_path.write_text(json.dumps(config))

        runner = CliRunner()
        result = runner.invoke(main, ["mcp", "uninstall"])

        assert result.exit_code == 0

        config = json.loads(mock_claude_config_path.read_text())
        assert "headroom" not in config["mcpServers"]
        assert "github" in config["mcpServers"]

    def test_uninstall_no_config_file(self, mock_claude_config_path):
        """Uninstall with no config file exits cleanly."""
        runner = CliRunner()
        result = runner.invoke(main, ["mcp", "uninstall"])

        assert result.exit_code == 0
        assert "nothing to uninstall" in result.output.lower()

    def test_uninstall_not_configured(self, mock_claude_config_path):
        """Uninstall when headroom not in config exits cleanly."""
        # Create config without headroom
        config = {"mcpServers": {"other": {"command": "other"}}}
        mock_claude_config_path.write_text(json.dumps(config))

        runner = CliRunner()
        result = runner.invoke(main, ["mcp", "uninstall"])

        assert result.exit_code == 0
        assert "not configured" in result.output.lower()


class TestMCPStatusCommand:
    """Test 'headroom mcp status' command."""

    def test_status_not_configured(self, mock_claude_config_path):
        """Status shows not configured when no config."""
        runner = CliRunner()
        result = runner.invoke(main, ["mcp", "status"])

        assert result.exit_code == 0
        assert "MCP SDK" in result.output
        # Should show not configured
        assert (
            "✗" in result.output
            or "Not configured" in result.output.lower()
            or "No config" in result.output
        )

    def test_status_configured(self, mock_claude_config_path, mock_mcp_available):
        """Status shows configured when installed."""
        runner = CliRunner()
        runner.invoke(main, ["mcp", "install"])

        result = runner.invoke(main, ["mcp", "status"])

        assert result.exit_code == 0
        assert "✓ Configured" in result.output


class TestMCPServeCommand:
    """Test 'headroom mcp serve' command."""

    def test_serve_help(self):
        """Serve command shows help."""
        runner = CliRunner()
        result = runner.invoke(main, ["mcp", "serve", "--help"])

        assert result.exit_code == 0
        assert "proxy-url" in result.output
        assert "debug" in result.output


@pytest.mark.skipif(not MCP_AVAILABLE, reason="MCP SDK not installed")
class TestMCPServerInitialization:
    """Test actual MCP server creation.

    These tests require the MCP SDK to be installed.
    """

    def test_mcp_server_can_be_created(self):
        """MCP server can be instantiated."""
        from headroom.ccr.mcp_server import create_ccr_mcp_server

        server = create_ccr_mcp_server()
        assert server is not None
        assert server.proxy_url == "http://127.0.0.1:8787"

    def test_mcp_server_with_custom_url(self):
        """MCP server accepts custom proxy URL."""
        from headroom.ccr.mcp_server import create_ccr_mcp_server

        server = create_ccr_mcp_server(proxy_url="http://custom:9000")
        assert server.proxy_url == "http://custom:9000"

    def test_mcp_server_has_correct_tool_name(self):
        """MCP server is configured for headroom_retrieve tool."""
        from headroom.ccr.mcp_server import create_ccr_mcp_server
        from headroom.ccr.tool_injection import CCR_TOOL_NAME

        server = create_ccr_mcp_server()

        # Verify the server was created with correct configuration
        assert server.server is not None
        assert server.server.name == "headroom"
        # The tool name should be headroom_retrieve
        assert CCR_TOOL_NAME == "headroom_retrieve"


class TestEndToEndFlow:
    """Test complete install -> status -> uninstall flow."""

    def test_full_lifecycle(self, mock_claude_config_path, mock_mcp_available):
        """Test complete lifecycle of MCP configuration."""
        runner = CliRunner()

        # Initially not configured
        result = runner.invoke(main, ["mcp", "status"])
        assert "No config" in result.output or "Not configured" in result.output.lower()

        # Install
        result = runner.invoke(main, ["mcp", "install"])
        assert result.exit_code == 0, f"Install failed: {result.output}"
        assert "installed" in result.output.lower()

        # Status shows configured
        result = runner.invoke(main, ["mcp", "status"])
        assert "✓ Configured" in result.output

        # Config file has correct content
        config = json.loads(mock_claude_config_path.read_text())
        assert config["mcpServers"]["headroom"]["command"] == "headroom"

        # Uninstall
        result = runner.invoke(main, ["mcp", "uninstall"])
        assert result.exit_code == 0
        assert "removed" in result.output.lower()

        # Status shows not configured
        result = runner.invoke(main, ["mcp", "status"])
        assert "headroom" not in result.output.lower() or "not configured" in result.output.lower()


class TestMCPInstallWithClaudeCLI:
    """Test mcp_install when the claude CLI is available."""

    def _make_run(self, get_rc=1, add_rc=0, remove_rc=0):
        """Return a subprocess.run mock with configurable return codes."""

        def run(cmd, **kwargs):
            if "get" in cmd:
                return MagicMock(returncode=get_rc, stderr="")
            if "remove" in cmd:
                return MagicMock(returncode=remove_rc, stderr="")
            if "add" in cmd:
                return MagicMock(returncode=add_rc, stderr="")
            return MagicMock(returncode=0, stderr="")

        return run

    def test_install_uses_claude_mcp_add(self, mock_mcp_available):
        """When claude CLI is available, install calls claude mcp add."""
        runner = CliRunner()
        with patch("headroom.cli.mcp.shutil.which", return_value="/usr/bin/claude"):
            with patch("headroom.cli.mcp.subprocess.run", side_effect=self._make_run()) as mock_run:
                result = runner.invoke(main, ["mcp", "install"])

        assert result.exit_code == 0, f"Failed: {result.output}"
        assert "installed" in result.output.lower()
        assert "claude mcp add" in result.output

        # Verify claude mcp add was called
        add_calls = [c for c in mock_run.call_args_list if "add" in c.args[0]]
        assert len(add_calls) == 1
        add_cmd = add_calls[0].args[0]
        assert "headroom" in add_cmd
        assert "-s" in add_cmd
        assert "user" in add_cmd

    def test_install_already_registered_no_force(self, mock_mcp_available):
        """Install without --force exits cleanly when already registered via claude CLI."""
        runner = CliRunner()
        with patch("headroom.cli.mcp.shutil.which", return_value="/usr/bin/claude"):
            # get returns 0 → already registered
            with patch("headroom.cli.mcp.subprocess.run", side_effect=self._make_run(get_rc=0)):
                result = runner.invoke(main, ["mcp", "install"])

        assert result.exit_code == 0
        assert "already configured" in result.output.lower()

    def test_install_force_calls_remove_then_add(self, mock_mcp_available):
        """--force calls claude mcp remove before claude mcp add."""
        runner = CliRunner()
        calls = []

        def capturing_run(cmd, **kwargs):
            calls.append(cmd)
            return MagicMock(returncode=0, stderr="")

        with patch("headroom.cli.mcp.shutil.which", return_value="/usr/bin/claude"):
            with patch("headroom.cli.mcp.subprocess.run", side_effect=capturing_run):
                result = runner.invoke(main, ["mcp", "install", "--force"])

        assert result.exit_code == 0, f"Failed: {result.output}"
        subcommands = [c[2] for c in calls]  # third element is the subcommand
        assert "remove" in subcommands
        assert "add" in subcommands
        assert subcommands.index("remove") < subcommands.index("add")

    def test_install_fallback_on_claude_mcp_add_failure(self, temp_claude_dir, mock_mcp_available):
        """If claude mcp add fails, falls back to writing mcp.json."""
        config_path = temp_claude_dir / "mcp.json"
        with patch("headroom.cli.mcp.MCP_CONFIG_PATH", config_path):
            with patch("headroom.cli.mcp.CLAUDE_CONFIG_DIR", temp_claude_dir):
                with patch("headroom.cli.mcp.shutil.which", return_value="/usr/bin/claude"):
                    with patch(
                        "headroom.cli.mcp.subprocess.run",
                        side_effect=self._make_run(add_rc=1),
                    ):
                        runner = CliRunner()
                        result = runner.invoke(main, ["mcp", "install"])

        assert result.exit_code == 0, f"Failed: {result.output}"
        assert config_path.exists()
        config = json.loads(config_path.read_text())
        assert "headroom" in config["mcpServers"]

    def test_install_with_custom_proxy_url_passes_e_flag(self, mock_mcp_available):
        """Custom proxy URL is passed as -e KEY=VALUE to claude mcp add."""
        calls = []

        def capturing_run(cmd, **kwargs):
            calls.append(list(cmd))
            # Return rc=1 for "get" so headroom is treated as not yet registered
            if "get" in cmd:
                return MagicMock(returncode=1, stderr="")
            return MagicMock(returncode=0, stderr="")

        runner = CliRunner()
        with patch("headroom.cli.mcp.shutil.which", return_value="/usr/bin/claude"):
            with patch("headroom.cli.mcp.subprocess.run", side_effect=capturing_run):
                result = runner.invoke(
                    main, ["mcp", "install", "--proxy-url", "http://custom:9000"]
                )

        assert result.exit_code == 0, f"Failed: {result.output}"
        add_calls = [c for c in calls if "add" in c]
        assert len(add_calls) == 1
        add_cmd = add_calls[0]
        assert "-e" in add_cmd
        env_idx = add_cmd.index("-e")
        assert add_cmd[env_idx + 1] == "HEADROOM_PROXY_URL=http://custom:9000"


class TestMCPUninstallWithClaudeCLI:
    """Test mcp_uninstall when the claude CLI is available."""

    def test_uninstall_calls_claude_mcp_remove(self):
        """Uninstall calls claude mcp remove when headroom is registered."""
        calls = []

        def capturing_run(cmd, **kwargs):
            calls.append(list(cmd))
            return MagicMock(returncode=0, stderr="")

        runner = CliRunner()
        with patch("headroom.cli.mcp.shutil.which", return_value="/usr/bin/claude"):
            with patch("headroom.cli.mcp.subprocess.run", side_effect=capturing_run):
                result = runner.invoke(main, ["mcp", "uninstall"])

        assert result.exit_code == 0
        assert "removed" in result.output.lower()
        subcommands = [c[2] for c in calls]
        assert "remove" in subcommands

    def test_uninstall_skips_remove_when_not_registered(self):
        """Uninstall does not call remove when headroom is not registered via claude CLI."""
        calls = []

        def capturing_run(cmd, **kwargs):
            calls.append(list(cmd))
            # mcp get returns non-zero → not registered
            if "get" in cmd:
                return MagicMock(returncode=1, stderr="")
            return MagicMock(returncode=0, stderr="")

        runner = CliRunner()
        with patch("headroom.cli.mcp.shutil.which", return_value="/usr/bin/claude"):
            with patch("headroom.cli.mcp.subprocess.run", side_effect=capturing_run):
                result = runner.invoke(main, ["mcp", "uninstall"])

        assert result.exit_code == 0
        subcommands = [c[2] for c in calls]
        assert "remove" not in subcommands