cmd/korap-mcp/config.go

package main

import (
	"fmt"
	"os"

	"github.com/alecthomas/kong"
	kongyaml "github.com/alecthomas/kong-yaml"

	"github.com/korap/korap-mcp/config"
	"github.com/korap/korap-mcp/logger"
	"github.com/rs/zerolog"
)

// Constants for server identification
const (
	ServerName    = "KorAP MCP Server"
	ServerVersion = "0.1.0"
)

// CLI represents the command line interface
type CLI struct {
	// Configuration file path
	Config string `short:"c" type:"path" help:"Configuration file path"`

	// OAuth2 authentication configuration
	OAuth config.OAuthConfig `embed:"" prefix:"oauth-"`

	// KorAP API configuration
	KorAP config.KorAPConfig `embed:"" prefix:"korap-"`

	// Logging configuration
	Logging config.LoggingConfig `embed:"" prefix:"log-"`

	// Version flag
	Version bool `short:"v" help:"Show version information"`
}

// SetupCLI initializes the CLI parser with configuration
func SetupCLI() (*CLI, *kong.Kong, error) {
	// Initialize default configuration
	cfg := config.DefaultConfig()

	cli := CLI{
		OAuth:   cfg.OAuth,
		KorAP:   cfg.KorAP,
		Logging: cfg.Logging,
	}

	// Setup kong with conditional YAML configuration
	var parser *kong.Kong
	var err error

	if len(os.Args) > 1 {
		// Check if config file is specified in arguments
		for i, arg := range os.Args {
			if (arg == "--config" || arg == "-c") && i+1 < len(os.Args) {
				parser, err = kong.New(&cli,
					kong.Name("korap-mcp"),
					kong.Description("A Model Context Protocol server for KorAP corpus analysis platform."),
					kong.Configuration(kongyaml.Loader, os.Args[i+1]),
					kong.HelpOptions(kong.HelpOptions{Compact: true}),
				)
				break
			}
		}
	}

	// Fallback to parser without config file
	if parser == nil {
		parser, err = kong.New(&cli,
			kong.Name("korap-mcp"),
			kong.Description("A Model Context Protocol server for KorAP corpus analysis platform."),
			kong.HelpOptions(kong.HelpOptions{Compact: true}),
		)
	}
	if err != nil {
		return nil, nil, fmt.Errorf("failed to create CLI parser: %w", err)
	}

	return &cli, parser, nil
}

// ValidateAndSetupLogging validates the configuration and sets up logging
func (c *CLI) ValidateAndSetupLogging() (zerolog.Logger, error) {
	// Create config struct for validation with constants
	fullConfig := config.Config{
		Server: config.ServerConfig{
			Name:       ServerName,
			Version:    ServerVersion,
			ConfigFile: c.Config,
		},
		OAuth:   c.OAuth,
		KorAP:   c.KorAP,
		Logging: c.Logging,
	}

	// Validate configuration
	if err := fullConfig.Validate(); err != nil {
		return zerolog.Logger{}, fmt.Errorf("configuration validation failed: %w", err)
	}

	// Setup zerolog logging
	logger, err := logger.SetupLogger(&c.Logging)
	if err != nil {
		return zerolog.Logger{}, fmt.Errorf("failed to setup logging: %w", err)
	}

	return logger, nil
}

// GetConfig returns the full configuration
func (c *CLI) GetConfig() *config.Config {
	return &config.Config{
		Server: config.ServerConfig{
			Name:       ServerName,
			Version:    ServerVersion,
			ConfigFile: c.Config,
		},
		OAuth:   c.OAuth,
		KorAP:   c.KorAP,
		Logging: c.Logging,
	}
}

// GetServerName returns the server name constant
func (c *CLI) GetServerName() string {
	return ServerName
}

// GetServerVersion returns the server version constant
func (c *CLI) GetServerVersion() string {
	return ServerVersion
}