package config

import (
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"runtime"

	"git.tukangketik.id/swanadiva/hostkeeper/internal/models"
)

// Config manages application configuration and paths
type Config struct {
	appName   string
	configDir string
	dataDir   string
	appConfig *models.AppConfig
}

// New creates a new Config instance
func New() (*Config, error) {
	appName := "hostkeeper"

	configDir, err := getConfigDir(appName)
	if err != nil {
		return nil, fmt.Errorf("failed to get config directory: %w", err)
	}

	dataDir := filepath.Join(configDir, "data")

	c := &Config{
		appName:   appName,
		configDir: configDir,
		dataDir:   dataDir,
	}

	// Create directories
	if err := os.MkdirAll(configDir, 0700); err != nil {
		return nil, fmt.Errorf("failed to create config directory: %w", err)
	}
	if err := os.MkdirAll(dataDir, 0700); err != nil {
		return nil, fmt.Errorf("failed to create data directory: %w", err)
	}

	// Load or create config
	if err := c.load(); err != nil {
		return nil, fmt.Errorf("failed to load config: %w", err)
	}

	return c, nil
}

// getConfigDir returns the OS-appropriate config directory for the app
func getConfigDir(appName string) (string, error) {
	switch runtime.GOOS {
	case "darwin":
		home, err := os.UserHomeDir()
		if err != nil {
			return "", err
		}
		return filepath.Join(home, "Library", "Application Support", appName), nil
	case "linux":
		if xdg := os.Getenv("XDG_CONFIG_HOME"); xdg != "" {
			return filepath.Join(xdg, appName), nil
		}
		home, err := os.UserHomeDir()
		if err != nil {
			return "", err
		}
		return filepath.Join(home, ".config", appName), nil
	case "windows":
		appData := os.Getenv("APPDATA")
		if appData != "" {
			return filepath.Join(appData, appName), nil
		}
		home, err := os.UserHomeDir()
		if err != nil {
			return "", err
		}
		return filepath.Join(home, "AppData", "Roaming", appName), nil
	default:
		home, err := os.UserHomeDir()
		if err != nil {
			return "", err
		}
		return filepath.Join(home, "."+appName), nil
	}
}

// load reads the config file, or creates a default one if it doesn't exist
func (c *Config) load() error {
	configPath := c.GetConfigFilePath()

	data, err := os.ReadFile(configPath)
	if err != nil {
		if os.IsNotExist(err) {
			// Create default config
			c.appConfig = models.DefaultConfig()
			return c.Save()
		}
		return err
	}

	c.appConfig = models.DefaultConfig()
	if err := json.Unmarshal(data, c.appConfig); err != nil {
		return fmt.Errorf("failed to parse config: %w", err)
	}

	return nil
}

// Save writes the current configuration to disk
func (c *Config) Save() error {
	configPath := c.GetConfigFilePath()

	data, err := json.MarshalIndent(c.appConfig, "", "  ")
	if err != nil {
		return fmt.Errorf("failed to marshal config: %w", err)
	}

	return os.WriteFile(configPath, data, 0600)
}

// GetAppConfig returns the application configuration
func (c *Config) GetAppConfig() *models.AppConfig {
	return c.appConfig
}

// UpdateAppConfig updates the application configuration
func (c *Config) UpdateAppConfig(cfg *models.AppConfig) error {
	c.appConfig = cfg
	return c.Save()
}

// GetConfigDir returns the configuration directory path
func (c *Config) GetConfigDir() string {
	return c.configDir
}

// GetDataDir returns the data directory path
func (c *Config) GetDataDir() string {
	return c.dataDir
}

// GetConfigFilePath returns the full path to the config JSON file
func (c *Config) GetConfigFilePath() string {
	return filepath.Join(c.configDir, "config.json")
}

// GetHostsFilePath returns the full path to the hosts JSON file
func (c *Config) GetHostsFilePath() string {
	return filepath.Join(c.dataDir, "hosts.json")
}

// GetKeysFilePath returns the full path to the keys JSON file
func (c *Config) GetKeysFilePath() string {
	return filepath.Join(c.dataDir, "keys.json")
}

// GetSnippetsFilePath returns the full path to the snippets JSON file
func (c *Config) GetSnippetsFilePath() string {
	return filepath.Join(c.dataDir, "snippets.json")
}