package xdg

import (
	"os"
	"path/filepath"

	"github.com/bnema/dumber/internal/application/port"
	"github.com/bnema/dumber/internal/infrastructure/config"
)

// Adapter implements port.XDGPaths using config.GetXDGDirs().
type Adapter struct {
	isDev      bool
	runtimeDir string
}

// New creates a new XDG paths adapter.
func New(isDev bool, runtimeDir string) *Adapter {
	return &Adapter{isDev: isDev, runtimeDir: runtimeDir}
}

func (a *Adapter) ConfigDir() (string, error) {
	return config.GetConfigDir()
}

func (a *Adapter) DataDir() (string, error) {
	return config.GetDataDir()
}

func (a *Adapter) StateDir() (string, error) {
	return config.GetStateDir()
}

func (a *Adapter) RuntimeDir() (string, error) {
	if a == nil || !a.isDev {
		if dir := os.Getenv("XDG_RUNTIME_DIR"); dir != "" {
			return dir, nil
		}
	}
	if a != nil && a.runtimeDir != "" {
		return a.runtimeDir, nil
	}

	stateDir, err := config.GetStateDir()
	if err != nil {
		return "", err
	}
	return filepath.Join(stateDir, "runtime"), nil
}

func (a *Adapter) CacheDir() (string, error) {
	dirs, err := config.GetXDGDirs()
	if err != nil {
		return "", err
	}
	return dirs.CacheHome, nil
}

func (a *Adapter) FilterJSONDir() (string, error) {
	dataDir, err := a.DataDir()
	if err != nil {
		return "", err
	}
	return filepath.Join(dataDir, "filters", "json"), nil
}

func (a *Adapter) FilterStoreDir() (string, error) {
	dataDir, err := a.DataDir()
	if err != nil {
		return "", err
	}
	return filepath.Join(dataDir, "filters", "store"), nil
}

func (a *Adapter) FilterCacheDir() (string, error) {
	return config.GetFilterCacheDir()
}

func (a *Adapter) ManDir() (string, error) {
	// Man pages go to the user's XDG_DATA_HOME/man/man1, not the dumber-specific dir.
	// This allows 'man dumber' to work without custom MANPATH configuration.
	home, err := os.UserHomeDir()
	if err != nil {
		return "", err
	}

	dataHome := os.Getenv("XDG_DATA_HOME")
	if dataHome == "" {
		dataHome = filepath.Join(home, ".local", "share")
	}

	return filepath.Join(dataHome, "man", "man1"), nil
}

func (a *Adapter) DownloadDir() (string, error) {
	// Check XDG_DOWNLOAD_DIR first (set by xdg-user-dirs).
	if dir := os.Getenv("XDG_DOWNLOAD_DIR"); dir != "" {
		return dir, nil
	}

	// Fallback to ~/Downloads.
	home, err := os.UserHomeDir()
	if err != nil {
		return "", err
	}
	return filepath.Join(home, "Downloads"), nil
}

var _ port.XDGPaths = (*Adapter)(nil)