package managementasset

import (
	"io/fs"
	"net/http"
	"os"
	"path/filepath"
	"strings"
)

const (
	IndexFile      = "index.html"
	ManagementFile = "management.html"
)

// Source describes the filesystem and entry file used for the management UI.
type Source struct {
	FileSystem http.FileSystem
	Entry      string
}

// Current returns the configured management UI source.
func Current() (*Source, error) {
	if override := strings.TrimSpace(os.Getenv("MANAGEMENT_STATIC_PATH")); override != "" {
		cleaned := filepath.Clean(override)
		info, err := os.Stat(cleaned)
		if err != nil {
			return nil, err
		}

		if !info.IsDir() {
			return &Source{
				FileSystem: http.Dir(filepath.Dir(cleaned)),
				Entry:      filepath.Base(cleaned),
			}, nil
		}

		entry := IndexFile
		if _, err = os.Stat(filepath.Join(cleaned, entry)); err != nil {
			if !os.IsNotExist(err) {
				return nil, err
			}
			entry = ManagementFile
		}
		return &Source{FileSystem: http.Dir(cleaned), Entry: entry}, nil
	}

	files := embeddedFiles()
	if files == nil {
		return nil, fs.ErrNotExist
	}
	return &Source{FileSystem: http.FS(files), Entry: IndexFile}, nil
}