package internal

import (
	"fmt"
	"os"
	"path/filepath"

	"gopkg.in/yaml.v3"
)

type UserMap struct {
	// Maps Jellyfin usernames -> relative media subdir (e.g., "mary_grace_allison" -> "Allison")
	Map map[string]string `yaml:"map"`
}

func LoadUserMap(path string) (*UserMap, error) {
	b, err := os.ReadFile(path)
	if err != nil { return nil, err }
	var m UserMap
	if err := yaml.Unmarshal(b, &m); err != nil { return nil, err }
	return &m, nil
}

func (m *UserMap) Resolve(username string) (string, error) {
	if dir, ok := m.Map[username]; ok && dir != "" {
		clean := filepath.Clean(dir)
		if clean == "." || clean == "/" { return "", fmt.Errorf("invalid target dir") }
		return clean, nil
	}
	return "", fmt.Errorf("no mapping for user %q", username)
}