export const ASSET_FAMILIES = [
  'color',
  'diffuse',
  'roughness',
  'normal',
  'metalness',
  'height',
  'opacity',
] as const

export type AssetFamily = typeof ASSET_FAMILIES[number]

const ASSET_FAMILY_BY_KEY = new Map(ASSET_FAMILIES.map((family) => [family.toLowerCase(), family]))
const FORBIDDEN_ASSET_FAMILY_ALIASES: ReadonlyMap<string, AssetFamily> = new Map([
  ['basecolor', 'color'],
  ['base_color', 'color'],
  ['normalopengl', 'normal'],
  ['normal_opengl', 'normal'],
  ['metallic', 'metalness'],
  ['occlusionroughnessmetallic', 'roughness'],
  ['occlusion_roughness_metallic', 'roughness'],
])

export function getAssetFamily(value: string): AssetFamily | undefined {
  return ASSET_FAMILY_BY_KEY.get(value.toLowerCase())
}

export function getForbiddenAssetFamilyAlias(value: string): AssetFamily | undefined {
  return FORBIDDEN_ASSET_FAMILY_ALIASES.get(value.toLowerCase())
}

function getFileStem(filename: string) {
  return filename.replace(/\.[^.]+$/, '')
}

export function getTextureNamingError(filename: string) {
  const stem = getFileStem(filename)
  const [prefix, ...targetParts] = stem.split('_')
  const family = getAssetFamily(prefix)
  const extension = filename.split('.').pop()

  if (family && targetParts.every(Boolean)) return null

  const aliasSuggestion = getForbiddenAssetFamilyAlias(prefix)

  if (aliasSuggestion && targetParts.every(Boolean)) {
    const target = targetParts.join('_')
    return `Convention invalide : ${filename}. Utilisez ${aliasSuggestion}_${target}.${extension} pour cibler "${target}", ou ${aliasSuggestion}.${extension} pour tout le modele.`
  }

  const reversedParts = stem.split('_')
  const reversedFamily = reversedParts.length > 1 ? getAssetFamily(reversedParts[reversedParts.length - 1]) : undefined
  const reversedAliasSuggestion = reversedParts.length > 1
    ? getForbiddenAssetFamilyAlias(reversedParts[reversedParts.length - 1])
    : undefined

  if (reversedFamily) {
    const target = reversedParts.slice(0, -1).join('_')
    return `Convention invalide : ${filename}. Utilisez ${reversedFamily}_${target}.${extension} pour cibler "${target}", ou ${reversedFamily}.${extension} pour tout le modele.`
  }

  if (reversedAliasSuggestion) {
    const target = reversedParts.slice(0, -1).join('_')
    return `Convention invalide : ${filename}. Utilisez ${reversedAliasSuggestion}_${target}.${extension} pour cibler "${target}", ou ${reversedAliasSuggestion}.${extension} pour tout le modele.`
  }

  return `Asset inconnu : ${filename}. Familles autorisees : ${formatAssetFamilies()}. Utilisez asset.png pour tout le modele ou asset_objet.png pour cibler un objet.`
}

export function formatAssetFamilies() {
  return ASSET_FAMILIES.join(', ')
}