export type FolderTreeNode = {
  id: string
  label: string
  count?: number
  color?: string
  children?: FolderTreeNode[]
}

export type LabelRowItem = {
  id: string
  label: string
  color: string
  count?: number
  /** Icône Iconify (ex. mdi:inbox) — onglets + sidebar pour libellés système. */
  icon?: string
  /** Onglet boîte de réception (Principale + ces onglets). */
  tabbed?: boolean
  /** Bloc favoris sous les dossiers principaux. */
  favorite?: boolean
  /** Masque de Principale quand le libellé est sur le mail (si activé). */
  excludeFromPrincipal?: boolean
  /** Pastille dans la liste / en-tête message. */
  showInMessageList?: boolean
  /** Désactivé : pas d’onglet, pas de sidebar, pas de pastille, exclude ignoré. */
  enabled?: boolean
}

export function buildFolderIdToLabelRecord(
  tree: FolderTreeNode[],
  labelRows: readonly LabelRowItem[]
): Record<string, string> {
  const m: Record<string, string> = {}
  for (const n of tree) {
    walkFolderTreeIds(n, m)
  }
  for (const row of labelRows) {
    m[row.id] = row.label
  }
  m.scheduled = "scheduled"
  return m
}

function walkFolderTreeIds(node: FolderTreeNode, acc: Record<string, string>) {
  acc[node.id] = node.label
  if (node.children?.length) {
    for (const c of node.children) walkFolderTreeIds(c, acc)
  }
}

/** Tous les ids de dossiers du sous-arbre (nœud + descendants). */
export function collectSubtreeFolderIds(
  tree: FolderTreeNode[],
  folderId: string
): string[] | null {
  for (const n of tree) {
    if (n.id === folderId) {
      const ids: string[] = []
      const collect = (node: FolderTreeNode) => {
        ids.push(node.id)
        node.children?.forEach(collect)
      }
      collect(n)
      return ids
    }
    if (n.children?.length) {
      const hit = collectSubtreeFolderIds(n.children, folderId)
      if (hit) return hit
    }
  }
  return null
}

/** @deprecated Préférer collectSubtreeFolderIds + libellé par id de dossier. */
export function subtreeMatchLabels(
  tree: FolderTreeNode[],
  folderId: string
): string[] | null {
  const ids = collectSubtreeFolderIds(tree, folderId)
  if (!ids) return null
  const labels: string[] = []
  const walk = (nodes: FolderTreeNode[]) => {
    for (const n of nodes) {
      if (ids.includes(n.id)) labels.push(n.label)
      if (n.children?.length) walk(n.children)
    }
  }
  walk(tree)
  return labels
}

export function buildEmailLabelToSidebarFolderId(
  folderIdToLabel: Record<string, string>
): Record<string, string> {
  const inv: Record<string, string> = {}
  for (const [id, lab] of Object.entries(folderIdToLabel)) {
    inv[lab] = id
  }
  inv.spam = "spam"
  inv.scheduled = "scheduled"
  return inv
}