"use client"

import { useMemo, type ReactNode } from "react"
import {
  Inbox,
  Send,
  FileEdit,
  ShieldAlert,
  Trash2,
} from "lucide-react"
import type { FolderTreeNode } from "@/lib/sidebar-nav-data"

export type MoveTarget = {
  id: string
  label: string
  icon?: ReactNode
  depth: number
  isFolder?: boolean
  isRecent?: boolean
  color?: string
}

const SYSTEM_DESTINATIONS: MoveTarget[] = [
  { id: "inbox", label: "Boîte de réception", icon: <Inbox className="size-4 shrink-0 text-[#5f6368]" strokeWidth={1.5} />, depth: 0 },
  { id: "sent", label: "Messages envoyés", icon: <Send className="size-4 shrink-0 text-[#5f6368]" strokeWidth={1.5} />, depth: 0 },
  { id: "drafts", label: "Brouillons", icon: <FileEdit className="size-4 shrink-0 text-[#5f6368]" strokeWidth={1.5} />, depth: 0 },
  { id: "spam", label: "Spam", icon: <ShieldAlert className="size-4 shrink-0 text-[#5f6368]" strokeWidth={1.5} />, depth: 0 },
  { id: "trash", label: "Corbeille", icon: <Trash2 className="size-4 shrink-0 text-[#5f6368]" strokeWidth={1.5} />, depth: 0 },
]

function flattenFolderTree(
  nodes: FolderTreeNode[],
  depth: number = 0
): MoveTarget[] {
  const out: MoveTarget[] = []
  for (const n of nodes) {
    out.push({
      id: n.id,
      label: n.label,
      icon: (
        <span
          className={`inline-block size-3 shrink-0 rounded-sm ${n.color ?? "bg-slate-400"}`}
        />
      ),
      depth,
      isFolder: true,
      color: n.color,
    })
    if (n.children?.length) {
      out.push(...flattenFolderTree(n.children, depth + 1))
    }
  }
  return out
}

export function useMoveTargets({
  folderTree,
  recentMoveTargets,
  currentFolderId,
}: {
  folderTree: FolderTreeNode[]
  recentMoveTargets: string[]
  currentFolderId: string
}): { recents: MoveTarget[]; system: MoveTarget[]; folders: MoveTarget[] } {
  return useMemo(() => {
    const allSystem = SYSTEM_DESTINATIONS.filter((d) => d.id !== currentFolderId)
    const allFolders = flattenFolderTree(folderTree).filter(
      (f) => f.id !== currentFolderId
    )
    const allById = new Map<string, MoveTarget>()
    for (const t of allSystem) allById.set(t.id, t)
    for (const t of allFolders) allById.set(t.id, t)

    const recents: MoveTarget[] = []
    for (const rid of recentMoveTargets) {
      if (rid === currentFolderId) continue
      const target = allById.get(rid)
      if (target) recents.push({ ...target, isRecent: true, depth: 0 })
    }

    return { recents, system: allSystem, folders: allFolders }
  }, [folderTree, recentMoveTargets, currentFolderId])
}

export { SYSTEM_DESTINATIONS, flattenFolderTree }