Sortable list persisted to a backend

"use client"

import { useState } from "react"
import { Badge } from "@/components/reui/badge"
import {
  Sortable,
  SortableItem,
  SortableItemHandle,
  type SortableCommitMeta,
} from "@/components/reui/sortable"
import { toast } from "sonner"

import { IconPlaceholder } from "@/app/(create)/components/icon-placeholder"

interface Item {
  id: string
  title: string
}

const defaultItems: Item[] = [
  { id: "1", title: "Draft the release notes" },
  { id: "2", title: "Review open pull requests" },
  { id: "3", title: "Update the changelog" },
  { id: "4", title: "Cut the release tag" },
  { id: "5", title: "Announce on the blog" },
]

// Simulated backend. Swap for a tRPC mutation or fetch in your app. Rejects
// roughly one in four calls so the optimistic rollback is easy to see.
function persistOrder(meta: SortableCommitMeta<Item>): Promise<void> {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      if (Math.random() < 0.25) {
        reject(new Error("Network error"))
      } else {
        resolve()
      }
    }, 700)
  })
}

export function Pattern() {
  const [items, setItems] = useState<Item[]>(defaultItems)

  // Sortable commits once, on drop. `onValueChange` has already applied the
  // new order optimistically; meta.previousValue is the order before the drag.
  const handleValueCommit = (next: Item[], meta: SortableCommitMeta<Item>) => {
    const previous = meta.previousValue
    const moved = next[meta.overIndex]

    toast.promise(persistOrder(meta), {
      loading: "Saving order...",
      success: () => `Saved "${moved.title}" at position ${meta.overIndex + 1}`,
      error: () => {
        // Roll back to the pre-drag order. In production prefer a refetch here
        // so a newer drag is not clobbered by this snapshot.
        setItems(previous)
        return "Could not save the new order. Restored."
      },
    })
  }

  return (
    <div className="mx-auto w-full max-w-xl p-6">
      <Sortable
        value={items}
        onValueChange={setItems}
        onValueCommit={handleValueCommit}
        getItemValue={(item) => item.id}
        strategy="vertical"
        className="space-y-2"
      >
        {items.map((item, index) => (
          <SortableItem key={item.id} value={item.id}>
            <div className="bg-background border-border flex items-center gap-3 rounded-md border p-3">
              <SortableItemHandle className="text-muted-foreground hover:text-foreground">
                <IconPlaceholder
                  lucide="GripVerticalIcon"
                  tabler="IconGripVertical"
                  hugeicons="DragDropVerticalIcon"
                  phosphor="DotsSixVerticalIcon"
                  remixicon="RiDraggable"
                  className="h-4 w-4"
                />
              </SortableItemHandle>
              <Badge variant="outline" className="tabular-nums">
                {index + 1}
              </Badge>
              <span className="min-w-0 flex-1 truncate text-sm font-medium">
                {item.title}
              </span>
            </div>
          </SortableItem>
        ))}
      </Sortable>
    </div>
  )
}