"use client";

import { useOptimistic, useTransition } from "react";
import type { ListShareData, ListShareItem } from "../server/share-queries";
import { toggleShareListItem } from "../server/share-actions";

export function ListSharedView({
  data,
  canWrite,
  token,
}: {
  data: ListShareData;
  canWrite: boolean;
  token: string;
}) {
  const [optimisticItems, setOptimisticItems] = useOptimistic(
    data.items,
    (current: ListShareItem[], { id, done }: { id: string; done: boolean }) =>
      current.map((item) => (item.id === id ? { ...item, done } : item)),
  );
  const [, startTransition] = useTransition();

  function toggle(item: ListShareItem) {
    if (!canWrite) return;
    const next = !item.done;
    startTransition(async () => {
      setOptimisticItems({ id: item.id, done: next });
      await toggleShareListItem(token, item.id);
    });
  }

  const open = optimisticItems.filter((i) => !i.done);
  const done = optimisticItems.filter((i) => i.done);

  return (
    <div className="mx-auto max-w-xl space-y-4 p-4">
      <header>
        <h1 className="text-2xl font-semibold">{data.name}</h1>
        <p className="text-sm text-muted-foreground capitalize">{data.type}</p>
      </header>

      {optimisticItems.length === 0 ? (
        <p className="text-sm text-muted-foreground">This list is empty.</p>
      ) : (
        <div className="space-y-4">
          {open.length > 0 && (
            <ul className="divide-y rounded-lg border bg-background">
              {open.map((item) => (
                <ItemRow key={item.id} item={item} canWrite={canWrite} onToggle={toggle} />
              ))}
            </ul>
          )}
          {done.length > 0 && (
            <details className="group">
              <summary className="cursor-pointer select-none text-sm text-muted-foreground">
                {done.length} completed
              </summary>
              <ul className="mt-2 divide-y rounded-lg border bg-background">
                {done.map((item) => (
                  <ItemRow key={item.id} item={item} canWrite={canWrite} onToggle={toggle} />
                ))}
              </ul>
            </details>
          )}
        </div>
      )}
    </div>
  );
}

function ItemRow({
  item,
  canWrite,
  onToggle,
}: {
  item: ListShareItem;
  canWrite: boolean;
  onToggle: (item: ListShareItem) => void;
}) {
  return (
    <li className="flex items-center gap-3 px-4 py-3">
      {canWrite ? (
        <input
          type="checkbox"
          aria-label={`Complete ${item.text}`}
          className="size-5 accent-primary"
          checked={item.done}
          onChange={() => onToggle(item)}
        />
      ) : (
        <span
          aria-hidden
          className={`size-5 shrink-0 rounded-sm border border-border ${item.done ? "bg-muted" : ""}`}
        />
      )}
      <span className={`text-sm ${item.done ? "text-muted-foreground line-through" : ""}`}>
        {item.text}
        {item.qty && (
          <span className="ml-1 text-xs text-muted-foreground">×{item.qty}</span>
        )}
      </span>
    </li>
  );
}