"use client";
import { useState, useTransition } from "react";
import Link from "next/link";
import { FolderHeart, X, Plus } from "lucide-react";
import { addImageToCollection, removeImageFromCollection, createCollection } from "@/app/actions/collections";

interface PickedCollection { id: number; name: string; slug?: string }

export function CollectionPicker({
  imageId,
  current,
  available,
}: {
  imageId: number;
  current: PickedCollection[];
  available: PickedCollection[];
}) {
  const [picked, setPicked] = useState(current);
  const [open, setOpen] = useState(false);
  const [draft, setDraft] = useState("");
  const [pool, setPool] = useState(available);
  const [, start] = useTransition();

  const add = (c: PickedCollection) => {
    if (picked.some(p => p.id === c.id)) return;
    setPicked((cur) => [...cur, c]);
    start(async () => { await addImageToCollection(c.id, imageId); });
  };

  const remove = (id: number) => {
    setPicked((cur) => cur.filter(c => c.id !== id));
    start(async () => { await removeImageFromCollection(id, imageId); });
  };

  const createNew = async (e: React.FormEvent) => {
    e.preventDefault();
    const name = draft.trim();
    if (!name) return;
    setDraft("");
    start(async () => {
      const created = await createCollection(name);
      if (created) {
        setPool((cur) => [...cur, { id: created.id, name, slug: created.slug }]);
        setPicked((cur) => [...cur, { id: created.id, name, slug: created.slug }]);
        await addImageToCollection(created.id, imageId);
      }
    });
  };

  const remaining = pool.filter(p => !picked.some(pp => pp.id === p.id));

  return (
    <div>
      <div className="text-[10px] uppercase tracking-wider font-mono text-[var(--color-fg-muted)] mb-2">
        Collections
      </div>
      <div className="flex flex-wrap gap-1.5">
        {picked.map((c) => (
          <span
            key={c.id}
            className="group flex items-center gap-1 px-2 py-1 rounded-full text-xs glass border-[var(--color-cyan)]/30 text-[var(--color-cyan)] bg-[color-mix(in_oklch,var(--color-cyan)_10%,transparent)]"
          >
            <FolderHeart className="w-3 h-3" />
            {c.slug ? (
              <Link
                href={`/collection/${c.slug}`}
                className="hover:underline"
              >
                {c.name}
              </Link>
            ) : (
              c.name
            )}
            <button onClick={() => remove(c.id)} className="opacity-50 hover:opacity-100">
              <X className="w-3 h-3" />
            </button>
          </span>
        ))}
        <button
          onClick={() => setOpen((o) => !o)}
          className="flex items-center gap-1 px-2 py-1 rounded-full text-xs border border-dashed border-[var(--color-glass-border)] text-[var(--color-fg-dim)] hover:text-[var(--color-cyan)] hover:border-[var(--color-cyan)]"
        >
          <Plus className="w-3 h-3" />
          Add to collection
        </button>
      </div>

      {open && (
        <div className="mt-2 glass rounded-xl p-3 space-y-2">
          {remaining.length > 0 && (
            <div className="flex flex-wrap gap-1.5">
              {remaining.map((c) => (
                <button
                  key={c.id}
                  onClick={() => add(c)}
                  className="text-xs px-2 py-1 rounded-full glass-strong hover:text-[var(--color-cyan)]"
                >
                  {c.name}
                </button>
              ))}
            </div>
          )}
          <form onSubmit={createNew} className="flex gap-1.5">
            <input
              value={draft}
              onChange={(e) => setDraft(e.target.value)}
              placeholder="New collection…"
              className="flex-1 bg-transparent text-xs px-2 py-1 rounded-md border border-[var(--color-glass-border)] outline-none focus:border-[var(--color-cyan)]"
            />
            <button type="submit" className="text-xs px-2 py-1 rounded-md bg-[var(--color-cyan)] text-black font-medium">
              Create
            </button>
          </form>
        </div>
      )}
    </div>
  );
}