import { Link, useSearchParams } from 'react-router';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { fileUrl } from '../lib/api';
import type { CollectionSummary, GenerationRow } from '../lib/api';
import { useCollectionsManager } from './useCollectionsManager';
import type { CollectionsManager } from './useCollectionsManager';

export const Collections = () => {
  const [searchParams] = useSearchParams();
  const openId = searchParams.get('collection') ?? undefined;
  const manager = useCollectionsManager(openId);

  if (manager.loading) return <p className="p-4 text-sm text-muted-foreground">Loading…</p>;
  if (openId) return <Detail manager={manager} searchParams={searchParams} />;

  return (
    <div className="space-y-6 p-4">
      <div className="flex gap-2">
        <Input
          placeholder="New collection — an afternoon, a suite, a client"
          value={manager.draftName}
          onChange={(ev) => manager.setDraftName(ev.target.value)}
          onKeyDown={(ev) => ev.key === 'Enter' && manager.create()}
        />
        <Button onClick={manager.create} disabled={!manager.draftName.trim()}>
          Create
        </Button>
      </div>

      {manager.error && <p className="text-sm text-destructive">{manager.error}</p>}

      {manager.collections.length === 0 ? (
        <p className="text-sm text-muted-foreground">
          No collections yet. Create one here, or pass <code className="text-foreground">?collection=name</code>{' '}
          when generating and it will be made for you.
        </p>
      ) : (
        <div className="grid gap-4 sm:grid-cols-2">
          {manager.collections.map((collection) => (
            <Card
              key={collection.id}
              collection={collection}
              searchParams={searchParams}
              onDelete={() => manager.remove(collection.id)}
            />
          ))}
        </div>
      )}
    </div>
  );
};

type CardProps = { collection: CollectionSummary; searchParams: URLSearchParams; onDelete: () => void };

const Card = ({ collection, searchParams, onDelete }: CardProps) => {
  const src = fileUrl(collection.cover_url);
  const to = (() => {
    const next = new URLSearchParams(searchParams);
    next.set('collection', collection.id);
    return { search: `?${next.toString()}` };
  })();

  return (
    <div className="group relative overflow-hidden rounded-lg border border-border">
      <Link to={to} className="block">
        <div className="flex aspect-video items-center justify-center bg-muted/30">
          {src ? (
            <img src={src} alt="" loading="lazy" className="size-full object-cover" />
          ) : (
            <span className="text-xs text-muted-foreground">empty</span>
          )}
        </div>
        <div className="space-y-0.5 p-3">
          <p className="truncate text-sm font-medium">{collection.name}</p>
          <p className="text-xs text-muted-foreground">
            {collection.item_count} image{collection.item_count === 1 ? '' : 's'}
          </p>
        </div>
      </Link>

      <button
        type="button"
        onClick={onDelete}
        // Deleting a collection does not delete images, which is why this needs no confirmation step.
        title="Delete collection (images are kept)"
        className="absolute right-2 top-2 rounded bg-black/60 px-2 py-1 text-xs text-white/70 opacity-0 transition group-hover:opacity-100 hover:text-white"
      >
        Delete
      </button>
    </div>
  );
};

type DetailProps = { manager: CollectionsManager; searchParams: URLSearchParams };

const Detail = ({ manager, searchParams }: DetailProps) => {
  const collection = manager.detail;

  const backTo = (() => {
    const next = new URLSearchParams(searchParams);
    next.delete('collection');
    const search = next.toString();
    return { search: search ? `?${search}` : '' };
  })();

  if (!collection) return <p className="p-4 text-sm text-muted-foreground">Loading…</p>;

  return (
    <div className="space-y-6 p-4">
      <div className="flex items-baseline gap-3">
        <Link to={backTo} className="text-sm text-muted-foreground hover:text-foreground">
          ‹ Collections
        </Link>
        <h2 className="text-lg font-semibold">{collection.name}</h2>
        <span className="text-sm text-muted-foreground">
          {collection.images.length} image{collection.images.length === 1 ? '' : 's'}
        </span>
      </div>

      {collection.images.length === 0 ? (
        <p className="text-sm text-muted-foreground">
          Nothing here yet. Add images from the gallery, or generate with{' '}
          <code className="text-foreground">?collection={collection.name}</code>.
        </p>
      ) : (
        <div className="grid gap-4 sm:grid-cols-2 lg:grid-cols-3">
          {collection.images.map((image) => (
            <Item key={image.id} image={image} onRemove={() => manager.removeImage(collection.id, image.id)} />
          ))}
        </div>
      )}
    </div>
  );
};

const Item = ({ image, onRemove }: { image: GenerationRow; onRemove: () => void }) => {
  const src = fileUrl(image.url);
  return (
    <figure className="group relative space-y-2">
      <div className="flex aspect-square items-center justify-center overflow-hidden rounded-lg border border-border bg-muted/30">
        {src ? (
          <img src={src} alt={image.prompt} loading="lazy" className="size-full object-cover" />
        ) : (
          <span className="px-3 text-center text-xs text-muted-foreground">{image.error ?? image.status}</span>
        )}
      </div>

      <button
        type="button"
        onClick={onRemove}
        title="Remove from this collection"
        className="absolute right-2 top-2 rounded bg-black/60 px-2 py-1 text-xs text-white/70 opacity-0 transition group-hover:opacity-100 hover:text-white"
      >
        Remove
      </button>

      <figcaption className="line-clamp-2 text-xs text-muted-foreground">{image.prompt}</figcaption>
    </figure>
  );
};