'use server';

import { redirect } from 'next/navigation';
import { prisma } from '@/lib/prisma';

function slugify(input: string) {
  return input
    .toUpperCase()
    .trim()
    .replace(/[^A-Z0-9]+/g, '_')
    .replace(/^_+|_+$/g, '');
}

async function uniqueSlug(base: string) {
  let slug = base || 'GALLERY';
  let n = 2;
  while (await prisma.galleryCategory.findUnique({ where: { slug } })) {
    slug = `${base}_${n}`;
    n += 1;
  }
  return slug;
}

async function fileToDataUrl(file: File): Promise<string> {
  const bytes = Buffer.from(await file.arrayBuffer());
  const mimeType = file.type || 'image/png';
  return `data:${mimeType};base64,${bytes.toString('base64')}`;
}

export async function uploadGalleryPhoto(formData: FormData) {
  const caption = String(formData.get('caption') ?? '').trim();
  const categoryId = String(formData.get('categoryId') ?? '').trim() || null;
  const file = formData.get('image') as File | null;

  if (!file || file.size === 0) {
    throw new Error('A photo is required.');
  }

  const imageDataUrl = await fileToDataUrl(file);

  await prisma.galleryPhoto.create({
    data: {
      imageDataUrl,
      caption: caption || null,
      categoryId,
    },
  });

  redirect('/admin/gallery');
}

export async function deleteGalleryPhoto(formData: FormData) {
  const id = String(formData.get('id') ?? '');
  if (!id) return;

  await prisma.galleryPhoto.delete({ where: { id } });
  redirect('/admin/gallery');
}

export async function createGalleryCategory(formData: FormData) {
  const name = String(formData.get('name') ?? '').trim();
  const redirectTo = String(formData.get('redirectTo') ?? '/admin/gallery/categories').trim();
  if (!name) throw new Error('Category name is required.');

  const slug = await uniqueSlug(slugify(name));

  await prisma.galleryCategory.create({ data: { name, slug } });

  redirect(redirectTo);
}

export async function deleteGalleryCategory(formData: FormData) {
  const id = String(formData.get('id') ?? '');
  if (!id) return;

  const inUse = await prisma.galleryPhoto.count({ where: { categoryId: id } });
  if (inUse > 0) {
    redirect('/admin/gallery/categories?error=in_use');
  }

  await prisma.galleryCategory.delete({ where: { id } });
  redirect('/admin/gallery/categories');
}