import type { RequestHandler } from './$types';
import { json, error } from '@sveltejs/kit';
import { createHash } from 'node:crypto';
import { existsSync } from 'node:fs';
import { mkdir, writeFile } from 'node:fs/promises';
import { join } from 'node:path';
import { getDb } from '$lib/server/db';
import { parsePositiveIntParam } from '$lib/server/api-helpers';
import { getRecipeById, updateImagePath } from '$lib/server/recipes/repository';
import { IMAGE_DIR } from '$lib/server/paths';

const MAX_BYTES = 10 * 1024 * 1024;

const EXT_BY_MIME: Record<string, string> = {
  'image/jpeg': '.jpg',
  'image/jpg': '.jpg',
  'image/png': '.png',
  'image/webp': '.webp',
  'image/gif': '.gif',
  'image/avif': '.avif'
};

export const POST: RequestHandler = async ({ params, request }) => {
  const id = parsePositiveIntParam(params.id, 'id');
  const db = getDb();
  if (!getRecipeById(db, id)) error(404, { message: 'Recipe not found' });

  const form = await request.formData().catch(() => null);
  const file = form?.get('file');
  if (!(file instanceof File)) error(400, { message: 'Field "file" missing' });
  if (file.size === 0) error(400, { message: 'Empty file' });
  if (file.size > MAX_BYTES) error(413, { message: 'Image too large (max 10 MB)' });

  const mime = file.type.toLowerCase();
  const ext = EXT_BY_MIME[mime];
  if (!ext) error(415, { message: `Image format ${file.type || 'unknown'} not supported` });

  const buf = Buffer.from(await file.arrayBuffer());
  const hash = createHash('sha256').update(buf).digest('hex');
  const filename = `${hash}${ext}`;
  const target = join(IMAGE_DIR, filename);
  if (!existsSync(target)) {
    await mkdir(IMAGE_DIR, { recursive: true });
    await writeFile(target, buf);
  }
  updateImagePath(db, id, filename);
  return json({ ok: true, image_path: filename });
};

export const DELETE: RequestHandler = ({ params }) => {
  const id = parsePositiveIntParam(params.id, 'id');
  const db = getDb();
  if (!getRecipeById(db, id)) error(404, { message: 'Recipe not found' });
  updateImagePath(db, id, null);
  return json({ ok: true });
};