import { writeFileSync, mkdirSync, existsSync } from 'fs';
import { fail } from '@sveltejs/kit';
import type { RequestEvent } from './$types';
import safePath, { storagePath, log } from '$lib';
import { hash } from 'crypto';
import path from 'path';

const mkdirIfNotExists = (path: string) => {
	if (!existsSync(path)) {
		mkdirSync(path);
	}
};

export const actions = {
	default: async ({ request, locals }: RequestEvent) => {
		let context: { [key: string]: string | string[] } = { requestId: locals.requestId };
		const data = await request.formData();

		const formFiles = data.getAll('files');
		if (!formFiles) {
			log.debug(context, 'missing files');
			return fail(400, { field: 'files', files: formFiles, missing: true });
		} else if (!(formFiles as File[])) {
			log.debug(context, 'invalid files');
			return fail(400, { field: 'files', files: formFiles, incorrect: true });
		}
		const files = formFiles as File[];
		const fileNames = files.map((file) => file.name);
		context = { fileNames, ...context };
		if (files.length === 0) {
			log.debug(context, 'empty files');
			return fail(400, { field: 'files', files: formFiles, empty: true });
		}

		const formName = data.get('name');
		if (!formName) {
			log.debug(context, 'missing name');
			return fail(400, { field: 'name', name: formName, missing: true });
		} else if (!(formName as string)) {
			log.debug(context, 'invalid name');
			return fail(400, { field: 'name', name: formName, incorrect: true });
		}

		const name = formName as string;
		context = { name, ...context };

		if (!safePath(storagePath, name)) {
			log.warn(context, 'Supplied name would cause dir traversal. Rejecting...');
			return fail(400, { field: 'name', name: name, incorrect: true });
		}

		log.info(context, 'Uploading files');

		files.forEach(async (file) => {
			const outPath = `${storagePath}/${name}`;
			const content = Buffer.from(await file.arrayBuffer());
			const ext = path.extname(file.name);

			mkdirIfNotExists(outPath);
			const filename = `${hash('sha1', content)}${ext}`;
			const fullPath = `${outPath}/${filename}`;
			context = { file: fullPath, ...context };
			if (existsSync(fullPath)) {
				log.debug(context, 'File has already been uploaded. Skipping...');
			} else {
				log.debug(context, 'saving file');
				writeFileSync(fullPath, Buffer.from(await file.arrayBuffer()), { flag: 'a+' });
			}
		});

		return {
			success: true,
		};
	},
};