import DI, {DDNames} from "@gongt/ts-stl-library/DI";
import * as multer from "multer";
import {diskStorage, Instance, memoryStorage} from "multer";
import {tmpdir} from "os";
import {MulterFileFilter, MulterFileLimits} from "./multer.types";

initFileUploadLimits({
	fieldSize: 1024 * 1024,
	fields: 1000,
	fileSize: 1024 * 1024, // 1mb
});

DI.set(DDNames.multerCreator, createFileHandler);

export function initDiskStorage(destination) {
	DI.set(DDNames.multerStorage, diskStorage({destination}));
}

export function initMemoryStorage() {
	DI.set(DDNames.multerStorage, memoryStorage())
}

export function initFileUploadLimits(limits: MulterFileLimits) {
	DI.set(DDNames.multerDefaults, limits)
}

export function createFileHandler(limits: MulterFileLimits = {}, fileFilter?: MulterFileFilter): Instance {
	limits = Object.assign(DI.get(DDNames.multerDefaults), limits);
	
	let storage = DI.get(DDNames.multerStorage, false);
	if (!storage) {
		initDiskStorage(tmpdir());
		storage = DI.get(DDNames.multerStorage, true);
	}
	return multer({
		storage: storage,
		limits,
		fileFilter,
	});
}