import { isomorphicGlobal } from './check-environment';

export class DependencyInjector<Def, Key extends keyof Def = keyof Def> {
	private dup: any;
	private register: Def;
	
	constructor(private name: string) {
		const symbol = Symbol.for('@@DependencyInjector/' + name);
		if (!isomorphicGlobal[symbol]) {
			isomorphicGlobal[symbol] = {};
		}
		this.register = isomorphicGlobal[symbol];
		this.dup = {};
	}
	
	get(name: Key, def?: Def[Key]): Def[Key] {
		if (!this.has(name)) {
			if (arguments.length === 2) {
				return def;
			}
			throw new Error(`not found dependency for: ${name}@${this.name}`);
		}
		return this.register[name];
	}
	
	has(name: Key): boolean {
		return this.register.hasOwnProperty(name);
	}
	
	keys() {
		return Object.keys(this.register);
	}
	
	overwrite(name: Key, value: Def[Key]) {
		this.register[name] = value;
		this.dup[name] = (new Error('')).stack;
	}
	
	set(name: Key, value: Def[Key]) {
		if (this.register[name]) {
			console.error(`last set:\n%s`, limitStack(this.dup[name]));
			console.error(`this set:\n%s`, limitStack((new Error('')).stack));
			throw new Error(`duplicate dependency: ${name}@${this.name}`);
		}
		this.register[name] = value;
		this.dup[name] = (new Error('')).stack;
	}
	
	values() {
		return Object.values(this.register);
	}
}

function limitStack(stack: string) {
	const arr = stack.split(/\n/);
	arr.shift(); // Error: xxx
	arr.shift(); // this file
	arr.length = 4;
	return arr.map(item => '\t' + item.trim()).join('\n');
}

export default new DependencyInjector<DefaultDependency>('default');

// DDN: default dependencies name
export enum DDNames {
	sessionHandler = 'sessionHandler',
	cookieHandler = 'cookieHandler',
	cookieSignKey = 'cookieSignKey',
	multerStorage = 'multerStorage',
	multerCreator = 'multerCreator',
	multerDefaults = 'multerDefaults',
	defaultUserHandler = 'defaultUserHandler',
	defaultJsonHandler = 'defaultJsonHandler',
	defaultUrlencodeHandler = 'defaultUrlencodeHandler',
	isDebugMode = 'isDebugMode',
	serverRequestKey = 'serverRequestKey',
	proxyRequest = 'proxyRequest',
	mongodbSchemaHook = 'mongodbSchemaHook',
	redisLockServer = 'redisLockServer',
	webListenPort = 'webListenPort',
}

export interface DefaultDependency {
	cookieHandler: any;
	cookieSignKey: any;
	databaseConnection: any;
	defaultJsonHandler: any;
	defaultUrlencodeHandler: any;
	defaultUserHandler: any;
	isDebugMode: boolean;
	mongodbSchemaHook: any;
	multerCreator: any;
	multerDefaults: any;
	multerStorage: any;
	proxyRequest: any;
	redisLockServer: any;
	serverRequestKey: any;
	sessionHandler: any;
	webListenPort: number;
}