import { Injectable } from "@angular/core";

export interface IFunc<T> {
	(prev?: T): T;
}

interface Option<T = any> {
	stroage?: "local" | "session";
	defaultValue?: T | IFunc<T>;
	serializer?: (v: T) => string;
	deserializer?: (v: string) => T;
}

export const isFunction = (value: unknown): value is Function => typeof value === "function";

@Injectable()
export class StorageService {
	constructor() {}

	private parseOption(option?: Option) {
		const storage = option?.stroage === "session" ? sessionStorage : localStorage;
		const serializer = option?.serializer ? option?.serializer : JSON.stringify;
		const deserializer = option?.deserializer ? option?.deserializer : JSON.parse;
		let defaultValue = option?.defaultValue;

		if (isFunction(option?.defaultValue)) {
			defaultValue = option?.defaultValue();
		}

		return {
			storage,
			serializer,
			deserializer,
			defaultValue,
		};
	}

	get<T>(key: string, option?: Option<T>) {
		const { storage, deserializer, defaultValue } = this.parseOption(option);
		try {
			const val = storage.getItem(key);
			if (val) {
				return deserializer(val);
			}
		} catch (error) {
			console.error(error);
		}
		return defaultValue;
	}

	set<T>(key: string, value: T | IFunc<T>, option?: Option<T>) {
		const { storage, serializer, defaultValue } = this.parseOption(option);
		const val = (isFunction(value) ? value() : value) ?? defaultValue;
		if (typeof val === "undefined") {
			storage.removeItem(key);
		} else {
			try {
				storage.setItem(key, serializer(val));
			} catch (error) {
				console.error(error);
			}
		}
	}

	remove(key: string, option?: Pick<Option, "stroage">) {
		const { storage } = this.parseOption(option);
		storage.removeItem(key);
	}

	clear(option?: Pick<Option, "stroage">) {
		const { storage } = this.parseOption(option);
		storage.clear();
	}

	keys(option?: Pick<Option, "stroage">) {
		const { storage } = this.parseOption(option);
		return Object.keys(storage);
	}
}