import { startOfToday, getTime } from "date-fns";
import * as fse from "fs-extra";
import { HOME_DIR } from "./config";

export class Cache<Info> {
	private cacheFile: string;
	protected cacheInfo: Info;

	constructor(filename: string) {
		this.cacheFile = `./${HOME_DIR}/${filename}`;
		fse.ensureFileSync(this.cacheFile);
	}

	protected readFile = () => {
		return fse.readFileSync(this.cacheFile, "utf8");
	};

	protected writeToFile = () => {
		return fse.writeFile(this.cacheFile, JSON.stringify(this.cacheInfo), "utf8");
	};
}

export class LastBuiltEntryCache extends Cache<string[]> {
	constructor() {
		super("last-build-entry-cache.json");
		try {
			this.cacheInfo = JSON.parse(this.readFile());
		} catch {
			this.cacheInfo = [];
		}
	}

	getEntry() {
		return this.cacheInfo;
	}

	refreshEntry(newEntry: string[]) {
		this.cacheInfo = newEntry;
		this.writeToFile();
	}
}

export interface EntryCacheInfo {
	entryList: string[];
	createTime: number;
}

export class DevEntryCache extends Cache<EntryCacheInfo> {
	private currentTime: number;

	constructor() {
		super("dev-entry-cache.json");
		this.currentTime = getTime(startOfToday());
		try {
			this.cacheInfo = JSON.parse(this.readFile());
			const { createTime } = this.cacheInfo;
			if (createTime && createTime < this.currentTime) {
				this.cacheInfo = {
					entryList: [],
					createTime: this.currentTime
				};
			}
		} catch {
			this.cacheInfo = {
				entryList: [],
				createTime: this.currentTime
			};
		}
	}

	getEntry() {
		return this.cacheInfo.entryList;
	}

	addEntry(entryName: string) {
		const entryList = this.cacheInfo.entryList;
		if (!entryList.includes(entryName)) {
			entryList.push(entryName);
			this.writeToFile();
		}
	}
}

export const lastBuiltEntryCache = new LastBuiltEntryCache();
export const devEntryCache = new DevEntryCache();