import {promises as fs, readFileSync} from "fs";

export default class FileCache {
    private readonly cache: Record<string, string> = {};

    public async get(file: string, forceRead: boolean = false): Promise<string> {
        if (forceRead || !this.cache[file]) {
            await this.load(file);
        }

        return this.cache[file];
    }

    public getSync(file: string, forceRead: boolean = false): string {
        if (forceRead || !this.cache[file]) {
            this.loadSync(file);
        }

        return this.cache[file];
    }

    public getOrFail(file: string): string {
        if (!this.cache[file]) throw new Error(file + ' not cached.');
        return this.cache[file];
    }

    public async load(file: string): Promise<void> {
        this.cache[file] = (await fs.readFile(file)).toString();
    }

    public loadSync(file: string): void {
        this.cache[file] = readFileSync(file).toString();
    }
}