import { SimpleAsyncValidateConfig } from "@olagg/validate";

export default class Result<T> {
    public isSuccess: boolean;
    public isFailure: boolean;
    public error?: unknown;
    private _data?: T;

    private constructor (isSuccess: boolean, error?: unknown, data?: T) {
        if (isSuccess && error) {
            throw new Error(`InvalidOperation: A result cannot be 
          successful and contain an error`);
        }
        if (!isSuccess && !error) {
            throw new Error(`InvalidOperation: A failing result 
          needs to contain an error message`);
        }

        this.isSuccess = isSuccess;
        this.isFailure = !isSuccess;
        this.error = error;
        this._data = data;

        Object.freeze(this);
    }

    public data () : T {
        if (!this.isSuccess || !this._data) {
            throw new Error("Cant retrieve the data from a failed result.");
        }

        return this._data;
    }

    public static success<U> (data?: U) : Result<U> {
        return new Result<U>(true, undefined, data);
    }

    public static failure<U> (error: unknown, ...args: unknown[]): Result<U> {
        let message = error;
        if (args.length) message = (message as string).concat(" " + args.join(" ") as string);
        return new Result<U>(false, message);
    }
}

SimpleAsyncValidateConfig.onFailure = (error: string) => {
    return Result.failure(error);
};