import { Injectable } from "@nestjs/common";
import { ConfigService } from "@nestjs/config";
import { ES256 } from "@sd-jwt/crypto-nodejs";
import { CryptoImplementation } from "./crypto-implementation";
import { ED25519 } from "./ed25519";

export type CryptoType = "ES256" | "Ed25519";

@Injectable()
export class CryptoImplementationService {
    constructor(private configServie: ConfigService) {}

    /**
     * Return the algorithm that is used for the crypto operations like signing.
     * @returns
     */
    getAlg(): CryptoType {
        return this.configServie.get("CRYPTO_ALG") as CryptoType;
    }

    /**
     * Returns the crypto implementation based on the configured algorithm.
     * @param alg
     * @returns
     */
    getCrypto(
        alg = this.configServie.get<string>("CRYPTO_ALG"),
    ): CryptoImplementation {
        switch (alg) {
            case "Ed25519":
                return ED25519;
            case "ES256":
                return ES256;
            default:
                throw new Error(`Unsupported algorithm ${alg}`);
        }
    }
}