import { CRYPTO_RSA_CODES, CryptoRsaError } from "../errors/errors.js";
import type {
    RsaJwk,
    RsaPrivateKey,
    RsaPrivateKeyFormat,
    RsaPublicKey,
    RsaPublicKeyFormat,
} from "./keys.types.js";
import {
    serializeRsaPrivateKeyJwk,
    serializeRsaPublicKeyJwk,
} from "./serialize-jwk.js";
import { serializeRsaPrivateKeyPkcs1 } from "./serialize-pkcs1-private.js";
import { serializeRsaPublicKeyPkcs1 } from "./serialize-pkcs1-public.js";
import { serializeRsaPrivateKeyPkcs8 } from "./serialize-pkcs8.js";
import { serializeRsaPublicKeySpki } from "./serialize-spki.js";

export interface SerializeRsaPublicKeyOptions {
    readonly format: RsaPublicKeyFormat;
}

export interface SerializeRsaPrivateKeyOptions {
    readonly format: RsaPrivateKeyFormat;
}

/**
 * Façade dispatcher for public-key serialisation. Returns `Uint8Array` for
 * binary formats (`pkcs1`, `spki`) and a structured `RsaJwk` object for the
 * JWK format.
 */
export function serializeRsaPublicKey(
    key: RsaPublicKey,
    options: SerializeRsaPublicKeyOptions
): Uint8Array | RsaJwk {
    switch (options.format) {
        case "pkcs1":
            return serializeRsaPublicKeyPkcs1(key);
        case "spki":
            return serializeRsaPublicKeySpki(key);
        case "jwk":
            return serializeRsaPublicKeyJwk(key);
        default:
            return assertNeverFormat(options.format);
    }
}

/**
 * Façade dispatcher for private-key serialisation. Returns `Uint8Array` for
 * binary formats (`pkcs1`, `pkcs8`) and a structured `RsaJwk` for JWK.
 */
export function serializeRsaPrivateKey(
    key: RsaPrivateKey,
    options: SerializeRsaPrivateKeyOptions
): Uint8Array | RsaJwk {
    switch (options.format) {
        case "pkcs1":
            return serializeRsaPrivateKeyPkcs1(key);
        case "pkcs8":
            return serializeRsaPrivateKeyPkcs8(key);
        case "jwk":
            return serializeRsaPrivateKeyJwk(key);
        default:
            return assertNeverFormat(options.format);
    }
}

function assertNeverFormat(value: never): never {
    throw new CryptoRsaError(
        CRYPTO_RSA_CODES.UNSUPPORTED_FORMAT,
        "error.crypto-rsa.unsupported-format.unknown",
        { context: { value: String(value) } }
    );
}