import * as core from "webcrypto-core";
import { EcCrypto } from "./crypto";
import { EcPrivateKey } from "./private_key";
import { EcPublicKey } from "./public_key";
import { CryptoKey } from "../../keys";
import { setCryptoKey, getCryptoKey } from "../storage";

export class EcdhProvider extends core.EcdhProvider {
  public override namedCurves = core.EcCurves.names;

  public async onGenerateKey(
    algorithm: EcKeyGenParams,
    extractable: boolean,
    keyUsages: KeyUsage[]
  ): Promise<CryptoKeyPair> {
    const keys = await EcCrypto.generateKey(
      {
        ...algorithm,
        name: this.name,
      },
      extractable,
      keyUsages
    );

    return {
      privateKey: setCryptoKey(keys.privateKey as CryptoKey),
      publicKey: setCryptoKey(keys.publicKey as CryptoKey),
    };
  }

  public async onExportKey(
    format: KeyFormat,
    key: CryptoKey
  ): Promise<JsonWebKey | ArrayBuffer> {
    return EcCrypto.exportKey(format, getCryptoKey(key));
  }

  public async onImportKey(
    format: KeyFormat,
    keyData: JsonWebKey | ArrayBuffer,
    algorithm: EcKeyImportParams,
    extractable: boolean,
    keyUsages: KeyUsage[]
  ): Promise<core.CryptoKey> {
    const key = await EcCrypto.importKey(
      format,
      keyData,
      { ...algorithm, name: this.name },
      extractable,
      keyUsages
    );
    return setCryptoKey(key);
  }

  public override checkCryptoKey(key: CryptoKey, keyUsage?: KeyUsage) {
    super.checkCryptoKey(key, keyUsage);
    const internalKey = getCryptoKey(key);
    if (
      !(
        internalKey instanceof EcPrivateKey ||
        internalKey instanceof EcPublicKey
      )
    ) {
      throw new TypeError("key: Is not EC CryptoKey");
    }
  }

  public async onDeriveBits(
    algorithm: EcdhKeyDeriveParams,
    baseKey: CryptoKey,
    length: number
  ): Promise<ArrayBuffer> {
    const bits = await EcCrypto.deriveBits(
      { ...algorithm, public: getCryptoKey(algorithm.public) },
      getCryptoKey(baseKey),
      length
    );
    return bits;
  }
}