package org.sufficientlysecure.keychain.operations;

import android.content.Context;
import android.support.annotation.NonNull;

import org.sufficientlysecure.keychain.R;
import org.sufficientlysecure.keychain.operations.results.EditKeyResult;
import org.sufficientlysecure.keychain.operations.results.OperationResult;
import org.sufficientlysecure.keychain.operations.results.PgpEditKeyResult;
import org.sufficientlysecure.keychain.operations.results.SaveKeyringResult;
import org.sufficientlysecure.keychain.pgp.CanonicalizedSecretKey;
import org.sufficientlysecure.keychain.pgp.CanonicalizedSecretKeyRing;
import org.sufficientlysecure.keychain.pgp.PgpKeyOperation;
import org.sufficientlysecure.keychain.pgp.Progressable;
import org.sufficientlysecure.keychain.pgp.UncachedKeyRing;
import org.sufficientlysecure.keychain.provider.CachedPublicKeyRing;
import org.sufficientlysecure.keychain.provider.ProviderHelper;
import org.sufficientlysecure.keychain.service.PassphraseChangeParcel;
import org.sufficientlysecure.keychain.service.SaveKeyringParcel;
import org.sufficientlysecure.keychain.service.input.CryptoInputParcel;
import org.sufficientlysecure.keychain.ui.util.KeyFormattingUtils;
import org.sufficientlysecure.keychain.util.ProgressScaler;

import java.util.Iterator;

/**
 * Created by alex on 3/14/16.
 */
public class PassphraseChangeOperation extends BaseOperation<PassphraseChangeParcel> {


    public PassphraseChangeOperation(Context context, ProviderHelper providerHelper, Progressable progressable) {
        super(context, providerHelper, progressable);
    }

    /**
     * Finds the first unstripped key & uses that for passphrase verification.
     * Might bring in complications
     *
     * @param passphraseParcel  primary input to the operation
     * @param cryptoInput input that changes if user interaction is required
     * @return the result of the operation
     */
    @NonNull
    public OperationResult execute(PassphraseChangeParcel passphraseParcel, CryptoInputParcel cryptoInput) {
        OperationResult.OperationLog log = new OperationResult.OperationLog();
        log.add(OperationResult.LogType.MSG_ED, 0);

        if (passphraseParcel == null || passphraseParcel.mMasterKeyId == null) {
            log.add(OperationResult.LogType.MSG_ED_ERROR_NO_PARCEL, 1);
            return new EditKeyResult(EditKeyResult.RESULT_ERROR, log, null);
        }

        // Perform actual modification
        PgpEditKeyResult modifyResult;
        {
            PgpKeyOperation keyOperations =
                    new PgpKeyOperation(new ProgressScaler(mProgressable, 0, 70, 100), mCancelled);

            try {
                    log.add(OperationResult.LogType.MSG_ED_FETCHING, 1,
                            KeyFormattingUtils.convertKeyIdToHex(passphraseParcel.mMasterKeyId));

                    CanonicalizedSecretKeyRing secRing =
                            mProviderHelper.getCanonicalizedSecretKeyRing(passphraseParcel.mMasterKeyId);
                    CachedPublicKeyRing cachedRing =
                            mProviderHelper.getCachedPublicKeyRing(passphraseParcel.mMasterKeyId);

                    passphraseParcel.mValidSubkeyId = getFirstValidKeyId(secRing, cachedRing);

                    if(passphraseParcel.mValidSubkeyId == null) {
                        log.add(OperationResult.LogType.MSG_MF_ERROR_ALL_KEYS_STRIPPED, 0);
                        return new EditKeyResult(EditKeyResult.RESULT_ERROR, log, null);
                    }

                    modifyResult = keyOperations.modifyKeyRingPassword(secRing, cryptoInput, passphraseParcel);

                    if (modifyResult.isPending()) {
                        log.add(modifyResult, 1);
                        return new EditKeyResult(log, modifyResult);
                    }
            } catch (ProviderHelper.NotFoundException e) {
                log.add(OperationResult.LogType.MSG_ED_ERROR_KEY_NOT_FOUND, 2);
                return new EditKeyResult(EditKeyResult.RESULT_ERROR, log, null);
            }
        }

        log.add(modifyResult, 1);

        // Check if the action was cancelled
        if (checkCancelled()) {
            log.add(OperationResult.LogType.MSG_OPERATION_CANCELLED, 0);
            return new EditKeyResult(PgpEditKeyResult.RESULT_CANCELLED, log, null);
        }

        if (!modifyResult.success()) {
            // error is already logged by modification
            return new EditKeyResult(EditKeyResult.RESULT_ERROR, log, null);
        }

        // Cannot cancel from here on out!
        mProgressable.setPreventCancel();

        // It's a success, so this must be non-null now
        UncachedKeyRing ring = modifyResult.getRing();

        SaveKeyringResult saveResult = mProviderHelper
                .saveSecretKeyRing(ring, new ProgressScaler(mProgressable, 70, 95, 100));
        log.add(saveResult, 1);

        // If the save operation didn't succeed, exit here
        if (!saveResult.success()) {
            return new EditKeyResult(EditKeyResult.RESULT_ERROR, log, null);
        }

        updateProgress(R.string.progress_done, 100, 100);
        log.add(OperationResult.LogType.MSG_ED_SUCCESS, 0);
        return new EditKeyResult(EditKeyResult.RESULT_OK, log, ring.getMasterKeyId());

    }

    private static Long getFirstValidKeyId (CanonicalizedSecretKeyRing secRing, CachedPublicKeyRing cachedRing) {

        Iterator<CanonicalizedSecretKey> secretKeyIterator = secRing.secretKeyIterator().iterator();

        while(secretKeyIterator.hasNext()) {
            try {
                long keyId = secretKeyIterator.next().getKeyId();
                CanonicalizedSecretKey.SecretKeyType keyType = cachedRing.getSecretKeyType(keyId);
                if( keyType == CanonicalizedSecretKey.SecretKeyType.PASSPHRASE
                        || keyType == CanonicalizedSecretKey.SecretKeyType.PASSPHRASE_EMPTY) {
                    return keyId;
                }
            } catch (ProviderHelper.NotFoundException e) {
                ;
            }
        }

        return null;
    }
}