/*
  Copyright 2020 Nokia
  <p>
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
  <p>
  http://www.apache.org/licenses/LICENSE-2.0
  <p>
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
 */

package org.onap.cvc.csar.cc.sol004.r130206;

import org.onap.cvc.csar.parser.ManifestFileModel;
import org.onap.cvc.csar.parser.ManifestFileSplitter;
import org.onap.cvc.csar.security.CmsSignatureData;
import org.onap.cvc.csar.security.CmsSignatureDataFactory;
import org.onap.cvc.csar.security.CmsSignatureLoadingException;
import org.onap.cvc.csar.security.CmsSignatureValidator;
import org.onap.cvc.csar.security.CmsSignatureValidatorException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.List;
import java.util.stream.Collectors;

public class FileSignatureValidator {

    private static final Logger LOG = LoggerFactory.getLogger(FileSignatureValidator.class);

    private final ManifestFileSplitter manifestFileSplitter = new ManifestFileSplitter();
    private final CmsSignatureValidator cmsSignatureValidator = new CmsSignatureValidator();
    private final CmsSignatureDataFactory cmsSignatureDataFactory = new CmsSignatureDataFactory();

    CmsSignatureData createSignatureDataForManifestFile(File manifestFile) throws CmsSignatureLoadingException {
        ManifestFileModel mf = manifestFileSplitter.split(manifestFile);
        return cmsSignatureDataFactory.createForFirstSigner(
            toBytes(mf.getCMS(), mf.getNewLine()),
            toBytes(mf.getData(), mf.getNewLine())
        );
    }

    public CmsSignatureData createSignatureData(Path filePath, Path cmsFilePath, Path certFilePath) throws CmsSignatureLoadingException, IOException {
        CmsSignatureData signatureData = cmsSignatureDataFactory.createForFirstSigner(
            Files.readAllBytes(cmsFilePath),
            Files.readAllBytes(filePath)
        );
        signatureData.loadCertificate(certFilePath);
        return signatureData;
    }

    public boolean isValid(CmsSignatureData signatureData) {
        try {
            return cmsSignatureValidator.verifySignedData(signatureData);
        } catch (CmsSignatureValidatorException e) {
            LOG.error("Unable to verify signed data!", e);
            return false;
        }
    }

    private byte[] toBytes(List<String> data, String newLine) {
        final String updatedData = data.stream().map(it -> it + newLine).collect(Collectors.joining());
        return updatedData.getBytes(Charset.defaultCharset());
    }

}