/*
 * Copyright (C) 2008-2022, Juick
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.juick.service;

import com.juick.KeystoreManager;
import com.juick.www.api.activity.model.objects.Actor;
import org.apache.commons.lang3.StringUtils;
import org.tomitribe.auth.signatures.*;
import java.io.IOException;
import java.util.*;

public class SignatureService {
    
    private final KeystoreManager keystoreManager;

    public SignatureService(KeystoreManager keystoreManager) {
        this.keystoreManager = keystoreManager;
    }

    public String addSignature(Actor from, String host, String method, String path, String dateString,
            String digestHeader) throws IOException {
        return addSignature(from, host, method, path, dateString, digestHeader, keystoreManager);
    }

    public String addSignature(Actor from, String host, String method, String path, String dateString,
            String digestHeader, KeystoreManager keystoreManager) throws IOException {
        List<String> requiredHeaders = StringUtils.isEmpty(digestHeader)
                ? Arrays.asList("(request-target)", "host", "date")
                : Arrays.asList("(request-target)", "host", "date", "digest");
        Signature templateSignature = new Signature(from.getPublicKey().getId(), "rsa-sha256", null, requiredHeaders);
        Map<String, String> headers = new HashMap<>();
        headers.put("host", host);
        headers.put("date", dateString);
        if (StringUtils.isNotEmpty(digestHeader)) {
            headers.put("digest", digestHeader);
        }
        Signer signer = new Signer(keystoreManager.getPrivateKey(), templateSignature);
        Signature signature = signer.sign(method.toLowerCase(), path, headers);
        // remove "Signature: " from result
        return signature.toString().substring(10);
    }
}