/*
 * Copyright (C) 2006 The Android Open Source Project
 *
 * 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
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * 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 android.net.http;

import android.compat.annotation.UnsupportedAppUsage;
import android.os.Build;

import java.security.cert.X509Certificate;

/**
 * This class represents a set of one or more SSL errors and the associated SSL
 * certificate.
 */
public class SslError {

    /**
     * Individual SSL errors (in the order from the least to the most severe):
     */

    /**
     * The certificate is not yet valid
     */
    public static final int SSL_NOTYETVALID = 0;
    /**
     * The certificate has expired
     */
    public static final int SSL_EXPIRED = 1;
    /**
     * Hostname mismatch
     */
    public static final int SSL_IDMISMATCH = 2;
    /**
     * The certificate authority is not trusted
     */
    public static final int SSL_UNTRUSTED = 3;
    /**
     * The date of the certificate is invalid
     */
    public static final int SSL_DATE_INVALID = 4;
    /**
     * A generic error occurred
     */
    public static final int SSL_INVALID = 5;


    /**
     * The number of different SSL errors.
     * @deprecated This constant is not necessary for using the SslError API and
     *             can change from release to release.
     */
    // Update if you add a new SSL error!!!
    @Deprecated
    public static final int SSL_MAX_ERROR = 6;

    /**
     * The SSL error set bitfield (each individual error is a bit index;
     * multiple individual errors can be OR-ed)
     */
    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
    int mErrors;

    /**
     * The SSL certificate associated with the error set
     */
    @UnsupportedAppUsage
    final SslCertificate mCertificate;

    /**
     * The URL associated with the error set.
     */
    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
    final String mUrl;

    /**
     * Creates a new SslError object using the supplied error and certificate.
     * The URL will be set to the empty string.
     * @param error The SSL error
     * @param certificate The associated SSL certificate
     * @deprecated Use {@link #SslError(int, SslCertificate, String)}
     */
    @Deprecated
    public SslError(int error, SslCertificate certificate) {
        this(error, certificate, "");
    }

    /**
     * Creates a new SslError object using the supplied error and certificate.
     * The URL will be set to the empty string.
     * @param error The SSL error
     * @param certificate The associated SSL certificate
     * @deprecated Use {@link #SslError(int, X509Certificate, String)}
     */
    @Deprecated
    public SslError(int error, X509Certificate certificate) {
        this(error, certificate, "");
    }

    /**
     * Creates a new SslError object using the supplied error, certificate and
     * URL.
     * @param error The SSL error
     * @param certificate The associated SSL certificate
     * @param url The associated URL
     */
    public SslError(int error, SslCertificate certificate, String url) {
        assert certificate != null;
        assert url != null;
        addError(error);
        mCertificate = certificate;
        mUrl = url;
    }

    /**
     * Creates a new SslError object using the supplied error, certificate and
     * URL.
     * @param error The SSL error
     * @param certificate The associated SSL certificate
     * @param url The associated URL
     */
    public SslError(int error, X509Certificate certificate, String url) {
        this(error, new SslCertificate(certificate), url);
    }

    /**
     * Creates an SslError object from a chromium error code.
     * @param error The chromium error code
     * @param certificate The associated SSL certificate
     * @param url The associated URL.
     * @hide  chromium error codes only available inside the framework
     */
    public static SslError SslErrorFromChromiumErrorCode(
            int error, SslCertificate cert, String url) {
        // The chromium error codes are in:
        // external/chromium/net/base/net_error_list.h
        assert (error >= -299 && error <= -200);
        if (error == -200)
            return new SslError(SSL_IDMISMATCH, cert, url);
        if (error == -201)
            return new SslError(SSL_DATE_INVALID, cert, url);
        if (error == -202)
            return new SslError(SSL_UNTRUSTED, cert, url);
        // Map all other codes to SSL_INVALID.
        return new SslError(SSL_INVALID, cert, url);
    }

    /**
     * Gets the SSL certificate associated with this object.
     * @return The SSL certificate, non-null.
     */
    public SslCertificate getCertificate() {
        return mCertificate;
    }

    /**
     * Gets the URL associated with this object.
     * @return The URL, non-null.
     */
    public String getUrl() {
        return mUrl;
    }

    /**
     * Adds the supplied SSL error to the set.
     * @param error The SSL error to add
     * @return True if the error being added is a known SSL error, otherwise
     *         false.
     */
    public boolean addError(int error) {
        boolean rval = (0 <= error && error < SslError.SSL_MAX_ERROR);
        if (rval) {
            mErrors |= (0x1 << error);
        }

        return rval;
    }

    /**
     * Determines whether this object includes the supplied error.
     * @param error The SSL error to check for
     * @return True if this object includes the error, otherwise false.
     */
    public boolean hasError(int error) {
        boolean rval = (0 <= error && error < SslError.SSL_MAX_ERROR);
        if (rval) {
            rval = ((mErrors & (0x1 << error)) != 0);
        }

        return rval;
    }

    /**
     * Gets the most severe SSL error in this object's set of errors.
     * Returns -1 if the set is empty.
     * @return The most severe SSL error, or -1 if the set is empty.
     */
    public int getPrimaryError() {
        if (mErrors != 0) {
            // go from the most to the least severe errors
            for (int error = SslError.SSL_MAX_ERROR - 1; error >= 0; --error) {
                if ((mErrors & (0x1 << error)) != 0) {
                    return error;
                }
            }
            // mErrors should never be set to an invalid value.
            assert false;
        }

        return -1;
    }

    /**
     * Returns a string representation of this object.
     * @return A String representation of this object.
     */
    public String toString() {
        return "primary error: " + getPrimaryError() +
                " certificate: " + getCertificate() +
                " on URL: " + getUrl();
    }
}