package com.tsi.navi.api.ssl;

import android.content.Context;

import com.tsi.navi.R;

import java.io.IOException;
import java.io.InputStream;
import java.security.KeyManagementException;
import java.security.KeyStore;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.Certificate;
import java.security.cert.CertificateException;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;

import javax.net.ssl.HostnameVerifier;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSession;
import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.TrustManager;
import javax.net.ssl.TrustManagerFactory;
import javax.net.ssl.X509TrustManager;

import okhttp3.OkHttpClient;

public class SSLUtil {


    // UnsafeOk
    // 안전하지 않음으로 HTTPS를 통과합니다.
    public static OkHttpClient.Builder getUnsafeOkHttpClient() {
        try {
            // Create a trust manager that does not validate certificate chains
            final TrustManager[] trustAllCerts = new TrustManager[] {
                    new X509TrustManager() {
                        @Override
                        public void checkClientTrusted(java.security.cert.X509Certificate[] chain, String authType) throws CertificateException {
                        }

                        @Override
                        public void checkServerTrusted(java.security.cert.X509Certificate[] chain, String authType) throws CertificateException {
                        }

                        @Override
                        public java.security.cert.X509Certificate[] getAcceptedIssuers() {
                            return new java.security.cert.X509Certificate[]{};
                        }
                    }
            };

            // Install the all-trusting trust manager
            final SSLContext sslContext = SSLContext.getInstance("SSL");
            sslContext.init(null, trustAllCerts, new java.security.SecureRandom());

            // Create an ssl socket factory with our all-trusting manager
            final SSLSocketFactory sslSocketFactory = sslContext.getSocketFactory();

            OkHttpClient.Builder builder = new OkHttpClient.Builder();
            builder.sslSocketFactory(sslSocketFactory, (X509TrustManager)trustAllCerts[0]);
            builder.hostnameVerifier(new HostnameVerifier() {
                @Override
                public boolean verify(String hostname, SSLSession session) {
                    return true;
                }
            });
            return builder;
        } catch (Exception e) {
            throw new RuntimeException(e);
        }

    }


    /**
     * localhost라는 인증서 정보로 ssl 연결을시도합니다.
     * @param context
     * @return
     */
    public static SSLSocketFactory getPinnedCertSslSocketFactory(Context context) {
        try {
            // Load CAs from an InputStream
            // (could be from a resource or ByteArrayInputStream or ...)
            CertificateFactory cf = CertificateFactory.getInstance("X.509");
            // From https://www.washington.edu/itconnect/security/ca/load-der.crt
            InputStream caInput = context.getResources().openRawResource(R.raw.localhost);
            Certificate ca = null;
            try {
                ca = cf.generateCertificate(caInput);
                System.out.println("ca=" + ((X509Certificate) ca).getSubjectDN());
            } catch (CertificateException e) {
                e.printStackTrace();
            } finally {
                caInput.close();
            }

            // Create a KeyStore containing our trusted CAs
            String keyStoreType = KeyStore.getDefaultType();
            KeyStore keyStore = KeyStore.getInstance(keyStoreType);
            keyStore.load(null, null);
            if (ca == null) {
                return null;
            }
            keyStore.setCertificateEntry("ca", ca);

            // Create a TrustManager that trusts the CAs in our KeyStore
            String tmfAlgorithm = TrustManagerFactory.getDefaultAlgorithm();
            TrustManagerFactory tmf = TrustManagerFactory.getInstance(tmfAlgorithm);
            tmf.init(keyStore);

            // Create an SSLContext that uses our TrustManager
            SSLContext sslContext= SSLContext.getInstance("TLS");
            sslContext.init(null, tmf.getTrustManagers(), null);

            return sslContext.getSocketFactory();
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (KeyStoreException e) {
            e.printStackTrace();
        } catch (KeyManagementException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
}