/*
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

package com.facebook.react.modules.network;

import android.content.Context;
import android.os.Build;
import androidx.annotation.Nullable;
import com.facebook.common.logging.FLog;
import java.io.File;
import java.security.Provider;
import java.security.Security;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;
import okhttp3.Cache;
import okhttp3.ConnectionSpec;
import okhttp3.OkHttpClient;
import okhttp3.TlsVersion;

/**
 * Helper class that provides the same OkHttpClient instance that will be used for all networking
 * requests.
 */
public class OkHttpClientProvider {

  // Centralized OkHttpClient for all networking requests.
  private static @Nullable OkHttpClient sClient;

  // User-provided OkHttpClient factory
  private static @Nullable OkHttpClientFactory sFactory;

  public static void setOkHttpClientFactory(OkHttpClientFactory factory) {
    sFactory = factory;
  }

  public static OkHttpClient getOkHttpClient() {
    if (sClient == null) {
      sClient = createClient();
    }
    return sClient;
  }

  public static OkHttpClient createClient() {
    if (sFactory != null) {
      return sFactory.createNewNetworkModuleClient();
    }
    return createClientBuilder().build();
  }

  public static OkHttpClient createClient(Context context) {
    if (sFactory != null) {
      return sFactory.createNewNetworkModuleClient();
    }
    return createClientBuilder(context).build();
  }

  public static OkHttpClient.Builder createClientBuilder() {
    // No timeouts by default
    OkHttpClient.Builder client =
        new OkHttpClient.Builder()
            .connectTimeout(0, TimeUnit.MILLISECONDS)
            .readTimeout(0, TimeUnit.MILLISECONDS)
            .writeTimeout(0, TimeUnit.MILLISECONDS)
            .cookieJar(new ReactCookieJarContainer());

    try {
      Class ConscryptProvider = Class.forName("org.conscrypt.OpenSSLProvider");
      Security.insertProviderAt((Provider) ConscryptProvider.newInstance(), 1);
      return client;
    } catch (Exception e) {
      return enableTls12OnPreLollipop(client);
    }
  }

  public static OkHttpClient.Builder createClientBuilder(Context context) {
    int cacheSize = 10 * 1024 * 1024; // 10 Mo
    return createClientBuilder(context, cacheSize);
  }

  public static OkHttpClient.Builder createClientBuilder(Context context, int cacheSize) {
    OkHttpClient.Builder client = createClientBuilder();

    if (cacheSize == 0) {
      return client;
    }

    File cacheDirectory = new File(context.getCacheDir(), "http-cache");
    Cache cache = new Cache(cacheDirectory, cacheSize);

    return client.cache(cache);
  }

  /*
   On Android 4.1-4.4 (API level 16 to 19) TLS 1.1 and 1.2 are
   available but not enabled by default. The following method
   enables it.
  */
  public static OkHttpClient.Builder enableTls12OnPreLollipop(OkHttpClient.Builder client) {
    if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.KITKAT) {
      try {
        client.sslSocketFactory(new TLSSocketFactory());

        ConnectionSpec cs =
            new ConnectionSpec.Builder(ConnectionSpec.MODERN_TLS)
                .tlsVersions(TlsVersion.TLS_1_2)
                .build();

        List<ConnectionSpec> specs = new ArrayList<>();
        specs.add(cs);
        specs.add(ConnectionSpec.COMPATIBLE_TLS);
        specs.add(ConnectionSpec.CLEARTEXT);

        client.connectionSpecs(specs);
      } catch (Exception exc) {
        FLog.e("OkHttpClientProvider", "Error while enabling TLS 1.2", exc);
      }
    }

    return client;
  }
}
