content: /*
   * Copyright (C) 2016 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 com.google.android.exoplayer2.upstream;
  
  import android.support.annotation.IntDef;
  import android.text.TextUtils;
  import com.google.android.exoplayer2.util.Predicate;
  import com.google.android.exoplayer2.util.Util;
  import java.io.IOException;
  import java.lang.annotation.Retention;
  import java.lang.annotation.RetentionPolicy;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  /**
   * An HTTP {@link DataSource}.
   */
  public interface HttpDataSource extends DataSource {
  
    /**
     * A factory for {@link HttpDataSource} instances.
     */
    interface Factory extends DataSource.Factory {
  
      @Override
      HttpDataSource createDataSource();
  
      /**
       * Gets the default request properties used by all {@link HttpDataSource}s created by the
       * factory. Changes to the properties will be reflected in any future requests made by
       * {@link HttpDataSource}s created by the factory.
       *
       * @return The default request properties of the factory.
       */
      RequestProperties getDefaultRequestProperties();
  
      /**
       * Sets a default request header for {@link HttpDataSource} instances created by the factory.
       *
       * @deprecated Use {@link #getDefaultRequestProperties} instead.
       * @param name The name of the header field.
       * @param value The value of the field.
       */
      @Deprecated
      void setDefaultRequestProperty(String name, String value);
  
      /**
       * Clears a default request header for {@link HttpDataSource} instances created by the factory.
       *
       * @deprecated Use {@link #getDefaultRequestProperties} instead.
       * @param name The name of the header field.
       */
      @Deprecated
      void clearDefaultRequestProperty(String name);
  
      /**
       * Clears all default request headers for all {@link HttpDataSource} instances created by the
       * factory.
       *
       * @deprecated Use {@link #getDefaultRequestProperties} instead.
       */
      @Deprecated
      void clearAllDefaultRequestProperties();
  
    }
  
    /**
     * Stores HTTP request properties (aka HTTP headers) and provides methods to modify the headers
     * in a thread safe way to avoid the potential of creating snapshots of an inconsistent or
     * unintended state.
     */
    final class RequestProperties {
  
      private final Map<String, String> requestProperties;
      private Map<String, String> requestPropertiesSnapshot;
  
      public RequestProperties() {
        requestProperties = new HashMap<>();
      }
  
      /**
       * Sets the specified property {@code value} for the specified {@code name}. If a property for
       * this name previously existed, the old value is replaced by the specified value.
       *
       * @param name The name of the request property.
       * @param value The value of the request property.
       */
      public synchronized void set(String name, String value) {
        requestPropertiesSnapshot = null;
        requestProperties.put(name, value);
      }
  
      /**
       * Sets the keys and values contained in the map. If a property previously existed, the old
       * value is replaced by the specified value. If a property previously existed and is not in the
       * map, the property is left unchanged.
       *
       * @param properties The request properties.
       */
      public synchronized void set(Map<String, String> properties) {
        requestPropertiesSnapshot = null;
        requestProperties.putAll(properties);
      }
  
      /**
       * Removes all properties previously existing and sets the keys and values of the map.
       *
       * @param properties The request properties.
       */
      public synchronized void clearAndSet(Map<String, String> properties) {
        requestPropertiesSnapshot = null;
        requestProperties.clear();
        requestProperties.putAll(properties);
      }
  
      /**
       * Removes a request property by name.
       *
       * @param name The name of the request property to remove.
       */
      public synchronized void remove(String name) {
        requestPropertiesSnapshot = null;
        requestProperties.remove(name);
      }
  
      /**
       * Clears all request properties.
       */
      public synchronized void clear() {
        requestPropertiesSnapshot = null;
        requestProperties.clear();
      }
  
      /**
       * Gets a snapshot of the request properties.
       *
       * @return A snapshot of the request properties.
       */
      public synchronized Map<String, String> getSnapshot() {
        if (requestPropertiesSnapshot == null) {
          requestPropertiesSnapshot = Collections.unmodifiableMap(new HashMap<>(requestProperties));
        }
        return requestPropertiesSnapshot;
      }
  
    }
  
    /**
     * Base implementation of {@link Factory} that sets default request properties.
     */
    abstract class BaseFactory implements Factory {
  
      private final RequestProperties defaultRequestProperties;
  
      public BaseFactory() {
        defaultRequestProperties = new RequestProperties();
      }
  
      @Override
      public final HttpDataSource createDataSource() {
        return createDataSourceInternal(defaultRequestProperties);
      }
  
      @Override
      public final RequestProperties getDefaultRequestProperties() {
        return defaultRequestProperties;
      }
  
      @Deprecated
      @Override
      public final void setDefaultRequestProperty(String name, String value) {
        defaultRequestProperties.set(name, value);
      }
  
      @Deprecated
      @Override
      public final void clearDefaultRequestProperty(String name) {
        defaultRequestProperties.remove(name);
      }
  
      @Deprecated
      @Override
      public final void clearAllDefaultRequestProperties() {
        defaultRequestProperties.clear();
      }
  
      /**
       * Called by {@link #createDataSource()} to create a {@link HttpDataSource} instance.
       *
       * @param defaultRequestProperties The default {@code RequestProperties} to be used by the
       *     {@link HttpDataSource} instance.
       * @return A {@link HttpDataSource} instance.
       */
      protected abstract HttpDataSource createDataSourceInternal(RequestProperties
          defaultRequestProperties);
  
    }
  
    /**
     * A {@link Predicate} that rejects content types often used for pay-walls.
     */
    Predicate<String> REJECT_PAYWALL_TYPES = new Predicate<String>() {
  
      @Override
      public boolean evaluate(String contentType) {
        contentType = Util.toLowerInvariant(contentType);
        return !TextUtils.isEmpty(contentType)
            && (!contentType.contains("text") || contentType.contains("text/vtt"))
            && !contentType.contains("html") && !contentType.contains("xml");
      }
  
    };
  
    /**
     * Thrown when an error is encountered when trying to read from a {@link HttpDataSource}.
     */
    class HttpDataSourceException extends IOException {
  
      @Retention(RetentionPolicy.SOURCE)
      @IntDef({TYPE_OPEN, TYPE_READ, TYPE_CLOSE})
      public @interface Type {}
      public static final int TYPE_OPEN = 1;
      public static final int TYPE_READ = 2;
      public static final int TYPE_CLOSE = 3;
  
      @Type public final int type;
  
      /**
       * The {@link DataSpec} associated with the current connection.
       */
      public final DataSpec dataSpec;
  
      public HttpDataSourceException(DataSpec dataSpec, @Type int type) {
        super();
        this.dataSpec = dataSpec;
        this.type = type;
      }
  
      public HttpDataSourceException(String message, DataSpec dataSpec, @Type int type) {
        super(message);
        this.dataSpec = dataSpec;
        this.type = type;
      }
  
      public HttpDataSourceException(IOException cause, DataSpec dataSpec, @Type int type) {
        super(cause);
        this.dataSpec = dataSpec;
        this.type = type;
      }
  
      public HttpDataSourceException(String message, IOException cause, DataSpec dataSpec,
          @Type int type) {
        super(message, cause);
        this.dataSpec = dataSpec;
        this.type = type;
      }
  
    }
  
    /**
     * Thrown when the content type is invalid.
     */
    final class InvalidContentTypeException extends HttpDataSourceException {
  
      public final String contentType;
  
      public InvalidContentTypeException(String contentType, DataSpec dataSpec) {
        super("Invalid content type: " + contentType, dataSpec, TYPE_OPEN);
        this.contentType = contentType;
      }
  
    }
  
    /**
     * Thrown when an attempt to open a connection results in a response code not in the 2xx range.
     */
    final class InvalidResponseCodeException extends HttpDataSourceException {
  
      /**
       * The response code that was outside of the 2xx range.
       */
      public final int responseCode;
  
      /**
       * An unmodifiable map of the response header fields and values.
       */
      public final Map<String, List<String>> headerFields;
  
      public InvalidResponseCodeException(int responseCode, Map<String, List<String>> headerFields,
          DataSpec dataSpec) {
        super("Response code: " + responseCode, dataSpec, TYPE_OPEN);
        this.responseCode = responseCode;
        this.headerFields = headerFields;
      }
  
    }
  
    @Override
    long open(DataSpec dataSpec) throws HttpDataSourceException;
  
    @Override
    void close() throws HttpDataSourceException;
  
    @Override
    int read(byte[] buffer, int offset, int readLength) throws HttpDataSourceException;
  
    /**
     * Sets the value of a request header. The value will be used for subsequent connections
     * established by the source.
     *
     * @param name The name of the header field.
     * @param value The value of the field.
     */
    void setRequestProperty(String name, String value);
  
    /**
     * Clears the value of a request header. The change will apply to subsequent connections
     * established by the source.
     *
     * @param name The name of the header field.
     */
    void clearRequestProperty(String name);
  
    /**
     * Clears all request headers that were set by {@link #setRequestProperty(String, String)}.
     */
    void clearAllRequestProperties();
  
    /**
     * Returns the headers provided in the response, or {@code null} if response headers are
     * unavailable.
     */
    Map<String, List<String>> getResponseHeaders();
  
  }
  