/*
 * 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.android.dialer.enrichedcall;

import android.app.Application;
import android.support.annotation.IntDef;
import android.support.annotation.MainThread;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import com.android.dialer.common.Assert;
import com.android.dialer.multimedia.MultimediaData;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

/** Performs all enriched calling logic. */
public interface EnrichedCallManager {

  /** Factory for {@link EnrichedCallManager}. */
  interface Factory {
    EnrichedCallManager getEnrichedCallManager();
  }

  /** Accessor for {@link EnrichedCallManager}. */
  class Accessor {

    /**
     * @throws IllegalArgumentException if application does not implement {@link
     *     EnrichedCallManager.Factory}
     */
    @NonNull
    public static EnrichedCallManager getInstance(@NonNull Application application) {
      Assert.isNotNull(application);

      return ((EnrichedCallManager.Factory) application).getEnrichedCallManager();
    }
  }

  /** Receives updates when enriched call capabilities are ready. */
  interface CapabilitiesListener {

    /** Callback fired when the capabilities are updated. */
    @MainThread
    void onCapabilitiesUpdated();
  }

  /**
   * Registers the given {@link CapabilitiesListener}.
   *
   * <p>As a result of this method, the listener will receive a call to {@link
   * CapabilitiesListener#onCapabilitiesUpdated()} after a call to {@link
   * #requestCapabilities(String)}.
   */
  @MainThread
  void registerCapabilitiesListener(@NonNull CapabilitiesListener listener);

  /**
   * Starts an asynchronous process to get enriched call capabilities of the given number.
   *
   * <p>Registered listeners will receive a call to {@link
   * CapabilitiesListener#onCapabilitiesUpdated()} on completion.
   *
   * @param number the remote number in any format
   */
  @MainThread
  void requestCapabilities(@NonNull String number);

  /**
   * Unregisters the given {@link CapabilitiesListener}.
   *
   * <p>As a result of this method, the listener will not receive capabilities of the given number.
   */
  @MainThread
  void unregisterCapabilitiesListener(@NonNull CapabilitiesListener listener);

  /** Gets the cached capabilities for the given number, else null */
  @MainThread
  @Nullable
  EnrichedCallCapabilities getCapabilities(@NonNull String number);

  /** Clears any cached data, such as capabilities. */
  @MainThread
  void clearCachedData();

  /** Possible states for call composer sessions. */
  @Retention(RetentionPolicy.SOURCE)
  @IntDef({
    STATE_NONE,
    STATE_STARTING,
    STATE_STARTED,
    STATE_START_FAILED,
    STATE_MESSAGE_SENT,
    STATE_MESSAGE_FAILED,
    STATE_CLOSED,
  })
  @interface State {}

  int STATE_NONE = 0;
  int STATE_STARTING = STATE_NONE + 1;
  int STATE_STARTED = STATE_STARTING + 1;
  int STATE_START_FAILED = STATE_STARTED + 1;
  int STATE_MESSAGE_SENT = STATE_START_FAILED + 1;
  int STATE_MESSAGE_FAILED = STATE_MESSAGE_SENT + 1;
  int STATE_CLOSED = STATE_MESSAGE_FAILED + 1;

  /**
   * Starts a call composer session with the given remote number.
   *
   * @param number the remote number in any format
   * @return the id for the started session, or {@link Session#NO_SESSION_ID} if the session fails
   */
  @MainThread
  long startCallComposerSession(@NonNull String number);

  /**
   * Sends the given information through an open enriched call session. As per the enriched calling
   * spec, up to two messages are sent: the first is an enriched call data message that optionally
   * includes the subject and the second is the optional image data message.
   *
   * @param sessionId the id for the session. See {@link #startCallComposerSession(String)}
   * @param data the {@link MultimediaData}
   * @throws IllegalArgumentException if there's no open session with the given number
   * @throws IllegalStateException if the session isn't in the {@link #STATE_STARTED} state
   */
  @MainThread
  void sendCallComposerData(long sessionId, @NonNull MultimediaData data);

  /**
   * Ends the given call composer session. Ending a session means that the call composer session
   * will be closed.
   *
   * @param sessionId the id of the session to end
   */
  @MainThread
  void endCallComposerSession(long sessionId);

  /**
   * Called once the capabilities are available for a corresponding call to {@link
   * #requestCapabilities(String)}.
   *
   * @param number the remote number in any format
   * @param capabilities the supported capabilities
   */
  @MainThread
  void onCapabilitiesReceived(
      @NonNull String number, @NonNull EnrichedCallCapabilities capabilities);

  /** Receives updates when the state of an enriched call changes. */
  interface StateChangedListener {

    /**
     * Callback fired when state changes. Listeners should call {@link #getSession(String)} to
     * retrieve the new state.
     */
    void onEnrichedCallStateChanged();
  }

  /**
   * Registers the given {@link StateChangedListener}.
   *
   * <p>As a result of this method, the listener will receive updates when the state of any enriched
   * call changes.
   */
  @MainThread
  void registerStateChangedListener(@NonNull StateChangedListener listener);

  /** Returns the {@link Session} for the given number, or {@code null} if no session exists. */
  @MainThread
  @Nullable
  Session getSession(@NonNull String number);

  /** Returns the {@link Session} for the given sessionId, or {@code null} if no session exists. */
  @MainThread
  @Nullable
  Session getSession(long sessionId);

  /**
   * Unregisters the given {@link StateChangedListener}.
   *
   * <p>As a result of this method, the listener will not receive updates when the state of enriched
   * calls changes.
   */
  @MainThread
  void unregisterStateChangedListener(@NonNull StateChangedListener listener);

  /**
   * Called when the status of an enriched call session changes.
   *
   *
   * @throws IllegalArgumentException if the state is invalid
   */
  @MainThread
  void onSessionStatusUpdate(long sessionId, @NonNull String number, int state);

  /**
   * Called when the status of an enriched call message updates.
   *
   *
   * @throws IllegalArgumentException if the state is invalid
   * @throws IllegalStateException if there's no session for the given id
   */
  @MainThread
  void onMessageUpdate(long sessionId, @NonNull String messageId, int state);

  /**
   * Called when call composer data arrives for the given session.
   *
   * @throws IllegalStateException if there's no session for the given id
   */
  @MainThread
  void onIncomingCallComposerData(long sessionId, @NonNull MultimediaData multimediaData);
}