/*
 * Copyright (C) 2015 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.util;

import android.annotation.SuppressLint;
import android.content.Context;
import android.net.Uri;
import android.telecom.PhoneAccount;
import android.telecom.PhoneAccountHandle;
import android.telecom.TelecomManager;
import com.android.dialer.common.LogUtil;
import com.android.dialer.phonenumberutil.PhoneNumberHelper;

import java.util.ArrayList;
import java.util.List;

/** Utilities related to calls that can be used by non system apps. */
public class CallUtil {

  /** Indicates that the video calling is not available. */
  public static final int VIDEO_CALLING_DISABLED = 0;

  /** Indicates that video calling is enabled, regardless of presence status. */
  public static final int VIDEO_CALLING_ENABLED = 1;

  /**
   * Indicates that video calling is enabled, but the availability of video call affordances is
   * determined by the presence status associated with contacts.
   */
  public static final int VIDEO_CALLING_PRESENCE = 2;

  private static boolean hasInitializedIsVideoEnabledState;
  private static boolean cachedIsVideoEnabledState;

  /** Return Uri with an appropriate scheme, accepting both SIP and usual phone call numbers. */
  public static Uri getCallUri(String number) {
    if (PhoneNumberHelper.isUriNumber(number)) {
      return Uri.fromParts(PhoneAccount.SCHEME_SIP, number, null);
    }
    return Uri.fromParts(PhoneAccount.SCHEME_TEL, number, null);
  }

  /**
   * Determines if video calling is available, and if so whether presence checking is available as
   * well.
   *
   * <p>Returns a bitmask with {@link #VIDEO_CALLING_ENABLED} to indicate that video calling is
   * available, and {@link #VIDEO_CALLING_PRESENCE} if presence indication is also available.
   *
   * @param context The context
   * @return A bit-mask describing the current video capabilities.
   */
  @SuppressLint("MissingPermission")
  public static int getVideoCallingAvailability(Context context) {
    if (!PermissionsUtil.hasPermission(context, android.Manifest.permission.READ_PHONE_STATE)) {
      return VIDEO_CALLING_DISABLED;
    }
    TelecomManager telecommMgr = (TelecomManager) context.getSystemService(Context.TELECOM_SERVICE);
    if (telecommMgr == null) {
      return VIDEO_CALLING_DISABLED;
    }

    List<PhoneAccountHandle> accountHandles = telecommMgr.getCallCapablePhoneAccounts();
    for (PhoneAccountHandle accountHandle : accountHandles) {
      PhoneAccount account = telecommMgr.getPhoneAccount(accountHandle);
      if (account != null) {
        if (account.hasCapabilities(PhoneAccount.CAPABILITY_VIDEO_CALLING)) {
          int videoCapabilities = VIDEO_CALLING_ENABLED;
          if (account.hasCapabilities(PhoneAccount.CAPABILITY_VIDEO_CALLING_RELIES_ON_PRESENCE)) {
            videoCapabilities |= VIDEO_CALLING_PRESENCE;
          }
          return videoCapabilities;
        }
      }
    }
    return VIDEO_CALLING_DISABLED;
  }

  /**
   * Returns a list of phone accounts that are able to call to numbers with the supplied scheme
   */
  public static List<PhoneAccount> getCallCapablePhoneAccounts(Context context, String scheme) {
    if (!PermissionsUtil.hasPermission(context, android.Manifest.permission.READ_PHONE_STATE)) {
      return null;
    }
    TelecomManager tm = (TelecomManager) context.getSystemService(Context.TELECOM_SERVICE);
    final ArrayList<PhoneAccount> accounts = new ArrayList<>();

    for (PhoneAccountHandle handle : tm.getCallCapablePhoneAccounts()) {
      final PhoneAccount account = tm.getPhoneAccount(handle);
      if (account != null && account.supportsUriScheme(scheme)) {
        accounts.add(account);
      }
    }
    return accounts;
  }

  /**
   * Determines if one of the call capable phone accounts defined supports video calling.
   *
   * @param context The context.
   * @return {@code true} if one of the call capable phone accounts supports video calling, {@code
   *     false} otherwise.
   */
  public static boolean isVideoEnabled(Context context) {
    boolean isVideoEnabled = (getVideoCallingAvailability(context) & VIDEO_CALLING_ENABLED) != 0;

    // Log everytime the video enabled state changes.
    if (!hasInitializedIsVideoEnabledState) {
      LogUtil.i("CallUtil.isVideoEnabled", "isVideoEnabled: " + isVideoEnabled);
      hasInitializedIsVideoEnabledState = true;
      cachedIsVideoEnabledState = isVideoEnabled;
    } else if (cachedIsVideoEnabledState != isVideoEnabled) {
      LogUtil.i(
          "CallUtil.isVideoEnabled",
          "isVideoEnabled changed from %b to %b",
          cachedIsVideoEnabledState,
          isVideoEnabled);
      cachedIsVideoEnabledState = isVideoEnabled;
    }

    return isVideoEnabled;
  }

  /**
   * Determines if one of the call capable phone accounts defined supports calling with a subject
   * specified.
   *
   * @param context The context.
   * @return {@code true} if one of the call capable phone accounts supports calling with a subject
   *     specified, {@code false} otherwise.
   */
  @SuppressLint("MissingPermission")
  public static boolean isCallWithSubjectSupported(Context context) {
    if (!PermissionsUtil.hasPermission(context, android.Manifest.permission.READ_PHONE_STATE)) {
      return false;
    }
    TelecomManager telecommMgr = (TelecomManager) context.getSystemService(Context.TELECOM_SERVICE);
    if (telecommMgr == null) {
      return false;
    }

    List<PhoneAccountHandle> accountHandles = telecommMgr.getCallCapablePhoneAccounts();
    for (PhoneAccountHandle accountHandle : accountHandles) {
      PhoneAccount account = telecommMgr.getPhoneAccount(accountHandle);
      if (account != null && account.hasCapabilities(PhoneAccount.CAPABILITY_CALL_SUBJECT)) {
        return true;
      }
    }
    return false;
  }
}