/*
 * Copyright (C) 2009 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 android.accessibilityservice;

import android.content.ComponentName;
import android.content.Context;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.content.pm.ResolveInfo;
import android.content.pm.ServiceInfo;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.content.res.XmlResourceParser;
import android.os.Build;
import android.os.Parcel;
import android.os.Parcelable;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.util.Xml;
import android.view.View;
import android.view.accessibility.AccessibilityEvent;

import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;

import java.io.IOException;

/**
 * This class describes an {@link AccessibilityService}. The system notifies an
 * {@link AccessibilityService} for {@link android.view.accessibility.AccessibilityEvent}s
 * according to the information encapsulated in this class.
 *
 * <div class="special reference">
 * <h3>Developer Guides</h3>
 * <p>For more information about creating AccessibilityServices, read the
 * <a href="{@docRoot}guide/topics/ui/accessibility/index.html">Accessibility</a>
 * developer guide.</p>
 * </div>
 *
 * @see AccessibilityService
 * @see android.view.accessibility.AccessibilityEvent
 * @see android.view.accessibility.AccessibilityManager
 */
public class AccessibilityServiceInfo implements Parcelable {

    private static final String TAG_ACCESSIBILITY_SERVICE = "accessibility-service";

    /**
     * Denotes spoken feedback.
     */
    public static final int FEEDBACK_SPOKEN = 0x0000001;

    /**
     * Denotes haptic feedback.
     */
    public static final int FEEDBACK_HAPTIC =  0x0000002;

    /**
     * Denotes audible (not spoken) feedback.
     */
    public static final int FEEDBACK_AUDIBLE = 0x0000004;

    /**
     * Denotes visual feedback.
     */
    public static final int FEEDBACK_VISUAL = 0x0000008;

    /**
     * Denotes generic feedback.
     */
    public static final int FEEDBACK_GENERIC = 0x0000010;

    /**
     * Denotes braille feedback.
     */
    public static final int FEEDBACK_BRAILLE = 0x0000020;

    /**
     * Mask for all feedback types.
     *
     * @see #FEEDBACK_SPOKEN
     * @see #FEEDBACK_HAPTIC
     * @see #FEEDBACK_AUDIBLE
     * @see #FEEDBACK_VISUAL
     * @see #FEEDBACK_GENERIC
     * @see #FEEDBACK_BRAILLE
     */
    public static final int FEEDBACK_ALL_MASK = 0xFFFFFFFF;

    /**
     * If an {@link AccessibilityService} is the default for a given type.
     * Default service is invoked only if no package specific one exists. In case of
     * more than one package specific service only the earlier registered is notified.
     */
    public static final int DEFAULT = 0x0000001;

    /**
     * If this flag is set the system will regard views that are not important
     * for accessibility in addition to the ones that are important for accessibility.
     * That is, views that are marked as not important for accessibility via
     * {@link View#IMPORTANT_FOR_ACCESSIBILITY_NO} and views that are marked as
     * potentially important for accessibility via
     * {@link View#IMPORTANT_FOR_ACCESSIBILITY_AUTO} for which the system has determined
     * that are not important for accessibility, are both reported while querying the
     * window content and also the accessibility service will receive accessibility events
     * from them.
     * <p>
     * <strong>Note:</strong> For accessibility services targeting API version
     * {@link Build.VERSION_CODES#JELLY_BEAN} or higher this flag has to be explicitly
     * set for the system to regard views that are not important for accessibility. For
     * accessibility services targeting API version lower than
     * {@link Build.VERSION_CODES#JELLY_BEAN} this flag is ignored and all views are
     * regarded for accessibility purposes.
     * </p>
     * <p>
     * Usually views not important for accessibility are layout managers that do not
     * react to user actions, do not draw any content, and do not have any special
     * semantics in the context of the screen content. For example, a three by three
     * grid can be implemented as three horizontal linear layouts and one vertical,
     * or three vertical linear layouts and one horizontal, or one grid layout, etc.
     * In this context the actual layout mangers used to achieve the grid configuration
     * are not important, rather it is important that there are nine evenly distributed
     * elements.
     * </p>
     */
    public static final int FLAG_INCLUDE_NOT_IMPORTANT_VIEWS = 0x0000002;

    /**
     * This flag requests that the system gets into touch exploration mode.
     * In this mode a single finger moving on the screen behaves as a mouse
     * pointer hovering over the user interface. The system will also detect
     * certain gestures performed on the touch screen and notify this service.
     * The system will enable touch exploration mode if there is at least one
     * accessibility service that has this flag set. Hence, clearing this
     * flag does not guarantee that the device will not be in touch exploration
     * mode since there may be another enabled service that requested it.
     */
    public static final int FLAG_REQUEST_TOUCH_EXPLORATION_MODE= 0x0000004;

    /**
     * The event types an {@link AccessibilityService} is interested in.
     * <p>
     *   <strong>Can be dynamically set at runtime.</strong>
     * </p>
     * @see android.view.accessibility.AccessibilityEvent#TYPE_VIEW_CLICKED
     * @see android.view.accessibility.AccessibilityEvent#TYPE_VIEW_LONG_CLICKED
     * @see android.view.accessibility.AccessibilityEvent#TYPE_VIEW_FOCUSED
     * @see android.view.accessibility.AccessibilityEvent#TYPE_VIEW_SELECTED
     * @see android.view.accessibility.AccessibilityEvent#TYPE_VIEW_TEXT_CHANGED
     * @see android.view.accessibility.AccessibilityEvent#TYPE_WINDOW_STATE_CHANGED
     * @see android.view.accessibility.AccessibilityEvent#TYPE_NOTIFICATION_STATE_CHANGED
     * @see android.view.accessibility.AccessibilityEvent#TYPE_TOUCH_EXPLORATION_GESTURE_START
     * @see android.view.accessibility.AccessibilityEvent#TYPE_TOUCH_EXPLORATION_GESTURE_END
     * @see android.view.accessibility.AccessibilityEvent#TYPE_VIEW_HOVER_ENTER
     * @see android.view.accessibility.AccessibilityEvent#TYPE_VIEW_HOVER_EXIT
     * @see android.view.accessibility.AccessibilityEvent#TYPE_VIEW_SCROLLED
     * @see android.view.accessibility.AccessibilityEvent#TYPE_VIEW_TEXT_SELECTION_CHANGED
     * @see android.view.accessibility.AccessibilityEvent#TYPE_WINDOW_CONTENT_CHANGED
     */
    public int eventTypes;

    /**
     * The package names an {@link AccessibilityService} is interested in. Setting
     * to <code>null</code> is equivalent to all packages.
     * <p>
     *   <strong>Can be dynamically set at runtime.</strong>
     * </p>
     */
    public String[] packageNames;

    /**
     * The feedback type an {@link AccessibilityService} provides.
     * <p>
     *   <strong>Can be dynamically set at runtime.</strong>
     * </p>
     * @see #FEEDBACK_AUDIBLE
     * @see #FEEDBACK_GENERIC
     * @see #FEEDBACK_HAPTIC
     * @see #FEEDBACK_SPOKEN
     * @see #FEEDBACK_VISUAL
     * @see #FEEDBACK_BRAILLE
     */
    public int feedbackType;

    /**
     * The timeout after the most recent event of a given type before an
     * {@link AccessibilityService} is notified.
     * <p>
     *   <strong>Can be dynamically set at runtime.</strong>.
     * </p>
     * <p>
     * <strong>Note:</strong> The event notification timeout is useful to avoid propagating
     *       events to the client too frequently since this is accomplished via an expensive
     *       interprocess call. One can think of the timeout as a criteria to determine when
     *       event generation has settled down.
     */
    public long notificationTimeout;

    /**
     * This field represents a set of flags used for configuring an
     * {@link AccessibilityService}.
     * <p>
     *   <strong>Can be dynamically set at runtime.</strong>
     * </p>
     * @see #DEFAULT
     * @see #FLAG_INCLUDE_NOT_IMPORTANT_VIEWS
     * @see #FLAG_REQUEST_TOUCH_EXPLORATION_MODE
     */
    public int flags;

    /**
     * The unique string Id to identify the accessibility service.
     */
    private String mId;

    /**
     * The Service that implements this accessibility service component.
     */
    private ResolveInfo mResolveInfo;

    /**
     * The accessibility service setting activity's name, used by the system
     * settings to launch the setting activity of this accessibility service.
     */
    private String mSettingsActivityName;

    /**
     * Flag whether this accessibility service can retrieve window content.
     */
    private boolean mCanRetrieveWindowContent;

    /**
     * Resource id of the description of the accessibility service.
     */
    private int mDescriptionResId;

    /**
     * Non localized description of the accessibility service.
     */
    private String mNonLocalizedDescription;

    /**
     * Creates a new instance.
     */
    public AccessibilityServiceInfo() {
        /* do nothing */
    }

    /**
     * Creates a new instance.
     *
     * @param resolveInfo The service resolve info.
     * @param context Context for accessing resources.
     * @throws XmlPullParserException If a XML parsing error occurs.
     * @throws IOException If a XML parsing error occurs.
     *
     * @hide
     */
    public AccessibilityServiceInfo(ResolveInfo resolveInfo, Context context)
            throws XmlPullParserException, IOException {
        ServiceInfo serviceInfo = resolveInfo.serviceInfo;
        mId = new ComponentName(serviceInfo.packageName, serviceInfo.name).flattenToShortString();
        mResolveInfo = resolveInfo;

        XmlResourceParser parser = null;

        try {
            PackageManager packageManager = context.getPackageManager();
            parser = serviceInfo.loadXmlMetaData(packageManager,
                    AccessibilityService.SERVICE_META_DATA);
            if (parser == null) {
                return;
            }

            int type = 0;
            while (type != XmlPullParser.END_DOCUMENT && type != XmlPullParser.START_TAG) {
                type = parser.next();
            }

            String nodeName = parser.getName();
            if (!TAG_ACCESSIBILITY_SERVICE.equals(nodeName)) {
                throw new XmlPullParserException( "Meta-data does not start with"
                        + TAG_ACCESSIBILITY_SERVICE + " tag");
            }

            AttributeSet allAttributes = Xml.asAttributeSet(parser);
            Resources resources = packageManager.getResourcesForApplication(
                    serviceInfo.applicationInfo);
            TypedArray asAttributes = resources.obtainAttributes(allAttributes,
                    com.android.internal.R.styleable.AccessibilityService);
            eventTypes = asAttributes.getInt(
                    com.android.internal.R.styleable.AccessibilityService_accessibilityEventTypes,
                    0);
            String packageNamez = asAttributes.getString(
                    com.android.internal.R.styleable.AccessibilityService_packageNames);
            if (packageNamez != null) {
                packageNames = packageNamez.split("(\\s)*,(\\s)*");
            }
            feedbackType = asAttributes.getInt(
                    com.android.internal.R.styleable.AccessibilityService_accessibilityFeedbackType,
                    0);
            notificationTimeout = asAttributes.getInt(
                    com.android.internal.R.styleable.AccessibilityService_notificationTimeout, 
                    0);
            flags = asAttributes.getInt(
                    com.android.internal.R.styleable.AccessibilityService_accessibilityFlags, 0);
            mSettingsActivityName = asAttributes.getString(
                    com.android.internal.R.styleable.AccessibilityService_settingsActivity);
            mCanRetrieveWindowContent = asAttributes.getBoolean(
                    com.android.internal.R.styleable.AccessibilityService_canRetrieveWindowContent,
                    false);
            TypedValue peekedValue = asAttributes.peekValue(
                    com.android.internal.R.styleable.AccessibilityService_description);
            if (peekedValue != null) {
                mDescriptionResId = peekedValue.resourceId;
                CharSequence nonLocalizedDescription = peekedValue.coerceToString();
                if (nonLocalizedDescription != null) {
                    mNonLocalizedDescription = nonLocalizedDescription.toString().trim();
                }
            }
            asAttributes.recycle();
        } catch (NameNotFoundException e) {
            throw new XmlPullParserException( "Unable to create context for: "
                    + serviceInfo.packageName);
        } finally {
            if (parser != null) {
                parser.close();
            }
        }
    }

    /**
     * Updates the properties that an AccessibilitySerivice can change dynamically.
     *
     * @param other The info from which to update the properties.
     *
     * @hide
     */
    public void updateDynamicallyConfigurableProperties(AccessibilityServiceInfo other) {
        eventTypes = other.eventTypes;
        packageNames = other.packageNames;
        feedbackType = other.feedbackType;
        notificationTimeout = other.notificationTimeout;
        flags = other.flags;
    }

    /**
     * The accessibility service id.
     * <p>
     *   <strong>Generated by the system.</strong>
     * </p>
     * @return The id.
     */
    public String getId() {
        return mId;
    }

    /**
     * The service {@link ResolveInfo}.
     * <p>
     *   <strong>Generated by the system.</strong>
     * </p>
     * @return The info.
     */
    public ResolveInfo getResolveInfo() {
        return mResolveInfo;
    }

    /**
     * The settings activity name.
     * <p>
     *    <strong>Statically set from
     *    {@link AccessibilityService#SERVICE_META_DATA meta-data}.</strong>
     * </p>
     * @return The settings activity name.
     */
    public String getSettingsActivityName() {
        return mSettingsActivityName;
    }

    /**
     * Whether this service can retrieve the current window's content.
     * <p>
     *    <strong>Statically set from
     *    {@link AccessibilityService#SERVICE_META_DATA meta-data}.</strong>
     * </p>
     * @return True if window content can be retrieved.
     */
    public boolean getCanRetrieveWindowContent() {
        return mCanRetrieveWindowContent;
    }

    /**
     * Gets the non-localized description of the accessibility service.
     * <p>
     *    <strong>Statically set from
     *    {@link AccessibilityService#SERVICE_META_DATA meta-data}.</strong>
     * </p>
     * @return The description.
     *
     * @deprecated Use {@link #loadDescription(PackageManager)}.
     */
    public String getDescription() {
        return mNonLocalizedDescription;
    }

    /**
     * The localized description of the accessibility service.
     * <p>
     *    <strong>Statically set from
     *    {@link AccessibilityService#SERVICE_META_DATA meta-data}.</strong>
     * </p>
     * @return The localized description.
     */
    public String loadDescription(PackageManager packageManager) {
        if (mDescriptionResId == 0) {
            return mNonLocalizedDescription;
        }
        ServiceInfo serviceInfo = mResolveInfo.serviceInfo;
        CharSequence description = packageManager.getText(serviceInfo.packageName,
                mDescriptionResId, serviceInfo.applicationInfo);
        if (description != null) {
            return description.toString().trim();
        }
        return null;
    }

    /**
     * {@inheritDoc}
     */
    public int describeContents() {
        return 0;
    }

    public void writeToParcel(Parcel parcel, int flagz) {
        parcel.writeInt(eventTypes);
        parcel.writeStringArray(packageNames);
        parcel.writeInt(feedbackType);
        parcel.writeLong(notificationTimeout);
        parcel.writeInt(flags);
        parcel.writeString(mId);
        parcel.writeParcelable(mResolveInfo, 0);
        parcel.writeString(mSettingsActivityName);
        parcel.writeInt(mCanRetrieveWindowContent ? 1 : 0);
        parcel.writeInt(mDescriptionResId);
        parcel.writeString(mNonLocalizedDescription);
    }

    private void initFromParcel(Parcel parcel) {
        eventTypes = parcel.readInt();
        packageNames = parcel.readStringArray();
        feedbackType = parcel.readInt();
        notificationTimeout = parcel.readLong();
        flags = parcel.readInt();
        mId = parcel.readString();
        mResolveInfo = parcel.readParcelable(null);
        mSettingsActivityName = parcel.readString();
        mCanRetrieveWindowContent = (parcel.readInt() == 1);
        mDescriptionResId = parcel.readInt();
        mNonLocalizedDescription = parcel.readString();
    }

    @Override
    public String toString() {
        StringBuilder stringBuilder = new StringBuilder();
        appendEventTypes(stringBuilder, eventTypes);
        stringBuilder.append(", ");
        appendPackageNames(stringBuilder, packageNames);
        stringBuilder.append(", ");
        appendFeedbackTypes(stringBuilder, feedbackType);
        stringBuilder.append(", ");
        stringBuilder.append("notificationTimeout: ").append(notificationTimeout);
        stringBuilder.append(", ");
        appendFlags(stringBuilder, flags);
        stringBuilder.append(", ");
        stringBuilder.append("id: ").append(mId);
        stringBuilder.append(", ");
        stringBuilder.append("resolveInfo: ").append(mResolveInfo);
        stringBuilder.append(", ");
        stringBuilder.append("settingsActivityName: ").append(mSettingsActivityName);
        stringBuilder.append(", ");
        stringBuilder.append("retrieveScreenContent: ").append(mCanRetrieveWindowContent);
        return stringBuilder.toString();
    }

    private static void appendFeedbackTypes(StringBuilder stringBuilder, int feedbackTypes) {
        stringBuilder.append("feedbackTypes:");
        stringBuilder.append("[");
        while (feedbackTypes != 0) {
            final int feedbackTypeBit = (1 << Integer.numberOfTrailingZeros(feedbackTypes));
            stringBuilder.append(feedbackTypeToString(feedbackTypeBit));
            feedbackTypes &= ~feedbackTypeBit;
            if (feedbackTypes != 0) {
                stringBuilder.append(", ");
            }
        }
        stringBuilder.append("]");
    }

    private static void appendPackageNames(StringBuilder stringBuilder, String[] packageNames) {
        stringBuilder.append("packageNames:");
        stringBuilder.append("[");
        if (packageNames != null) {
            final int packageNameCount = packageNames.length;
            for (int i = 0; i < packageNameCount; i++) {
                stringBuilder.append(packageNames[i]);
                if (i < packageNameCount - 1) {
                    stringBuilder.append(", ");
                }
            }
        }
        stringBuilder.append("]");
    }

    private static void appendEventTypes(StringBuilder stringBuilder, int eventTypes) {
        stringBuilder.append("eventTypes:");
        stringBuilder.append("[");
        while (eventTypes != 0) {
            final int eventTypeBit = (1 << Integer.numberOfTrailingZeros(eventTypes));
            stringBuilder.append(AccessibilityEvent.eventTypeToString(eventTypeBit));
            eventTypes &= ~eventTypeBit;
            if (eventTypes != 0) {
                stringBuilder.append(", ");
            }
        }
        stringBuilder.append("]");
    }

    private static void appendFlags(StringBuilder stringBuilder, int flags) {
        stringBuilder.append("flags:");
        stringBuilder.append("[");
        while (flags != 0) {
            final int flagBit = (1 << Integer.numberOfTrailingZeros(flags));
            stringBuilder.append(flagToString(flagBit));
            flags &= ~flagBit;
            if (flags != 0) {
                stringBuilder.append(", ");
            }
        }
        stringBuilder.append("]");
    }

    /**
     * Returns the string representation of a feedback type. For example,
     * {@link #FEEDBACK_SPOKEN} is represented by the string FEEDBACK_SPOKEN.
     *
     * @param feedbackType The feedback type.
     * @return The string representation.
     */
    public static String feedbackTypeToString(int feedbackType) {
        StringBuilder builder = new StringBuilder();
        builder.append("[");
        while (feedbackType != 0) {
            final int feedbackTypeFlag = 1 << Integer.numberOfTrailingZeros(feedbackType);
            feedbackType &= ~feedbackTypeFlag;
            switch (feedbackTypeFlag) {
                case FEEDBACK_AUDIBLE:
                    if (builder.length() > 1) {
                        builder.append(", ");
                    }
                    builder.append("FEEDBACK_AUDIBLE");
                    break;
                case FEEDBACK_HAPTIC:
                    if (builder.length() > 1) {
                        builder.append(", ");
                    }
                    builder.append("FEEDBACK_HAPTIC");
                    break;
                case FEEDBACK_GENERIC:
                    if (builder.length() > 1) {
                        builder.append(", ");
                    }
                    builder.append("FEEDBACK_GENERIC");
                    break;
                case FEEDBACK_SPOKEN:
                    if (builder.length() > 1) {
                        builder.append(", ");
                    }
                    builder.append("FEEDBACK_SPOKEN");
                    break;
                case FEEDBACK_VISUAL:
                    if (builder.length() > 1) {
                        builder.append(", ");
                    }
                    builder.append("FEEDBACK_VISUAL");
                    break;
                case FEEDBACK_BRAILLE:
                    if (builder.length() > 1) {
                        builder.append(", ");
                    }
                    builder.append("FEEDBACK_BRAILLE");
                    break;
            }
        }
        builder.append("]");
        return builder.toString();
    }

    /**
     * Returns the string representation of a flag. For example,
     * {@link #DEFAULT} is represented by the string DEFAULT.
     *
     * @param flag The flag.
     * @return The string representation.
     */
    public static String flagToString(int flag) {
        switch (flag) {
            case DEFAULT:
                return "DEFAULT";
            case FLAG_INCLUDE_NOT_IMPORTANT_VIEWS:
                return "FLAG_INCLUDE_NOT_IMPORTANT_VIEWS";
            case FLAG_REQUEST_TOUCH_EXPLORATION_MODE:
                return "FLAG_REQUEST_TOUCH_EXPLORATION_MODE";
            default:
                return null;
        }
    }

    /**
     * @see Parcelable.Creator
     */
    public static final Parcelable.Creator<AccessibilityServiceInfo> CREATOR =
            new Parcelable.Creator<AccessibilityServiceInfo>() {
        public AccessibilityServiceInfo createFromParcel(Parcel parcel) {
            AccessibilityServiceInfo info = new AccessibilityServiceInfo();
            info.initFromParcel(parcel);
            return info;
        }

        public AccessibilityServiceInfo[] newArray(int size) {
            return new AccessibilityServiceInfo[size];
        }
    };
}