/*
 * Copyright (C) 2007-2008 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.view.inputmethod;

import android.annotation.NonNull;
import android.content.ComponentName;
import android.content.Context;
import android.content.pm.ApplicationInfo;
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.Resources.NotFoundException;
import android.content.res.TypedArray;
import android.content.res.XmlResourceParser;
import android.graphics.drawable.Drawable;
import android.os.Parcel;
import android.os.Parcelable;
import android.util.AttributeSet;
import android.util.Printer;
import android.util.Slog;
import android.util.Xml;
import android.view.inputmethod.InputMethodSubtype.InputMethodSubtypeBuilder;

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

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

/**
 * This class is used to specify meta information of an input method.
 *
 * <p>It should be defined in an XML resource file with an {@code <input-method>} element.
 * For more information, see the guide to
 * <a href="{@docRoot}guide/topics/text/creating-input-method.html">
 * Creating an Input Method</a>.</p>
 *
 * @see InputMethodSubtype
 *
 * @attr ref android.R.styleable#InputMethod_settingsActivity
 * @attr ref android.R.styleable#InputMethod_isDefault
 * @attr ref android.R.styleable#InputMethod_supportsSwitchingToNextInputMethod
 */
public final class InputMethodInfo implements Parcelable {
    static final String TAG = "InputMethodInfo";

    /**
     * The Service that implements this input method component.
     */
    final ResolveInfo mService;

    /**
     * The unique string Id to identify the input method.  This is generated
     * from the input method component.
     */
    final String mId;

    /**
     * The input method setting activity's name, used by the system settings to
     * launch the setting activity of this input method.
     */
    final String mSettingsActivityName;

    /**
     * The resource in the input method's .apk that holds a boolean indicating
     * whether it should be considered the default input method for this
     * system.  This is a resource ID instead of the final value so that it
     * can change based on the configuration (in particular locale).
     */
    final int mIsDefaultResId;

    /**
     * An array-like container of the subtypes.
     */
    private final InputMethodSubtypeArray mSubtypes;

    private final boolean mIsAuxIme;

    /**
     * Caveat: mForceDefault must be false for production. This flag is only for test.
     */
    private final boolean mForceDefault;

    /**
     * The flag whether this IME supports ways to switch to a next input method (e.g. globe key.)
     */
    private final boolean mSupportsSwitchingToNextInputMethod;

    /**
     * @param service the {@link ResolveInfo} corresponds in which the IME is implemented.
     * @return a unique ID to be returned by {@link #getId()}. We have used
     *         {@link ComponentName#flattenToShortString()} for this purpose (and it is already
     *         unrealistic to switch to a different scheme as it is already implicitly assumed in
     *         many places).
     * @hide
     */
    public static String computeId(@NonNull ResolveInfo service) {
        final ServiceInfo si = service.serviceInfo;
        return new ComponentName(si.packageName, si.name).flattenToShortString();
    }

    /**
     * Constructor.
     *
     * @param context The Context in which we are parsing the input method.
     * @param service The ResolveInfo returned from the package manager about
     * this input method's component.
     */
    public InputMethodInfo(Context context, ResolveInfo service)
            throws XmlPullParserException, IOException {
        this(context, service, null);
    }

    /**
     * Constructor.
     *
     * @param context The Context in which we are parsing the input method.
     * @param service The ResolveInfo returned from the package manager about
     * this input method's component.
     * @param additionalSubtypes additional subtypes being added to this InputMethodInfo
     * @hide
     */
    public InputMethodInfo(Context context, ResolveInfo service,
            List<InputMethodSubtype> additionalSubtypes)
            throws XmlPullParserException, IOException {
        mService = service;
        ServiceInfo si = service.serviceInfo;
        mId = computeId(service);
        boolean isAuxIme = true;
        boolean supportsSwitchingToNextInputMethod = false; // false as default
        mForceDefault = false;

        PackageManager pm = context.getPackageManager();
        String settingsActivityComponent = null;
        int isDefaultResId = 0;

        XmlResourceParser parser = null;
        final ArrayList<InputMethodSubtype> subtypes = new ArrayList<InputMethodSubtype>();
        try {
            parser = si.loadXmlMetaData(pm, InputMethod.SERVICE_META_DATA);
            if (parser == null) {
                throw new XmlPullParserException("No "
                        + InputMethod.SERVICE_META_DATA + " meta-data");
            }

            Resources res = pm.getResourcesForApplication(si.applicationInfo);

            AttributeSet attrs = Xml.asAttributeSet(parser);

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

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

            TypedArray sa = res.obtainAttributes(attrs,
                    com.android.internal.R.styleable.InputMethod);
            settingsActivityComponent = sa.getString(
                    com.android.internal.R.styleable.InputMethod_settingsActivity);
            isDefaultResId = sa.getResourceId(
                    com.android.internal.R.styleable.InputMethod_isDefault, 0);
            supportsSwitchingToNextInputMethod = sa.getBoolean(
                    com.android.internal.R.styleable.InputMethod_supportsSwitchingToNextInputMethod,
                    false);
            sa.recycle();

            final int depth = parser.getDepth();
            // Parse all subtypes
            while (((type = parser.next()) != XmlPullParser.END_TAG || parser.getDepth() > depth)
                    && type != XmlPullParser.END_DOCUMENT) {
                if (type == XmlPullParser.START_TAG) {
                    nodeName = parser.getName();
                    if (!"subtype".equals(nodeName)) {
                        throw new XmlPullParserException(
                                "Meta-data in input-method does not start with subtype tag");
                    }
                    final TypedArray a = res.obtainAttributes(
                            attrs, com.android.internal.R.styleable.InputMethod_Subtype);
                    final InputMethodSubtype subtype = new InputMethodSubtypeBuilder()
                            .setSubtypeNameResId(a.getResourceId(com.android.internal.R.styleable
                                    .InputMethod_Subtype_label, 0))
                            .setSubtypeIconResId(a.getResourceId(com.android.internal.R.styleable
                                    .InputMethod_Subtype_icon, 0))
                            .setLanguageTag(a.getString(com.android.internal.R.styleable
                                    .InputMethod_Subtype_languageTag))
                            .setSubtypeLocale(a.getString(com.android.internal.R.styleable
                                    .InputMethod_Subtype_imeSubtypeLocale))
                            .setSubtypeMode(a.getString(com.android.internal.R.styleable
                                    .InputMethod_Subtype_imeSubtypeMode))
                            .setSubtypeExtraValue(a.getString(com.android.internal.R.styleable
                                    .InputMethod_Subtype_imeSubtypeExtraValue))
                            .setIsAuxiliary(a.getBoolean(com.android.internal.R.styleable
                                    .InputMethod_Subtype_isAuxiliary, false))
                            .setOverridesImplicitlyEnabledSubtype(a.getBoolean(
                                    com.android.internal.R.styleable
                                    .InputMethod_Subtype_overridesImplicitlyEnabledSubtype, false))
                            .setSubtypeId(a.getInt(com.android.internal.R.styleable
                                    .InputMethod_Subtype_subtypeId, 0 /* use Arrays.hashCode */))
                            .setIsAsciiCapable(a.getBoolean(com.android.internal.R.styleable
                                    .InputMethod_Subtype_isAsciiCapable, false)).build();
                    if (!subtype.isAuxiliary()) {
                        isAuxIme = false;
                    }
                    subtypes.add(subtype);
                }
            }
        } catch (NameNotFoundException | IndexOutOfBoundsException | NumberFormatException e) {
            throw new XmlPullParserException(
                    "Unable to create context for: " + si.packageName);
        } finally {
            if (parser != null) parser.close();
        }

        if (subtypes.size() == 0) {
            isAuxIme = false;
        }

        if (additionalSubtypes != null) {
            final int N = additionalSubtypes.size();
            for (int i = 0; i < N; ++i) {
                final InputMethodSubtype subtype = additionalSubtypes.get(i);
                if (!subtypes.contains(subtype)) {
                    subtypes.add(subtype);
                } else {
                    Slog.w(TAG, "Duplicated subtype definition found: "
                            + subtype.getLocale() + ", " + subtype.getMode());
                }
            }
        }
        mSubtypes = new InputMethodSubtypeArray(subtypes);
        mSettingsActivityName = settingsActivityComponent;
        mIsDefaultResId = isDefaultResId;
        mIsAuxIme = isAuxIme;
        mSupportsSwitchingToNextInputMethod = supportsSwitchingToNextInputMethod;
    }

    InputMethodInfo(Parcel source) {
        mId = source.readString();
        mSettingsActivityName = source.readString();
        mIsDefaultResId = source.readInt();
        mIsAuxIme = source.readInt() == 1;
        mSupportsSwitchingToNextInputMethod = source.readInt() == 1;
        mService = ResolveInfo.CREATOR.createFromParcel(source);
        mSubtypes = new InputMethodSubtypeArray(source);
        mForceDefault = false;
    }

    /**
     * Temporary API for creating a built-in input method for test.
     */
    public InputMethodInfo(String packageName, String className,
            CharSequence label, String settingsActivity) {
        this(buildDummyResolveInfo(packageName, className, label), false /* isAuxIme */,
                settingsActivity, null /* subtypes */, 0 /* isDefaultResId */,
                false /* forceDefault */, true /* supportsSwitchingToNextInputMethod */);
    }

    /**
     * Temporary API for creating a built-in input method for test.
     * @hide
     */
    public InputMethodInfo(ResolveInfo ri, boolean isAuxIme,
            String settingsActivity, List<InputMethodSubtype> subtypes, int isDefaultResId,
            boolean forceDefault) {
        this(ri, isAuxIme, settingsActivity, subtypes, isDefaultResId, forceDefault,
                true /* supportsSwitchingToNextInputMethod */);
    }

    /**
     * Temporary API for creating a built-in input method for test.
     * @hide
     */
    public InputMethodInfo(ResolveInfo ri, boolean isAuxIme, String settingsActivity,
            List<InputMethodSubtype> subtypes, int isDefaultResId, boolean forceDefault,
            boolean supportsSwitchingToNextInputMethod) {
        final ServiceInfo si = ri.serviceInfo;
        mService = ri;
        mId = new ComponentName(si.packageName, si.name).flattenToShortString();
        mSettingsActivityName = settingsActivity;
        mIsDefaultResId = isDefaultResId;
        mIsAuxIme = isAuxIme;
        mSubtypes = new InputMethodSubtypeArray(subtypes);
        mForceDefault = forceDefault;
        mSupportsSwitchingToNextInputMethod = supportsSwitchingToNextInputMethod;
    }

    private static ResolveInfo buildDummyResolveInfo(String packageName, String className,
            CharSequence label) {
        ResolveInfo ri = new ResolveInfo();
        ServiceInfo si = new ServiceInfo();
        ApplicationInfo ai = new ApplicationInfo();
        ai.packageName = packageName;
        ai.enabled = true;
        si.applicationInfo = ai;
        si.enabled = true;
        si.packageName = packageName;
        si.name = className;
        si.exported = true;
        si.nonLocalizedLabel = label;
        ri.serviceInfo = si;
        return ri;
    }

    /**
     * Return a unique ID for this input method.  The ID is generated from
     * the package and class name implementing the method.
     */
    public String getId() {
        return mId;
    }

    /**
     * Return the .apk package that implements this input method.
     */
    public String getPackageName() {
        return mService.serviceInfo.packageName;
    }

    /**
     * Return the class name of the service component that implements
     * this input method.
     */
    public String getServiceName() {
        return mService.serviceInfo.name;
    }

    /**
     * Return the raw information about the Service implementing this
     * input method.  Do not modify the returned object.
     */
    public ServiceInfo getServiceInfo() {
        return mService.serviceInfo;
    }

    /**
     * Return the component of the service that implements this input
     * method.
     */
    public ComponentName getComponent() {
        return new ComponentName(mService.serviceInfo.packageName,
                mService.serviceInfo.name);
    }

    /**
     * Load the user-displayed label for this input method.
     *
     * @param pm Supply a PackageManager used to load the input method's
     * resources.
     */
    public CharSequence loadLabel(PackageManager pm) {
        return mService.loadLabel(pm);
    }

    /**
     * Load the user-displayed icon for this input method.
     *
     * @param pm Supply a PackageManager used to load the input method's
     * resources.
     */
    public Drawable loadIcon(PackageManager pm) {
        return mService.loadIcon(pm);
    }

    /**
     * Return the class name of an activity that provides a settings UI for
     * the input method.  You can launch this activity be starting it with
     * an {@link android.content.Intent} whose action is MAIN and with an
     * explicit {@link android.content.ComponentName}
     * composed of {@link #getPackageName} and the class name returned here.
     *
     * <p>A null will be returned if there is no settings activity associated
     * with the input method.</p>
     */
    public String getSettingsActivity() {
        return mSettingsActivityName;
    }

    /**
     * Return the count of the subtypes of Input Method.
     */
    public int getSubtypeCount() {
        return mSubtypes.getCount();
    }

    /**
     * Return the Input Method's subtype at the specified index.
     *
     * @param index the index of the subtype to return.
     */
    public InputMethodSubtype getSubtypeAt(int index) {
        return mSubtypes.get(index);
    }

    /**
     * Return the resource identifier of a resource inside of this input
     * method's .apk that determines whether it should be considered a
     * default input method for the system.
     */
    public int getIsDefaultResourceId() {
        return mIsDefaultResId;
    }

    /**
     * Return whether or not this ime is a default ime or not.
     * @hide
     */
    public boolean isDefault(Context context) {
        if (mForceDefault) {
            return true;
        }
        try {
            if (getIsDefaultResourceId() == 0) {
                return false;
            }
            final Resources res = context.createPackageContext(getPackageName(), 0).getResources();
            return res.getBoolean(getIsDefaultResourceId());
        } catch (NameNotFoundException | NotFoundException e) {
            return false;
        }
    }

    public void dump(Printer pw, String prefix) {
        pw.println(prefix + "mId=" + mId
                + " mSettingsActivityName=" + mSettingsActivityName
                + " mSupportsSwitchingToNextInputMethod=" + mSupportsSwitchingToNextInputMethod);
        pw.println(prefix + "mIsDefaultResId=0x"
                + Integer.toHexString(mIsDefaultResId));
        pw.println(prefix + "Service:");
        mService.dump(pw, prefix + "  ");
    }

    @Override
    public String toString() {
        return "InputMethodInfo{" + mId
                + ", settings: "
                + mSettingsActivityName + "}";
    }

    /**
     * Used to test whether the given parameter object is an
     * {@link InputMethodInfo} and its Id is the same to this one.
     *
     * @return true if the given parameter object is an
     *         {@link InputMethodInfo} and its Id is the same to this one.
     */
    @Override
    public boolean equals(Object o) {
        if (o == this) return true;
        if (o == null) return false;

        if (!(o instanceof InputMethodInfo)) return false;

        InputMethodInfo obj = (InputMethodInfo) o;
        return mId.equals(obj.mId);
    }

    @Override
    public int hashCode() {
        return mId.hashCode();
    }

    /**
     * @hide
     */
    public boolean isAuxiliaryIme() {
        return mIsAuxIme;
    }

    /**
     * @return true if this input method supports ways to switch to a next input method.
     * @hide
     */
    public boolean supportsSwitchingToNextInputMethod() {
        return mSupportsSwitchingToNextInputMethod;
    }

    /**
     * Used to package this object into a {@link Parcel}.
     *
     * @param dest The {@link Parcel} to be written.
     * @param flags The flags used for parceling.
     */
    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(mId);
        dest.writeString(mSettingsActivityName);
        dest.writeInt(mIsDefaultResId);
        dest.writeInt(mIsAuxIme ? 1 : 0);
        dest.writeInt(mSupportsSwitchingToNextInputMethod ? 1 : 0);
        mService.writeToParcel(dest, flags);
        mSubtypes.writeToParcel(dest);
    }

    /**
     * Used to make this class parcelable.
     */
    public static final Parcelable.Creator<InputMethodInfo> CREATOR
            = new Parcelable.Creator<InputMethodInfo>() {
        @Override
        public InputMethodInfo createFromParcel(Parcel source) {
            return new InputMethodInfo(source);
        }

        @Override
        public InputMethodInfo[] newArray(int size) {
            return new InputMethodInfo[size];
        }
    };

    @Override
    public int describeContents() {
        return 0;
    }
}