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

import android.content.ComponentName;
import android.content.Context;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.content.pm.ServiceInfo;
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.Xml;

import java.io.IOException;

/**
 * This class is used to specify meta information of an input method.
 */
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;
    
    /**
     * 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 {
        mService = service;
        ServiceInfo si = service.serviceInfo;
        mId = new ComponentName(si.packageName, si.name).flattenToShortString();
        
        PackageManager pm = context.getPackageManager();
        String settingsActivityComponent = null;
        int isDefaultResId = 0;
        
        XmlResourceParser parser = null;
        try {
            parser = si.loadXmlMetaData(pm, InputMethod.SERVICE_META_DATA);
            if (parser == null) {
                throw new XmlPullParserException("No "
                        + InputMethod.SERVICE_META_DATA + " meta-data");
            }
        
            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 = context.getResources().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);
            sa.recycle();
        } finally {
            if (parser != null) parser.close();
        }
        
        mSettingsActivityName = settingsActivityComponent;
        mIsDefaultResId = isDefaultResId;
    }

    InputMethodInfo(Parcel source) {
        mId = source.readString();
        mSettingsActivityName = source.readString();
        mIsDefaultResId = source.readInt();
        mService = ResolveInfo.CREATOR.createFromParcel(source);
    }
    
    /**
     * Temporary API for creating a built-in input method.
     */
    public InputMethodInfo(String packageName, String className,
            CharSequence label, String settingsActivity) {
        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;
        mService = ri;
        mId = new ComponentName(si.packageName, si.name).flattenToShortString();
        mSettingsActivityName = settingsActivity;
        mIsDefaultResId = 0;
    }
    
    /**
     * 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.
     */
    public String getSettingsActivity() {
        return mSettingsActivityName;
    }
    
    /**
     * 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;
    }
    
    public void dump(Printer pw, String prefix) {
        pw.println(prefix + "mId=" + mId
                + " mSettingsActivityName=" + mSettingsActivityName);
        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);
    }
    
    /**
     * Used to package this object into a {@link Parcel}.
     * 
     * @param dest The {@link Parcel} to be written.
     * @param flags The flags used for parceling.
     */
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(mId);
        dest.writeString(mSettingsActivityName);
        dest.writeInt(mIsDefaultResId);
        mService.writeToParcel(dest, flags);
    }

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

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

    public int describeContents() {
        return 0;
    }
}
