/*
 * Copyright (C) 2011 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.textservice;

import com.android.internal.util.ArrayUtils;

import android.os.Parcel;
import android.os.Parcelable;

import java.util.Arrays;

/**
 * This class contains a metadata of suggestions from the text service
 */
public final class SuggestionsInfo implements Parcelable {
    private static final String[] EMPTY = ArrayUtils.emptyArray(String.class);
    private static final int NOT_A_LENGTH = -1;

    /**
     * Flag of the attributes of the suggestions that can be obtained by
     * {@link #getSuggestionsAttributes}: this tells that the requested word was found
     * in the dictionary in the text service.
     */
    public static final int RESULT_ATTR_IN_THE_DICTIONARY = 0x0001;
    /**
     * Flag of the attributes of the suggestions that can be obtained by
     * {@link #getSuggestionsAttributes}: this tells that the text service thinks the requested
     * word looks like a typo.
     */
    public static final int RESULT_ATTR_LOOKS_LIKE_TYPO = 0x0002;
    /**
     * Flag of the attributes of the suggestions that can be obtained by
     * {@link #getSuggestionsAttributes}: this tells that the text service thinks
     * the result suggestions include highly recommended ones.
     */
    public static final int RESULT_ATTR_HAS_RECOMMENDED_SUGGESTIONS = 0x0004;
    private final int mSuggestionsAttributes;
    private final String[] mSuggestions;
    private final int[] mStartPosArray;
    private final int[] mLengthArray;
    private final boolean mSuggestionsAvailable;
    private int mCookie;
    private int mSequence;

    /**
     * Constructor.
     * @param suggestionsAttributes from the text service
     * @param suggestions from the text service
     */
    public SuggestionsInfo(int suggestionsAttributes, String[] suggestions) {
        this(suggestionsAttributes, suggestions, 0, 0);
    }

    /**
     * Constructor.
     * @param suggestionsAttributes from the text service
     * @param suggestions from the text service
     * @param cookie the cookie of the input TextInfo
     * @param sequence the cookie of the input TextInfo
     */
    public SuggestionsInfo(
            int suggestionsAttributes, String[] suggestions, int cookie, int sequence) {
        this(suggestionsAttributes, suggestions, cookie, sequence, null, null);
    }

    /**
     * @hide
     * Constructor.
     * @param suggestionsAttributes from the text service
     * @param suggestions from the text service
     * @param cookie the cookie of the input TextInfo
     * @param sequence the cookie of the input TextInfo
     * @param startPosArray the array of start positions of suggestions
     * @param lengthArray the array of length of suggestions
     */
    public SuggestionsInfo(
            int suggestionsAttributes, String[] suggestions, int cookie, int sequence,
            int[] startPosArray, int[] lengthArray) {
        final int suggestsLen;
        if (suggestions == null) {
            mSuggestions = EMPTY;
            mSuggestionsAvailable = false;
            suggestsLen = 0;
            mStartPosArray = new int[0];
            mLengthArray = new int[0];
        } else {
            mSuggestions = suggestions;
            mSuggestionsAvailable = true;
            suggestsLen = suggestions.length;
            if (startPosArray == null || lengthArray == null) {
                mStartPosArray = new int[suggestsLen];
                mLengthArray = new int[suggestsLen];
                for (int i = 0; i < suggestsLen; ++i) {
                    mStartPosArray[i] = 0;
                    mLengthArray[i] = NOT_A_LENGTH;
                }
            } else if (suggestsLen != startPosArray.length || suggestsLen != lengthArray.length) {
                throw new IllegalArgumentException();
            } else {
                mStartPosArray = Arrays.copyOf(startPosArray, suggestsLen);
                mLengthArray = Arrays.copyOf(lengthArray, suggestsLen);
            }
        }
        mSuggestionsAttributes = suggestionsAttributes;
        mCookie = cookie;
        mSequence = sequence;
    }

    public SuggestionsInfo(Parcel source) {
        mSuggestionsAttributes = source.readInt();
        mSuggestions = source.readStringArray();
        mCookie = source.readInt();
        mSequence = source.readInt();
        mSuggestionsAvailable = source.readInt() == 1;
        mStartPosArray = new int[mSuggestions.length];
        mLengthArray = new int[mSuggestions.length];
        source.readIntArray(mStartPosArray);
        source.readIntArray(mLengthArray);
    }

    /**
     * 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.writeInt(mSuggestionsAttributes);
        dest.writeStringArray(mSuggestions);
        dest.writeInt(mCookie);
        dest.writeInt(mSequence);
        dest.writeInt(mSuggestionsAvailable ? 1 : 0);
        dest.writeIntArray(mStartPosArray);
        dest.writeIntArray(mLengthArray);
    }

    /**
     * Set the cookie and the sequence of SuggestionsInfo which are set to TextInfo from a client
     * application
     * @param cookie the cookie of an input TextInfo
     * @param sequence the cookie of an input TextInfo
     */
    public void setCookieAndSequence(int cookie, int sequence) {
        mCookie = cookie;
        mSequence = sequence;
    }

    /**
     * @return the cookie which may be set by a client application
     */
    public int getCookie() {
        return mCookie;
    }

    /**
     * @return the sequence which may be set by a client application
     */
    public int getSequence() {
        return mSequence;
    }

    /**
     * @return the attributes of suggestions. This includes whether the spell checker has the word
     * in its dictionary or not and whether the spell checker has confident suggestions for the
     * word or not.
     */
    public int getSuggestionsAttributes() {
        return mSuggestionsAttributes;
    }

    /**
     * @return the count of the suggestions. If there's no suggestions at all, this method returns
     * -1. Even if this method returns 0, it doesn't necessarily mean that there are no suggestions
     * for the requested word. For instance, the caller could have been asked to limit the maximum
     * number of suggestions returned.
     */
    public int getSuggestionsCount() {
        if (!mSuggestionsAvailable) {
            return -1;
        }
        return mSuggestions.length;
    }

    /**
     * @param i the id of suggestions
     * @return the suggestion at the specified id
     */
    public String getSuggestionAt(int i) {
        return mSuggestions[i];
    }

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

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

    /**
     * Used to make this class parcelable.
     */
    @Override
    public int describeContents() {
        return 0;
    }

    /**
     * @hide
     */
    public int getSuggestionStartPosAt(int i) {
        if (i >= 0 && i < mStartPosArray.length) {
            return mStartPosArray[i];
        }
        return -1;
    }

    /**
     * @hide
     */
    public int getSuggestionLengthAt(int i) {
        if (i >= 0 && i < mLengthArray.length) {
            return mLengthArray[i];
        }
        return -1;
    }
}