/*
 * Copyright (C) 2017 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.textclassifier;

import android.content.res.AssetFileDescriptor;

Java wrapper for TextClassifier native library interface. This library is used for detecting
entities in text.
/**
 * Java wrapper for TextClassifier native library interface. This library is used for detecting
 * entities in text.
 */
final class TextClassifierImplNative {

    static {
        System.loadLibrary("textclassifier");
    }

    private final long mModelPtr;

    
Creates a new instance of TextClassifierImplNative, using the provided model image, given as
a file descriptor.
/**
     * Creates a new instance of TextClassifierImplNative, using the provided model image, given as
     * a file descriptor.
     */
    TextClassifierImplNative(int fd) {
        mModelPtr = nativeNew(fd);
        if (mModelPtr == 0L) {
            throw new IllegalArgumentException("Couldn't initialize TC from file descriptor.");
        }
    }

    
Creates a new instance of TextClassifierImplNative, using the provided model image, given as
a file path.
/**
     * Creates a new instance of TextClassifierImplNative, using the provided model image, given as
     * a file path.
     */
    TextClassifierImplNative(String path) {
        mModelPtr = nativeNewFromPath(path);
        if (mModelPtr == 0L) {
            throw new IllegalArgumentException("Couldn't initialize TC from given file.");
        }
    }

    
Creates a new instance of TextClassifierImplNative, using the provided model image, given as
an AssetFileDescriptor.
/**
     * Creates a new instance of TextClassifierImplNative, using the provided model image, given as
     * an AssetFileDescriptor.
     */
    TextClassifierImplNative(AssetFileDescriptor afd) {
        mModelPtr = nativeNewFromAssetFileDescriptor(afd, afd.getStartOffset(), afd.getLength());
        if (mModelPtr == 0L) {
            throw new IllegalArgumentException(
                    "Couldn't initialize TC from given AssetFileDescriptor");
        }
    }

    
Given a string context and current selection, computes the SmartSelection suggestion.
The begin and end are character indices into the context UTF8 string. selectionBegin is
the character index where the selection begins, and selectionEnd is the index of one
character past the selection span.
The return value is an array of two ints: suggested selection beginning and end, with the
same semantics as the input selectionBeginning and selectionEnd.
/**
     * Given a string context and current selection, computes the SmartSelection suggestion.
     *
     * <p>The begin and end are character indices into the context UTF8 string. selectionBegin is
     * the character index where the selection begins, and selectionEnd is the index of one
     * character past the selection span.
     *
     * <p>The return value is an array of two ints: suggested selection beginning and end, with the
     * same semantics as the input selectionBeginning and selectionEnd.
     */
    public int[] suggestSelection(
            String context, int selectionBegin, int selectionEnd, SelectionOptions options) {
        return nativeSuggestSelection(mModelPtr, context, selectionBegin, selectionEnd, options);
    }

    
Given a string context and current selection, classifies the type of the selected text.
The begin and end params are character indices in the context string.
Returns an array of ClassificationResult objects with the probability scores for different
collections.
/**
     * Given a string context and current selection, classifies the type of the selected text.
     *
     * <p>The begin and end params are character indices in the context string.
     *
     * <p>Returns an array of ClassificationResult objects with the probability scores for different
     * collections.
     */
    public ClassificationResult[] classifyText(
            String context, int selectionBegin, int selectionEnd, ClassificationOptions options) {
        return nativeClassifyText(mModelPtr, context, selectionBegin, selectionEnd, options);
    }

    
Annotates given input text. The annotations should cover the whole input context except for
whitespaces, and are sorted by their position in the context string.
/**
     * Annotates given input text. The annotations should cover the whole input context except for
     * whitespaces, and are sorted by their position in the context string.
     */
    public AnnotatedSpan[] annotate(String text, AnnotationOptions options) {
        return nativeAnnotate(mModelPtr, text, options);
    }

    
Frees up the allocated memory. /** Frees up the allocated memory. */
    public void close() {
        nativeClose(mModelPtr);
    }

    
Returns a comma separated list of locales supported by the model as BCP 47 tags. /** Returns a comma separated list of locales supported by the model as BCP 47 tags. */
    public static String getLocales(int fd) {
        return nativeGetLocales(fd);
    }

    
Returns the version of the model. /** Returns the version of the model. */
    public static int getVersion(int fd) {
        return nativeGetVersion(fd);
    }

    
Represents a datetime parsing result from classifyText calls. /** Represents a datetime parsing result from classifyText calls. */
    public static final class DatetimeResult {
        static final int GRANULARITY_YEAR = 0;
        static final int GRANULARITY_MONTH = 1;
        static final int GRANULARITY_WEEK = 2;
        static final int GRANULARITY_DAY = 3;
        static final int GRANULARITY_HOUR = 4;
        static final int GRANULARITY_MINUTE = 5;
        static final int GRANULARITY_SECOND = 6;

        private final long mTimeMsUtc;
        private final int mGranularity;

        DatetimeResult(long timeMsUtc, int granularity) {
            mGranularity = granularity;
            mTimeMsUtc = timeMsUtc;
        }

        public long getTimeMsUtc() {
            return mTimeMsUtc;
        }

        public int getGranularity() {
            return mGranularity;
        }
    }

    
Represents a result of classifyText method call. /** Represents a result of classifyText method call. */
    public static final class ClassificationResult {
        private final String mCollection;
        private final float mScore;
        private final DatetimeResult mDatetimeResult;

        ClassificationResult(
                String collection, float score, DatetimeResult datetimeResult) {
            mCollection = collection;
            mScore = score;
            mDatetimeResult = datetimeResult;
        }

        public String getCollection() {
            if (mCollection.equals(TextClassifier.TYPE_DATE) && mDatetimeResult != null) {
                switch (mDatetimeResult.getGranularity()) {
                    case DatetimeResult.GRANULARITY_HOUR:
                        // fall through
                    case DatetimeResult.GRANULARITY_MINUTE:
                        // fall through
                    case DatetimeResult.GRANULARITY_SECOND:
                        return TextClassifier.TYPE_DATE_TIME;
                    default:
                        return TextClassifier.TYPE_DATE;
                }
            }
            return mCollection;
        }

        public float getScore() {
            return mScore;
        }

        public DatetimeResult getDatetimeResult() {
            return mDatetimeResult;
        }
    }

    
Represents a result of Annotate call. /** Represents a result of Annotate call. */
    public static final class AnnotatedSpan {
        private final int mStartIndex;
        private final int mEndIndex;
        private final ClassificationResult[] mClassification;

        AnnotatedSpan(
                int startIndex, int endIndex, ClassificationResult[] classification) {
            mStartIndex = startIndex;
            mEndIndex = endIndex;
            mClassification = classification;
        }

        public int getStartIndex() {
            return mStartIndex;
        }

        public int getEndIndex() {
            return mEndIndex;
        }

        public ClassificationResult[] getClassification() {
            return mClassification;
        }
    }

    
Represents options for the suggestSelection call. /** Represents options for the suggestSelection call. */
    public static final class SelectionOptions {
        private final String mLocales;

        SelectionOptions(String locales) {
            mLocales = locales;
        }

        public String getLocales() {
            return mLocales;
        }
    }

    
Represents options for the classifyText call. /** Represents options for the classifyText call. */
    public static final class ClassificationOptions {
        private final long mReferenceTimeMsUtc;
        private final String mReferenceTimezone;
        private final String mLocales;

        ClassificationOptions(long referenceTimeMsUtc, String referenceTimezone, String locale) {
            mReferenceTimeMsUtc = referenceTimeMsUtc;
            mReferenceTimezone = referenceTimezone;
            mLocales = locale;
        }

        public long getReferenceTimeMsUtc() {
            return mReferenceTimeMsUtc;
        }

        public String getReferenceTimezone() {
            return mReferenceTimezone;
        }

        public String getLocale() {
            return mLocales;
        }
    }

    
Represents options for the Annotate call. /** Represents options for the Annotate call. */
    public static final class AnnotationOptions {
        private final long mReferenceTimeMsUtc;
        private final String mReferenceTimezone;
        private final String mLocales;

        AnnotationOptions(long referenceTimeMsUtc, String referenceTimezone, String locale) {
            mReferenceTimeMsUtc = referenceTimeMsUtc;
            mReferenceTimezone = referenceTimezone;
            mLocales = locale;
        }

        public long getReferenceTimeMsUtc() {
            return mReferenceTimeMsUtc;
        }

        public String getReferenceTimezone() {
            return mReferenceTimezone;
        }

        public String getLocale() {
            return mLocales;
        }
    }

    private static native long nativeNew(int fd);

    private static native long nativeNewFromPath(String path);

    private static native long nativeNewFromAssetFileDescriptor(
            AssetFileDescriptor afd, long offset, long size);

    private static native int[] nativeSuggestSelection(
            long context,
            String text,
            int selectionBegin,
            int selectionEnd,
            SelectionOptions options);

    private static native ClassificationResult[] nativeClassifyText(
            long context,
            String text,
            int selectionBegin,
            int selectionEnd,
            ClassificationOptions options);

    private static native AnnotatedSpan[] nativeAnnotate(
            long context, String text, AnnotationOptions options);

    private static native void nativeClose(long context);

    private static native String nativeGetLocales(int fd);

    private static native int nativeGetVersion(int fd);
}