/*
 * Copyright (C) 2014 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 com.android.inputmethod.latin.makedict;

import com.android.inputmethod.annotations.UsedForTesting;
import com.android.inputmethod.latin.BinaryDictionary;
import com.android.inputmethod.latin.utils.CombinedFormatUtils;

import java.util.Arrays;

public final class ProbabilityInfo {
    public final int mProbability;
    // mTimestamp, mLevel and mCount are historical info. These values are depend on the
    // implementation in native code; thus, we must not use them and have any assumptions about
    // them except for tests.
    public final int mTimestamp;
    public final int mLevel;
    public final int mCount;

    @UsedForTesting
    public static ProbabilityInfo max(final ProbabilityInfo probabilityInfo1,
            final ProbabilityInfo probabilityInfo2) {
        if (probabilityInfo1 == null) {
            return probabilityInfo2;
        }
        if (probabilityInfo2 == null) {
            return probabilityInfo1;
        }
        if (probabilityInfo1.mProbability > probabilityInfo2.mProbability) {
            return probabilityInfo1;
        } else {
            return probabilityInfo2;
        }
    }

    public ProbabilityInfo(final int probability) {
        this(probability, BinaryDictionary.NOT_A_VALID_TIMESTAMP, 0, 0);
    }

    public ProbabilityInfo(final int probability, final int timestamp, final int level,
            final int count) {
        mProbability = probability;
        mTimestamp = timestamp;
        mLevel = level;
        mCount = count;
    }

    public boolean hasHistoricalInfo() {
        return mTimestamp != BinaryDictionary.NOT_A_VALID_TIMESTAMP;
    }

    @Override
    public int hashCode() {
        if (hasHistoricalInfo()) {
            return Arrays.hashCode(new Object[] { mProbability, mTimestamp, mLevel, mCount });
        } else {
            return Arrays.hashCode(new Object[] { mProbability });
        }
    }

    @Override
    public String toString() {
        return CombinedFormatUtils.formatProbabilityInfo(this);
    }

    @Override
    public boolean equals(Object o) {
        if (o == this) return true;
        if (!(o instanceof ProbabilityInfo)) return false;
        final ProbabilityInfo p = (ProbabilityInfo)o;
        if (!hasHistoricalInfo() && !p.hasHistoricalInfo()) {
            return mProbability == p.mProbability;
        }
        return mProbability == p.mProbability && mTimestamp == p.mTimestamp && mLevel == p.mLevel
                && mCount == p.mCount;
    }
}