/*
 * Copyright (C) 2013 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;

import android.test.AndroidTestCase;
import android.test.suitebuilder.annotation.LargeTest;

import com.android.inputmethod.latin.makedict.DictEncoder;
import com.android.inputmethod.latin.makedict.FormatSpec;
import com.android.inputmethod.latin.makedict.FusionDictionary;
import com.android.inputmethod.latin.makedict.FusionDictionary.PtNodeArray;
import com.android.inputmethod.latin.makedict.UnsupportedFormatException;
import com.android.inputmethod.latin.makedict.Ver3DictEncoder;

import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.Locale;

@LargeTest
public class BinaryDictionaryTests extends AndroidTestCase {
    private static final FormatSpec.FormatOptions FORMAT_OPTIONS =
            new FormatSpec.FormatOptions(3 /* version */, true /* supportsDynamicUpdate */);
    private static final String TEST_DICT_FILE_EXTENSION = ".testDict";
    private static final String TEST_LOCALE = "test";

    @Override
    protected void setUp() throws Exception {
        super.setUp();
    }

    @Override
    protected void tearDown() throws Exception {
        super.tearDown();
    }

    private File createEmptyDictionaryAndGetFile(final String filename) throws IOException,
            UnsupportedFormatException {
        final FusionDictionary dict = new FusionDictionary(new PtNodeArray(),
                new FusionDictionary.DictionaryOptions(new HashMap<String,String>(), false, false));
        final File file = File.createTempFile(filename, TEST_DICT_FILE_EXTENSION,
                getContext().getCacheDir());
        final DictEncoder dictEncoder = new Ver3DictEncoder(file);
        dictEncoder.writeDictionary(dict, FORMAT_OPTIONS);
        return file;
    }

    public void testIsValidDictionary() {
        File dictFile = null;
        try {
            dictFile = createEmptyDictionaryAndGetFile("TestBinaryDictionary");
        } catch (IOException e) {
            fail("IOException while writing an initial dictionary : " + e);
        } catch (UnsupportedFormatException e) {
            fail("UnsupportedFormatException while writing an initial dictionary : " + e);
        }
        BinaryDictionary binaryDictionary = new BinaryDictionary(dictFile.getAbsolutePath(),
                0 /* offset */, dictFile.length(), true /* useFullEditDistance */,
                Locale.getDefault(), TEST_LOCALE, true /* isUpdatable */);
        assertTrue("binaryDictionary must be valid for existing valid dictionary file.",
                binaryDictionary.isValidDictionary());
        binaryDictionary.close();
        assertFalse("binaryDictionary must be invalid after closing.",
                binaryDictionary.isValidDictionary());
        dictFile.delete();
        binaryDictionary = new BinaryDictionary(dictFile.getAbsolutePath(), 0 /* offset */,
                dictFile.length(), true /* useFullEditDistance */, Locale.getDefault(),
                TEST_LOCALE, true /* isUpdatable */);
        assertFalse("binaryDictionary must be invalid for not existing dictionary file.",
                binaryDictionary.isValidDictionary());
        binaryDictionary.close();
    }

    public void testAddUnigramWord() {
        File dictFile = null;
        try {
            dictFile = createEmptyDictionaryAndGetFile("TestBinaryDictionary");
        } catch (IOException e) {
            fail("IOException while writing an initial dictionary : " + e);
        } catch (UnsupportedFormatException e) {
            fail("UnsupportedFormatException while writing an initial dictionary : " + e);
        }
        BinaryDictionary binaryDictionary = new BinaryDictionary(dictFile.getAbsolutePath(),
                0 /* offset */, dictFile.length(), true /* useFullEditDistance */,
                Locale.getDefault(), TEST_LOCALE, true /* isUpdatable */);

        final int probability = 100;
        binaryDictionary.addUnigramWord("aaa", probability);
        // Reallocate and create.
        binaryDictionary.addUnigramWord("aab", probability);
        // Insert into children.
        binaryDictionary.addUnigramWord("aac", probability);
        // Make terminal.
        binaryDictionary.addUnigramWord("aa", probability);
        // Create children.
        binaryDictionary.addUnigramWord("aaaa", probability);
        // Reallocate and make termianl.
        binaryDictionary.addUnigramWord("a", probability);

        final int updatedProbability = 200;
        // Update.
        binaryDictionary.addUnigramWord("aaa", updatedProbability);

        assertEquals(probability, binaryDictionary.getFrequency("aab"));
        assertEquals(probability, binaryDictionary.getFrequency("aac"));
        assertEquals(probability, binaryDictionary.getFrequency("aac"));
        assertEquals(probability, binaryDictionary.getFrequency("aaaa"));
        assertEquals(probability, binaryDictionary.getFrequency("a"));
        assertEquals(updatedProbability, binaryDictionary.getFrequency("aaa"));
    }

    public void testAddBigramWords() {
        // TODO: Add a test to check the frequency of the bigram score which uses current value
        // calculated in the native code
        File dictFile = null;
        try {
            dictFile = createEmptyDictionaryAndGetFile("TestBinaryDictionary");
        } catch (IOException e) {
            fail("IOException while writing an initial dictionary : " + e);
        } catch (UnsupportedFormatException e) {
            fail("UnsupportedFormatException while writing an initial dictionary : " + e);
        }
        BinaryDictionary binaryDictionary = new BinaryDictionary(dictFile.getAbsolutePath(),
                0 /* offset */, dictFile.length(), true /* useFullEditDistance */,
                Locale.getDefault(), TEST_LOCALE, true /* isUpdatable */);

        final int unigramProbability = 100;
        final int bigramProbability = 10;
        binaryDictionary.addUnigramWord("aaa", unigramProbability);
        binaryDictionary.addUnigramWord("abb", unigramProbability);
        binaryDictionary.addUnigramWord("bcc", unigramProbability);
        binaryDictionary.addBigramWords("aaa", "abb", bigramProbability);
        binaryDictionary.addBigramWords("aaa", "bcc", bigramProbability);
        binaryDictionary.addBigramWords("abb", "aaa", bigramProbability);
        binaryDictionary.addBigramWords("abb", "bcc", bigramProbability);

        assertEquals(true, binaryDictionary.isValidBigram("aaa", "abb"));
        assertEquals(true, binaryDictionary.isValidBigram("aaa", "bcc"));
        assertEquals(true, binaryDictionary.isValidBigram("abb", "aaa"));
        assertEquals(true, binaryDictionary.isValidBigram("abb", "bcc"));

        assertEquals(false, binaryDictionary.isValidBigram("bcc", "aaa"));
        assertEquals(false, binaryDictionary.isValidBigram("bcc", "bbc"));
        assertEquals(false, binaryDictionary.isValidBigram("aaa", "aaa"));

        dictFile.delete();
    }
}