1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.inputmethod.latin.makedict;
18
19import com.android.inputmethod.latin.makedict.FormatSpec.DictionaryOptions;
20import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions;
21
22import javax.annotation.Nonnull;
23import javax.annotation.Nullable;
24
25/**
26 * Class representing dictionary header.
27 */
28public final class DictionaryHeader {
29    public final int mBodyOffset;
30    @Nonnull
31    public final DictionaryOptions mDictionaryOptions;
32    @Nonnull
33    public final FormatOptions mFormatOptions;
34    @Nonnull
35    public final String mLocaleString;
36    @Nonnull
37    public final String mVersionString;
38    @Nonnull
39    public final String mIdString;
40
41    // Note that these are corresponding definitions in native code in latinime::HeaderPolicy
42    // and latinime::HeaderReadWriteUtils.
43    // TODO: Standardize the key names and bump up the format version, taking care not to
44    // break format version 2 dictionaries.
45    public static final String DICTIONARY_VERSION_KEY = "version";
46    public static final String DICTIONARY_LOCALE_KEY = "locale";
47    public static final String DICTIONARY_ID_KEY = "dictionary";
48    public static final String DICTIONARY_DESCRIPTION_KEY = "description";
49    public static final String DICTIONARY_DATE_KEY = "date";
50    public static final String HAS_HISTORICAL_INFO_KEY = "HAS_HISTORICAL_INFO";
51    public static final String USES_FORGETTING_CURVE_KEY = "USES_FORGETTING_CURVE";
52    public static final String FORGETTING_CURVE_PROBABILITY_VALUES_TABLE_ID_KEY =
53            "FORGETTING_CURVE_PROBABILITY_VALUES_TABLE_ID";
54    public static final String MAX_UNIGRAM_COUNT_KEY = "MAX_UNIGRAM_ENTRY_COUNT";
55    public static final String MAX_BIGRAM_COUNT_KEY = "MAX_BIGRAM_ENTRY_COUNT";
56    public static final String MAX_TRIGRAM_COUNT_KEY = "MAX_TRIGRAM_ENTRY_COUNT";
57    public static final String ATTRIBUTE_VALUE_TRUE = "1";
58    public static final String CODE_POINT_TABLE_KEY = "codePointTable";
59
60    public DictionaryHeader(final int headerSize,
61            @Nonnull final DictionaryOptions dictionaryOptions,
62            @Nonnull final FormatOptions formatOptions) throws UnsupportedFormatException {
63        mDictionaryOptions = dictionaryOptions;
64        mFormatOptions = formatOptions;
65        mBodyOffset = formatOptions.mVersion < FormatSpec.VERSION4 ? headerSize : 0;
66        final String localeString = dictionaryOptions.mAttributes.get(DICTIONARY_LOCALE_KEY);
67        if (null == localeString) {
68            throw new UnsupportedFormatException("Cannot create a FileHeader without a locale");
69        }
70        final String versionString = dictionaryOptions.mAttributes.get(DICTIONARY_VERSION_KEY);
71        if (null == versionString) {
72            throw new UnsupportedFormatException(
73                    "Cannot create a FileHeader without a version");
74        }
75        final String idString = dictionaryOptions.mAttributes.get(DICTIONARY_ID_KEY);
76        if (null == idString) {
77            throw new UnsupportedFormatException("Cannot create a FileHeader without an ID");
78        }
79        mLocaleString = localeString;
80        mVersionString = versionString;
81        mIdString = idString;
82    }
83
84    // Helper method to get the description
85    @Nullable
86    public String getDescription() {
87        // TODO: Right now each dictionary file comes with a description in its own language.
88        // It will display as is no matter the device's locale. It should be internationalized.
89        return mDictionaryOptions.mAttributes.get(DICTIONARY_DESCRIPTION_KEY);
90    }
91}