/*
 * 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.annotation.Nullable;
import android.util.KeyValueListParser;
import android.util.Slog;

import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.StringJoiner;

/**
 * TextClassifier specific settings.
 * This is encoded as a key=value list, separated by commas. Ex:
 *
 * <pre>
 * smart_selection_dark_launch              (boolean)
 * smart_selection_enabled_for_edit_text    (boolean)
 * suggest_selection_max_range_length       (int)
 * classify_text_max_range_length           (int)
 * generate_links_max_text_length           (int)
 * entity_list_default                      (String[])
 * entity_list_not_editable                 (String[])
 * entity_list_editable                     (String[])
 * </pre>
 *
 * <p>
 * Type: string
 * see also android.provider.Settings.Global.TEXT_CLASSIFIER_CONSTANTS
 *
 * Example of setting the values for testing.
 * adb shell settings put global text_classifier_constants \
 *      smart_selection_dark_launch=true,smart_selection_enabled_for_edit_text=true,\
 *      entity_list_default=phone:address
 * @hide
 */
public final class TextClassifierConstants {

    private static final String LOG_TAG = "TextClassifierConstants";

    private static final String SMART_SELECTION_DARK_LAUNCH =
            "smart_selection_dark_launch";
    private static final String SMART_SELECTION_ENABLED_FOR_EDIT_TEXT =
            "smart_selection_enabled_for_edit_text";
    private static final String SMART_LINKIFY_ENABLED =
            "smart_linkify_enabled";
    private static final String SUGGEST_SELECTION_MAX_RANGE_LENGTH =
            "suggest_selection_max_range_length";
    private static final String CLASSIFY_TEXT_MAX_RANGE_LENGTH =
            "classify_text_max_range_length";
    private static final String GENERATE_LINKS_MAX_TEXT_LENGTH =
            "generate_links_max_text_length";
    private static final String GENERATE_LINKS_LOG_SAMPLE_RATE =
            "generate_links_log_sample_rate";
    private static final String ENTITY_LIST_DEFAULT =
            "entity_list_default";
    private static final String ENTITY_LIST_NOT_EDITABLE =
            "entity_list_not_editable";
    private static final String ENTITY_LIST_EDITABLE =
            "entity_list_editable";

    private static final boolean SMART_SELECTION_DARK_LAUNCH_DEFAULT = false;
    private static final boolean SMART_SELECTION_ENABLED_FOR_EDIT_TEXT_DEFAULT = true;
    private static final boolean SMART_LINKIFY_ENABLED_DEFAULT = true;
    private static final int SUGGEST_SELECTION_MAX_RANGE_LENGTH_DEFAULT = 10 * 1000;
    private static final int CLASSIFY_TEXT_MAX_RANGE_LENGTH_DEFAULT = 10 * 1000;
    private static final int GENERATE_LINKS_MAX_TEXT_LENGTH_DEFAULT = 100 * 1000;
    private static final int GENERATE_LINKS_LOG_SAMPLE_RATE_DEFAULT = 100;
    private static final String ENTITY_LIST_DELIMITER = ":";
    private static final String ENTITY_LIST_DEFAULT_VALUE = new StringJoiner(ENTITY_LIST_DELIMITER)
            .add(TextClassifier.TYPE_ADDRESS)
            .add(TextClassifier.TYPE_EMAIL)
            .add(TextClassifier.TYPE_PHONE)
            .add(TextClassifier.TYPE_URL)
            .add(TextClassifier.TYPE_DATE)
            .add(TextClassifier.TYPE_DATE_TIME)
            .add(TextClassifier.TYPE_FLIGHT_NUMBER).toString();

    /** Default settings. */
    static final TextClassifierConstants DEFAULT = new TextClassifierConstants();

    private final boolean mDarkLaunch;
    private final boolean mSuggestSelectionEnabledForEditableText;
    private final boolean mSmartLinkifyEnabled;
    private final int mSuggestSelectionMaxRangeLength;
    private final int mClassifyTextMaxRangeLength;
    private final int mGenerateLinksMaxTextLength;
    private final int mGenerateLinksLogSampleRate;
    private final List<String> mEntityListDefault;
    private final List<String> mEntityListNotEditable;
    private final List<String> mEntityListEditable;

    private TextClassifierConstants() {
        mDarkLaunch = SMART_SELECTION_DARK_LAUNCH_DEFAULT;
        mSuggestSelectionEnabledForEditableText = SMART_SELECTION_ENABLED_FOR_EDIT_TEXT_DEFAULT;
        mSmartLinkifyEnabled = SMART_LINKIFY_ENABLED_DEFAULT;
        mSuggestSelectionMaxRangeLength = SUGGEST_SELECTION_MAX_RANGE_LENGTH_DEFAULT;
        mClassifyTextMaxRangeLength = CLASSIFY_TEXT_MAX_RANGE_LENGTH_DEFAULT;
        mGenerateLinksMaxTextLength = GENERATE_LINKS_MAX_TEXT_LENGTH_DEFAULT;
        mGenerateLinksLogSampleRate = GENERATE_LINKS_LOG_SAMPLE_RATE_DEFAULT;
        mEntityListDefault = parseEntityList(ENTITY_LIST_DEFAULT_VALUE);
        mEntityListNotEditable = mEntityListDefault;
        mEntityListEditable = mEntityListDefault;
    }

    private TextClassifierConstants(@Nullable String settings) {
        final KeyValueListParser parser = new KeyValueListParser(',');
        try {
            parser.setString(settings);
        } catch (IllegalArgumentException e) {
            // Failed to parse the settings string, log this and move on with defaults.
            Slog.e(LOG_TAG, "Bad TextClassifier settings: " + settings);
        }
        mDarkLaunch = parser.getBoolean(
                SMART_SELECTION_DARK_LAUNCH,
                SMART_SELECTION_DARK_LAUNCH_DEFAULT);
        mSuggestSelectionEnabledForEditableText = parser.getBoolean(
                SMART_SELECTION_ENABLED_FOR_EDIT_TEXT,
                SMART_SELECTION_ENABLED_FOR_EDIT_TEXT_DEFAULT);
        mSmartLinkifyEnabled = parser.getBoolean(
                SMART_LINKIFY_ENABLED,
                SMART_LINKIFY_ENABLED_DEFAULT);
        mSuggestSelectionMaxRangeLength = parser.getInt(
                SUGGEST_SELECTION_MAX_RANGE_LENGTH,
                SUGGEST_SELECTION_MAX_RANGE_LENGTH_DEFAULT);
        mClassifyTextMaxRangeLength = parser.getInt(
                CLASSIFY_TEXT_MAX_RANGE_LENGTH,
                CLASSIFY_TEXT_MAX_RANGE_LENGTH_DEFAULT);
        mGenerateLinksMaxTextLength = parser.getInt(
                GENERATE_LINKS_MAX_TEXT_LENGTH,
                GENERATE_LINKS_MAX_TEXT_LENGTH_DEFAULT);
        mGenerateLinksLogSampleRate = parser.getInt(
                GENERATE_LINKS_LOG_SAMPLE_RATE,
                GENERATE_LINKS_LOG_SAMPLE_RATE_DEFAULT);
        mEntityListDefault = parseEntityList(parser.getString(
                ENTITY_LIST_DEFAULT,
                ENTITY_LIST_DEFAULT_VALUE));
        mEntityListNotEditable = parseEntityList(parser.getString(
                ENTITY_LIST_NOT_EDITABLE,
                ENTITY_LIST_DEFAULT_VALUE));
        mEntityListEditable = parseEntityList(parser.getString(
                ENTITY_LIST_EDITABLE,
                ENTITY_LIST_DEFAULT_VALUE));
    }

    /** Load from a settings string. */
    public static TextClassifierConstants loadFromString(String settings) {
        return new TextClassifierConstants(settings);
    }

    public boolean isDarkLaunch() {
        return mDarkLaunch;
    }

    public boolean isSuggestSelectionEnabledForEditableText() {
        return mSuggestSelectionEnabledForEditableText;
    }

    public boolean isSmartLinkifyEnabled() {
        return mSmartLinkifyEnabled;
    }

    public int getSuggestSelectionMaxRangeLength() {
        return mSuggestSelectionMaxRangeLength;
    }

    public int getClassifyTextMaxRangeLength() {
        return mClassifyTextMaxRangeLength;
    }

    public int getGenerateLinksMaxTextLength() {
        return mGenerateLinksMaxTextLength;
    }

    public int getGenerateLinksLogSampleRate() {
        return mGenerateLinksLogSampleRate;
    }

    public List<String> getEntityListDefault() {
        return mEntityListDefault;
    }

    public List<String> getEntityListNotEditable() {
        return mEntityListNotEditable;
    }

    public List<String> getEntityListEditable() {
        return mEntityListEditable;
    }

    private static List<String> parseEntityList(String listStr) {
        return Collections.unmodifiableList(Arrays.asList(listStr.split(ENTITY_LIST_DELIMITER)));
    }
}