/*
 * Copyright (c) 2013 Menny Even-Danan
 *
 * 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.anysoftkeyboard.dictionaries;

import android.content.Context;
import android.content.SharedPreferences;
import android.text.TextUtils;
import android.util.AttributeSet;
import androidx.annotation.NonNull;
import androidx.collection.ArrayMap;
import com.anysoftkeyboard.addons.AddOn;
import com.anysoftkeyboard.addons.AddOnsFactory;
import com.anysoftkeyboard.base.utils.Logger;
import com.anysoftkeyboard.keyboards.AnyKeyboard;
import com.anysoftkeyboard.keyboards.KeyboardFactory;
import com.anysoftkeyboard.prefs.DirectBootAwareSharedPreferences;
import com.menny.android.anysoftkeyboard.AnyApplication;
import com.menny.android.anysoftkeyboard.BuildConfig;
import com.menny.android.anysoftkeyboard.R;
import io.reactivex.Observable;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import java.util.Map;

public class ExternalDictionaryFactory extends AddOnsFactory<DictionaryAddOnAndBuilder> {

  private static final String PREFS_KEY_POSTFIX_OVERRIDE_DICTIONARY = "_override_dictionary";
  private static final String TAG = "ASKExtDictFactory";
  private static final String XML_LANGUAGE_ATTRIBUTE = "locale";
  private static final String XML_ASSETS_ATTRIBUTE = "dictionaryAssertName";
  private static final String XML_RESOURCE_ATTRIBUTE = "dictionaryResourceId";
  private static final String XML_AUTO_TEXT_RESOURCE_ATTRIBUTE = "autoTextResourceId";
  private static final String XML_INITIAL_SUGGESTIONS_ARRAY_RESOURCE_ATTRIBUTE =
      "initialSuggestions";

  private final Map<String, DictionaryAddOnAndBuilder> mBuildersByLocale = new ArrayMap<>();

  public ExternalDictionaryFactory(Context context) {
    super(
        context,
        DirectBootAwareSharedPreferences.create(context),
        TAG,
        "com.menny.android.anysoftkeyboard.DICTIONARY",
        "com.menny.android.anysoftkeyboard.dictionaries",
        "Dictionaries",
        "Dictionary",
        "dictionary_",
        R.xml.english_dictionaries,
        0,
        true,
        BuildConfig.TESTING_BUILD);
  }

  public static String getDictionaryOverrideKey(AnyKeyboard currentKeyboard) {
    return String.format(
        Locale.US,
        "%s%s%s",
        KeyboardFactory.PREF_ID_PREFIX,
        currentKeyboard.getKeyboardId(),
        PREFS_KEY_POSTFIX_OVERRIDE_DICTIONARY);
  }

  public static boolean isOverrideDictionaryPrefKey(String key) {
    return !TextUtils.isEmpty(key)
        && key.startsWith(KeyboardFactory.PREF_ID_PREFIX)
        && key.endsWith(PREFS_KEY_POSTFIX_OVERRIDE_DICTIONARY);
  }

  @Override
  protected synchronized void clearAddOnList() {
    super.clearAddOnList();
    mBuildersByLocale.clear();
  }

  @Override
  protected void loadAddOns() {
    super.loadAddOns();

    for (DictionaryAddOnAndBuilder addOn : getAllAddOns())
      mBuildersByLocale.put(addOn.getLanguage(), addOn);
  }

  public synchronized DictionaryAddOnAndBuilder getDictionaryBuilderByLocale(String locale) {
    if (mBuildersByLocale.size() == 0) loadAddOns();

    return mBuildersByLocale.get(locale);
  }

  @Override
  protected boolean isAddOnEnabledByDefault(@NonNull String addOnId) {
    return true;
  }

  @Override
  public boolean isAddOnEnabled(String addOnId) {
    return true;
  }

  @Override
  public void setAddOnEnabled(String addOnId, boolean enabled) {
    throw new UnsupportedOperationException("This is not supported for dictionaries.");
  }

  @Override
  protected DictionaryAddOnAndBuilder createConcreteAddOn(
      Context askContext,
      Context context,
      int apiVersion,
      CharSequence prefId,
      CharSequence name,
      CharSequence description,
      boolean isHidden,
      int sortIndex,
      AttributeSet attrs) {
    final String language = attrs.getAttributeValue(null, XML_LANGUAGE_ATTRIBUTE);
    final String assets = attrs.getAttributeValue(null, XML_ASSETS_ATTRIBUTE);
    final int dictionaryResourceId =
        attrs.getAttributeResourceValue(null, XML_RESOURCE_ATTRIBUTE, AddOn.INVALID_RES_ID);
    final int autoTextResId =
        attrs.getAttributeResourceValue(
            null, XML_AUTO_TEXT_RESOURCE_ATTRIBUTE, AddOn.INVALID_RES_ID);
    final int initialSuggestionsId =
        attrs.getAttributeResourceValue(
            null, XML_INITIAL_SUGGESTIONS_ARRAY_RESOURCE_ATTRIBUTE, AddOn.INVALID_RES_ID);
    // asserting
    if ((language == null)
        || ((assets == null) && (dictionaryResourceId == AddOn.INVALID_RES_ID))) {
      Logger.e(
          TAG,
          "External dictionary does not include all mandatory details! Will not create"
              + " dictionary.");
      return null;
    } else {
      final DictionaryAddOnAndBuilder creator;
      if (dictionaryResourceId == AddOn.INVALID_RES_ID)
        creator =
            new DictionaryAddOnAndBuilder(
                askContext,
                context,
                apiVersion,
                prefId,
                name,
                description,
                isHidden,
                sortIndex,
                language,
                assets,
                initialSuggestionsId);
      else
        creator =
            new DictionaryAddOnAndBuilder(
                askContext,
                context,
                apiVersion,
                prefId,
                name,
                description,
                isHidden,
                sortIndex,
                language,
                dictionaryResourceId,
                autoTextResId,
                initialSuggestionsId);

      return creator;
    }
  }

  @NonNull
  public List<DictionaryAddOnAndBuilder> getBuildersForKeyboard(AnyKeyboard keyboard) {
    List<DictionaryAddOnAndBuilder> builders = new ArrayList<>();
    final String dictionaryValue =
        mSharedPreferences.getString(getDictionaryOverrideKey(keyboard), null);

    if (TextUtils.isEmpty(dictionaryValue)) {
      final DictionaryAddOnAndBuilder builderByLocale =
          AnyApplication.getExternalDictionaryFactory(mContext)
              .getDictionaryBuilderByLocale(keyboard.getDefaultDictionaryLocale());
      if (builderByLocale != null) builders.add(builderByLocale);
    } else {
      String[] ids = dictionaryValue.split(":", -1);
      for (String id : ids) {
        final DictionaryAddOnAndBuilder addOnById =
            AnyApplication.getExternalDictionaryFactory(mContext).getAddOnById(id);
        if (addOnById != null) builders.add(addOnById);
      }
    }

    return builders;
  }

  public void setBuildersForKeyboard(
      AnyKeyboard keyboard, List<DictionaryAddOnAndBuilder> buildersForKeyboard) {
    final String mappingSettingsKey = getDictionaryOverrideKey(keyboard);
    SharedPreferences.Editor editor = mSharedPreferences.edit();
    if (buildersForKeyboard.size() == 0) {
      editor.remove(mappingSettingsKey);
    } else {
      StringBuilder stringBuilder = new StringBuilder(buildersForKeyboard.size() * 24);
      for (DictionaryAddOnAndBuilder builder : buildersForKeyboard) {
        if (stringBuilder.length() > 0) stringBuilder.append(':');
        stringBuilder.append(builder.getId());
      }
      editor.putString(mappingSettingsKey, stringBuilder.toString());
    }
    editor.apply();
  }

  @NonNull
  public static Iterable<String> getLocalesFromDictionaryAddOns(@NonNull Context context) {
    return Observable.fromIterable(
            AnyApplication.getExternalDictionaryFactory(context).getAllAddOns())
        .filter(addOn -> !TextUtils.isEmpty(addOn.getLanguage()))
        .map(DictionaryAddOnAndBuilder::getLanguage)
        .distinct() // will not return any previously seen value
        .blockingIterable();
  }
}
