/*
 * Copyright (C) 2011 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.speech.tts;

import org.xmlpull.v1.XmlPullParserException;

import android.content.Context;
import android.content.Intent;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.content.pm.ResolveInfo;
import android.content.pm.ServiceInfo;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.content.res.XmlResourceParser;

import static android.provider.Settings.Secure.getString;

import android.provider.Settings;
import android.speech.tts.TextToSpeech.Engine;
import android.speech.tts.TextToSpeech.EngineInfo;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.util.Log;
import android.util.Xml;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.MissingResourceException;

Support class for querying the list of available engines
on the device and deciding which one to use etc.
Comments in this class the use the shorthand "system engines" for engines that
are a part of the system image.
This class is thread-safe/
@hide
/**
 * Support class for querying the list of available engines
 * on the device and deciding which one to use etc.
 *
 * Comments in this class the use the shorthand "system engines" for engines that
 * are a part of the system image.
 *
 * This class is thread-safe/
 *
 * @hide
 */
public class TtsEngines {
    private static final String TAG = "TtsEngines";
    private static final boolean DBG = false;

    
Locale delimiter used by the old-style 3 char locale string format (like "eng-usa") /** Locale delimiter used by the old-style 3 char locale string format (like "eng-usa") */
    private static final String LOCALE_DELIMITER_OLD = "-";

    
Locale delimiter used by the new-style locale string format (Locale.toString() results,
like "en_US") /** Locale delimiter used by the new-style locale string format (Locale.toString() results,
     * like "en_US") */
    private static final String LOCALE_DELIMITER_NEW = "_";

    private final Context mContext;

    
Mapping of various language strings to the normalized Locale form /** Mapping of various language strings to the normalized Locale form */
    private static final Map<String, String> sNormalizeLanguage;

    
Mapping of various country strings to the normalized Locale form /** Mapping of various country strings to the normalized Locale form */
    private static final Map<String, String> sNormalizeCountry;

    // Populate the sNormalize* maps
    static {
        HashMap<String, String> normalizeLanguage = new HashMap<String, String>();
        for (String language : Locale.getISOLanguages()) {
            try {
                normalizeLanguage.put(new Locale(language).getISO3Language(), language);
            } catch (MissingResourceException e) {
                continue;
            }
        }
        sNormalizeLanguage = Collections.unmodifiableMap(normalizeLanguage);

        HashMap<String, String> normalizeCountry = new HashMap<String, String>();
        for (String country : Locale.getISOCountries()) {
            try {
                normalizeCountry.put(new Locale("", country).getISO3Country(), country);
            } catch (MissingResourceException e) {
                continue;
            }
        }
        sNormalizeCountry = Collections.unmodifiableMap(normalizeCountry);
    }

    public TtsEngines(Context ctx) {
        mContext = ctx;
    }

    
Returns:
the default TTS engine. If the user has set a default, and the engine is available on the device, the default is returned. Otherwise, the highest ranked engine is returned as per EngineInfoComparator./**
     * @return the default TTS engine. If the user has set a default, and the engine
     *         is available on the device, the default is returned. Otherwise,
     *         the highest ranked engine is returned as per {@link EngineInfoComparator}.
     */
    public String getDefaultEngine() {
        String engine = getString(mContext.getContentResolver(),
                Settings.Secure.TTS_DEFAULT_SYNTH);
        return isEngineInstalled(engine) ? engine : getHighestRankedEngineName();
    }

    
Returns:
the package name of the highest ranked system engine, null if no TTS engines were present in the system image./**
     * @return the package name of the highest ranked system engine, {@code null}
     *         if no TTS engines were present in the system image.
     */
    public String getHighestRankedEngineName() {
        final List<EngineInfo> engines = getEngines();

        if (engines.size() > 0 && engines.get(0).system) {
            return engines.get(0).name;
        }

        return null;
    }

    
Returns the engine info for a given engine name. Note that engines are
identified by their package name.
/**
     * Returns the engine info for a given engine name. Note that engines are
     * identified by their package name.
     */
    public EngineInfo getEngineInfo(String packageName) {
        PackageManager pm = mContext.getPackageManager();
        Intent intent = new Intent(Engine.INTENT_ACTION_TTS_SERVICE);
        intent.setPackage(packageName);
        List<ResolveInfo> resolveInfos = pm.queryIntentServices(intent,
                PackageManager.MATCH_DEFAULT_ONLY);
        // Note that the current API allows only one engine per
        // package name. Since the "engine name" is the same as
        // the package name.
        if (resolveInfos != null && resolveInfos.size() == 1) {
            return getEngineInfo(resolveInfos.get(0), pm);
        }

        return null;
    }

    
Gets a list of all installed TTS engines.
Returns:
A list of engine info objects. The list can be empty, but never null./**
     * Gets a list of all installed TTS engines.
     *
     * @return A list of engine info objects. The list can be empty, but never {@code null}.
     */
    public List<EngineInfo> getEngines() {
        PackageManager pm = mContext.getPackageManager();
        Intent intent = new Intent(Engine.INTENT_ACTION_TTS_SERVICE);
        List<ResolveInfo> resolveInfos =
                pm.queryIntentServices(intent, PackageManager.MATCH_DEFAULT_ONLY);
        if (resolveInfos == null) return Collections.emptyList();

        List<EngineInfo> engines = new ArrayList<EngineInfo>(resolveInfos.size());

        for (ResolveInfo resolveInfo : resolveInfos) {
            EngineInfo engine = getEngineInfo(resolveInfo, pm);
            if (engine != null) {
                engines.add(engine);
            }
        }
        Collections.sort(engines, EngineInfoComparator.INSTANCE);

        return engines;
    }

    private boolean isSystemEngine(ServiceInfo info) {
        final ApplicationInfo appInfo = info.applicationInfo;
        return appInfo != null && (appInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0;
    }

    
Returns:
true if a given engine is installed on the system./**
     * @return true if a given engine is installed on the system.
     */
    public boolean isEngineInstalled(String engine) {
        if (engine == null) {
            return false;
        }

        return getEngineInfo(engine) != null;
    }

    
Returns:
an intent that can launch the settings activity for a given tts engine./**
     * @return an intent that can launch the settings activity for a given tts engine.
     */
    public Intent getSettingsIntent(String engine) {
        PackageManager pm = mContext.getPackageManager();
        Intent intent = new Intent(Engine.INTENT_ACTION_TTS_SERVICE);
        intent.setPackage(engine);
        List<ResolveInfo> resolveInfos = pm.queryIntentServices(intent,
                PackageManager.MATCH_DEFAULT_ONLY | PackageManager.GET_META_DATA);
        // Note that the current API allows only one engine per
        // package name. Since the "engine name" is the same as
        // the package name.
        if (resolveInfos != null && resolveInfos.size() == 1) {
            ServiceInfo service = resolveInfos.get(0).serviceInfo;
            if (service != null) {
                final String settings = settingsActivityFromServiceInfo(service, pm);
                if (settings != null) {
                    Intent i = new Intent();
                    i.setClassName(engine, settings);
                    return i;
                }
            }
        }

        return null;
    }

    
The name of the XML tag that text to speech engines must use to declare their meta data. TextToSpeechEngine.TextToSpeechEngine /**
     * The name of the XML tag that text to speech engines must use to
     * declare their meta data.
     *
     * {@link com.android.internal.R.styleable#TextToSpeechEngine}
     */
    private static final String XML_TAG_NAME = "tts-engine";

    private String settingsActivityFromServiceInfo(ServiceInfo si, PackageManager pm) {
        XmlResourceParser parser = null;
        try {
            parser = si.loadXmlMetaData(pm, TextToSpeech.Engine.SERVICE_META_DATA);
            if (parser == null) {
                Log.w(TAG, "No meta-data found for :" + si);
                return null;
            }

            final Resources res = pm.getResourcesForApplication(si.applicationInfo);

            int type;
            while ((type = parser.next()) != XmlResourceParser.END_DOCUMENT) {
                if (type == XmlResourceParser.START_TAG) {
                    if (!XML_TAG_NAME.equals(parser.getName())) {
                        Log.w(TAG, "Package " + si + " uses unknown tag :"
                                + parser.getName());
                        return null;
                    }

                    final AttributeSet attrs = Xml.asAttributeSet(parser);
                    final TypedArray array = res.obtainAttributes(attrs,
                            com.android.internal.R.styleable.TextToSpeechEngine);
                    final String settings = array.getString(
                            com.android.internal.R.styleable.TextToSpeechEngine_settingsActivity);
                    array.recycle();

                    return settings;
                }
            }

            return null;
        } catch (NameNotFoundException e) {
            Log.w(TAG, "Could not load resources for : " + si);
            return null;
        } catch (XmlPullParserException e) {
            Log.w(TAG, "Error parsing metadata for " + si + ":" + e);
            return null;
        } catch (IOException e) {
            Log.w(TAG, "Error parsing metadata for " + si + ":" + e);
            return null;
        } finally {
            if (parser != null) {
                parser.close();
            }
        }
    }

    private EngineInfo getEngineInfo(ResolveInfo resolve, PackageManager pm) {
        ServiceInfo service = resolve.serviceInfo;
        if (service != null) {
            EngineInfo engine = new EngineInfo();
            // Using just the package name isn't great, since it disallows having
            // multiple engines in the same package, but that's what the existing API does.
            engine.name = service.packageName;
            CharSequence label = service.loadLabel(pm);
            engine.label = TextUtils.isEmpty(label) ? engine.name : label.toString();
            engine.icon = service.getIconResource();
            engine.priority = resolve.priority;
            engine.system = isSystemEngine(service);
            return engine;
        }

        return null;
    }

    private static class EngineInfoComparator implements Comparator<EngineInfo> {
        private EngineInfoComparator() { }

        static EngineInfoComparator INSTANCE = new EngineInfoComparator();

        
Engines that are a part of the system image are always lesser
than those that are not. Within system engines / non system engines
the engines are sorted in order of their declared priority.
/**
         * Engines that are a part of the system image are always lesser
         * than those that are not. Within system engines / non system engines
         * the engines are sorted in order of their declared priority.
         */
        @Override
        public int compare(EngineInfo lhs, EngineInfo rhs) {
            if (lhs.system && !rhs.system) {
                return -1;
            } else if (rhs.system && !lhs.system) {
                return 1;
            } else {
                // Either both system engines, or both non system
                // engines.
                //
                // Note, this isn't a typo. Higher priority numbers imply
                // higher priority, but are "lower" in the sort order.
                return rhs.priority - lhs.priority;
            }
        }
    }

    
Returns the default locale for a given TTS engine. Attempts to read the value from Secure.TTS_DEFAULT_LOCALE, failing which the default phone locale is returned. 
Params:
engineName – the engine to return the locale for.
Returns:
the locale preference for this engine. Will be non null./**
     * Returns the default locale for a given TTS engine. Attempts to read the
     * value from {@link Settings.Secure#TTS_DEFAULT_LOCALE}, failing which the
     * default phone locale is returned.
     *
     * @param engineName the engine to return the locale for.
     * @return the locale preference for this engine. Will be non null.
     */
    public Locale getLocalePrefForEngine(String engineName) {
        return getLocalePrefForEngine(engineName,
                getString(mContext.getContentResolver(), Settings.Secure.TTS_DEFAULT_LOCALE));
    }

    
Returns the default locale for a given TTS engine from given settings string. /**
     * Returns the default locale for a given TTS engine from given settings string. */
    public Locale getLocalePrefForEngine(String engineName, String prefValue) {
        String localeString = parseEnginePrefFromList(
                prefValue,
                engineName);

        if (TextUtils.isEmpty(localeString)) {
            // The new style setting is unset, attempt to return the old style setting.
            return Locale.getDefault();
        }

        Locale result = parseLocaleString(localeString);
        if (result == null) {
            Log.w(TAG, "Failed to parse locale " + localeString + ", returning en_US instead");
            result = Locale.US;
        }

        if (DBG) Log.d(TAG, "getLocalePrefForEngine(" + engineName + ")= " + result);

        return result;
    }


    
True if a given TTS engine uses the default phone locale as a default locale. Attempts to read the value from Secure.TTS_DEFAULT_LOCALE. If its value is empty, this methods returns true. 
Params:
engineName – the engine to return the locale for./**
     * True if a given TTS engine uses the default phone locale as a default locale. Attempts to
     * read the value from {@link Settings.Secure#TTS_DEFAULT_LOCALE}. If
     * its  value is empty, this methods returns true.
     *
     * @param engineName the engine to return the locale for.
     */
    public boolean isLocaleSetToDefaultForEngine(String engineName) {
        return TextUtils.isEmpty(parseEnginePrefFromList(
                    getString(mContext.getContentResolver(), Settings.Secure.TTS_DEFAULT_LOCALE),
                    engineName));
    }

    
Parses a locale encoded as a string, and tries its best to return a valid Locale object, even if the input string is encoded using the old-style 3 character format e.g. "deu-deu". At the end, we test if the resulting locale can return ISO3 language and country codes (Locale.getISO3Language() and Locale.getISO3Country()), if it fails to do so, we return null. /**
     * Parses a locale encoded as a string, and tries its best to return a valid {@link Locale}
     * object, even if the input string is encoded using the old-style 3 character format e.g.
     * "deu-deu". At the end, we test if the resulting locale can return ISO3 language and
     * country codes ({@link Locale#getISO3Language()} and {@link Locale#getISO3Country()}),
     * if it fails to do so, we return null.
     */
    public Locale parseLocaleString(String localeString) {
        String language = "", country = "", variant = "";
        if (!TextUtils.isEmpty(localeString)) {
            String[] split = localeString.split(
                    "[" + LOCALE_DELIMITER_OLD + LOCALE_DELIMITER_NEW + "]");
            language = split[0].toLowerCase();
            if (split.length == 0) {
                Log.w(TAG, "Failed to convert " + localeString + " to a valid Locale object. Only" +
                            " separators");
                return null;
            }
            if (split.length > 3) {
                Log.w(TAG, "Failed to convert " + localeString + " to a valid Locale object. Too" +
                        " many separators");
                return null;
            }
            if (split.length >= 2) {
                country = split[1].toUpperCase();
            }
            if (split.length >= 3) {
                variant = split[2];
            }

        }

        String normalizedLanguage = sNormalizeLanguage.get(language);
        if (normalizedLanguage != null) {
            language = normalizedLanguage;
        }

        String normalizedCountry= sNormalizeCountry.get(country);
        if (normalizedCountry != null) {
            country = normalizedCountry;
        }

        if (DBG) Log.d(TAG, "parseLocalePref(" + language + "," + country +
                "," + variant +")");

        Locale result = new Locale(language, country, variant);
        try {
            result.getISO3Language();
            result.getISO3Country();
            return result;
        } catch(MissingResourceException e) {
            Log.w(TAG, "Failed to convert " + localeString + " to a valid Locale object.");
            return null;
        }
    }

    
This method tries its best to return a valid Locale object from the TTS-specific Locale input (returned by TextToSpeech.getLanguage and TextToSpeech.getDefaultLanguage). A TTS Locale language field contains a three-letter ISO 639-2/T code (where a proper Locale would use a two-letter ISO 639-1 code), and the country field contains a three-letter ISO 3166 country code (where a proper Locale would use a two-letter ISO 3166-1 code). This method tries to convert three-letter language and country codes into their two-letter equivalents. If it fails to do so, it keeps the value from the TTS locale. /**
     * This method tries its best to return a valid {@link Locale} object from the TTS-specific
     * Locale input (returned by {@link TextToSpeech#getLanguage}
     * and {@link TextToSpeech#getDefaultLanguage}). A TTS Locale language field contains
     * a three-letter ISO 639-2/T code (where a proper Locale would use a two-letter ISO 639-1
     * code), and the country field contains a three-letter ISO 3166 country code (where a proper
     * Locale would use a two-letter ISO 3166-1 code).
     *
     * This method tries to convert three-letter language and country codes into their two-letter
     * equivalents. If it fails to do so, it keeps the value from the TTS locale.
     */
    public static Locale normalizeTTSLocale(Locale ttsLocale) {
        String language = ttsLocale.getLanguage();
        if (!TextUtils.isEmpty(language)) {
            String normalizedLanguage = sNormalizeLanguage.get(language);
            if (normalizedLanguage != null) {
                language = normalizedLanguage;
            }
        }

        String country = ttsLocale.getCountry();
        if (!TextUtils.isEmpty(country)) {
            String normalizedCountry= sNormalizeCountry.get(country);
            if (normalizedCountry != null) {
                country = normalizedCountry;
            }
        }
        return new Locale(language, country, ttsLocale.getVariant());
    }

    
Return the old-style string form of the locale. It consists of 3 letter codes:

  
"ISO 639-2/T language code" if the locale has no country entry
  
 "ISO 639-2/T language codeLOCALE_DELIMITERISO 3166 country code" if the locale has no variant entry
  
 "ISO 639-2/T language codeLOCALE_DELIMITERISO 3166 country codeLOCALE_DELIMITERvariant" if the locale has a variant entry
 If we fail to generate those codes using Locale.getISO3Country() and Locale.getISO3Language(), then we return new String[]{"eng","USA",""}; /**
     * Return the old-style string form of the locale. It consists of 3 letter codes:
     * <ul>
     *   <li>"ISO 639-2/T language code" if the locale has no country entry</li>
     *   <li> "ISO 639-2/T language code{@link #LOCALE_DELIMITER}ISO 3166 country code"
     *     if the locale has no variant entry</li>
     *   <li> "ISO 639-2/T language code{@link #LOCALE_DELIMITER}ISO 3166 country
     *     code{@link #LOCALE_DELIMITER}variant" if the locale has a variant entry</li>
     * </ul>
     * If we fail to generate those codes using {@link Locale#getISO3Country()} and
     * {@link Locale#getISO3Language()}, then we return new String[]{"eng","USA",""};
     */
    static public String[] toOldLocaleStringFormat(Locale locale) {
        String[] ret = new String[]{"","",""};
        try {
            // Note that the default locale might have an empty variant
            // or language.
            ret[0] = locale.getISO3Language();
            ret[1] = locale.getISO3Country();
            ret[2] = locale.getVariant();

            return ret;
        } catch (MissingResourceException e) {
            // Default locale does not have a ISO 3166 and/or ISO 639-2/T codes. Return the
            // default "eng-usa" (that would be the result of Locale.getDefault() == Locale.US).
            return new String[]{"eng","USA",""};
        }
    }

    
Parses a comma separated list of engine locale preferences. The list is of the form "engine_name_1:locale_1,engine_name_2:locale2" and so on and so forth. Returns null if the list is empty, malformed or if there is no engine specific preference in the list. /**
     * Parses a comma separated list of engine locale preferences. The list is of the
     * form {@code "engine_name_1:locale_1,engine_name_2:locale2"} and so on and
     * so forth. Returns null if the list is empty, malformed or if there is no engine
     * specific preference in the list.
     */
    private static String parseEnginePrefFromList(String prefValue, String engineName) {
        if (TextUtils.isEmpty(prefValue)) {
            return null;
        }

        String[] prefValues = prefValue.split(",");

        for (String value : prefValues) {
            final int delimiter = value.indexOf(':');
            if (delimiter > 0) {
                if (engineName.equals(value.substring(0, delimiter))) {
                    return value.substring(delimiter + 1);
                }
            }
        }

        return null;
    }

    
Serialize the locale to a string and store it as a default locale for the given engine. If the passed locale is null, an empty string will be serialized; that empty string, when read back, will evaluate to Locale.getDefault(). /**
     * Serialize the locale to a string and store it as a default locale for the given engine. If
     * the passed locale is null, an empty string will be serialized; that empty string, when
     * read back, will evaluate to {@link Locale#getDefault()}.
     */
    public synchronized void updateLocalePrefForEngine(String engineName, Locale newLocale) {
        final String prefList = Settings.Secure.getString(mContext.getContentResolver(),
                Settings.Secure.TTS_DEFAULT_LOCALE);
        if (DBG) {
            Log.d(TAG, "updateLocalePrefForEngine(" + engineName + ", " + newLocale +
                    "), originally: " + prefList);
        }

        final String newPrefList = updateValueInCommaSeparatedList(prefList,
                engineName, (newLocale != null) ? newLocale.toString() : "");

        if (DBG) Log.d(TAG, "updateLocalePrefForEngine(), writing: " + newPrefList.toString());

        Settings.Secure.putString(mContext.getContentResolver(),
                Settings.Secure.TTS_DEFAULT_LOCALE, newPrefList.toString());
    }

    
Updates the value for a given key in a comma separated list of key value pairs,
each of which are delimited by a colon. If no value exists for the given key,
the kay value pair are appended to the end of the list.
/**
     * Updates the value for a given key in a comma separated list of key value pairs,
     * each of which are delimited by a colon. If no value exists for the given key,
     * the kay value pair are appended to the end of the list.
     */
    private String updateValueInCommaSeparatedList(String list, String key,
            String newValue) {
        StringBuilder newPrefList = new StringBuilder();
        if (TextUtils.isEmpty(list)) {
            // If empty, create a new list with a single entry.
            newPrefList.append(key).append(':').append(newValue);
        } else {
            String[] prefValues = list.split(",");
            // Whether this is the first iteration in the loop.
            boolean first = true;
            // Whether we found the given key.
            boolean found = false;
            for (String value : prefValues) {
                final int delimiter = value.indexOf(':');
                if (delimiter > 0) {
                    if (key.equals(value.substring(0, delimiter))) {
                        if (first) {
                            first = false;
                        } else {
                            newPrefList.append(',');
                        }
                        found = true;
                        newPrefList.append(key).append(':').append(newValue);
                    } else {
                        if (first) {
                            first = false;
                        } else {
                            newPrefList.append(',');
                        }
                        // Copy across the entire key + value as is.
                        newPrefList.append(value);
                    }
                }
            }

            if (!found) {
                // Not found, but the rest of the keys would have been copied
                // over already, so just append it to the end.
                newPrefList.append(',');
                newPrefList.append(key).append(':').append(newValue);
            }
        }

        return newPrefList.toString();
    }
}