package de.thedevstack.conversationsplus;

import android.app.Application;
import android.content.Context;
import android.content.pm.PackageManager;
import android.preference.PreferenceManager;

import java.io.File;

import de.thedevstack.conversationsplus.persistance.FileBackend;
import de.thedevstack.conversationsplus.utils.ImageUtil;
import de.thedevstack.conversationsplus.utils.SerialSingleThreadExecutor;

/**
 * This class is used to provide static access to the applicationcontext.
 */
public class ConversationsPlusApplication extends Application {
    /**
     * Application instance for static access
     */
    private static ConversationsPlusApplication instance;

    private final SerialSingleThreadExecutor mFileAddingExecutor = new SerialSingleThreadExecutor();
    private final SerialSingleThreadExecutor mDatabaseExecutor = new SerialSingleThreadExecutor();

    /**
     * Initializes the application and saves its instance.
     */
    public void onCreate(){
        super.onCreate();
        ConversationsPlusApplication.instance = this;
        ConversationsPlusPreferences.init(PreferenceManager.getDefaultSharedPreferences(getAppContext()));
        ImageUtil.initBitmapCache();
        FileBackend.init();
    }

    /**
     * Returns the instance of the application
     * @return this application instance
     */
    public static ConversationsPlusApplication getInstance() {
        return ConversationsPlusApplication.instance;
    }

    public static void executeFileAdding(Runnable r) {
        getInstance().mFileAddingExecutor.execute(r);
    }

    public static void executeDatabaseOperation(Runnable r) {
        getInstance().mDatabaseExecutor.execute(r);
    }

    /**
     * Returns the application's context.
     * @return Context the application's context
     */
    public static Context getAppContext() {
        return ConversationsPlusApplication.instance.getApplicationContext();
    }

    /**
     * Returns the application's private data directory.
     * @return File the application's private data dir
     */
    public static File getPrivateFilesDir() {
        return ConversationsPlusApplication.instance.getFilesDir();
    }

    /**
     * Returns the version of the application.
     * @see android.content.pm.PackageInfo#versionName
     * @return a string representation of the version stored in packageInfo
     */
    public static String getVersion() {
        final String packageName = ConversationsPlusApplication.getAppContext().getPackageName();
        if (packageName != null) {
            try {
                return ConversationsPlusApplication.getAppContext().getPackageManager().getPackageInfo(packageName, 0).versionName;
            } catch (final PackageManager.NameNotFoundException e) {
                return "unknown";
            }
        } else {
            return "unknown";
        }
    }

    /**
     * Returns the application's name.
     * @return the name as it is defined in R.string.app_name
     */
    public static String getName() {
        return ConversationsPlusApplication.getAppContext().getString(R.string.app_name);
    }

    /**
     * Returns the name and the version of this application.
     * @see #getName() and #getVersion
     * @return a concatination of name and version with a whitespace in between
     */
    public static String getNameAndVersion() {
        return getName() + " " + getVersion();
    }
}