package cn.finalteam.rxgalleryfinal.utils;

import android.annotation.SuppressLint;
import android.content.Context;
import android.content.pm.PackageManager;
import android.os.Environment;

import java.io.File;
import java.io.IOException;

import static android.os.Environment.MEDIA_MOUNTED;

/**
 * Provides application storage paths
 *
 * @author Sergey Tarasevich (nostra13[at]gmail[dot]com)
 * @since 1.0.0
 */
public final class StorageUtils {

    private static final String EXTERNAL_STORAGE_PERMISSION = "android.permission.WRITE_EXTERNAL_STORAGE";
    private static final String INDIVIDUAL_DIR_NAME = "rxgalleryfinal";

    private StorageUtils() {
    }

    /**
     * Returns application cache directory. Cache directory will be created on SD card
     * <i>("/Android/data/[app_package_name]/cache")</i> if card is mounted and app has appropriate permission. Else -
     * Android defines cache directory on device's file system.
     *
     * @param context Application context
     * @return Cache {@link File directory}.<br />
     * <b>NOTE:</b> Can be null in some unpredictable cases (if SD card is unmounted and
     * {@link android.content.Context#getCacheDir() Context.getCacheDir()} returns null).
     */
    public static File getCacheDirectory(Context context) {
        return getCacheDirectory(context, true);
    }

    /**
     * Returns application cache directory. Cache directory will be created on SD card
     * <i>("/Android/data/[app_package_name]/cache")</i> (if card is mounted and app has appropriate permission) or
     * on device's file system depending incoming parameters.
     *
     * @param context        Application context
     * @param preferExternal Whether prefer external location for cache
     * @return Cache {@link File directory}.<br />
     * <b>NOTE:</b> Can be null in some unpredictable cases (if SD card is unmounted and
     * {@link android.content.Context#getCacheDir() Context.getCacheDir()} returns null).
     */
    public static File getCacheDirectory(Context context, boolean preferExternal) {
        File appCacheDir = null;

        if (preferExternal && existSDcard() && hasExternalStoragePermission(context)) {
            appCacheDir = getExternalCacheDir(context);
        }
        if (appCacheDir == null) {
            appCacheDir = context.getCacheDir();
        }
        if (appCacheDir == null) {
            @SuppressLint("SdCardPath") String cacheDirPath = "/data/data/" + context.getPackageName() + "/cache/";
            Logger.w(String.format("Can't define system cache directory! '%s' will be used.", cacheDirPath));
            appCacheDir = new File(cacheDirPath);
        }
        return appCacheDir;
    }

    public static boolean existSDcard() {
        String externalStorageState;
        try {
            externalStorageState = Environment.getExternalStorageState();
        } catch (NullPointerException e) { // (sh)it happens (Issue #660)
            externalStorageState = "";
        }
        return MEDIA_MOUNTED.equals(externalStorageState);
    }

    /**
     * Returns individual application cache directory (for only image caching from ImageLoader). Cache directory will be
     * created on SD card <i>("/Android/data/[app_package_name]/cache/uil-images")</i> if card is mounted and app has
     * appropriate permission. Else - Android defines cache directory on device's file system.
     *
     * @param context Application context
     * @return Cache {@link File directory}
     */
    public static File getIndividualCacheDirectory(Context context) {
        return getIndividualCacheDirectory(context, INDIVIDUAL_DIR_NAME);
    }

    /**
     * Returns individual application cache directory (for only image caching from ImageLoader). Cache directory will be
     * created on SD card <i>("/Android/data/[app_package_name]/cache/uil-images")</i> if card is mounted and app has
     * appropriate permission. Else - Android defines cache directory on device's file system.
     *
     * @param context  Application context
     * @param cacheDir Cache directory path (e.g.: "AppCacheDir", "AppDir/cache/images")
     * @return Cache {@link File directory}
     */
    public static File getIndividualCacheDirectory(Context context, String cacheDir) {
        File appCacheDir = getCacheDirectory(context);
        File individualCacheDir = new File(appCacheDir, cacheDir);
        if (!individualCacheDir.exists()) {
            if (!individualCacheDir.mkdir()) {
                individualCacheDir = appCacheDir;
            }
        }
        return individualCacheDir;
    }

    /**
     * Returns specified application cache directory. Cache directory will be created on SD card by defined path if card
     * is mounted and app has appropriate permission. Else - Android defines cache directory on device's file system.
     *
     * @param context  Application context
     * @param cacheDir Cache directory path (e.g.: "AppCacheDir", "AppDir/cache/images")
     * @return Cache {@link File directory}
     */
    public static File getOwnCacheDirectory(Context context, String cacheDir) {
        File appCacheDir = null;
        if (MEDIA_MOUNTED.equals(Environment.getExternalStorageState()) && hasExternalStoragePermission(context)) {
            appCacheDir = new File(Environment.getExternalStorageDirectory(), cacheDir);
        }
        if (appCacheDir == null || (!appCacheDir.exists() && !appCacheDir.mkdirs())) {
            appCacheDir = context.getCacheDir();
        }
        return appCacheDir;
    }

    /**
     * Returns specified application cache directory. Cache directory will be created on SD card by defined path if card
     * is mounted and app has appropriate permission. Else - Android defines cache directory on device's file system.
     *
     * @param context  Application context
     * @param cacheDir Cache directory path (e.g.: "AppCacheDir", "AppDir/cache/images")
     * @return Cache {@link File directory}
     */
    public static File getOwnCacheDirectory(Context context, String cacheDir, boolean preferExternal) {
        File appCacheDir = null;
        if (preferExternal && MEDIA_MOUNTED.equals(Environment.getExternalStorageState()) && hasExternalStoragePermission(context)) {
            appCacheDir = new File(Environment.getExternalStorageDirectory(), cacheDir);
        }
        if (appCacheDir == null || (!appCacheDir.exists() && !appCacheDir.mkdirs())) {
            appCacheDir = context.getCacheDir();
        }
        return appCacheDir;
    }

    private static File getExternalCacheDir(Context context) {
        File dataDir = new File(new File(Environment.getExternalStorageDirectory(), "Android"), "data");
        File appCacheDir = new File(new File(dataDir, context.getPackageName()), "cache");
        if (!appCacheDir.exists()) {
            if (!appCacheDir.mkdirs()) {
                Logger.w("Unable to create external cache directory");
                return null;
            }
            try {
                new File(appCacheDir, ".nomedia").createNewFile();
            } catch (IOException e) {
                Logger.i("Can't create \".nomedia\" file in application external cache directory");
            }
        }
        return appCacheDir;
    }

    private static boolean hasExternalStoragePermission(Context context) {
        int perm = context.checkCallingOrSelfPermission(EXTERNAL_STORAGE_PERMISSION);
        return perm == PackageManager.PERMISSION_GRANTED;
    }
}