/*
 * Copyright (C) 2010 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 com.android.camera;

import android.content.ContentResolver;
import android.content.ContentValues;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Point;
import android.location.Location;
import android.net.Uri;
import android.os.Environment;
import android.os.StatFs;
import android.provider.MediaStore.Images.Media;
import android.util.LruCache;

import com.android.camera.data.FilmstripItemData;
import com.android.camera.debug.Log;
import com.android.camera.exif.ExifInterface;
import com.android.camera.util.AndroidContext;
import com.android.camera.util.Size;
import com.google.common.base.Optional;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.OutputStream;
import java.util.HashMap;
import java.util.UUID;

import javax.annotation.Nonnull;

public class Storage {
    public final String DIRECTORY;
    public static final String JPEG_POSTFIX = ".jpg";
    public static final String GIF_POSTFIX = ".gif";
    public static final long UNAVAILABLE = -1L;
    public static final long PREPARING = -2L;
    public static final long UNKNOWN_SIZE = -3L;
    public static final long ACCESS_FAILURE = -4L;
    public static final long LOW_STORAGE_THRESHOLD_BYTES = 50000000;
    public static final String CAMERA_SESSION_SCHEME = "camera_session";
    private static final Log.Tag TAG = new Log.Tag("Storage");
    private static final String GOOGLE_COM = "google.com";
    private HashMap<Uri, Uri> sSessionsToContentUris = new HashMap<>();
    private HashMap<Uri, Uri> sContentUrisToSessions = new HashMap<>();
    private LruCache<Uri, Bitmap> sSessionsToPlaceholderBitmap =
            // 20MB cache as an upper bound for session bitmap storage
            new LruCache<Uri, Bitmap>(20 * 1024 * 1024) {
                @Override
                protected int sizeOf(Uri key, Bitmap value) {
                    return value.getByteCount();
                }
            };
    private HashMap<Uri, Point> sSessionsToSizes = new HashMap<>();
    private HashMap<Uri, Integer> sSessionsToPlaceholderVersions = new HashMap<>();

    private static class Singleton {
        private static final Storage INSTANCE = new Storage(AndroidContext.instance().get());
    }

    public static Storage instance() {
        return Singleton.INSTANCE;
    }

    private Storage(Context context) {
        DIRECTORY = context.getExternalFilesDir(Environment.DIRECTORY_PICTURES).getPath();
    }

    /**
     * Save the image with default JPEG MIME type and add it to the MediaStore.
     *
     * @param resolver The The content resolver to use.
     * @param title The title of the media file.
     * @param date The date for the media file.
     * @param location The location of the media file.
     * @param orientation The orientation of the media file.
     * @param exif The EXIF info. Can be {@code null}.
     * @param jpeg The JPEG data.
     * @param width The width of the media file after the orientation is
     *              applied.
     * @param height The height of the media file after the orientation is
     *               applied.
     */
    public Uri addImage(ContentResolver resolver, String title, long date,
            Location location, int orientation, ExifInterface exif, byte[] jpeg, int width,
            int height) throws IOException {

        return addImage(resolver, title, date, location, orientation, exif, jpeg, width, height,
              FilmstripItemData.MIME_TYPE_JPEG);
    }

    /**
     * Saves the media with a given MIME type and adds it to the MediaStore.
     * <p>
     * The path will be automatically generated according to the title.
     * </p>
     *
     * @param resolver The The content resolver to use.
     * @param title The title of the media file.
     * @param data The data to save.
     * @param date The date for the media file.
     * @param location The location of the media file.
     * @param orientation The orientation of the media file.
     * @param exif The EXIF info. Can be {@code null}.
     * @param width The width of the media file after the orientation is
     *            applied.
     * @param height The height of the media file after the orientation is
     *            applied.
     * @param mimeType The MIME type of the data.
     * @return The URI of the added image, or null if the image could not be
     *         added.
     */
    public Uri addImage(ContentResolver resolver, String title, long date,
            Location location, int orientation, ExifInterface exif, byte[] data, int width,
            int height, String mimeType) throws IOException {

        if (data.length > 0) {
            Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
            return addImageToMediaStore(resolver, title, date, location, orientation, data.length,
                    bitmap, width, height, mimeType, exif);
        }
        return null;
    }

    /**
     * Add the entry for the media file to media store.
     *
     * @param resolver The The content resolver to use.
     * @param title The title of the media file.
     * @param date The date for the media file.
     * @param location The location of the media file.
     * @param orientation The orientation of the media file.
     * @param bitmap The bitmap representation of the media to store.
     * @param width The width of the media file after the orientation is
     *            applied.
     * @param height The height of the media file after the orientation is
     *            applied.
     * @param mimeType The MIME type of the data.
     * @param exif The exif of the image.
     * @return The content URI of the inserted media file or null, if the image
     *         could not be added.
     */
    public Uri addImageToMediaStore(ContentResolver resolver, String title, long date,
            Location location, int orientation, long jpegLength, Bitmap bitmap, int width,
            int height, String mimeType, ExifInterface exif) {
        // Insert into MediaStore.
        ContentValues values = getContentValuesForData(title, date, location, mimeType, true);

        Uri uri = null;
        try {
            uri = resolver.insert(Media.EXTERNAL_CONTENT_URI, values);
            writeBitmap(uri, exif, bitmap, resolver);
        } catch (Throwable th)  {
            // This can happen when the external volume is already mounted, but
            // MediaScanner has not notify MediaProvider to add that volume.
            // The picture is still safe and MediaScanner will find it and
            // insert it into MediaProvider. The only problem is that the user
            // cannot click the thumbnail to review the picture.
            Log.e(TAG, "Failed to write MediaStore" + th);
            if (uri != null) {
                resolver.delete(uri, null, null);
            }
        }
        return uri;
    }

    private void writeBitmap(Uri uri, ExifInterface exif, Bitmap bitmap, ContentResolver resolver)
            throws FileNotFoundException, IOException {
        OutputStream os = resolver.openOutputStream(uri);
        if (exif != null) {
            exif.writeExif(bitmap, os);
        } else {
            bitmap.compress(Bitmap.CompressFormat.JPEG, 90, os);
        }
        os.close();

        ContentValues publishValues = new ContentValues();
        publishValues.put(Media.IS_PENDING, 0);
        resolver.update(uri, publishValues, null, null);
        Log.i(TAG, "Image with uri: " + uri + " was published to the MediaStore");
    }

    // Get a ContentValues object for the given photo data
    public ContentValues getContentValuesForData(String title, long date, Location location,
                                                 String mimeType, boolean isPending) {

        ContentValues values = new ContentValues(11);
        values.put(Media.TITLE, title);
        values.put(Media.DISPLAY_NAME, title + JPEG_POSTFIX);
        values.put(Media.DATE_TAKEN, date);
        values.put(Media.MIME_TYPE, mimeType);

        if (isPending) {
            values.put(Media.IS_PENDING, 1);
        } else {
            values.put(Media.IS_PENDING, 0);
        }

        if (location != null) {
            values.put(Media.LATITUDE, location.getLatitude());
            values.put(Media.LONGITUDE, location.getLongitude());
        }
        return values;
    }

    /**
     * Add a placeholder for a new image that does not exist yet.
     *
     * @param placeholder the placeholder image
     * @return A new URI used to reference this placeholder
     */
    public Uri addPlaceholder(Bitmap placeholder) {
        Uri uri = generateUniquePlaceholderUri();
        replacePlaceholder(uri, placeholder);
        return uri;
    }

    /**
     * Remove a placeholder from in memory storage.
     */
    public void removePlaceholder(Uri uri) {
        sSessionsToSizes.remove(uri);
        sSessionsToPlaceholderBitmap.remove(uri);
        sSessionsToPlaceholderVersions.remove(uri);
    }

    /**
     * Add or replace placeholder for a new image that does not exist yet.
     *
     * @param uri the uri of the placeholder to replace, or null if this is a
     *            new one
     * @param placeholder the placeholder image
     * @return A URI used to reference this placeholder
     */
    public void replacePlaceholder(Uri uri, Bitmap placeholder) {
        Log.v(TAG, "session bitmap cache size: " + sSessionsToPlaceholderBitmap.size());
        Point size = new Point(placeholder.getWidth(), placeholder.getHeight());
        sSessionsToSizes.put(uri, size);
        sSessionsToPlaceholderBitmap.put(uri, placeholder);
        Integer currentVersion = sSessionsToPlaceholderVersions.get(uri);
        sSessionsToPlaceholderVersions.put(uri, currentVersion == null ? 0 : currentVersion + 1);
    }

    /**
     * Creates an empty placeholder.
     *
     * @param size the size of the placeholder in pixels.
     * @return A new URI used to reference this placeholder
     */
    @Nonnull
    public Uri addEmptyPlaceholder(@Nonnull Size size) {
        Uri uri = generateUniquePlaceholderUri();
        sSessionsToSizes.put(uri, new Point(size.getWidth(), size.getHeight()));
        sSessionsToPlaceholderBitmap.remove(uri);
        Integer currentVersion = sSessionsToPlaceholderVersions.get(uri);
        sSessionsToPlaceholderVersions.put(uri, currentVersion == null ? 0 : currentVersion + 1);
        return uri;
    }

    /**
     * Take jpeg bytes and add them to the media store, either replacing an existing item
     * or a placeholder uri to replace
     * @param imageUri The content uri or session uri of the image being updated
     * @param resolver The content resolver to use
     * @param title of the image
     * @param date of the image
     * @param location of the image
     * @param orientation of the image
     * @param exif of the image
     * @param jpeg bytes of the image
     * @param width of the image
     * @param height of the image
     * @param mimeType of the image
     * @return The content uri of the newly inserted or replaced item.
     */
    public Uri updateImage(Uri imageUri, ContentResolver resolver, String title, long date,
           Location location, int orientation, ExifInterface exif,
           byte[] jpeg, int width, int height, String mimeType) throws IOException {
        Bitmap bitmap = BitmapFactory.decodeByteArray(jpeg, 0, jpeg.length);
        return updateImage(imageUri, resolver, title, date, location, orientation, jpeg.length,
                bitmap, width, height, mimeType, exif);
    }

    private Uri generateUniquePlaceholderUri() {
        Uri.Builder builder = new Uri.Builder();
        String uuid = UUID.randomUUID().toString();
        builder.scheme(CAMERA_SESSION_SCHEME).authority(GOOGLE_COM).appendPath(uuid);
        return builder.build();
    }

    /**
     * Renames a file.
     *
     * <p/>
     * Can only be used for regular files, not directories.
     *
     * @param inputPath the original path of the file
     * @param newFilePath the new path of the file
     * @return false if rename was not successful
     */
    public boolean renameFile(File inputPath, File newFilePath) {
        if (newFilePath.exists()) {
            Log.e(TAG, "File path already exists: " + newFilePath.getAbsolutePath());
            return false;
        }
        if (inputPath.isDirectory()) {
            Log.e(TAG, "Input path is directory: " + inputPath.getAbsolutePath());
            return false;
        }
        if (!createDirectoryIfNeeded(newFilePath.getAbsolutePath())) {
            Log.e(TAG, "Failed to create parent directory for file: " +
                    newFilePath.getAbsolutePath());
            return false;
        }
        return inputPath.renameTo(newFilePath);
    }

    /**
     * Given a file path, makes sure the directory it's in exists, and if not
     * that it is created.
     *
     * @param filePath the absolute path of a file, e.g. '/foo/bar/file.jpg'.
     * @return Whether the directory exists. If 'false' is returned, this file
     *         cannot be written to since the parent directory could not be
     *         created.
     */
    private boolean createDirectoryIfNeeded(String filePath) {
        File parentFile = new File(filePath).getParentFile();

        // If the parent exists, return 'true' if it is a directory. If it's a
        // file, return 'false'.
        if (parentFile.exists()) {
            return parentFile.isDirectory();
        }

        // If the parent does not exists, attempt to create it and return
        // whether creating it succeeded.
        return parentFile.mkdirs();
    }

    /** Updates the image values in MediaStore. */
    private Uri updateImage(Uri imageUri, ContentResolver resolver, String title,
            long date, Location location, int orientation, int jpegLength,
            Bitmap bitmap, int width, int height, String mimeType, ExifInterface exif) {

        Uri resultUri = imageUri;
        if (isSessionUri(imageUri)) {
            // If this is a session uri, then we need to add the image
            resultUri = addImageToMediaStore(resolver, title, date, location, orientation,
                    jpegLength, bitmap, width, height, mimeType, exif);
            sSessionsToContentUris.put(imageUri, resultUri);
            sContentUrisToSessions.put(resultUri, imageUri);
        } else {
            // Update the MediaStore
            ContentValues values = getContentValuesForData(title, date, location, mimeType, false);
            resolver.update(imageUri, values, null, null);
            Log.i(TAG, "Image with uri: " + imageUri + " was updated in the MediaStore");
        }
        return resultUri;
    }

    private String generateFilepath(String title, String mimeType) {
        return generateFilepath(DIRECTORY, title, mimeType);
    }

    public String generateFilepath(String directory, String title, String mimeType) {
        String extension = null;
        if (FilmstripItemData.MIME_TYPE_JPEG.equals(mimeType)) {
            extension = JPEG_POSTFIX;
        } else if (FilmstripItemData.MIME_TYPE_GIF.equals(mimeType)) {
            extension = GIF_POSTFIX;
        } else {
            throw new IllegalArgumentException("Invalid mimeType: " + mimeType);
        }
        return (new File(directory, title + extension)).getAbsolutePath();
    }

    /**
     * Returns the jpeg bytes for a placeholder session
     *
     * @param uri the session uri to look up
     * @return The bitmap or null
     */
    public Optional<Bitmap> getPlaceholderForSession(Uri uri) {
        return Optional.fromNullable(sSessionsToPlaceholderBitmap.get(uri));
    }

    /**
     * @return Whether a placeholder size for the session with the given URI
     *         exists.
     */
    public boolean containsPlaceholderSize(Uri uri) {
        return sSessionsToSizes.containsKey(uri);
    }

    /**
     * Returns the dimensions of the placeholder image
     *
     * @param uri the session uri to look up
     * @return The size
     */
    public Point getSizeForSession(Uri uri) {
        return sSessionsToSizes.get(uri);
    }

    /**
     * Takes a session URI and returns the finished image's content URI
     *
     * @param uri the uri of the session that was replaced
     * @return The uri of the new media item, if it exists, or null.
     */
    public Uri getContentUriForSessionUri(Uri uri) {
        return sSessionsToContentUris.get(uri);
    }

    /**
     * Takes a content URI and returns the original Session Uri if any
     *
     * @param contentUri the uri of the media store content
     * @return The session uri of the original session, if it exists, or null.
     */
    public Uri getSessionUriFromContentUri(Uri contentUri) {
        return sContentUrisToSessions.get(contentUri);
    }

    /**
     * Determines if a URI points to a camera session
     *
     * @param uri the uri to check
     * @return true if it is a session uri.
     */
    public boolean isSessionUri(Uri uri) {
        return uri.getScheme().equals(CAMERA_SESSION_SCHEME);
    }

    public long getAvailableSpace() {
        String state = Environment.getExternalStorageState();
        Log.d(TAG, "External storage state=" + state);
        if (Environment.MEDIA_CHECKING.equals(state)) {
            return PREPARING;
        }
        if (!Environment.MEDIA_MOUNTED.equals(state)) {
            return UNAVAILABLE;
        }

        File dir = new File(DIRECTORY);
        dir.mkdirs();
        if (!dir.isDirectory() || !dir.canWrite()) {
            Log.d(TAG, DIRECTORY + " mounted, but isn't directory or cannot write");
            return UNAVAILABLE;
        }

        try {
            StatFs stat = new StatFs(DIRECTORY);
            return stat.getAvailableBlocks() * (long) stat.getBlockSize();
        } catch (Exception e) {
            Log.i(TAG, "Fail to access external storage", e);
        }
        return UNKNOWN_SIZE;
    }

    /**
     * OSX requires plugged-in USB storage to have path /DCIM/NNNAAAAA to be
     * imported. This is a temporary fix for bug#1655552.
     */
    public void ensureOSXCompatible() {
        File nnnAAAAA = new File(DIRECTORY, "100ANDRO");
        if (!(nnnAAAAA.exists() || nnnAAAAA.mkdirs())) {
            Log.e(TAG, "Failed to create " + nnnAAAAA.getPath());
        }
    }

}