/**
 *   ownCloud Android client application
 *
 *   @author Bartek Przybylski
 *   @author David A. Velasco
 *   Copyright (C) 2011  Bartek Przybylski
 *   Copyright (C) 2015 ownCloud Inc.
 *
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License version 2,
 *   as published by the Free Software Foundation.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

package com.owncloud.android.providers;

import java.io.File;
import java.util.ArrayList;
import java.util.HashMap;

import com.owncloud.android.MainApp;
import com.owncloud.android.R;
import com.owncloud.android.datamodel.OCFile;
import com.owncloud.android.db.ProviderMeta;
import com.owncloud.android.db.ProviderMeta.ProviderTableMeta;
import com.owncloud.android.lib.common.accounts.AccountUtils;
import com.owncloud.android.lib.common.utils.Log_OC;
import com.owncloud.android.lib.resources.shares.ShareType;
import com.owncloud.android.utils.FileStorageUtils;

import android.accounts.Account;
import android.accounts.AccountManager;
import android.content.ContentProvider;
import android.content.ContentProviderOperation;
import android.content.ContentProviderResult;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.Context;
import android.content.OperationApplicationException;
import android.content.UriMatcher;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteQueryBuilder;
import android.net.Uri;
import android.text.TextUtils;

/**
 * The ContentProvider for the ownCloud App.
 */
public class FileContentProvider extends ContentProvider {

    private DataBaseHelper mDbHelper;

    // Projection for filelist table
    private static HashMap<String, String> mFileProjectionMap;
    static {
        mFileProjectionMap = new HashMap<String, String>();
        mFileProjectionMap.put(ProviderTableMeta._ID, ProviderTableMeta._ID);
        mFileProjectionMap.put(ProviderTableMeta.FILE_PARENT,
                ProviderTableMeta.FILE_PARENT);
        mFileProjectionMap.put(ProviderTableMeta.FILE_PATH,
                ProviderTableMeta.FILE_PATH);
        mFileProjectionMap.put(ProviderTableMeta.FILE_NAME,
                ProviderTableMeta.FILE_NAME);
        mFileProjectionMap.put(ProviderTableMeta.FILE_CREATION,
                ProviderTableMeta.FILE_CREATION);
        mFileProjectionMap.put(ProviderTableMeta.FILE_MODIFIED,
                ProviderTableMeta.FILE_MODIFIED);
        mFileProjectionMap.put(ProviderTableMeta.FILE_MODIFIED_AT_LAST_SYNC_FOR_DATA,
                ProviderTableMeta.FILE_MODIFIED_AT_LAST_SYNC_FOR_DATA);
        mFileProjectionMap.put(ProviderTableMeta.FILE_CONTENT_LENGTH,
                ProviderTableMeta.FILE_CONTENT_LENGTH);
        mFileProjectionMap.put(ProviderTableMeta.FILE_CONTENT_TYPE,
                ProviderTableMeta.FILE_CONTENT_TYPE);
        mFileProjectionMap.put(ProviderTableMeta.FILE_STORAGE_PATH,
                ProviderTableMeta.FILE_STORAGE_PATH);
        mFileProjectionMap.put(ProviderTableMeta.FILE_LAST_SYNC_DATE,
                ProviderTableMeta.FILE_LAST_SYNC_DATE);
        mFileProjectionMap.put(ProviderTableMeta.FILE_LAST_SYNC_DATE_FOR_DATA,
                ProviderTableMeta.FILE_LAST_SYNC_DATE_FOR_DATA);
        mFileProjectionMap.put(ProviderTableMeta.FILE_KEEP_IN_SYNC,
                ProviderTableMeta.FILE_KEEP_IN_SYNC);
        mFileProjectionMap.put(ProviderTableMeta.FILE_ACCOUNT_OWNER,
                ProviderTableMeta.FILE_ACCOUNT_OWNER);
        mFileProjectionMap.put(ProviderTableMeta.FILE_ETAG,
                ProviderTableMeta.FILE_ETAG);
        mFileProjectionMap.put(ProviderTableMeta.FILE_SHARED_VIA_LINK,
                ProviderTableMeta.FILE_SHARED_VIA_LINK);
        mFileProjectionMap.put(ProviderTableMeta.FILE_SHARED_WITH_SHAREE,
                ProviderTableMeta.FILE_SHARED_WITH_SHAREE);
        mFileProjectionMap.put(ProviderTableMeta.FILE_PUBLIC_LINK,
                ProviderTableMeta.FILE_PUBLIC_LINK);
        mFileProjectionMap.put(ProviderTableMeta.FILE_PERMISSIONS,
                ProviderTableMeta.FILE_PERMISSIONS);
        mFileProjectionMap.put(ProviderTableMeta.FILE_REMOTE_ID,
                ProviderTableMeta.FILE_REMOTE_ID);
        mFileProjectionMap.put(ProviderTableMeta.FILE_UPDATE_THUMBNAIL,
                ProviderTableMeta.FILE_UPDATE_THUMBNAIL);
        mFileProjectionMap.put(ProviderTableMeta.FILE_IS_DOWNLOADING,
                ProviderTableMeta.FILE_IS_DOWNLOADING);
        mFileProjectionMap.put(ProviderTableMeta.FILE_ETAG_IN_CONFLICT,
                ProviderTableMeta.FILE_ETAG_IN_CONFLICT);
    }

    private static final int SINGLE_FILE = 1;
    private static final int DIRECTORY = 2;
    private static final int ROOT_DIRECTORY = 3;
    private static final int SHARES = 4;

    private static final String TAG = FileContentProvider.class.getSimpleName();

    // Projection for ocshares table
    private static HashMap<String, String> mOCSharesProjectionMap;
    static {
        mOCSharesProjectionMap = new HashMap<String, String>();
        mOCSharesProjectionMap.put(ProviderTableMeta._ID, ProviderTableMeta._ID);
        mOCSharesProjectionMap.put(ProviderTableMeta.OCSHARES_FILE_SOURCE,
                ProviderTableMeta.OCSHARES_FILE_SOURCE);
        mOCSharesProjectionMap.put(ProviderTableMeta.OCSHARES_ITEM_SOURCE,
                ProviderTableMeta.OCSHARES_ITEM_SOURCE);
        mOCSharesProjectionMap.put(ProviderTableMeta.OCSHARES_SHARE_TYPE,
                ProviderTableMeta.OCSHARES_SHARE_TYPE);
        mOCSharesProjectionMap.put(ProviderTableMeta.OCSHARES_SHARE_WITH,
                ProviderTableMeta.OCSHARES_SHARE_WITH);
        mOCSharesProjectionMap.put(ProviderTableMeta.OCSHARES_PATH,
                ProviderTableMeta.OCSHARES_PATH);
        mOCSharesProjectionMap.put(ProviderTableMeta.OCSHARES_PERMISSIONS,
                ProviderTableMeta.OCSHARES_PERMISSIONS);
        mOCSharesProjectionMap.put(ProviderTableMeta.OCSHARES_SHARED_DATE,
                ProviderTableMeta.OCSHARES_SHARED_DATE);
        mOCSharesProjectionMap.put(ProviderTableMeta.OCSHARES_EXPIRATION_DATE,
                ProviderTableMeta.OCSHARES_EXPIRATION_DATE);
        mOCSharesProjectionMap.put(ProviderTableMeta.OCSHARES_TOKEN,
                ProviderTableMeta.OCSHARES_TOKEN);
        mOCSharesProjectionMap.put(ProviderTableMeta.OCSHARES_SHARE_WITH_DISPLAY_NAME,
                ProviderTableMeta.OCSHARES_SHARE_WITH_DISPLAY_NAME);
        mOCSharesProjectionMap.put(ProviderTableMeta.OCSHARES_IS_DIRECTORY,
                ProviderTableMeta.OCSHARES_IS_DIRECTORY);
        mOCSharesProjectionMap.put(ProviderTableMeta.OCSHARES_USER_ID,
                ProviderTableMeta.OCSHARES_USER_ID);
        mOCSharesProjectionMap.put(ProviderTableMeta.OCSHARES_ID_REMOTE_SHARED,
                ProviderTableMeta.OCSHARES_ID_REMOTE_SHARED);
        mOCSharesProjectionMap.put(ProviderTableMeta.OCSHARES_ACCOUNT_OWNER,
                ProviderTableMeta.OCSHARES_ACCOUNT_OWNER);
    }

    private UriMatcher mUriMatcher;

    @Override
    public int delete(Uri uri, String where, String[] whereArgs) {
        //Log_OC.d(TAG, "Deleting " + uri + " at provider " + this);
        int count = 0;
        SQLiteDatabase db = mDbHelper.getWritableDatabase();
        db.beginTransaction();
        try {
            count = delete(db, uri, where, whereArgs);
            db.setTransactionSuccessful();
        } finally {
            db.endTransaction();
        }
        getContext().getContentResolver().notifyChange(uri, null);
        return count;
    }

    private int delete(SQLiteDatabase db, Uri uri, String where, String[] whereArgs) {
        int count = 0;
        switch (mUriMatcher.match(uri)) {
        case SINGLE_FILE:
            Cursor c = query(db, uri, null, where, whereArgs, null);
            String remoteId = "";
            if (c != null && c.moveToFirst()) {
                remoteId = c.getString(c.getColumnIndex(ProviderTableMeta.FILE_REMOTE_ID));
                //ThumbnailsCacheManager.removeFileFromCache(remoteId);
                c.close();
            }
            Log_OC.d(TAG, "Removing FILE " + remoteId);

            count = db.delete(ProviderTableMeta.FILE_TABLE_NAME,
                    ProviderTableMeta._ID
                            + "="
                            + uri.getPathSegments().get(1)
                            + (!TextUtils.isEmpty(where) ? " AND (" + where
                                    + ")" : ""), whereArgs);
            break;
        case DIRECTORY:
            // deletion of folder is recursive
            /*
            Uri folderUri = ContentUris.withAppendedId(ProviderTableMeta.CONTENT_URI_FILE, Long.parseLong(uri.getPathSegments().get(1)));
            Cursor folder = query(db, folderUri, null, null, null, null);
            String folderName = "(unknown)";
            if (folder != null && folder.moveToFirst()) {
                folderName = folder.getString(folder.getColumnIndex(ProviderTableMeta.FILE_PATH));
            }
            */
            Cursor children = query(uri, null, null, null, null);
            if (children != null && children.moveToFirst())  {
                long childId;
                boolean isDir;
                while (!children.isAfterLast()) {
                    childId = children.getLong(children.getColumnIndex(ProviderTableMeta._ID));
                    isDir = "DIR".equals(children.getString(
                            children.getColumnIndex(ProviderTableMeta.FILE_CONTENT_TYPE)
                    ));
                    //remotePath = children.getString(children.getColumnIndex(ProviderTableMeta.FILE_PATH));
                    if (isDir) {
                        count += delete(
                            db,
                            ContentUris.withAppendedId(ProviderTableMeta.CONTENT_URI_DIR, childId),
                            null,
                            null
                        );
                    } else {
                        count += delete(
                            db,
                            ContentUris.withAppendedId(ProviderTableMeta.CONTENT_URI_FILE, childId),
                            null,
                            null
                        );
                    }
                    children.moveToNext();
                }
                children.close();
            } /*else {
                Log_OC.d(TAG, "No child to remove in DIRECTORY " + folderName);
            }
            Log_OC.d(TAG, "Removing DIRECTORY " + folderName + " (or maybe not) ");
            */
            count += db.delete(ProviderTableMeta.FILE_TABLE_NAME,
                    ProviderTableMeta._ID
                    + "="
                    + uri.getPathSegments().get(1)
                    + (!TextUtils.isEmpty(where) ? " AND (" + where
                            + ")" : ""), whereArgs);
            /* Just for log
             if (folder != null) {
                folder.close();
            }*/
            break;
        case ROOT_DIRECTORY:
            //Log_OC.d(TAG, "Removing ROOT!");
            count = db.delete(ProviderTableMeta.FILE_TABLE_NAME, where, whereArgs);
            break;
        case SHARES:
            count = db.delete(ProviderTableMeta.OCSHARES_TABLE_NAME, where, whereArgs);
            break;
        default:
            //Log_OC.e(TAG, "Unknown uri " + uri);
            throw new IllegalArgumentException("Unknown uri: " + uri.toString());
        }
        return count;
    }

    @Override
    public String getType(Uri uri) {
        switch (mUriMatcher.match(uri)) {
        case ROOT_DIRECTORY:
            return ProviderTableMeta.CONTENT_TYPE;
        case SINGLE_FILE:
            return ProviderTableMeta.CONTENT_TYPE_ITEM;
        default:
            throw new IllegalArgumentException("Unknown Uri id."
                    + uri.toString());
        }
    }

    @Override
    public Uri insert(Uri uri, ContentValues values) {
        Uri newUri = null;
        SQLiteDatabase db = mDbHelper.getWritableDatabase();
        db.beginTransaction();
        try {
            newUri = insert(db, uri, values);
            db.setTransactionSuccessful();
        } finally {
            db.endTransaction();
        }
        getContext().getContentResolver().notifyChange(newUri, null);
        return newUri;
    }

    private Uri insert(SQLiteDatabase db, Uri uri, ContentValues values) {
        switch (mUriMatcher.match(uri)){
        case ROOT_DIRECTORY:
        case SINGLE_FILE:
            String remotePath = values.getAsString(ProviderTableMeta.FILE_PATH);
            String accountName = values.getAsString(ProviderTableMeta.FILE_ACCOUNT_OWNER);
            String[] projection = new String[] {
                    ProviderTableMeta._ID, ProviderTableMeta.FILE_PATH,
                    ProviderTableMeta.FILE_ACCOUNT_OWNER
            };
            String where = ProviderTableMeta.FILE_PATH + "=? AND " +
                    ProviderTableMeta.FILE_ACCOUNT_OWNER + "=?";
            String[] whereArgs = new String[] {remotePath, accountName};
            Cursor doubleCheck = query(db, uri, projection, where, whereArgs, null);
            // ugly patch; serious refactorization is needed to reduce work in
            // FileDataStorageManager and bring it to FileContentProvider
            if (doubleCheck == null || !doubleCheck.moveToFirst()) {
                if (doubleCheck != null) {
                    doubleCheck.close();
                }
                long rowId = db.insert(ProviderTableMeta.FILE_TABLE_NAME, null, values);
                if (rowId > 0) {
                    return ContentUris.withAppendedId(ProviderTableMeta.CONTENT_URI_FILE, rowId);
                } else {
                    throw new SQLException("ERROR " + uri);
                }
            } else {
                // file is already inserted; race condition, let's avoid a duplicated entry
                Uri insertedFileUri = ContentUris.withAppendedId(
                        ProviderTableMeta.CONTENT_URI_FILE,
                        doubleCheck.getLong(doubleCheck.getColumnIndex(ProviderTableMeta._ID))
                );
                doubleCheck.close();

                return insertedFileUri;
            }

        case SHARES:
            Uri insertedShareUri = null;
            long rowId = db.insert(ProviderTableMeta.OCSHARES_TABLE_NAME, null, values);
            if (rowId >0) {
                insertedShareUri =
                        ContentUris.withAppendedId(ProviderTableMeta.CONTENT_URI_SHARE, rowId);
            } else {
                throw new SQLException("ERROR " + uri);

            }
            updateFilesTableAccordingToShareInsertion(db, values);
            return insertedShareUri;


        default:
            throw new IllegalArgumentException("Unknown uri id: " + uri);
        }

    }

    private void updateFilesTableAccordingToShareInsertion(
            SQLiteDatabase db, ContentValues newShare
            ) {
        ContentValues fileValues = new ContentValues();
        int newShareType = newShare.getAsInteger(ProviderTableMeta.OCSHARES_SHARE_TYPE);
        if (newShareType == ShareType.PUBLIC_LINK.getValue()) {
            fileValues.put(ProviderTableMeta.FILE_SHARED_VIA_LINK, 1);
        } else if (newShareType == ShareType.USER.getValue() || newShareType == ShareType.GROUP.getValue()) {
            fileValues.put(ProviderTableMeta.FILE_SHARED_WITH_SHAREE, 1);
        }

        String where = ProviderTableMeta.FILE_PATH + "=? AND " +
                ProviderTableMeta.FILE_ACCOUNT_OWNER + "=?";
        String[] whereArgs = new String[] {
                newShare.getAsString(ProviderTableMeta.OCSHARES_PATH),
                newShare.getAsString(ProviderTableMeta.OCSHARES_ACCOUNT_OWNER)
        };
        db.update(ProviderTableMeta.FILE_TABLE_NAME, fileValues, where, whereArgs);
    }


    @Override
    public boolean onCreate() {
        mDbHelper = new DataBaseHelper(getContext());

        String authority = getContext().getResources().getString(R.string.authority);
        mUriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
        mUriMatcher.addURI(authority, null, ROOT_DIRECTORY);
        mUriMatcher.addURI(authority, "file/", SINGLE_FILE);
        mUriMatcher.addURI(authority, "file/#", SINGLE_FILE);
        mUriMatcher.addURI(authority, "dir/", DIRECTORY);
        mUriMatcher.addURI(authority, "dir/#", DIRECTORY);
        mUriMatcher.addURI(authority, "shares/", SHARES);
        mUriMatcher.addURI(authority, "shares/#", SHARES);

        return true;
    }


    @Override
    public Cursor query(
            Uri uri,
            String[] projection,
            String selection,
            String[] selectionArgs,
            String sortOrder
        ) {

        Cursor result = null;
        SQLiteDatabase db = mDbHelper.getReadableDatabase();
        db.beginTransaction();
        try {
            result = query(db, uri, projection, selection, selectionArgs, sortOrder);
            db.setTransactionSuccessful();
        } finally {
            db.endTransaction();
        }
        return result;
    }

    private Cursor query(
            SQLiteDatabase db,
            Uri uri,
            String[] projection,
            String selection,
            String[] selectionArgs,
            String sortOrder
        ) {

        SQLiteQueryBuilder sqlQuery = new SQLiteQueryBuilder();

        sqlQuery.setTables(ProviderTableMeta.FILE_TABLE_NAME);
        sqlQuery.setProjectionMap(mFileProjectionMap);

        switch (mUriMatcher.match(uri)) {
        case ROOT_DIRECTORY:
            break;
        case DIRECTORY:
            String folderId = uri.getPathSegments().get(1);
            sqlQuery.appendWhere(ProviderTableMeta.FILE_PARENT + "="
                    + folderId);
            break;
        case SINGLE_FILE:
            if (uri.getPathSegments().size() > 1) {
                sqlQuery.appendWhere(ProviderTableMeta._ID + "="
                        + uri.getPathSegments().get(1));
            }
            break;
        case SHARES:
            sqlQuery.setTables(ProviderTableMeta.OCSHARES_TABLE_NAME);
            sqlQuery.setProjectionMap(mOCSharesProjectionMap);
            if (uri.getPathSegments().size() > 1) {
                sqlQuery.appendWhere(ProviderTableMeta._ID + "="
                        + uri.getPathSegments().get(1));
            }
            break;
        default:
            throw new IllegalArgumentException("Unknown uri id: " + uri);
        }

        String order;
        if (TextUtils.isEmpty(sortOrder)) {
            if (mUriMatcher.match(uri) == SHARES) {
                order = ProviderTableMeta.OCSHARES_DEFAULT_SORT_ORDER;
            } else {

                order = ProviderTableMeta.FILE_DEFAULT_SORT_ORDER;
            }
        } else {
            order = sortOrder;
        }

        // DB case_sensitive
        db.execSQL("PRAGMA case_sensitive_like = true");
        Cursor c = sqlQuery.query(db, projection, selection, selectionArgs, null, null, order);
        c.setNotificationUri(getContext().getContentResolver(), uri);
        return c;
    }

    @Override
    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {

        int count = 0;
        SQLiteDatabase db = mDbHelper.getWritableDatabase();
        db.beginTransaction();
        try {
            count = update(db, uri, values, selection, selectionArgs);
            db.setTransactionSuccessful();
        } finally {
            db.endTransaction();
        }
        getContext().getContentResolver().notifyChange(uri, null);
        return count;
    }



    private int update(
            SQLiteDatabase db,
            Uri uri,
            ContentValues values,
            String selection,
            String[] selectionArgs
        ) {
        switch (mUriMatcher.match(uri)) {
            case DIRECTORY:
                return  0; //updateFolderSize(db, selectionArgs[0]);
            case SHARES:
                return db.update(
                        ProviderTableMeta.OCSHARES_TABLE_NAME, values, selection, selectionArgs
                );
            default:
                return db.update(
                        ProviderTableMeta.FILE_TABLE_NAME, values, selection, selectionArgs
                );
        }
    }

    @Override
    public ContentProviderResult[] applyBatch (ArrayList<ContentProviderOperation> operations)
            throws OperationApplicationException {
        Log_OC.d("FileContentProvider", "applying batch in provider " + this +
                " (temporary: " + isTemporary() + ")" );
        ContentProviderResult[] results = new ContentProviderResult[operations.size()];
        int i=0;

        SQLiteDatabase db = mDbHelper.getWritableDatabase();
        db.beginTransaction();  // it's supposed that transactions can be nested
        try {
            for (ContentProviderOperation operation : operations) {
                results[i] = operation.apply(this, results, i);
                i++;
            }
            db.setTransactionSuccessful();
        } finally {
            db.endTransaction();
        }
        Log_OC.d("FileContentProvider", "applied batch in provider " + this);
        return results;
    }


    class DataBaseHelper extends SQLiteOpenHelper {

        public DataBaseHelper(Context context) {
            super(context, ProviderMeta.DB_NAME, null, ProviderMeta.DB_VERSION);

        }

        @Override
        public void onCreate(SQLiteDatabase db) {
            // files table
            Log_OC.i("SQL", "Entering in onCreate");
            db.execSQL("CREATE TABLE " + ProviderTableMeta.FILE_TABLE_NAME + "("
                    + ProviderTableMeta._ID + " INTEGER PRIMARY KEY, "
                    + ProviderTableMeta.FILE_NAME + " TEXT, "
                    + ProviderTableMeta.FILE_PATH + " TEXT, "
                    + ProviderTableMeta.FILE_PARENT + " INTEGER, "
                    + ProviderTableMeta.FILE_CREATION + " INTEGER, "
                    + ProviderTableMeta.FILE_MODIFIED + " INTEGER, "
                    + ProviderTableMeta.FILE_CONTENT_TYPE + " TEXT, "
                    + ProviderTableMeta.FILE_CONTENT_LENGTH + " INTEGER, "
                    + ProviderTableMeta.FILE_STORAGE_PATH + " TEXT, "
                    + ProviderTableMeta.FILE_ACCOUNT_OWNER + " TEXT, "
                    + ProviderTableMeta.FILE_LAST_SYNC_DATE + " INTEGER, "
                    + ProviderTableMeta.FILE_KEEP_IN_SYNC + " INTEGER, "
                    + ProviderTableMeta.FILE_LAST_SYNC_DATE_FOR_DATA + " INTEGER, "
                    + ProviderTableMeta.FILE_MODIFIED_AT_LAST_SYNC_FOR_DATA + " INTEGER, "
                    + ProviderTableMeta.FILE_ETAG + " TEXT, "
                    + ProviderTableMeta.FILE_SHARED_VIA_LINK + " INTEGER, "
                    + ProviderTableMeta.FILE_PUBLIC_LINK  + " TEXT, "
                    + ProviderTableMeta.FILE_PERMISSIONS  + " TEXT null,"
                    + ProviderTableMeta.FILE_REMOTE_ID  + " TEXT null,"
                    + ProviderTableMeta.FILE_UPDATE_THUMBNAIL  + " INTEGER," //boolean
                    + ProviderTableMeta.FILE_IS_DOWNLOADING  + " INTEGER," //boolean
                    + ProviderTableMeta.FILE_ETAG_IN_CONFLICT + " TEXT,"
                    + ProviderTableMeta.FILE_SHARED_WITH_SHAREE + " INTEGER);"
                    );

            // Create table ocshares
            db.execSQL("CREATE TABLE " + ProviderTableMeta.OCSHARES_TABLE_NAME + "("
                    + ProviderTableMeta._ID + " INTEGER PRIMARY KEY, "
                    + ProviderTableMeta.OCSHARES_FILE_SOURCE + " INTEGER, "
                    + ProviderTableMeta.OCSHARES_ITEM_SOURCE + " INTEGER, "
                    + ProviderTableMeta.OCSHARES_SHARE_TYPE + " INTEGER, "
                    + ProviderTableMeta.OCSHARES_SHARE_WITH + " TEXT, "
                    + ProviderTableMeta.OCSHARES_PATH + " TEXT, "
                    + ProviderTableMeta.OCSHARES_PERMISSIONS+ " INTEGER, "
                    + ProviderTableMeta.OCSHARES_SHARED_DATE + " INTEGER, "
                    + ProviderTableMeta.OCSHARES_EXPIRATION_DATE + " INTEGER, "
                    + ProviderTableMeta.OCSHARES_TOKEN + " TEXT, "
                    + ProviderTableMeta.OCSHARES_SHARE_WITH_DISPLAY_NAME + " TEXT, "
                    + ProviderTableMeta.OCSHARES_IS_DIRECTORY + " INTEGER, "  // boolean
                    + ProviderTableMeta.OCSHARES_USER_ID + " INTEGER, "
                    + ProviderTableMeta.OCSHARES_ID_REMOTE_SHARED + " INTEGER,"
                    + ProviderTableMeta.OCSHARES_ACCOUNT_OWNER + " TEXT );" );
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            Log_OC.i("SQL", "Entering in onUpgrade");
            boolean upgraded = false;
            if (oldVersion == 1 && newVersion >= 2) {
                Log_OC.i("SQL", "Entering in the #1 ADD in onUpgrade");
                db.execSQL("ALTER TABLE " + ProviderTableMeta.FILE_TABLE_NAME +
                           " ADD COLUMN " + ProviderTableMeta.FILE_KEEP_IN_SYNC  + " INTEGER " +
                           " DEFAULT 0");
                upgraded = true;
            }
            if (oldVersion < 3 && newVersion >= 3) {
                Log_OC.i("SQL", "Entering in the #2 ADD in onUpgrade");
                db.beginTransaction();
                try {
                    db.execSQL("ALTER TABLE " + ProviderTableMeta.FILE_TABLE_NAME +
                               " ADD COLUMN " + ProviderTableMeta.FILE_LAST_SYNC_DATE_FOR_DATA  +
                               " INTEGER " + " DEFAULT 0");

                    // assume there are not local changes pending to upload
                    db.execSQL("UPDATE " + ProviderTableMeta.FILE_TABLE_NAME +
                            " SET " + ProviderTableMeta.FILE_LAST_SYNC_DATE_FOR_DATA + " = "
                            + System.currentTimeMillis() +
                            " WHERE " + ProviderTableMeta.FILE_STORAGE_PATH + " IS NOT NULL");

                    upgraded = true;
                    db.setTransactionSuccessful();
                } finally {
                    db.endTransaction();
                }
            }
            if (oldVersion < 4 && newVersion >= 4) {
                Log_OC.i("SQL", "Entering in the #3 ADD in onUpgrade");
                db.beginTransaction();
                try {
                    db.execSQL("ALTER TABLE " + ProviderTableMeta.FILE_TABLE_NAME +
                            " ADD COLUMN " + ProviderTableMeta.FILE_MODIFIED_AT_LAST_SYNC_FOR_DATA +
                            " INTEGER " + " DEFAULT 0");

                    db.execSQL("UPDATE " + ProviderTableMeta.FILE_TABLE_NAME +
                           " SET " + ProviderTableMeta.FILE_MODIFIED_AT_LAST_SYNC_FOR_DATA + " = " +
                            ProviderTableMeta.FILE_MODIFIED +
                           " WHERE " + ProviderTableMeta.FILE_STORAGE_PATH + " IS NOT NULL");

                    upgraded = true;
                    db.setTransactionSuccessful();
                } finally {
                    db.endTransaction();
                }
            }
            if (!upgraded)
                Log_OC.i("SQL", "OUT of the ADD in onUpgrade; oldVersion == " + oldVersion +
                        ", newVersion == " + newVersion);

            if (oldVersion < 5 && newVersion >= 5) {
                Log_OC.i("SQL", "Entering in the #4 ADD in onUpgrade");
                db.beginTransaction();
                try {
                    db.execSQL("ALTER TABLE " + ProviderTableMeta.FILE_TABLE_NAME +
                            " ADD COLUMN " + ProviderTableMeta.FILE_ETAG + " TEXT " +
                            " DEFAULT NULL");

                    upgraded = true;
                    db.setTransactionSuccessful();
                } finally {
                    db.endTransaction();
                }
            }
            if (!upgraded)
                Log_OC.i("SQL", "OUT of the ADD in onUpgrade; oldVersion == " + oldVersion +
                        ", newVersion == " + newVersion);

            if (oldVersion < 6 && newVersion >= 6) {
                Log_OC.i("SQL", "Entering in the #5 ADD in onUpgrade");
                db.beginTransaction();
                try {
                    db .execSQL("ALTER TABLE " + ProviderTableMeta.FILE_TABLE_NAME +
                            " ADD COLUMN " + ProviderTableMeta.FILE_SHARED_VIA_LINK + " INTEGER " +
                            " DEFAULT 0");

                    db .execSQL("ALTER TABLE " + ProviderTableMeta.FILE_TABLE_NAME +
                            " ADD COLUMN " + ProviderTableMeta.FILE_PUBLIC_LINK + " TEXT " +
                            " DEFAULT NULL");

                    // Create table ocshares
                    db.execSQL("CREATE TABLE " + ProviderTableMeta.OCSHARES_TABLE_NAME + "("
                            + ProviderTableMeta._ID + " INTEGER PRIMARY KEY, "
                            + ProviderTableMeta.OCSHARES_FILE_SOURCE + " INTEGER, "
                            + ProviderTableMeta.OCSHARES_ITEM_SOURCE + " INTEGER, "
                            + ProviderTableMeta.OCSHARES_SHARE_TYPE + " INTEGER, "
                            + ProviderTableMeta.OCSHARES_SHARE_WITH + " TEXT, "
                            + ProviderTableMeta.OCSHARES_PATH + " TEXT, "
                            + ProviderTableMeta.OCSHARES_PERMISSIONS + " INTEGER, "
                            + ProviderTableMeta.OCSHARES_SHARED_DATE + " INTEGER, "
                            + ProviderTableMeta.OCSHARES_EXPIRATION_DATE + " INTEGER, "
                            + ProviderTableMeta.OCSHARES_TOKEN + " TEXT, "
                            + ProviderTableMeta.OCSHARES_SHARE_WITH_DISPLAY_NAME + " TEXT, "
                            + ProviderTableMeta.OCSHARES_IS_DIRECTORY + " INTEGER, "  // boolean
                            + ProviderTableMeta.OCSHARES_USER_ID + " INTEGER, "
                            + ProviderTableMeta.OCSHARES_ID_REMOTE_SHARED + " INTEGER,"
                            + ProviderTableMeta.OCSHARES_ACCOUNT_OWNER + " TEXT );");

                    upgraded = true;
                    db.setTransactionSuccessful();
                } finally {
                    db.endTransaction();
                }
            }
            if (!upgraded)
                Log_OC.i("SQL", "OUT of the ADD in onUpgrade; oldVersion == " + oldVersion +
                        ", newVersion == " + newVersion);

            if (oldVersion < 7 && newVersion >= 7) {
                Log_OC.i("SQL", "Entering in the #7 ADD in onUpgrade");
                db.beginTransaction();
                try {
                    db.execSQL("ALTER TABLE " + ProviderTableMeta.FILE_TABLE_NAME +
                            " ADD COLUMN " + ProviderTableMeta.FILE_PERMISSIONS + " TEXT " +
                            " DEFAULT NULL");

                    db.execSQL("ALTER TABLE " + ProviderTableMeta.FILE_TABLE_NAME +
                            " ADD COLUMN " + ProviderTableMeta.FILE_REMOTE_ID + " TEXT " +
                            " DEFAULT NULL");

                    upgraded = true;
                    db.setTransactionSuccessful();
                } finally {
                    db.endTransaction();
                }
            }
            if (!upgraded)
                Log_OC.i("SQL", "OUT of the ADD in onUpgrade; oldVersion == " + oldVersion +
                        ", newVersion == " + newVersion);

            if (oldVersion < 8 && newVersion >= 8) {
                Log_OC.i("SQL", "Entering in the #8 ADD in onUpgrade");
                db.beginTransaction();
                try {
                    db.execSQL("ALTER TABLE " + ProviderTableMeta.FILE_TABLE_NAME +
                            " ADD COLUMN " + ProviderTableMeta.FILE_UPDATE_THUMBNAIL + " INTEGER " +
                            " DEFAULT 0");

                    upgraded = true;
                    db.setTransactionSuccessful();
                } finally {
                    db.endTransaction();
                }
            }
            if (!upgraded)
                Log_OC.i("SQL", "OUT of the ADD in onUpgrade; oldVersion == " + oldVersion +
                        ", newVersion == " + newVersion);

            if (oldVersion < 9 && newVersion >= 9) {
                Log_OC.i("SQL", "Entering in the #9 ADD in onUpgrade");
                db.beginTransaction();
                try {
                    db .execSQL("ALTER TABLE " + ProviderTableMeta.FILE_TABLE_NAME +
                            " ADD COLUMN " + ProviderTableMeta.FILE_IS_DOWNLOADING + " INTEGER " +
                            " DEFAULT 0");

                    upgraded = true;
                    db.setTransactionSuccessful();
                } finally {
                    db.endTransaction();
                }
            }
            if (!upgraded)
                Log_OC.i("SQL", "OUT of the ADD in onUpgrade; oldVersion == " + oldVersion +
                        ", newVersion == " + newVersion);

            if (oldVersion < 10 && newVersion >= 10) {
                Log_OC.i("SQL", "Entering in the #10 ADD in onUpgrade");
                updateAccountName(db);
                upgraded = true;
            }
             if (!upgraded)
                Log_OC.i("SQL", "OUT of the ADD in onUpgrade; oldVersion == " + oldVersion +
                        ", newVersion == " + newVersion);

            if (oldVersion < 11 && newVersion >= 11) {
                Log_OC.i("SQL", "Entering in the #11 ADD in onUpgrade");
                db.beginTransaction();
                try {
                    db .execSQL("ALTER TABLE " + ProviderTableMeta.FILE_TABLE_NAME +
                            " ADD COLUMN " + ProviderTableMeta.FILE_ETAG_IN_CONFLICT + " TEXT " +
                            " DEFAULT NULL");

                    upgraded = true;
                    db.setTransactionSuccessful();
                } finally {
                    db.endTransaction();
                }
            }
            if (!upgraded)
                Log_OC.i("SQL", "OUT of the ADD in onUpgrade; oldVersion == " + oldVersion +
                        ", newVersion == " + newVersion);

            if (oldVersion < 12 && newVersion >= 12) {
                Log_OC.i("SQL", "Entering in the #12 ADD in onUpgrade");
                db.beginTransaction();
                try {
                    db .execSQL("ALTER TABLE " + ProviderTableMeta.FILE_TABLE_NAME +
                            " ADD COLUMN " + ProviderTableMeta.FILE_SHARED_WITH_SHAREE + " INTEGER " +
                            " DEFAULT 0");
                    upgraded = true;
                    db.setTransactionSuccessful();
                } finally {
                    db.endTransaction();
                }
            }
            if (!upgraded)
                Log_OC.i("SQL", "OUT of the ADD in onUpgrade; oldVersion == " + oldVersion +
                        ", newVersion == " + newVersion);

        }
    }


    /**
     * Version 10 of database does not modify its scheme. It coincides with the upgrade of the ownCloud account names
     * structure to include in it the path to the server instance. Updating the account names and path to local files
     * in the files table is a must to keep the existing account working and the database clean.
     *
     * See {@link com.owncloud.android.authentication.AccountUtils#updateAccountVersion(android.content.Context)}
     *
     * @param db        Database where table of files is included.
     */
    private void updateAccountName(SQLiteDatabase db){
        Log_OC.d("SQL", "THREAD:  "+ Thread.currentThread().getName());
        AccountManager ama = AccountManager.get(getContext());
        try {
            // get accounts from AccountManager ;  we can't be sure if accounts in it are updated or not although
            // we know the update was previously done in {link @FileActivity#onCreate} because the changes through
            // AccountManager are not synchronous
            Account[] accounts = AccountManager.get(getContext()).getAccountsByType(
                    MainApp.getAccountType());
            String serverUrl, username, oldAccountName, newAccountName;
			for (Account account : accounts) {
                // build both old and new account name
                serverUrl = ama.getUserData(account, AccountUtils.Constants.KEY_OC_BASE_URL);
                username = account.name.substring(0, account.name.lastIndexOf('@'));
                oldAccountName = AccountUtils.buildAccountNameOld(Uri.parse(serverUrl), username);
                newAccountName = AccountUtils.buildAccountName(Uri.parse(serverUrl), username);

                // update values in database
                db.beginTransaction();
                try {
                    ContentValues cv = new ContentValues();
                    cv.put(ProviderTableMeta.FILE_ACCOUNT_OWNER, newAccountName);
                    int num = db.update(ProviderTableMeta.FILE_TABLE_NAME,
                            cv,
                            ProviderTableMeta.FILE_ACCOUNT_OWNER + "=?",
                            new String[]{oldAccountName});

                    Log_OC.d("SQL", "Updated account in database: old name == " + oldAccountName +
                            ", new name == " + newAccountName + " (" + num + " rows updated )");

                    // update path for downloaded files
                    updateDownloadedFiles(db, newAccountName, oldAccountName);

                    db.setTransactionSuccessful();

                } catch (SQLException e) {
                    Log_OC.e(TAG, "SQL Exception upgrading account names or paths in database", e);
                } finally {
                    db.endTransaction();
                }
			}
        } catch (Exception e) {
            Log_OC.e(TAG, "Exception upgrading account names or paths in database", e);
        }
    }


    /**
     * Rename the local ownCloud folder of one account to match the a rename of the account itself. Updates the
     * table of files in database so that the paths to the local files keep being the same.
     *
     * @param db                    Database where table of files is included.
     * @param newAccountName        New name for the target OC account.
     * @param oldAccountName        Old name of the target OC account.
     */
    private void updateDownloadedFiles(SQLiteDatabase db, String newAccountName,
                                       String oldAccountName) {

        String whereClause = ProviderTableMeta.FILE_ACCOUNT_OWNER + "=? AND " +
                ProviderTableMeta.FILE_STORAGE_PATH + " IS NOT NULL";

        Cursor c = db.query(ProviderTableMeta.FILE_TABLE_NAME,
                null,
                whereClause,
                new String[] { newAccountName },
                null, null, null);

        try {
            if (c.moveToFirst()) {
                // create storage path
                String oldAccountPath = FileStorageUtils.getSavePath(oldAccountName);
                String newAccountPath = FileStorageUtils.getSavePath(newAccountName);

                // move files
                File oldAccountFolder = new File(oldAccountPath);
                File newAccountFolder = new File(newAccountPath);
                oldAccountFolder.renameTo(newAccountFolder);

                // update database
                do {
                    // Update database
                    String oldPath = c.getString(
                            c.getColumnIndex(ProviderTableMeta.FILE_STORAGE_PATH));
                    OCFile file = new OCFile(
                            c.getString(c.getColumnIndex(ProviderTableMeta.FILE_PATH)));
                    String newPath = FileStorageUtils.getDefaultSavePathFor(newAccountName, file);

                    ContentValues cv = new ContentValues();
                    cv.put(ProviderTableMeta.FILE_STORAGE_PATH, newPath);
                    db.update(ProviderTableMeta.FILE_TABLE_NAME,
                            cv,
                            ProviderTableMeta.FILE_STORAGE_PATH + "=?",
                            new String[]{oldPath});

                    Log_OC.v("SQL", "Updated path of downloaded file: old file name == " + oldPath +
                            ", new file name == " + newPath);

                } while (c.moveToNext());
            }
        } finally {
            c.close();
        }

    }

}