// Licensed to the Software Freedom Conservancy (SFC) under one

// or more contributor license agreements. See the NOTICE file

// distributed with this work for additional information

// regarding copyright ownership. The SFC licenses this file

// to you 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.

/**

* @fileoverview Atoms for executing SQL queries on web client database.

*

*/

goog.provide('bot.storage.database');

goog.provide('bot.storage.database.ResultSet');

goog.require('bot');

goog.require('bot.Error');

goog.require('bot.ErrorCode');

/**

* Opens the database to access its contents. This function will create the

* database if it does not exist. For details,

* @see http://www.w3.org/TR/webdatabase/#databases

*

* @param {string} databaseName The name of the database.

* @param {string=} opt_version The expected database version to be opened;

* defaults to the empty string.

* @param {string=} opt_displayName The name to be displayed to the user;

* defaults to the databaseName.

* @param {number=} opt_size The estimated initial quota size of the database;

* default value is 5MB.

* @param {!Window=} opt_window The window associated with the database;

* defaults to the main window.

* @return {!Database} The object to access the web database.

*

*/

bot.storage.database.openOrCreate = function(databaseName, opt_version,

opt_displayName, opt_size, opt_window) {

var version = opt_version || '';

var displayName = opt_displayName || (databaseName + 'name');

var size = opt_size || 5 * 1024 * 1024;

var win = opt_window || bot.getWindow();

return win.openDatabase(databaseName, version, displayName, size);

};

/**

* It executes a single SQL query on a given web database storage.

*

* @param {string} databaseName The name of the database.

* @param {string} query The SQL statement.

* @param {!Array.<*>} args Arguments needed for the SQL statement.

* @param {!function(!SQLTransaction, !bot.storage.database.ResultSet)}

* queryResultCallback Callback function to be invoked on successful query

* statement execution.

* @param {!function(!SQLError)} txErrorCallback

* Callback function to be invoked on transaction (commit) failure.

* @param {!function()=} opt_txSuccessCallback

* Callback function to be invoked on successful transaction execution.

* @param {function(!SQLTransaction, !SQLError)=} opt_queryErrorCallback

* Callback function to be invoked on successful query statement execution.

* @see http://www.w3.org/TR/webdatabase/#executing-sql-statements

*/

bot.storage.database.executeSql = function(databaseName, query, args,

queryResultCallback, txErrorCallback, opt_txSuccessCallback,

opt_queryErrorCallback) {

var db;

try {

db = bot.storage.database.openOrCreate(databaseName);

} catch (e) {

throw new bot.Error(bot.ErrorCode.UNKNOWN_ERROR, e.message);

}

var queryCallback = function(tx, result) {

var wrappedResult = new bot.storage.database.ResultSet(result);

queryResultCallback(tx, wrappedResult);

};

var transactionCallback = function(tx) {

tx.executeSql(query, args, queryCallback, opt_queryErrorCallback);

};

db.transaction(transactionCallback, txErrorCallback,

opt_txSuccessCallback);

};

/**

* A wrapper of the SQLResultSet object returned by the SQL statement.

*

* @param {!SQLResultSet} sqlResultSet The original SQLResultSet object.

* @constructor

*/

bot.storage.database.ResultSet = function(sqlResultSet) {

/**

* The database rows returned from the SQL query.

* @type {!Array.<*>}

*/

this.rows = [];

for (var i = 0; i < sqlResultSet.rows.length; i++) {

this.rows[i] = sqlResultSet.rows.item(i);

}

/**

* The number of rows that were changed by the SQL statement

* @type {number}

*/

this.rowsAffected = sqlResultSet.rowsAffected;

/**

* The row ID of the row that the SQLResultSet object's SQL statement

* inserted into the database, if the statement inserted a row; else

* it is assigned to -1. Originally, accessing insertId attribute of

* a SQLResultSet object returns the exception INVALID_ACCESS_ERR

* if no rows are inserted.

* @type {number}

*/

this.insertId = -1;

try {

this.insertId = sqlResultSet.insertId;

} catch (error) {

// If accessing sqlResultSet.insertId results in INVALID_ACCESS_ERR

// exception, this.insertId will be assigned to -1.

}

};