/*

 * Copyright (C) 2007 Apple Inc. All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1.  Redistributions of source code must retain the above copyright

 *     notice, this list of conditions and the following disclaimer.

 * 2.  Redistributions in binary form must reproduce the above copyright

 *     notice, this list of conditions and the following disclaimer in the

 *     documentation and/or other materials provided with the distribution.

 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of

 *     its contributors may be used to endorse or promote products derived

 *     from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY

 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND

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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#include "config.h"

#include "SQLStatement.h"

#if ENABLE(DATABASE)

#include "Database.h"

#include "Logging.h"

#include "SQLError.h"

#include "SQLiteDatabase.h"

#include "SQLiteStatement.h"

#include "SQLStatementCallback.h"

#include "SQLStatementErrorCallback.h"

#include "SQLTransaction.h"

#include "SQLValue.h"

namespace WebCore {

PassRefPtr<SQLStatement> SQLStatement::create(const String& statement, const Vector<SQLValue>& arguments, PassRefPtr<SQLStatementCallback> callback, PassRefPtr<SQLStatementErrorCallback> errorCallback, bool readOnly)

{

    return adoptRef(new SQLStatement(statement, arguments, callback, errorCallback, readOnly));

}

SQLStatement::SQLStatement(const String& statement, const Vector<SQLValue>& arguments, PassRefPtr<SQLStatementCallback> callback, PassRefPtr<SQLStatementErrorCallback> errorCallback, bool readOnly)

    : m_statement(statement.crossThreadString())

    , m_arguments(arguments)

    , m_statementCallback(callback)

    , m_statementErrorCallback(errorCallback)

    , m_readOnly(readOnly)

{

}

bool SQLStatement::execute(Database* db)

{

    ASSERT(!m_resultSet);

    // If we're re-running this statement after a quota violation, we need to clear that error now

    clearFailureDueToQuota();

    // This transaction might have been marked bad while it was being set up on the main thread,

    // so if there is still an error, return false.

    if (m_error)

        return false;

    if (m_readOnly)

        db->setAuthorizerReadOnly();

    SQLiteDatabase* database = &db->sqliteDatabase();

    SQLiteStatement statement(*database, m_statement);

    int result = statement.prepare();

    if (result != SQLResultOk) {

        LOG(StorageAPI, "Unable to verify correctness of statement %s - error %i (%s)", m_statement.ascii().data(), result, database->lastErrorMsg());

        m_error = SQLError::create(SQLError::SYNTAX_ERR, database->lastErrorMsg());

        return false;

    }

    // FIXME:  If the statement uses the ?### syntax supported by sqlite, the bind parameter count is very likely off from the number of question marks.

    // If this is the case, they might be trying to do something fishy or malicious

    if (statement.bindParameterCount() != m_arguments.size()) {

        LOG(StorageAPI, "Bind parameter count doesn't match number of question marks");

        m_error = SQLError::create(SQLError::SYNTAX_ERR, "number of '?'s in statement string does not match argument count");

        return false;

    }

    for (unsigned i = 0; i < m_arguments.size(); ++i) {

        result = statement.bindValue(i + 1, m_arguments[i]);

        if (result == SQLResultFull) {

            setFailureDueToQuota();

            return false;

        }

        if (result != SQLResultOk) {

            LOG(StorageAPI, "Failed to bind value index %i to statement for query '%s'", i + 1, m_statement.ascii().data());

            m_error = SQLError::create(SQLError::DATABASE_ERR, database->lastErrorMsg());

            return false;

        }

    }

    RefPtr<SQLResultSet> resultSet = SQLResultSet::create();

    // Step so we can fetch the column names.

    result = statement.step();

    if (result == SQLResultRow) {

        int columnCount = statement.columnCount();

        SQLResultSetRowList* rows = resultSet->rows();

        for (int i = 0; i < columnCount; i++)

            rows->addColumn(statement.getColumnName(i));

        do {

            for (int i = 0; i < columnCount; i++)

                rows->addResult(statement.getColumnValue(i));

            result = statement.step();

        } while (result == SQLResultRow);

        if (result != SQLResultDone) {

            m_error = SQLError::create(SQLError::DATABASE_ERR, database->lastErrorMsg());

            return false;

        }

    } else if (result == SQLResultDone) {

        // Didn't find anything, or was an insert

        if (db->lastActionWasInsert())

            resultSet->setInsertId(database->lastInsertRowID());

    } else if (result == SQLResultFull) {

        // Return the Quota error - the delegate will be asked for more space and this statement might be re-run

        setFailureDueToQuota();

        return false;

    } else {

        m_error = SQLError::create(SQLError::DATABASE_ERR, database->lastErrorMsg());

        return false;

    }

    // FIXME: If the spec allows triggers, and we want to be "accurate" in a different way, we'd use

    // sqlite3_total_changes() here instead of sqlite3_changed, because that includes rows modified from within a trigger

    // For now, this seems sufficient

    resultSet->setRowsAffected(database->lastChanges());

    m_resultSet = resultSet;

    return true;

}

void SQLStatement::setDatabaseDeletedError()

{

    ASSERT(!m_error && !m_resultSet);

    m_error = SQLError::create(SQLError::UNKNOWN_ERR, "unable to execute statement, because the user deleted the database");

}

void SQLStatement::setVersionMismatchedError()

{

    ASSERT(!m_error && !m_resultSet);

    m_error = SQLError::create(SQLError::VERSION_ERR, "current version of the database and `oldVersion` argument do not match");

}

bool SQLStatement::performCallback(SQLTransaction* transaction)

{

    ASSERT(transaction);

    bool callbackError = false;

    // Call the appropriate statement callback and track if it resulted in an error,

    // because then we need to jump to the transaction error callback.

    if (m_error) {

        ASSERT(m_statementErrorCallback);

        callbackError = m_statementErrorCallback->handleEvent(transaction->database()->scriptExecutionContext(), transaction, m_error.get());

    } else if (m_statementCallback)

        callbackError = !m_statementCallback->handleEvent(transaction->database()->scriptExecutionContext(), transaction, m_resultSet.get());

    // Now release our callbacks, to break reference cycles.

    m_statementCallback = 0;

    m_statementErrorCallback = 0;

    return callbackError;

}

void SQLStatement::setFailureDueToQuota()

{

    ASSERT(!m_error && !m_resultSet);

    m_error = SQLError::create(SQLError::QUOTA_ERR, "there was not enough remaining storage space, or the storage quota was reached and the user declined to allow more space");

}

void SQLStatement::clearFailureDueToQuota()

{

    if (lastExecutionFailedDueToQuota())

        m_error = 0;

}

bool SQLStatement::lastExecutionFailedDueToQuota() const

{

    return m_error && m_error->code() == SQLError::QUOTA_ERR;

}

} // namespace WebCore

#endif // ENABLE(DATABASE)