/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-

 * vim: sw=2 ts=2 sts=2 et

 * This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozStorageStatementData_h

#define mozStorageStatementData_h

#include "sqlite3.h"

#include "nsAutoPtr.h"

#include "nsTArray.h"

#include "nsIEventTarget.h"

#include "MainThreadUtils.h"

#include "mozStorageBindingParamsArray.h"

#include "mozIStorageBaseStatement.h"

#include "mozStorageConnection.h"

#include "StorageBaseStatementInternal.h"

struct sqlite3_stmt;

namespace mozilla {

namespace storage {

class StatementData {

 public:

  StatementData(sqlite3_stmt *aStatement,

                already_AddRefed<BindingParamsArray> aParamsArray,

                StorageBaseStatementInternal *aStatementOwner)

      : mStatement(aStatement),

        mParamsArray(aParamsArray),

        mStatementOwner(aStatementOwner) {

    NS_PRECONDITION(mStatementOwner, "Must have a statement owner!");

  }

  StatementData(const StatementData &aSource)

      : mStatement(aSource.mStatement),

        mParamsArray(aSource.mParamsArray),

        mStatementOwner(aSource.mStatementOwner) {

    NS_PRECONDITION(mStatementOwner, "Must have a statement owner!");

  }

  StatementData() : mStatement(nullptr) {}

  ~StatementData() {

    // We need to ensure that mParamsArray is released on the main thread,

    // as the binding arguments may be XPConnect values, which are safe

    // to release only on the main thread.

    NS_ReleaseOnMainThreadSystemGroup("StatementData::mParamsArray",

                                      mParamsArray.forget());

  }

  /**

   * Return the sqlite statement, fetching it from the storage statement.  In

   * the case of AsyncStatements this may actually create the statement

   */

  inline int getSqliteStatement(sqlite3_stmt **_stmt) {

    if (!mStatement) {

      int rc = mStatementOwner->getAsyncStatement(&mStatement);

      NS_ENSURE_TRUE(rc == SQLITE_OK, rc);

    }

    *_stmt = mStatement;

    return SQLITE_OK;

  }

  operator BindingParamsArray *() const { return mParamsArray; }

  /**

   * NULLs out our sqlite3_stmt (it is held by the owner) after reseting it and

   * clear all bindings to it.  This is expected to occur on the async thread.

   */

  inline void reset() {

    NS_PRECONDITION(mStatementOwner, "Must have a statement owner!");

    // In the AsyncStatement case we may never have populated mStatement if the

    // AsyncExecuteStatements got canceled or a failure occurred in constructing

    // the statement.

    if (mStatement) {

      (void)::sqlite3_reset(mStatement);

      (void)::sqlite3_clear_bindings(mStatement);

      mStatement = nullptr;

    }

  }

  /**

   * Indicates if this statement has parameters to be bound before it is

   * executed.

   *

   * @return true if the statement has parameters to bind against, false

   *         otherwise.

   */

  inline bool hasParametersToBeBound() const { return !!mParamsArray; }

  /**

   * Indicates the number of implicit statements generated by this statement

   * requiring a transaction for execution.  For example a single statement

   * with N BindingParams will execute N implicit staments.

   *

   * @return number of statements requiring a transaction for execution.

   *

   * @note In the case of AsyncStatements this may actually create the

   *       statement.

   */

  inline uint32_t needsTransaction() {

    MOZ_ASSERT(!NS_IsMainThread());

    // Be sure to use the getSqliteStatement helper, since sqlite3_stmt_readonly

    // can only analyze prepared statements and AsyncStatements are prepared

    // lazily.

    sqlite3_stmt *stmt;

    int rc = getSqliteStatement(&stmt);

    if (SQLITE_OK != rc || ::sqlite3_stmt_readonly(stmt)) {

      return 0;

    }

    return mParamsArray ? mParamsArray->length() : 1;

  }

 private:

  sqlite3_stmt *mStatement;

  RefPtr<BindingParamsArray> mParamsArray;

  /**

   * We hold onto a reference of the statement's owner so it doesn't get

   * destroyed out from under us.

   */

  nsCOMPtr<StorageBaseStatementInternal> mStatementOwner;

};

}  // namespace storage

}  // namespace mozilla

#endif  // mozStorageStatementData_h