/*
 * Copyright (C) 2007, 2013 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
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 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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 */
#ifndef SQLTransactionBackend_h
#define SQLTransactionBackend_h

#include "modules/webdatabase/DatabaseBasicTypes.h"
#include "modules/webdatabase/SQLStatement.h"
#include "modules/webdatabase/SQLTransactionStateMachine.h"
#include "platform/heap/Handle.h"
#include "wtf/Deque.h"
#include "wtf/Forward.h"
#include "wtf/ThreadingPrimitives.h"
#include <memory>

namespace blink {

class Database;
class SQLErrorData;
class SQLiteTransaction;
class SQLStatementBackend;
class SQLTransaction;
class SQLTransactionBackend;
class SQLValue;

class SQLTransactionWrapper
    : public GarbageCollectedFinalized<SQLTransactionWrapper> {
 public:
  virtual ~SQLTransactionWrapper() {}
  DEFINE_INLINE_VIRTUAL_TRACE() {}
  virtual bool performPreflight(SQLTransactionBackend*) = 0;
  virtual bool performPostflight(SQLTransactionBackend*) = 0;
  virtual SQLErrorData* sqlError() const = 0;
  virtual void handleCommitFailedAfterPostflight(SQLTransactionBackend*) = 0;
};

class SQLTransactionBackend final
    : public GarbageCollectedFinalized<SQLTransactionBackend>,
      public SQLTransactionStateMachine<SQLTransactionBackend> {
 public:
  static SQLTransactionBackend* create(Database*,
                                       SQLTransaction*,
                                       SQLTransactionWrapper*,
                                       bool readOnly);

  ~SQLTransactionBackend() override;
  DECLARE_TRACE();

  void lockAcquired();
  void performNextStep();

  Database* database() { return m_database.get(); }
  bool isReadOnly() { return m_readOnly; }
  void notifyDatabaseThreadIsShuttingDown();

  // APIs called from the frontend published:
  void requestTransitToState(SQLTransactionState);
  SQLErrorData* transactionError();
  SQLStatement* currentStatement();
  void setShouldRetryCurrentStatement(bool);
  void executeSQL(SQLStatement*,
                  const String& statement,
                  const Vector<SQLValue>& arguments,
                  int permissions);

 private:
  SQLTransactionBackend(Database*,
                        SQLTransaction*,
                        SQLTransactionWrapper*,
                        bool readOnly);

  void doCleanup();

  void enqueueStatementBackend(SQLStatementBackend*);

  // State Machine functions:
  StateFunction stateFunctionFor(SQLTransactionState) override;
  void computeNextStateAndCleanupIfNeeded();

  // State functions:
  SQLTransactionState acquireLock();
  SQLTransactionState openTransactionAndPreflight();
  SQLTransactionState runStatements();
  SQLTransactionState postflightAndCommit();
  SQLTransactionState cleanupAndTerminate();
  SQLTransactionState cleanupAfterTransactionErrorCallback();

  SQLTransactionState unreachableState();
  SQLTransactionState sendToFrontendState();

  SQLTransactionState nextStateForCurrentStatementError();
  SQLTransactionState nextStateForTransactionError();
  SQLTransactionState runCurrentStatementAndGetNextState();

  void getNextStatement();

  CrossThreadPersistent<SQLTransaction> m_frontend;
  CrossThreadPersistent<SQLStatementBackend> m_currentStatementBackend;

  Member<Database> m_database;
  Member<SQLTransactionWrapper> m_wrapper;
  std::unique_ptr<SQLErrorData> m_transactionError;

  bool m_hasCallback;
  bool m_hasSuccessCallback;
  bool m_hasErrorCallback;
  bool m_shouldRetryCurrentStatement;
  bool m_modifiedDatabase;
  bool m_lockAcquired;
  bool m_readOnly;
  bool m_hasVersionMismatch;

  Mutex m_statementMutex;
  Deque<CrossThreadPersistent<SQLStatementBackend>> m_statementQueue;

  std::unique_ptr<SQLiteTransaction> m_sqliteTransaction;
};

}  // namespace blink

#endif  // SQLTransactionBackend_h