/*
 * Copyright (C) 2012 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.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 INC. OR
 * 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 ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 */

#ifndef DatabaseManager_h
#define DatabaseManager_h

#include "DatabaseBasicTypes.h"
#include "DatabaseDetails.h"
#include "DatabaseError.h"
#include <wtf/Assertions.h>
#include <wtf/HashMap.h>
#include <wtf/HashSet.h>
#include <wtf/Lock.h>
#include <wtf/PassRefPtr.h>
#include <wtf/Threading.h>

namespace WebCore {

class AbstractDatabaseServer;
class Database;
class DatabaseCallback;
class DatabaseContext;
class DatabaseManagerClient;
class DatabaseSync;
class DatabaseTaskSynchronizer;
class SecurityOrigin;
class ScriptExecutionContext;

class DatabaseManager {
    WTF_MAKE_NONCOPYABLE(DatabaseManager); WTF_MAKE_FAST_ALLOCATED;
    friend class WTF::NeverDestroyed<DatabaseManager>;
public:
    WEBCORE_EXPORT static DatabaseManager& singleton();

    WEBCORE_EXPORT void initialize(const String& databasePath);
    WEBCORE_EXPORT void setClient(DatabaseManagerClient*);
    String databaseDirectoryPath() const;
    void setDatabaseDirectoryPath(const String&);

    bool isAvailable();
    WEBCORE_EXPORT void setIsAvailable(bool);

    // This gets a DatabaseContext for the specified ScriptExecutionContext.
    // If one doesn't already exist, it will create a new one.
    RefPtr<DatabaseContext> databaseContextFor(ScriptExecutionContext*);

    // These 2 methods are for DatabaseContext (un)registration, and should only
    // be called by the DatabaseContext constructor and destructor.
    void registerDatabaseContext(DatabaseContext*);
    void unregisterDatabaseContext(DatabaseContext*);

#if !ASSERT_DISABLED
    void didConstructDatabaseContext();
    void didDestructDatabaseContext();
#else
    void didConstructDatabaseContext() { }
    void didDestructDatabaseContext() { }
#endif

    static ExceptionCode exceptionCodeForDatabaseError(DatabaseError);

    RefPtr<Database> openDatabase(ScriptExecutionContext*, const String& name, const String& expectedVersion, const String& displayName, unsigned long estimatedSize, PassRefPtr<DatabaseCallback>, DatabaseError&);

    WEBCORE_EXPORT bool hasOpenDatabases(ScriptExecutionContext*);

    WEBCORE_EXPORT void closeAllDatabases();

    void stopDatabases(ScriptExecutionContext*, DatabaseTaskSynchronizer*);

    String fullPathForDatabase(SecurityOrigin*, const String& name, bool createIfDoesNotExist = true);

    bool hasEntryForOrigin(SecurityOrigin*);
    WEBCORE_EXPORT void origins(Vector<RefPtr<SecurityOrigin>>& result);
    WEBCORE_EXPORT bool databaseNamesForOrigin(SecurityOrigin*, Vector<String>& result);
    WEBCORE_EXPORT DatabaseDetails detailsForNameAndOrigin(const String&, SecurityOrigin*);

    WEBCORE_EXPORT unsigned long long usageForOrigin(SecurityOrigin*);
    WEBCORE_EXPORT unsigned long long quotaForOrigin(SecurityOrigin*);

    WEBCORE_EXPORT void setQuota(SecurityOrigin*, unsigned long long);

    WEBCORE_EXPORT void deleteAllDatabases();
    WEBCORE_EXPORT bool deleteOrigin(SecurityOrigin*);
    WEBCORE_EXPORT bool deleteDatabase(SecurityOrigin*, const String& name);

private:
    class ProposedDatabase {
    public:
        ProposedDatabase(DatabaseManager&, SecurityOrigin*,
            const String& name, const String& displayName, unsigned long estimatedSize);
        ~ProposedDatabase();

        SecurityOrigin* origin() { return m_origin.get(); }
        DatabaseDetails& details() { return m_details; }

    private:
        DatabaseManager& m_manager;
        RefPtr<SecurityOrigin> m_origin;
        DatabaseDetails m_details;
    };

    DatabaseManager();
    ~DatabaseManager() = delete;

    // This gets a DatabaseContext for the specified ScriptExecutionContext if
    // it already exist previously. Otherwise, it returns 0.
    RefPtr<DatabaseContext> existingDatabaseContextFor(ScriptExecutionContext*);

    PassRefPtr<Database> openDatabaseBackend(ScriptExecutionContext*, const String& name, const String& expectedVersion, const String& displayName, unsigned long estimatedSize, bool setVersionInNewDatabase, DatabaseError&, String& errorMessage);

    void addProposedDatabase(ProposedDatabase*);
    void removeProposedDatabase(ProposedDatabase*);

    static void logErrorMessage(ScriptExecutionContext*, const String& message);

    AbstractDatabaseServer* m_server;
    DatabaseManagerClient* m_client;
    bool m_databaseIsAvailable;

    // Access to the following fields require locking m_lock below:
    typedef HashMap<ScriptExecutionContext*, DatabaseContext*> ContextMap;
    ContextMap m_contextMap;
#if !ASSERT_DISABLED
    int m_databaseContextRegisteredCount;
    int m_databaseContextInstanceCount;
#endif
    HashSet<ProposedDatabase*> m_proposedDatabases;

    // This mutex protects m_contextMap, and m_proposedDatabases.
    Lock m_mutex;
};

} // namespace WebCore

#endif // DatabaseManager_h