/**
 * Orthanc - A Lightweight, RESTful DICOM Store
 * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
 * Department, University Hospital of Liege, Belgium
 * Copyright (C) 2017-2018 Osimis S.A., Belgium
 *
 * This program is free software: you can redistribute it and/or
 * modify it under the terms of the GNU Affero General Public License
 * as published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Affero General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 **/


#include "../../Framework/Plugins/StorageBackend.h"

#include "../../Framework/Common/FileValue.h"
#include "../../Framework/PostgreSQL/PostgreSQLDatabase.h"
#include "../../Framework/PostgreSQL/PostgreSQLLargeObject.h"
#include "../../Framework/PostgreSQL/PostgreSQLTransaction.h"

#include <Plugins/Samples/Common/OrthancPluginCppWrapper.h>
#include <Core/Logging.h>


namespace OrthancDatabases
{
  class PostgreSQLStorageArea : public StorageBackend
  {
  private:
    class Factory : public IDatabaseFactory
    {
    private:
      PostgreSQLStorageArea&  that_;

    public:
      Factory(PostgreSQLStorageArea& that) :
      that_(that)
      {
      }

      virtual Dialect GetDialect() const
      {
        return Dialect_PostgreSQL;
      }

      virtual IDatabase* Open()
      {
        return that_.OpenInternal();
      }
    };

    OrthancPluginContext*  context_;
    PostgreSQLParameters   parameters_;
    bool                   clearAll_;

    IDatabase* OpenInternal()
    {
      std::auto_ptr<PostgreSQLDatabase> db(new PostgreSQLDatabase(parameters_));

      db->Open();

      if (parameters_.HasLock())
      {
        db->AdvisoryLock(43 /* some arbitrary constant */);
      }

      if (clearAll_)
      {
        db->ClearAll();
      }

      {
        PostgreSQLTransaction t(*db);

        if (!db->DoesTableExist("StorageArea"))
        {
          db->Execute("CREATE TABLE IF NOT EXISTS StorageArea("
                      "uuid VARCHAR NOT NULL PRIMARY KEY,"
                      "content OID NOT NULL,"
                      "type INTEGER NOT NULL)");

          // Automatically remove the large objects associated with the table
          db->Execute("CREATE OR REPLACE RULE StorageAreaDelete AS ON DELETE "
                      "TO StorageArea DO SELECT lo_unlink(old.content);");
        }

        t.Commit();
      }

      return db.release();
    }

  public:
    PostgreSQLStorageArea(const PostgreSQLParameters& parameters) :
    StorageBackend(new Factory(*this)),
    parameters_(parameters),
    clearAll_(false)
    {
    }

    void SetClearAll(bool clear)
    {
      clearAll_ = clear;
    }


    virtual void Create(DatabaseManager::Transaction& transaction,
                        const std::string& uuid,
                        const void* content,
                        size_t size,
                        OrthancPluginContentType type)
    {
      std::auto_ptr<FileValue> file(new FileValue(content, size));
      
      {
        DatabaseManager::CachedStatement statement(
          STATEMENT_FROM_HERE, GetManager(),
          "INSERT INTO StorageArea VALUES (${uuid}, ${content}, ${type})");
     
        statement.SetParameterType("uuid", ValueType_Utf8String);
        statement.SetParameterType("content", ValueType_File);
        statement.SetParameterType("type", ValueType_Integer64);

        Dictionary args;
        args.SetUtf8Value("uuid", uuid);
        args.SetValue("content", file.release());
        args.SetIntegerValue("type", type);
     
        statement.Execute(args);
      }
    }


    virtual void Read(void*& content,
                      size_t& size,
                      DatabaseManager::Transaction& transaction, 
                      const std::string& uuid,
                      OrthancPluginContentType type) 
    {
      DatabaseManager::CachedStatement statement(
        STATEMENT_FROM_HERE, GetManager(),
        "SELECT content FROM StorageArea WHERE uuid=$1 AND type=$2");
     
      statement.SetParameterType("uuid", ValueType_Utf8String);
      statement.SetParameterType("type", ValueType_Integer64);

      Dictionary args;
      args.SetUtf8Value("uuid", uuid);
      args.SetIntegerValue("type", type);
     
      statement.Execute(args);

      if (statement.IsDone())
      {
        throw Orthanc::OrthancException(Orthanc::ErrorCode_UnknownResource);
      }
      else if (statement.GetResultFieldsCount() != 1 ||
               statement.GetResultField(0).GetType() != ValueType_File)
      {
        throw Orthanc::OrthancException(Orthanc::ErrorCode_Database);        
      }
      else
      {
        const FileValue& value = dynamic_cast<const FileValue&>(statement.GetResultField(0));
        ReadFromString(content, size, value.GetContent());
      }
    }


    virtual void Remove(DatabaseManager::Transaction& transaction,
                        const std::string& uuid,
                        OrthancPluginContentType type)
    {
      DatabaseManager::CachedStatement statement(
        STATEMENT_FROM_HERE, GetManager(),
        "DELETE FROM StorageArea WHERE uuid=${uuid} AND type=${type}");
     
      statement.SetParameterType("uuid", ValueType_Utf8String);
      statement.SetParameterType("type", ValueType_Integer64);

      Dictionary args;
      args.SetUtf8Value("uuid", uuid);
      args.SetIntegerValue("type", type);
     
      statement.Execute(args);
    }
  };
}


static bool DisplayPerformanceWarning()
{
  (void) DisplayPerformanceWarning;   // Disable warning about unused function
  LOG(WARNING) << "Performance warning in PostgreSQL storage area: "
               << "Non-release build, runtime debug assertions are turned on";
  return true;
}


extern "C"
{
  ORTHANC_PLUGINS_API int32_t OrthancPluginInitialize(OrthancPluginContext* context)
  {
    Orthanc::Logging::Initialize(context);

    assert(DisplayPerformanceWarning());

    /* Check the version of the Orthanc core */
    if (OrthancPluginCheckVersion(context) == 0)
    {
      char info[1024];
      sprintf(info, "Your version of Orthanc (%s) must be above %d.%d.%d to run this plugin",
              context->orthancVersion,
              ORTHANC_PLUGINS_MINIMAL_MAJOR_NUMBER,
              ORTHANC_PLUGINS_MINIMAL_MINOR_NUMBER,
              ORTHANC_PLUGINS_MINIMAL_REVISION_NUMBER);
      OrthancPluginLogError(context, info);
      return -1;
    }

    OrthancPluginSetDescription(context, "Stores the Orthanc storage area into a PostgreSQL database.");

    OrthancPlugins::OrthancConfiguration configuration(context);

    if (!configuration.IsSection("PostgreSQL"))
    {
      LOG(WARNING) << "No available configuration for the PostgreSQL storage area plugin";
      return 0;
    }

    OrthancPlugins::OrthancConfiguration postgresql;
    configuration.GetSection(postgresql, "PostgreSQL");

    bool enable;
    if (!postgresql.LookupBooleanValue(enable, "EnableStorage") ||
        !enable)
    {
      LOG(WARNING) << "The PostgreSQL storage area is currently disabled, set \"EnableStorage\" "
                   << "to \"true\" in the \"PostgreSQL\" section of the configuration file of Orthanc";
      return 0;
    }

    try
    {
      OrthancDatabases::PostgreSQLParameters parameters(postgresql);
      OrthancDatabases::StorageBackend::Register
        (context, new OrthancDatabases::PostgreSQLStorageArea(parameters));
    }
    catch (Orthanc::OrthancException& e)
    {
      LOG(ERROR) << e.What();
      return -1;
    }
    catch (...)
    {
      LOG(ERROR) << "Native exception while initializing the plugin";
      return -1;
    }

    return 0;
  }


  ORTHANC_PLUGINS_API void OrthancPluginFinalize()
  {
    LOG(WARNING) << "PostgreSQL storage area is finalizing";
    OrthancDatabases::StorageBackend::Finalize();
  }


  ORTHANC_PLUGINS_API const char* OrthancPluginGetName()
  {
    return "postgresql-storage";
  }


  ORTHANC_PLUGINS_API const char* OrthancPluginGetVersion()
  {
    return ORTHANC_PLUGIN_VERSION;
  }
}