/**
 * Orthanc - A Lightweight, RESTful DICOM Store
 * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
 * Department, University Hospital of Liege, Belgium
 * Copyright (C) 2017-2021 Osimis S.A., Belgium
 *
 * This program is free software: you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * In addition, as a special exception, the copyright holders of this
 * program give permission to link the code of its release with the
 * OpenSSL project's "OpenSSL" library (or with modified versions of it
 * that use the same license as the "OpenSSL" library), and distribute
 * the linked executables. You must obey the GNU General Public License
 * in all respects for all of the code used other than "OpenSSL". If you
 * modify file(s) with this exception, you may extend this exception to
 * your version of the file(s), but you are not obligated to do so. If
 * you do not wish to do so, delete this exception statement from your
 * version. If you delete this exception statement from all source files
 * in the program, then also delete it here.
 * 
 * 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
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 **/


#pragma once

#include "../../OrthancFramework/Sources/Cache/LeastRecentlyUsedIndex.h"
#include "../../OrthancFramework/Sources/DicomFormat/DicomMap.h"

#include "Database/IDatabaseWrapper.h"
#include "DicomInstanceOrigin.h"

#include <boost/thread.hpp>
#include <boost/noncopyable.hpp>

namespace Orthanc
{
  class DatabaseLookup;
  class ParsedDicomFile;
  class ServerContext;

  class ServerIndex : public boost::noncopyable
  {
  public:
    typedef std::list<FileInfo> Attachments;
    typedef std::map<std::pair<ResourceType, MetadataType>, std::string>  MetadataMap;

  private:
    class Listener;
    class Transaction;
    class UnstableResourcePayload;
    class MainDicomTagsRegistry;

    bool done_;
    boost::mutex mutex_;
    boost::thread flushThread_;
    boost::thread unstableResourcesMonitorThread_;

    std::unique_ptr<Listener> listener_;
    IDatabaseWrapper& db_;
    LeastRecentlyUsedIndex<int64_t, UnstableResourcePayload>  unstableResources_;

    uint64_t     maximumStorageSize_;
    unsigned int maximumPatients_;
    std::unique_ptr<MainDicomTagsRegistry>  mainDicomTagsRegistry_;

    static void FlushThread(ServerIndex* that,
                            unsigned int threadSleep);

    static void UnstableResourcesMonitorThread(ServerIndex* that,
                                               unsigned int threadSleep);

    // A transaction must be running
    static void MainDicomTagsToJson(Json::Value& result,
                                    IDatabaseWrapper& db,
                                    int64_t resourceId,
                                    ResourceType resourceType);

    bool IsRecyclingNeeded(uint64_t instanceSize);

    void Recycle(uint64_t instanceSize,
                 const std::string& newPatientId);

    void StandaloneRecycling();

    void MarkAsUnstable(int64_t id,
                        Orthanc::ResourceType type,
                        const std::string& publicId);

    void LogChange(int64_t internalId,
                   ChangeType changeType,
                   ResourceType resourceType,
                   const std::string& publicId);

    void SignalNewResource(ChangeType changeType,
                           ResourceType level,
                           const std::string& publicId,
                           int64_t internalId);

    uint64_t IncrementGlobalSequenceInternal(GlobalProperty property);

    void NormalizeLookup(std::vector<DatabaseConstraint>& target,
                         const DatabaseLookup& source,
                         ResourceType level) const;

    // A transaction must be running
    static SeriesStatus GetSeriesStatus(IDatabaseWrapper& db,
                                        int64_t id,
                                        int64_t expectedNumberOfInstances);

    bool IsUnstableResource(int64_t id);

  public:
    ServerIndex(ServerContext& context,
                IDatabaseWrapper& database,
                unsigned int threadSleep);

    ~ServerIndex();

    void Stop();

    uint64_t GetMaximumStorageSize() const
    {
      return maximumStorageSize_;
    }

    uint64_t GetMaximumPatientCount() const
    {
      return maximumPatients_;
    }

    // "size == 0" means no limit on the storage size
    void SetMaximumStorageSize(uint64_t size);

    // "count == 0" means no limit on the number of patients
    void SetMaximumPatientCount(unsigned int count);

    StoreStatus Store(std::map<MetadataType, std::string>& instanceMetadata,
                      const DicomMap& dicomSummary,
                      const Attachments& attachments,
                      const MetadataMap& metadata,
                      const DicomInstanceOrigin& origin,
                      bool overwrite,
                      bool hasTransferSyntax,
                      DicomTransferSyntax transferSyntax,
                      bool hasPixelDataOffset,
                      uint64_t pixelDataOffset);

    bool DeleteResource(Json::Value& target /* out */,
                        const std::string& uuid,
                        ResourceType expectedType);

    void LogExportedResource(const std::string& publicId,
                             const std::string& remoteModality);

    bool IsProtectedPatient(const std::string& publicId);

    void SetProtectedPatient(const std::string& publicId,
                             bool isProtected);

    void GetChildren(std::list<std::string>& result,
                     const std::string& publicId);

    void GetChildInstances(std::list<std::string>& result,
                           const std::string& publicId);

    void SetMetadata(const std::string& publicId,
                     MetadataType type,
                     const std::string& value);

    void DeleteMetadata(const std::string& publicId,
                        MetadataType type);

    bool LookupMetadata(std::string& target,
                        const std::string& publicId,
                        ResourceType expectedType,
                        MetadataType type);

    void ListAvailableAttachments(std::set<FileContentType>& target,
                                  const std::string& publicId,
                                  ResourceType expectedType);

    bool LookupParent(std::string& target,
                      const std::string& publicId);

    uint64_t IncrementGlobalSequence(GlobalProperty sequence);

    void LogChange(ChangeType changeType,
                   const std::string& publicId);

    void DeleteChanges();

    void DeleteExportedResources();

    void GetResourceStatistics(/* out */ ResourceType& type,
                               /* out */ uint64_t& diskSize, 
                               /* out */ uint64_t& uncompressedSize, 
                               /* out */ unsigned int& countStudies, 
                               /* out */ unsigned int& countSeries, 
                               /* out */ unsigned int& countInstances, 
                               /* out */ uint64_t& dicomDiskSize, 
                               /* out */ uint64_t& dicomUncompressedSize, 
                               const std::string& publicId);

    void LookupIdentifierExact(std::vector<std::string>& result,
                               ResourceType level,
                               const DicomTag& tag,
                               const std::string& value);

    StoreStatus AddAttachment(const FileInfo& attachment,
                              const std::string& publicId);

    void DeleteAttachment(const std::string& publicId,
                          FileContentType type);

    void SetGlobalProperty(GlobalProperty property,
                           const std::string& value);

    bool LookupGlobalProperty(std::string& value,
                              GlobalProperty property);

    std::string GetGlobalProperty(GlobalProperty property,
                                  const std::string& defaultValue);

    bool GetMainDicomTags(DicomMap& result,
                          const std::string& publicId,
                          ResourceType expectedType,
                          ResourceType levelOfInterest);

    // Only applicable at the instance level
    bool GetAllMainDicomTags(DicomMap& result,
                             const std::string& instancePublicId);

    bool LookupResourceType(ResourceType& type,
                            const std::string& publicId);

    unsigned int GetDatabaseVersion();

    bool LookupParent(std::string& target,
                      const std::string& publicId,
                      ResourceType parentType);

    void ReconstructInstance(const ParsedDicomFile& dicom);

    void ApplyLookupResources(std::vector<std::string>& resourcesId,
                              std::vector<std::string>* instancesId,  // Can be NULL if not needed
                              const DatabaseLookup& lookup,
                              ResourceType queryLevel,
                              size_t limit);



    /***
     ** PROTOTYPING FOR DB REFACTORING BELOW
     ***/
    
  public:
    class ReadOnlyTransaction : public boost::noncopyable
    {
    protected:
      IDatabaseWrapper&  db_;
      
    public:
      explicit ReadOnlyTransaction(IDatabaseWrapper& db) :
        db_(db)
      {
      }

      /**
       * Higher-level constructions
       **/

      SeriesStatus GetSeriesStatus(int64_t id,
                                   int64_t expectedNumberOfInstances)
      {
        return ServerIndex::GetSeriesStatus(db_, id, expectedNumberOfInstances);
      }

      void MainDicomTagsToJson(Json::Value& result,
                               int64_t resourceId,
                               ResourceType resourceType)
      {
        ServerIndex::MainDicomTagsToJson(result, db_, resourceId, resourceType);
      }

      /**
       * Read-only methods from "IDatabaseWrapper"
       **/

      void GetAllMetadata(std::map<MetadataType, std::string>& target,
                          int64_t id)
      {
        db_.GetAllMetadata(target, id);
      }

      void GetAllPublicIds(std::list<std::string>& target,
                           ResourceType resourceType)
      {
        return db_.GetAllPublicIds(target, resourceType);
      }

      void GetAllPublicIds(std::list<std::string>& target,
                           ResourceType resourceType,
                           size_t since,
                           size_t limit)
      {
        return db_.GetAllPublicIds(target, resourceType, since, limit);
      }  

      void GetChanges(std::list<ServerIndexChange>& target /*out*/,
                      bool& done /*out*/,
                      int64_t since,
                      uint32_t maxResults)
      {
        db_.GetChanges(target, done, since, maxResults);
      }

      void GetChildrenPublicId(std::list<std::string>& target,
                               int64_t id)
      {
        db_.GetChildrenPublicId(target, id);
      }

      void GetExportedResources(std::list<ExportedResource>& target /*out*/,
                                bool& done /*out*/,
                                int64_t since,
                                uint32_t maxResults)
      {
        return db_.GetExportedResources(target, done, since, maxResults);
      }

      void GetLastChange(std::list<ServerIndexChange>& target /*out*/)
      {
        db_.GetLastChange(target);
      }

      void GetLastExportedResource(std::list<ExportedResource>& target /*out*/)
      {
        return db_.GetLastExportedResource(target);
      }

      int64_t GetLastChangeIndex()
      {
        return db_.GetLastChangeIndex();
      }

      void GetMainDicomTags(DicomMap& map,
                            int64_t id)
      {
        db_.GetMainDicomTags(map, id);
      }

      uint64_t GetResourceCount(ResourceType resourceType)
      {
        return db_.GetResourceCount(resourceType);
      }
      
      uint64_t GetTotalCompressedSize()
      {
        return db_.GetTotalCompressedSize();
      }
    
      uint64_t GetTotalUncompressedSize()
      {
        return db_.GetTotalUncompressedSize();
      }
      
      bool LookupAttachment(FileInfo& attachment,
                            int64_t id,
                            FileContentType contentType)
      {
        return db_.LookupAttachment(attachment, id, contentType);
      }
      
      bool LookupResource(int64_t& id,
                          ResourceType& type,
                          const std::string& publicId)
      {
        return db_.LookupResource(id, type, publicId);
      }
      
      bool LookupResourceAndParent(int64_t& id,
                                   ResourceType& type,
                                   std::string& parentPublicId,
                                   const std::string& publicId)
      {
        return db_.LookupResourceAndParent(id, type, parentPublicId, publicId);
      }
    };


    class ReadWriteTransaction : public ReadOnlyTransaction
    {
    public:
      explicit ReadWriteTransaction(IDatabaseWrapper& db) :
        ReadOnlyTransaction(db)
      {
      }

    };


    class IReadOnlyOperations : public boost::noncopyable
    {
    public:
      virtual ~IReadOnlyOperations()
      {
      }

      virtual void Apply(ReadOnlyTransaction& transaction) = 0;
    };


    class IReadWriteOperations : public boost::noncopyable
    {
    public:
      virtual ~IReadWriteOperations()
      {
      }

      virtual void Apply(ReadWriteTransaction& transaction) = 0;
    };


    typedef void (*ReadOnlyFunction) (ReadOnlyTransaction& transaction);  // TODO - Is this useful?
    typedef void (*ReadWriteFunction) (ReadWriteTransaction& transaction);  // TODO - Is this useful?

    
  private:
    class ReadOnlyWrapper;  // TODO - Is this useful?
    class ReadWriteWrapper;  // TODO - Is this useful?

    void ApplyInternal(IReadOnlyOperations* readOperations,
                       IReadWriteOperations* writeOperations);
    
    unsigned int maxRetries_;

  public:
    void Apply(IReadOnlyOperations& operations);
  
    void Apply(IReadWriteOperations& operations);

    void Apply(ReadOnlyFunction func);

    void Apply(ReadWriteFunction func);

    bool ExpandResource(Json::Value& target,
                        const std::string& publicId,
                        ResourceType level);

    void GetAllMetadata(std::map<MetadataType, std::string>& target,
                        const std::string& publicId,
                        ResourceType level);

    void GetAllUuids(std::list<std::string>& target,
                     ResourceType resourceType);

    void GetAllUuids(std::list<std::string>& target,
                     ResourceType resourceType,
                     size_t since,
                     size_t limit);

    void GetGlobalStatistics(/* out */ uint64_t& diskSize,
                             /* out */ uint64_t& uncompressedSize,
                             /* out */ uint64_t& countPatients, 
                             /* out */ uint64_t& countStudies, 
                             /* out */ uint64_t& countSeries, 
                             /* out */ uint64_t& countInstances);

    bool LookupAttachment(FileInfo& attachment,
                          const std::string& instancePublicId,
                          FileContentType contentType);

    void GetChanges(Json::Value& target,
                    int64_t since,
                    unsigned int maxResults);

    void GetLastChange(Json::Value& target);

    void GetExportedResources(Json::Value& target,
                              int64_t since,
                              unsigned int maxResults);

    void GetLastExportedResource(Json::Value& target);

  };
}