// Copyright (c) 2011-2016 The Cryptonote developers
// Distributed under the MIT/X11 software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#pragma once

#include <cstdint>
#include <future>
#include <system_error>
#include <unordered_set>

#include "crypto/crypto.h"
#include "CryptoNoteCore/CryptoNoteBasic.h"

#include "IObservable.h"
#include "IStreamSerializable.h"
#include "ITransfersSynchronizer.h"

namespace CryptoNote {

struct CompleteBlock;

class IBlockchainSynchronizerObserver {
public:
  virtual void synchronizationProgressUpdated(uint32_t processedBlockCount, uint32_t totalBlockCount) {}
  virtual void synchronizationCompleted(std::error_code result) {}
};

class IBlockchainConsumerObserver;

class IBlockchainConsumer : public IObservable<IBlockchainConsumerObserver> {
public:
  virtual ~IBlockchainConsumer() {}
  virtual SynchronizationStart getSyncStart() = 0;
  virtual const std::unordered_set<Crypto::Hash>& getKnownPoolTxIds() const = 0;
  virtual void onBlockchainDetach(uint32_t height) = 0;
  virtual bool onNewBlocks(const CompleteBlock* blocks, uint32_t startHeight, uint32_t count) = 0;
  virtual std::error_code onPoolUpdated(const std::vector<std::unique_ptr<ITransactionReader>>& addedTransactions, const std::vector<Crypto::Hash>& deletedTransactions) = 0;

  virtual std::error_code addUnconfirmedTransaction(const ITransactionReader& transaction) = 0;
  virtual void removeUnconfirmedTransaction(const Crypto::Hash& transactionHash) = 0;
};

class IBlockchainConsumerObserver {
public:
  virtual void onBlocksAdded(IBlockchainConsumer* consumer, const std::vector<Crypto::Hash>& blockHashes) {}
  virtual void onBlockchainDetach(IBlockchainConsumer* consumer, uint32_t blockIndex) {}
  virtual void onTransactionDeleteBegin(IBlockchainConsumer* consumer, Crypto::Hash transactionHash) {}
  virtual void onTransactionDeleteEnd(IBlockchainConsumer* consumer, Crypto::Hash transactionHash) {}
  virtual void onTransactionUpdated(IBlockchainConsumer* consumer, const Crypto::Hash& transactionHash, const std::vector<ITransfersContainer*>& containers) {}
};

class IBlockchainSynchronizer :
  public IObservable<IBlockchainSynchronizerObserver>,
  public IStreamSerializable {
public:
  virtual void addConsumer(IBlockchainConsumer* consumer) = 0;
  virtual bool removeConsumer(IBlockchainConsumer* consumer) = 0;
  virtual IStreamSerializable* getConsumerState(IBlockchainConsumer* consumer) const = 0;
  virtual std::vector<Crypto::Hash> getConsumerKnownBlocks(IBlockchainConsumer& consumer) const = 0;

  virtual std::future<std::error_code> addUnconfirmedTransaction(const ITransactionReader& transaction) = 0;
  virtual std::future<void> removeUnconfirmedTransaction(const Crypto::Hash& transactionHash) = 0;

  virtual void start() = 0;
  virtual void stop() = 0;
};

}