#include "pch.h"
#include "IEngine.h"
#include "Crypto.h"
#include <stdexcept>
#include <filesystem>

using namespace craftlab::fakeraid;

namespace craftlab::fakeraid
{
	class Engine : public IEngine
	{
	public:
		Engine(const std::vector<std::string>& path);

		void DirExistsOrThrow() const override;
		std::vector<std::string> GetRootPaths() const override;
		std::vector<std::string> GetPaths() const override;
		std::deque<std::string> GetCurrentDir() const override;
		bool SetWorkingDirectory(const std::vector<std::string>& path) override;
		FileAndSumListByRepositoryIndex ListFiles() override;
		void ListFilesRecur(FileAndSumListByRepositoryIndex*, bool* threadStopping) override;
		size_t CountFilesRecur() override;
		void Cd(const std::string& dirName) override;

		std::string BuildCurrentDirPath(const std::string& root, const PathParts& pathParts) const override;
		std::string BuildCurrentDirPath(const File& file) const override;
		std::string BuildFullPath(const File& file) const override;

		bool AnyFileExists(const std::vector<std::string>& files, const std::string& dropTo) const override;

		void RemoveFiles(const std::vector<std::string>& paths) const override;
		void RemoveDirs(const std::vector<std::string>& paths) const override;
		void CopyItems(const std::vector<CopyInstruction>& itemsToCopy) const override;

		void AddFiles(const std::vector<std::string>& files, const std::string& destination) const override;

	private:
		void ListFiles(FileAndSumListByRepositoryIndex& result, const PathParts& currentDir, std::string* lastFileScanned =nullptr, bool* threadStopping =nullptr);
		FileAndSumList ListFiles(const std::string& root, const PathParts& path, int repositoryIndex, std::string* lastFileScanned =nullptr, bool* threadStopping =nullptr);

		void CopyItem(const CopyInstruction& dst) const;

		const std::vector<std::string> rootPaths;
		std::deque<std::string> currentDir;
	};
}

Engine::Engine(const std::vector<std::string>& path): rootPaths(path), currentDir()
{}

std::vector<std::string> Engine::GetRootPaths() const
{
	return rootPaths;
}

std::vector<std::string> Engine::GetPaths() const
{
	std::vector<std::string> paths;
	const std::string workingDir = BuildCurrentDirPath("", currentDir);
	std::transform(rootPaths.begin(), rootPaths.end(), std::back_inserter(paths), [&workingDir](const std::string& val)
	{
		return (std::filesystem::path(val) / std::filesystem::path(workingDir)).string();
	});
	return paths;
}

std::deque<std::string> Engine::GetCurrentDir() const
{
	return currentDir;
}

std::string Engine::BuildCurrentDirPath(const std::string& root, const PathParts& _currentDir) const
{
	std::filesystem::path result(root);

	for (const std::string& path : _currentDir)
		result = result / path;
	return result.string();
}

std::string Engine::BuildCurrentDirPath(const File& file) const
{
	std::filesystem::path result;

	for (const std::string& path : file.directory)
		result = result / path;
	result = result / file.fileName;
	return result.string();
}

std::string Engine::BuildFullPath(const File& file) const
{
	std::filesystem::path result(rootPaths[file.repositoryIndex]);

	for (const std::string& path : file.directory)
		result /= path;
	result /= file.fileName;
	return result.string();
}

bool vectorEquals(const std::vector<std::string>& a, const std::deque<std::string>& b)
{
	if (a.size() != b.size())
		return false;
	auto iterA = a.begin();
	auto iterB = b.begin();
	while (iterA != a.end())
	{
		if (*iterA != *iterB)
			return false;
		++iterA;
		++iterB;
	}
	return true;
}

bool Engine::SetWorkingDirectory(const std::vector<std::string>& path)
{
	if (vectorEquals(path, currentDir))
		return false;
	currentDir.clear();
	std::copy(path.begin(), path.end(), std::back_inserter(currentDir));
	return true;
}

void Engine::Cd(const std::string& dirName)
{
	currentDir.push_back(dirName);
}

FileAndSumList Engine::ListFiles(const std::string& root, const std::deque<std::string>& wd, int repositoryIndex, std::string* lastFileScanned, bool* threadStopping)
{
	FileAndSumList result {};
	const std::string path = BuildCurrentDirPath(root, wd);
	Crypto cryptoEngine;

	std::filesystem::directory_iterator directoryIterator; // FIXME error handling
	try
	{
		directoryIterator = std::filesystem::directory_iterator(path);
	}
	catch (std::exception& e)
	{
		return result; // FIXME
	}
	for (const std::filesystem::directory_entry& file : directoryIterator)
	{
		bool isDirectory = false;
		bool isFile = false;

		try
		{
			isDirectory = file.is_directory();
			isFile = file.is_regular_file();
		}
		catch (std::exception& e)
		{}
		if (isDirectory || isFile)
		{
			FileAndSum fileInfos;
			fileInfos.fileName = file.path().filename().string();
			fileInfos.isDir = file.is_directory();
			fileInfos.directory = wd;
			fileInfos.repositoryIndex = repositoryIndex;

			if (nullptr != lastFileScanned)
				*lastFileScanned = BuildCurrentDirPath(fileInfos);

			try
			{
				cryptoEngine.Compute(path, fileInfos);
			}
			catch (std::runtime_error&)
			{
			}
			result.push_back(fileInfos);
		}
		if (threadStopping && *threadStopping)
			return result;
	}
	return result;
}

void Engine::ListFiles(FileAndSumListByRepositoryIndex& result, const std::deque<std::string>& currentDir, std::string* lastFileScanned, bool* threadStopping)
{
	int index = 0;
	for (const auto& i : rootPaths)
	{
		const FileAndSumList files = ListFiles(i, currentDir, index++, lastFileScanned, threadStopping);
		result.FileAndSumListByRepositoryIndex.push_back(files);
		for (const FileAndSum& file : files)
			result.FileList[BuildCurrentDirPath(file)] = file;
		if (threadStopping && *threadStopping)
			return;
	}
}

FileAndSumListByRepositoryIndex Engine::ListFiles()
{
	FileAndSumListByRepositoryIndex result;
	ListFiles(result, currentDir);
	return result;
}

void Engine::ListFilesRecur(FileAndSumListByRepositoryIndex* result, bool* threadStopping)
{
	std::deque<PathParts> itemsToDo { currentDir };

	do
	{
		FileAndSumListByRepositoryIndex newItems;
		const PathParts currentPath = itemsToDo.front();
		ListFiles(newItems, currentPath, &result->lastInsertedFilename, threadStopping);
		itemsToDo.pop_front();
		std::copy(newItems.FileAndSumListByRepositoryIndex.begin(), newItems.FileAndSumListByRepositoryIndex.end(), std::back_inserter(result->FileAndSumListByRepositoryIndex));
		for (const auto& file : newItems.FileList)
		{
			result->FileList[file.first] = file.second;
			if (file.second.isDir)
			{
				PathParts dirPath = currentPath;
				dirPath.push_back(file.second.fileName);
				itemsToDo.push_back(dirPath);
			}
		}
	} while (!itemsToDo.empty() && !*threadStopping);
}

size_t Engine::CountFilesRecur()
{
	size_t result =0;
	std::deque<std::filesystem::path> itemsToDo;

	for (const auto& i: rootPaths)
		itemsToDo.push_back(i);

	do
	{
		std::filesystem::directory_iterator directoryIterator; // FIXME error handling
		try
		{
			directoryIterator = std::filesystem::directory_iterator(itemsToDo.front());
		}
		catch (std::exception& e)
		{
			itemsToDo.pop_front();
			continue;
		}
		for (const std::filesystem::directory_entry& file : directoryIterator)
		{
			try {
				if (file.is_regular_file())
					++result;
				else if (file.is_directory())
				{
					itemsToDo.push_back(file.path());
					++result;
				}
			}
			catch (std::exception)
			{}
		}
		itemsToDo.pop_front();
	} while (!itemsToDo.empty());
	return result;
}

void Engine::DirExistsOrThrow() const
{
	char errorBuffer[1024];
	for (const std::string& fullPath : GetPaths())
	{
		struct stat fileInfo;

		if (stat(fullPath.c_str(), &fileInfo))
		{
			strerror_s(errorBuffer, errno);
			throw std::runtime_error("cannot access " + fullPath + ": " + errorBuffer);
		}
		if (!(fileInfo.st_mode & S_IFDIR))
		{
			strerror_s(errorBuffer, ENOTDIR);
			throw std::runtime_error("cannot access " + fullPath + ": " + errorBuffer);
		}
	}
}

void Engine::RemoveFiles(const std::vector<std::string>& paths) const
{
	for (const std::string& path: paths)
		std::filesystem::remove(path); // FIXME error handling
}

void Engine::RemoveDirs(const std::vector<std::string>& paths) const
{
	for (const std::string& path : paths)
		std::filesystem::remove_all(path); // FIXME error handling
}

void Engine::CopyItem(const IEngine::CopyInstruction& item) const
{
	std::filesystem::copy(item.source, item.destination, std::filesystem::copy_options::overwrite_existing | std::filesystem::copy_options::recursive); // FIXME error handling
}

void Engine::CopyItems(const std::vector<IEngine::CopyInstruction>& paths) const
{
	for (const CopyInstruction& item: paths)
		CopyItem(item);
}

bool Engine::AnyFileExists(const std::vector<std::string>& files, const std::string& destination) const
{
	for (const std::string _file : files)
	{
		std::filesystem::path file(_file);
		for (const std::string& root : rootPaths)
		{
			std::filesystem::path outputPath(root + "/" + destination);
			outputPath /= file.filename();
			if (std::filesystem::exists(outputPath))
			{
				if (std::filesystem::equivalent(outputPath, file)) // FIXME error handling
					throw IEngine::SameFileError();
				return true;
			}
		}
	}
	return false;
}

void Engine::AddFiles(const std::vector<std::string>& files, const std::string& _destination) const
{
	for (const std::string _file : files)
	{
		std::filesystem::path file(_file);
		for (const std::string& root : rootPaths)
		{
			std::filesystem::path destination(root + "/" + _destination);
			destination /= file.filename();
			std::filesystem::copy(file, destination, std::filesystem::copy_options::overwrite_existing | std::filesystem::copy_options::recursive); // FIXME error handling
		}
	}
}

IEngine* EngineManager::Open(const std::vector<std::string>& path)
{
	return new Engine(path);
}