#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 Cd(const std::string& dirName) override;

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

	private:
		FileAndSumList ListFiles(const std::string& root, int repositoryIndex);
		std::string BuildCurrentDirPath(const std::string& root ="") 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();
	std::transform(rootPaths.begin(), rootPaths.end(), std::back_inserter(paths), [&workingDir](const std::string& val) { return val + "/" + workingDir; });
	return paths;
}

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

std::string Engine::BuildCurrentDirPath(const std::string& root) const
{
	std::stringstream ss;
	ss << root;
	bool written = !root.empty();

	for (const std::string& path : currentDir)
	{
		if (written)
			ss << "/";
		ss << path;
		written = true;
	}
	return ss.str();
}

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, int repositoryIndex)
{
	FileAndSumList result;
	const std::string path = BuildCurrentDirPath(root);
	Crypto cryptoEngine;
	for (const std::filesystem::directory_entry& file : std::filesystem::directory_iterator(path))
	{
		if (file.is_directory() || file.is_regular_file())
		{
			FileAndSum fileInfos;
			fileInfos.fileName = file.path().filename().string();
			fileInfos.isDir = file.is_directory();
			fileInfos.repositoryIndex = repositoryIndex;
			try
			{
				cryptoEngine.Compute(path, fileInfos);
			}
			catch (std::runtime_error&)
			{}
			result.push_back(fileInfos);
		}
	}
	return result;
}

FileAndSumListByRepositoryIndex Engine::ListFiles()
{
	FileAndSumListByRepositoryIndex result;
	int index = 0;
	for (const auto& i : rootPaths)
	{
		const FileAndSumList files = ListFiles(i, index++);
		result.FileAndSumListByRepositoryIndex.push_back(files);
		for (const FileAndSum& file : files)
			result.FileList[file.fileName] = file;
	}
	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);
}

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

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