#include <set>
#include "pch.h"
#include "FileDiff.h"
#include "IEngine.h"

using namespace craftlab::fakeraid;

FileDiff::FileDiff()
{
}

FileDiff::~FileDiff()
{
}

FileDiff::FileVersionList FileDiff::GroupBy(const IEngine& engine, const FileAndSumListByRepositoryIndex& fileListsWithRepo, size_t indexCount)
{
	FileVersionList result;
	for (const FileAndSumList& fileLists : fileListsWithRepo.FileAndSumListByRepositoryIndex)
	{
		for (const FileAndSum& i : fileLists)
		{
			const std::string fullPath = engine.BuildCurrentDirPath(i);
			if (!result.contains(fullPath))
				result.emplace(fullPath, std::vector<std::optional<FileAndSum>>(indexCount, std::nullopt));
			result[fullPath][i.repositoryIndex] = i;
		}
	}
	return result;
}

std::vector<int> FileDiff::computeVersionIds(const ListOfOptionalFileAndSum& versions)
{
	std::vector<int> result;
	std::map<CheckSum, int> versionList;
	for (const OptionalFileAndSum& version : versions)
	{
		if (version.has_value())
		{
			if (versionList.contains(version->checksum))
				result.push_back(versionList[version->checksum]);
			else
			{
				int nextId = (int) versionList.size() + 1;
				versionList.emplace(version->checksum, nextId);
				result.push_back(nextId);
			}
		}
		else
			result.push_back(0);
	}
	return result;
}

void FileDiff::CheckVersions(DiffResult& output, const std::string& fileKey, const FileDiff::ListOfOptionalFileAndSum& versions)
{
	const auto& firstVersionIter = std::find_if(versions.begin(), versions.end(), [](const OptionalFileAndSum& i) { return i.has_value(); });
	const FileAndSum& firstVersion = firstVersionIter->value();
	std::vector<bool> filePresent(versions.size(), true);
	int idx =0;

	for (const OptionalFileAndSum& i : versions)
	{
		if (!i.has_value())
		{
			filePresent[idx] = false;
			continue;
		}
		if (firstVersion.checksum != i->checksum)
		{
			output.differentFiles.emplace(fileKey, computeVersionIds(versions));
			return;
		}
	}
	if (std::find(filePresent.begin(), filePresent.end(), false) != filePresent.end())
	{
		if (firstVersion.isDir)
			output.missingDirs.emplace(fileKey, filePresent);
		else
			output.missingFiles.emplace(fileKey, filePresent);
	}
	else
		output.correctFiles.push_back(firstVersion);
}

DiffResult FileDiff::Process(const IEngine& engine, const FileAndSumListByRepositoryIndex& fileLists)
{
	DiffResult result;
	const FileVersionList& fileAndVersionLists = GroupBy(engine, fileLists, engine.GetRootPaths().size());

	for (const std::pair<std::string, ListOfOptionalFileAndSum>& key : fileAndVersionLists)
		CheckVersions(result, key.first, key.second);
	result.FileList = fileLists.FileList;
	return result;
}

bool DiffResult::HasError() const
{
	return !differentFiles.empty() || !missingDirs.empty() || !missingFiles.empty();
}

size_t FileAndSumListByRepositoryIndex::ExistingFileCount() const
{
	size_t result {};
	for (const auto& i : FileAndSumListByRepositoryIndex)
		result += i.size();
	return result;
}