#include "../include/UserManager.h"
#include "../../libs/libbcrypt/bcrypt.h"

// TODO read userStorage file location from config

// initialize static filename to empty string
std::string UserManager::filename = "";

void UserManager::init(const std::string &file) {
	filename = file;
	std::ifstream ifile(filename);
	if (!ifile.is_open()) {
		// create new file by adding a user if userStorage does not exist
		addUser("user", "pass");
		std::cout << "Created \"" << filename << "\" and added the default user" << std::endl;
	}
	ifile.close();
}

bool UserManager::isAllowed(const std::string &name, const std::string &pw) {
	std::map<std::string, std::string> user_map;
	readFromFile(user_map);
	auto it = user_map.find(name);
	// check if user exists and pw is valid
	if (it != user_map.end()) {

		// check bcrypt hash
		std::string hash = it->second;
		int ret = bcrypt_checkpw(pw.c_str(), hash.c_str());
		if (ret != 0)
			return false;

		return true;
	}
	return false;
}

bool UserManager::addUser(const std::string &name, const std::string &pw) {
	std::map<std::string, std::string> user_map;
	readFromFile(user_map);
	auto it = user_map.find(name);
	// if user exists, do nothing
	if (it != user_map.end()) {
		return false;
	}

	// calculate bcrypt hash
	std::string salt;
	std::string hash;
	salt.resize(BCRYPT_HASHSIZE);
	hash.resize(BCRYPT_HASHSIZE);

	int ret = bcrypt_gensalt(10, &salt.front());
	if (ret != 0)
		return false;
	ret = bcrypt_hashpw(pw.c_str(), salt.c_str(), &hash.front());
	if (ret != 0)
		return false;

	user_map.insert(std::pair<std::string, std::string>(name, hash));
	writeToFile(user_map);
	return true;
}

bool UserManager::deleteUser(const std::string &name, const std::string &pw) {
	// TODO check pw before delete
	std::map<std::string, std::string> user_map;
	readFromFile(user_map);
	auto it = user_map.find(name);
	if (it == user_map.end()) {
		return false;
	}
	if (it->second.compare(pw) != 0) {
		return false;
	}
	user_map.erase(it);
	writeToFile(user_map);
	return true;
}

// read content from file into given map
void UserManager::readFromFile(std::map<std::string, std::string> &user_map) {
	std::ifstream ifile(filename);
	std::string line;
	while (getline(ifile, line)) {
		std::stringstream ss(line);
		std::string segment;
		std::vector<std::string> v;
		while (std::getline(ss, segment, ';')) {
			v.push_back(segment);
		}
		user_map.insert(std::pair<std::string, std::string>(v.at(0), v.at(1)));
	}
	ifile.close();
}

// write content from map to file
void UserManager::writeToFile(std::map<std::string, std::string> &user_map) {
	std::ofstream file;
	file.open(filename);
	for (auto const &x : user_map) {
		file << x.first << ";" << x.second << std::endl;
	}
	file.close();
}