#include "PasswordManager.h"

//#include <botan/filters.h>
//#include <botan/pipe.h>
//#include <botan/sha2_64.h>
//#include <botan/hash.h>
//#include <botan/hmac.h>
//#include <botan/pbkdf2.h>
//#include <botan/rng.h>
//#include <botan/base64.h>
//#include <botan/loadstor.h>
//#include <botan/mem_ops.h>
#include <botan/auto_rng.h>
#include <botan/base64.h>
#include <botan/psk_db_sql.h>
#include <botan/sqlite3.h>
#include <botan/scrypt.h>
#include <boost/lexical_cast.hpp>



Botan::secure_vector<uint8_t> PasswordManager::KeyStrengthener::derive(const std::string &passphrase)
{
	Botan::secure_vector<uint8_t> master_key(m_keySize);
	m_hasher->derive_key(master_key.data(), master_key.size(), passphrase.c_str(), passphrase.length(), m_salt.data(), m_salt.size());

	return master_key;
}

void PasswordManager::KeyStrengthener::saveParams(std::shared_ptr<Botan::Sqlite3_Database> db, const std::string &table_name)
{
	auto sc = dynamic_cast<Botan::Scrypt*>(m_hasher.get());
	size_t i1 = sc->N();
	size_t i2 = sc->r();
	size_t i3 = sc->p();

	// SAVE parameters in database
	auto stmt = db->new_statement("INSERT INTO " + table_name + "(id, algo, i1, i2, i3, ks, salt) VALUES(?1, ?2, ?3, ?4, ?5)");
	stmt->bind(1, 1);
	stmt->bind(2, "Scrypt");
	stmt->bind(3, i1);
	stmt->bind(4, i2);
	stmt->bind(5, i3);
	stmt->bind(6, m_keySize);
	stmt->bind(7, Botan::base64_encode(m_salt));
	stmt->spin();

}

// -------------------------

void PasswordManager::openDatabase(std::shared_ptr<Botan::Sqlite3_Database> db, std::string passphrase)
{
//	std::string psk_db_file_name;
//	auto db = std::make_shared<Botan::Sqlite3_Database>(psk_db_file_name);

	KeyStrengthener ks;
	// if (database exists)
	if (isPskStoreInitialized(db)) {
		ks = getKeyStrengthener(db);
	}
	else {
		initializeNewPskStore(db);
		ks = createKeyStrengthener();
		ks.saveParams(db, m_secretAlgoTableName);
	}

	Botan::secure_vector<uint8_t> master_key = ks.derive(passphrase);
	m_pskDatabase = std::make_unique<Botan::Encrypted_PSK_Database_SQL>(master_key, db, m_passwordTableName);
}


void PasswordManager::closeDatabase()
{
	m_pskDatabase.reset();
}


void PasswordManager::set(const std::string &id, const std::string &passwd)
{
	if (m_pskDatabase) {

	}
	else {
		throw PasswordManagerLockedException();
	}
}

std::string PasswordManager::get(const std::string &id, const std::string &passwd)
{
	if (m_pskDatabase) {

	}
	else {
		throw PasswordManagerLockedException();
	}
}

void PasswordManager::remove(const std::string &id)
{
	if (m_pskDatabase) {

	}
	else {
		throw PasswordManagerLockedException();
	}
}


void PasswordManager::initializeNewPskStore(std::shared_ptr<Botan::Sqlite3_Database> db)
{
	// Create tables
	// - psk_masterkey_algo
	// - psk_passwd
	std::string create_statement =
			"CREATE TABLE IF NOT EXISTS " + m_secretAlgoTableName + "( \n"
			" id INTEGER PRIMARY KEY \n"
			" algo TEXT \n"
			" i1 INTEGER \n"
			" i2 INTEGER \n"
			" i3 INTEGER \n"
			" ks INTEGER \n"
			" salt TEXT \n"
			");";
	db->create_table(create_statement);

}

bool PasswordManager::isPskStoreInitialized(std::shared_ptr<Botan::Sqlite3_Database> db)
{
	// Is the table with the secret data present and filled?
	auto stmt = db->new_statement("SELECT name FROM sqlite_master WHERE type='table' AND name=?1");
	stmt->bind(1, m_secretAlgoTableName);
	bool ok = stmt->step();
	if (ok) {
		auto stmt = db->new_statement("SELECT algo FROM " + m_secretAlgoTableName + " WHERE id=1");
		return stmt->step();
	}
	return false;
}

PasswordManager::KeyStrengthener PasswordManager::getKeyStrengthener(std::shared_ptr<Botan::Sqlite3_Database> db)
{
	auto stmt = db->new_statement("SELECT algo, i1, i2, i3, ks, salt FROM " + m_secretAlgoTableName + " WHERE id=1");
	if (stmt->step()) {
		std::string algo = stmt->get_str(0);
		size_t i1 = boost::lexical_cast<size_t>(stmt->get_str(1));
		size_t i2 = boost::lexical_cast<size_t>(stmt->get_str(2));
		size_t i3 = boost::lexical_cast<size_t>(stmt->get_str(3));
		size_t ks = boost::lexical_cast<size_t>(stmt->get_str(4));

		auto pwh_fam = Botan::PasswordHashFamily::create(algo);
		return KeyStrengthener(
					pwh_fam->from_params(i1, i2, i3),
					Botan::base64_decode(stmt->get_str(5)),
					ks
					);
	}
	else {

	}
}

PasswordManager::KeyStrengthener PasswordManager::createKeyStrengthener()
{
//	std::unique_ptr<Botan::PasswordHash> pwh;

	size_t key_size = 64;
	Botan::secure_vector<uint8_t> salt(key_size);
	Botan::AutoSeeded_RNG rng;
	rng.randomize(salt.data(), salt.size());

	const std::string algo = "Scrypt";
	auto pwh_fam = Botan::PasswordHashFamily::create(algo);
	return KeyStrengthener(
				pwh_fam->tune(key_size, std::chrono::seconds(2), 130),
				salt,
				key_size
				);
}