#include "storage.h"

#include "config.h"

#include <chrono>

#include <SQLiteCpp/SQLiteCpp.h>

using namespace std::string_literals;

Storage::Storage(const Config& config):
 m_db(config.getDataPath() + "/whiteboard.db3", SQLite::OPEN_READWRITE | SQLite::OPEN_CREATE),
 m_maxage(config.getMaxage())
{
 m_db.exec("CREATE TABLE IF NOT EXISTS documents (id VARCHAR(16) PRIMARY KEY, value BLOB, rev INTEGER, cursorpos INTEGER, timestamp BIGINT)");
}

uint64_t Storage::getNumberOfDocuments()
{
 SQLite::Statement query(m_db, "SELECT COUNT(*) FROM documents");
 if (!query.executeStep())
  throw std::runtime_error("Count not possible");
 
 return static_cast<int64_t>(query.getColumn(0));
}

void Storage::cleanup()
{
 if (m_maxage == 0)
  return;

 SQLite::Statement query(m_db, "DELETE FROM documents WHERE timestamp + ? < unixepoch()");
 query.bind(1, static_cast<int64_t>(m_maxage));

 query.exec();
}

bool Storage::exists(const std::string& id)
{
 SQLite::Statement query(m_db, "SELECT id FROM documents WHERE id = ?");
 query.bind(1, id);

 return query.executeStep();
}

std::string Storage::getDocument(const std::string& id)
{
 SQLite::Statement query(m_db, "SELECT value FROM documents WHERE id = ?");
 query.bind(1, id);

 if (!query.executeStep())
  throw std::runtime_error("id "s + id + " not found"s);

 return query.getColumn(0);
}

int Storage::getRevision(const std::string& id)
{
 SQLite::Statement query(m_db, "SELECT rev FROM documents WHERE id = ?");
 query.bind(1, id);

 if (!query.executeStep())
  throw std::runtime_error("id "s + id + " not found"s);

 return query.getColumn(0);
}

int Storage::getCursorPos(const std::string& id)
{
 SQLite::Statement query(m_db, "SELECT cursorpos FROM documents WHERE id = ?");
 query.bind(1, id);

 if (!query.executeStep())
  throw std::runtime_error("id "s + id + " not found"s);

 return query.getColumn(0);
}

std::tuple<std::string, int, int> Storage::getRow(const std::string& id)
{
 SQLite::Statement query(m_db, "SELECT value, rev, cursorpos FROM documents WHERE id = ?");
 query.bind(1, id);

 if (!query.executeStep())
  throw std::runtime_error("id "s + id + " not found"s);

 return {query.getColumn(0), query.getColumn(1), query.getColumn(2)};
}
 
void Storage::setDocument(const std::string& id, const std::string& document)
{
 SQLite::Statement query(m_db, "UPDATE documents SET value = ? WHERE id = ?");
 query.bind(1, document);
 query.bind(2, id);

 if (!query.exec()) {
  SQLite::Statement query(m_db, "INSERT INTO documents (id, value, rev, cursorpos, timestamp) values (?, ?, ?, ?, unixepoch())");
  query.bind(1, id);
  query.bind(2, document);
  query.bind(3, 0);
  query.bind(4, 0);
  query.exec();
 }
}

void Storage::setRevision(const std::string& id, int rev)
{
 SQLite::Statement query(m_db, "UPDATE documents SET rev = ? WHERE id = ?");
 query.bind(1, rev);
 query.bind(2, id);

 if (!query.exec())
  throw std::runtime_error("Unable to insert row with id "s + id);
}

void Storage::setCursorPos(const std::string& id, int cursorPos)
{
 SQLite::Statement query(m_db, "UPDATE documents SET cursorpos = ? WHERE id = ?");
 query.bind(1, cursorPos);
 query.bind(2, id);

 if (!query.exec())
  throw std::runtime_error("Unable to insert row with id "s + id);
}

void Storage::setRow(const std::string& id, const std::string& document, int rev, int cursorPos)
{
 SQLite::Statement query(m_db, "INSERT OR REPLACE INTO documents (id, value, rev, cursorpos, timestamp) values (?, ?, ?, ?, unixepoch())");
 query.bind(1, id);
 query.bind(2, document);
 query.bind(3, rev);
 query.bind(4, cursorPos);
 if (!query.exec())
  throw std::runtime_error("Unable to insert row with id "s + id);
}