/*
 * MySQLBackend.hh
 *
 *  Created on: Feb 26, 2016
 *      Author: nbarros
 */

#ifndef SRC_DB_PGSQLBACKEND_HH_
#define SRC_DB_PGSQLBACKEND_HH_


#include <RAT/json.hh>
#include <RAT/DBTable.hh>
#include <RAT/Log.hh>
#include <utility>
#include <string>
#include <set>

// Use the C-interface, as there is no native C++ interface
// Adding an explicit C++ interface would only increse the number of dependencies
extern "C" {
#include <libpq-fe.h>
}

using std::string;

namespace RAT {


class PgSQLBackend {
public:
  PgSQLBackend(const std::string &conn_str = "");
  virtual ~PgSQLBackend();

  void SetConnOpts(const string &opts) {conn_options_ = opts;}
  const string& GetConnOpts() const {return conn_options_;}

  void SetConnURL(const std::string &url) {server_url_=url;}
  const string& GetConnURL() const {return server_url_;}

  void Disconnect();
  void Connect();

  void InsertObject(DBTable &tbl);

  std::set<std::string> GetListIndexes(const std::string &type_name, const int &run = 0);

  std::set<std::string> GetListTypes(const int run = 0);

  /**
   * Fetches the first object that matches the type and index requested. Useful for
   * cases where the run number is not known, or is irrelevant as all we care is the object structure.
   * @param tblname
   * @param index
   * @param found
   * @param size_bytes
   * @return
   */
  json::Value FetchObjFast(const std::string &tblname, const std::string &index,bool &found, size_t &size_bytes);
  json::Value FetchObject(const std::string &tblname, const std::string &index, const int &runNumber, const int &passNumber, bool &found, size_t &size_bytes);
  //json::Value FetchObjectWithTag(const std::string &tblname, const std::string &index, const int &runNumber, const int &passNumber, const std::string &tag, bool &found, size_t &size_bytes);

  void SetReconnectRetries(const unsigned int &nretries) {num_reconn_ = nretries;};
  const unsigned int& GetReconnRetries() const {return num_reconn_;};

  // Defines that from now on, connections should be opened and closed as needed
  void SetBoRCompleted(bool status = true) {bor_done_ = status;};
  bool GetBoRCompleted() const {return bor_done_;};

//  bool GetLastQueryFail() {return last_query_fail_;}
//  const std::string &GetLastQueryMsg() {return last_query_msg_;}

  void SetDbTag(const std::string &tag); // {ratdb_tag_ = tag;}
  std::string GetDbTag() { return ratdb_tag_;}
protected:
  void CheckAndResetConn();
  void ClearResultset();
//  void ParseConnectionStr(const std::string url);
  void ExecuteSelectQuery(const char* query);
  void FailQuery(const char* query);

  PGconn     *pg_conn_;
  PGresult   *pg_res_;
  PGnotify   *pg_notify_;
  std::string server_url_;
  std::string conn_options_;
  unsigned int num_reconn_;
  unsigned int num_sec_wait_;
  bool bor_done_;
  bool bor_warn_given_;
//  bool last_query_fail_;
//  std::string last_query_msg_;
  std::string ratdb_tag_;
  std::string ratdb_header_tbl_;
  static const std::string ratdb_header_tbl_base_;
};

inline void PgSQLBackend::ExecuteSelectQuery(const char* query) {
  pg_res_ = PQexec(pg_conn_, query);

  if (PQresultStatus(pg_res_) != PGRES_TUPLES_OK)
  {
    FailQuery(query);
  }
#ifdef RATDEBUG
  else {
    detail << "PgSQLBackend::RATDB query executed successfully." << newline;
  }
#endif /*RATDEBUG*/
  // If the query executed fine, there is nothing else to do

}

inline void PgSQLBackend::ClearResultset() {
  PQclear(pg_res_);
  pg_res_ = NULL;
}

} /* namespace RAT */

#endif /* SRC_DB_PGSQLBACKEND_HH_ */