#ifndef _electrical_data_h_
#define _electrical_data_h_
#include <vector>
#include <complex>
#include "events.h"
#include "AdmittanceNetwork.h"

/**
 * This inteface class is used to access electrical data for the model.
 * The electrical model consists of buses, or nodes, labeled
 * from 0 to N-1, where N is the number of nodes. All units
 * are assumed to be compatible with the "p.u." system.
 */
class ElectricalData
{
	public:
		/**
		 * Structure that describes a transmission line.
		 */
		struct line_t
		{
			/// Default constructor
			line_t():
				from(0),to(0),y(){}
			/**
			 * Create a line from not "from" to "to" with admittance y.
			 */
			line_t(unsigned from, unsigned to, Complex y):
				from(from),to(to),y(y){}
			/// Nodes connected by the line
			unsigned from, to;
			/// Admittance of the line
			Complex y;
		};
		/**
		 * Structure that characterizes a synchronous machine.
		 */
		struct genr_t
		{
			/// The constructor sets some a reasonable (maybe) initial condition
			genr_t():Tspd1(20.0),Tspd2(20.0),Ef_max(5.0),
			Xd(0.001,0.01),M(3.0),R(50.0),Te(1.0),Vref(1.0),Agc(200.0),FreqTol(1.0),
			w0(0.0),Ef0(1.0),T0(0.0),Pm0(1.0),C0(0.0),Ps(1.0),
			fix_at_Pm0(true){} 
			/// Speed governor time constants
			double Tspd1, Tspd2;
			/// Maximum excitation voltage
			double Ef_max;
			/// Machine reactance
			Complex Xd;
			/// Inertia constant
			double M;
			/// Droop
			double R;
			/// Time constant for the exicitation contoller
			double Te;
			/// Voltage magnitude reference
			double Vref;
			/// Area control gain for this machine
			double Agc;
			/// Frequency tolerance (Hertz)
			double FreqTol;
			/// Initial angular velocity (p.u.)
			double w0;
			/// Initial exiciter field voltage (p.u.)
			double Ef0;
			/// Initial power angle (radians)
			double T0;
			/// Initial mechanical power output (p.u.)
			double Pm0;
			/// Initial governor signal
			double C0;
			/// Power set point
			double Ps;
			/**
			 *  If true, the simulator will always use
			 *  Pm0 for the setpoint. This flag is 
			 *  included for backwards compatibility
			 */
			bool fix_at_Pm0;
		};
		
		/// Constructor
		ElectricalData(){}
		/// Get the number of generators in the model
		virtual unsigned getGenrCount() = 0;
		/// Get the total number of nodes in the model
		virtual unsigned getNodeCount() = 0;
		/// Get the list of nodes that are generation points
		virtual const std::vector<unsigned>& getGenrs() = 0;
		/// Get the list of electrical lines
		virtual const std::vector<line_t>& getLines() = 0;
		/** 
		 * Get the Norton equilvalent current at a load node.
		 * This should be zero except for active loads.
		 */
		virtual Complex getCurrent(unsigned node) = 0;
		/**
		  * Get the Norton equivalent admittance at a load node.
		  * If there is no load, then this should return zero.
		  */
		virtual Complex getAdmittance(unsigned node) = 0;
		/// Get the parameters for a synchronous machine
		virtual genr_t getGenrParams(unsigned genr) = 0;
		/**
		 * Construct an admittance network for this data
		 * and store it in the supplied Ybus which must have
		 * the appropriate size.
		 */
		void buildAdmitMatrix(AdmittanceNetwork& Y);
		/// Destructor
		virtual ~ElectricalData(){}
};

#endif