using System.Text.Json.Nodes;

namespace InnovEnergy.Lib.StatusApi;




/// SIGN CONVENTION
///
/// Voltages have to be measured/indicated so that they are guaranteed to be never negative.
/// In the case of AC this is accomplished by using the RMS measurement.
/// The sign convention of the current (and hence power, since voltage defined to be never negative)
/// depends on the type of the device.
/// If the device can only produce (e.g. PV) or only consume (e.g. Loads),
/// then the current has to be 0 or positive.
/// If the device is a prosumer (e.g. inverter, battery, grid...)
/// then a positive sign denotes current (power) flow away from the grid (to the "right")
/// and a negative sign denotes current (power) flow towards the grid (to the "left")




/// the currently known DeviceTypes, to be serialized as string in JSON 
public enum DeviceType
{
    None,
    PvOnAcIn    ,
    PvOnAcOut   ,
    PvOnDc      ,
    Load        ,
    CriticalLoad,
    Battery     ,
    Grid        ,
    Inverter    ,
    AcInToAcOut ,
    DcDc        ,
    DcLoad      ,
    Losses
}


public interface IJson
{
    JsonNode ToJson();
}


/// A phase must have at least a known Voltage and Current.
/// For DC this is already enough.
/// For AC the values have to be in RMS (not amplitude or P2P)
/// Power can be inferred, P = UI
public interface IPhase : IJson
{
    public Double Voltage { get; }  // U, non-negative
    public Double Current { get; }  // I, sign depends on device type, see sign convention above
}

/// An AC phase additionally needs a field Phi denoting
/// the phase difference between voltage and current
/// Phi has to be in the interval [0,2pi)
/// Apparent Power = U*I
/// Active Power   = cos(phi)*U*I
/// Reactive Power = sin(phi)*U*I
/// Power Factor   = cos(phi)
/// Active Power is signed (via cos(phi))
/// Current and Voltage are RMS and unsigned
public interface IAcPhase : IPhase 
{
    public Double Phi { get; }
}

/// a device must have a Name and DeviceType 
public interface IDevice : IJson
{
    DeviceType Type { get; }
    String?    Name { get; }
}

/// A DC device must have a field denoting its DC connection
public interface IDcDevice : IDevice
{
    public IPhase Dc { get; }
}

/// An AC device can have 1 to 3 AC phases
/// An AC device also needs a Frequency measurement
/// Total power can be obtained by summing the power of the phases
public interface IAcDevice : IDevice
{
    public IAcPhase[] Ac        { get; } // 1 to 3 phases
    public Double     Frequency { get; } // non-negative
}

/// A low voltage 48V DC device
/// Needed to distinguish the two sides of the DCDC
/// Will be dropped once we get HV batteries
public interface IDc48Device : IDevice
{
    public IPhase? Dc48 { get; }
}

public interface IBattery : IJson
{
    public Double Soc         { get; }
    public Double Temperature { get; }
}

public interface IDc48Battery : IDc48Device, IBattery
{
}

public interface IDcBattery : IDcDevice, IBattery
{
}


/// An inverter has both an AC and a DC connection 
public interface IInverter : IAcDevice, IDcDevice
{    
}

public interface IDeviceStack : IJson
{
    public IDevice[] Top          { get; } 
    public IDevice[] Right        { get; } 
    public IDevice[] Bottom       { get; } 
    public Boolean   Disconnected { get; } 
}

public interface IInstallationStatus: IJson
{
    public IDeviceStack[] Stacks { get; }
}