using InnovEnergy.Lib.Protocols.Modbus.Channels;
using InnovEnergy.Lib.Protocols.Modbus.Clients;
using InnovEnergy.Lib.Protocols.Modbus.Slaves;
using InnovEnergy.Lib.Units.Composite;
using InnovEnergy.Lib.Utils;

namespace InnovEnergy.Lib.Devices.AMPT;

public class AmptDevices
{
    private readonly ModbusDevice<CommunicationUnitRegisters>            _CommunicationUnit;
    private readonly IEnumerable<ModbusDevice<StringOptimizerRegisters>> _StringOptimizers;

    public AmptDevices(String hostname, UInt16 port = 502) : this(new TcpChannel(hostname, port))
    {
    }

    public AmptDevices(Channel transport) : this(new ModbusTcpClient(transport, 2))
    {
    }
    
    
    public AmptDevices(ModbusClient modbusClient)
    {
        _CommunicationUnit = new ModbusDevice<CommunicationUnitRegisters>(modbusClient);
        _StringOptimizers = StringOptimizers(modbusClient);
    }

    public AmptStatus Read()
    {
        CommunicationUnitRegisters? cuStatus = null;

        try
        {
            cuStatus = _CommunicationUnit.Read();
        }
        catch (Exception e)
        {
            Console.WriteLine( "Failed to read Ampt data \n"+ e.Message );
            // TODO: log
        }

        // CommunicationUnit knows how many StringOptimizers are connected
        var nStringOptimizers = cuStatus?.NumberOfStringOptimizers ?? 0;
        
        // hardcoded: every SO has 2 strings (produced like this by AMPT)
        var nStrings = nStringOptimizers * 2; 
        
        // read stati from optimizers
        var soStati = _StringOptimizers
                      .Take(nStringOptimizers)
                      .Select(so => so.Read())
                      .ToArray(nStringOptimizers);
        
        // every SO has 2 strings but ONE Dc Link Connection 
        // they are connected to a shared Dc Link, so Voltage seen by them should be approx the same.
        // voltages are averaged, currents added
        
        // TODO: alarm when we see substantially different voltages
        
        var busVoltage = nStringOptimizers == 0 ? 0 : soStati.Average(r => r.Voltage);
        var busCurrent = nStringOptimizers == 0 ? 0 : soStati.Sum    (r => r.Current);
        var dc         = DcBus.FromVoltageCurrent(busVoltage, busCurrent);
        
        // flatten the 2 strings of each SO into one array 
        var strings = soStati.SelectMany(GetStrings).ToArray(nStrings); 

        return new AmptStatus(dc, strings);
    }

    
    
    private static IEnumerable<DcBus> GetStrings(StringOptimizerRegisters r)
    {
        // hardcoded: every SO has 2 strings (produced like this by AMPT)
        
        yield return DcBus.FromVoltageCurrent(r.String1Voltage, r.String1Current);
        yield return DcBus.FromVoltageCurrent(r.String2Voltage, r.String2Current);
    }


    private static IEnumerable<ModbusDevice<StringOptimizerRegisters>> StringOptimizers(ModbusClient modbusClient)
    {
        var cache = new List<ModbusDevice<StringOptimizerRegisters>>();

        ModbusDevice<StringOptimizerRegisters> GetOptimizer(Int32 i)
        {
            if (i < cache.Count)
                return cache[i];

            var modbusDevice = new ModbusDevice<StringOptimizerRegisters>(modbusClient, i * 16);
            cache.Add(modbusDevice);
            return modbusDevice;
        }

        return Enumerable
              .Range(0, Byte.MaxValue)
              .Select(GetOptimizer);
    }
}