using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using Xylem.Common.Hardware.WaterMeter.WaterMeterRegisters;

namespace Xylem.Common.Hardware.WaterMeter.Genesis.Registers
{
    /// <summary>
    /// Representing all registers from one meter.
    /// create empty list on construction.
    /// updated after read register
    /// </summary>
    public class MeterRegisters
    {
        /// <summary>
        /// Dictionary of meter registers
        /// </summary>
        public readonly ConcurrentDictionary<RegisterDefinition, Byte[]> MeterRegisterDic;
        
        /// <summary>
        /// create empty list on construction.
        /// </summary>
        public MeterRegisters()
        {
            MeterRegisterDic = new ConcurrentDictionary<RegisterDefinition, Byte[]>();
        }

        /// <summary>
        /// add empty registers
        /// </summary>
        /// <param name="adds"></param>
        public void AddRegistersDefinitions(List<IRegister> adds)
        {
            foreach (var add in adds)
            {
                try
                {
                    if (add is RegisterDefinition addGenesisRegister)
                    {
                        MeterRegisterDic.TryAdd(addGenesisRegister, null);
                    }
                }
                catch (Exception )
                {
                    // ignored
                }
            }
        }

        /// <summary>
        /// Search register referenced by name as combination of application name and register name
        /// Example:  GENSISFLOW_LedMode
        /// </summary>
        /// <param name="name"></param>
        /// <returns></returns>
        public RegisterDefinition GetRegisterDefinitionByName(String name)
        {
            if (MeterRegisterDic == null || !MeterRegisterDic.Any())
            {
                throw new ApplicationException($"Register {name} is not available. Registers are not loaded!");
            }
            
            var regDef = MeterRegisterDic.Where(f => f.Key.GetIdent().ToLower() == name.ToLower()).ToList();
            
            if (regDef.Count() == 1)
            {
                return regDef.First().Key;
            }
            var r =  regDef.Count() >= 1 ? regDef.Last().Key : new RegisterDefinition();

            if (!string.IsNullOrEmpty(r.AppName))
            {
                return r;
            }
            // if no register is available throw ex 
            throw new ApplicationException($"Register {name} is not available. Check the configuration.json for latest version!");
        }

        /// <summary>
        /// Get current value of register in program.
        /// ATTENTION: this is not the current meter register!
        /// for meter register use read register in advance
        /// </summary>
        /// <param name="register">register to get</param>
        /// <returns>current value</returns>
        public Byte[] Get(String register)
        {
            var reg = GetRegisterDefinitionByName(register);
            if (!MeterRegisterDic.ContainsKey(reg)) return null;
            if (MeterRegisterDic.Count(f => f.Key.GetIdent() == register) > 1)
            {
                if (MeterRegisterDic.Any(f => f.Key.GetIdent() == register && f.Value != null))
                {
                    var regDs = MeterRegisterDic.Last(f => f.Key.GetIdent() == register && f.Value != null);
                    return regDs.Value;
                  
                }
         
             
            }
            var regD = MeterRegisterDic.First(f => f.Key.GetIdent() == register);
            return regD.Value;
        }

        /// <summary>
        /// Set register in program
        /// ATTENTION: this is not stored to the meter!
        /// to store to meter register use write register!
        /// </summary>
        /// <param name="register">Register to set</param>
        /// <param name="value">Value to set</param>
        public void Set(RegisterDefinition register, Byte[] value)
        {
            if (MeterRegisterDic.ContainsKey(register))
            {
                MeterRegisterDic[register] = value;
            }
            else if (register.DataType != null && register.RegisterDetail != null)
            {
                throw new ApplicationException("unknown register");
            }
        }
    }
}