using Esiur.Core;
using Esiur.Data;
using Esiur.Resource;
using Mono.Unix.Native;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Management;
using System.Net.NetworkInformation;
using System.Net.Sockets;
using System.Text;
using System.Timers;

namespace AZ.Compute.Agent
{
    [Resource]
    public partial class Node
    {

        System.Timers.Timer timer;
        PerformanceCounter cpuCounter;
        PerformanceCounter ramCounter;
        NetworkInterface nic;
        ulong totalNetworkBytes;

        const double nicSpeed = 1 * 1024 * 1024; // 1 MBps

        // linux
        float prevCpuIdle = 0f;
        float prevCpuTotal = 0f;


        [Export] string id;
        [Export] string ip;

        [Export] float cpu;
        [Export] float ram;
        [Export] float network;

        [Export] uint tasks;

        [Export] uint cpuClock;
        [Export] uint cpuMaxClock;

        [Export] float networkSpeed;

        [Export] Job[] jobs = new Job[0];


        [Export]
        public async AsyncReply<Job> Compute(string fileName, string arguments)
        {
            var psi = new ProcessStartInfo()
            {
                FileName = fileName,
                Arguments = arguments
            };

            var p = Process.Start(psi);

            var job = await Warehouse.New<Job>(fileName, null, this);
            job.Process = p;


            Jobs = jobs.Append(job).ToArray();

            return job;
        }

        ulong GetNetworkLinux()
        {
            var netLines = File
                .ReadAllLines("/proc/net/dev")
                .Skip(3)
                .First()
                .Split(' ', StringSplitOptions.RemoveEmptyEntries)
                .Skip(1)
                .Select(ulong.Parse)
                .ToArray();


            return netLines[0] + netLines[8];
        }

        float GetLinuxCPU(float interval = 5)
        {
            var cpuLine = File
                .ReadAllLines("/proc/stat")
                .First()
                .Split(' ', StringSplitOptions.RemoveEmptyEntries)
                .Skip(1)
                .Select(float.Parse)
                .ToArray();

            var idle = cpuLine[3];
            var total = cpuLine.Sum();

            var percent = 100.0 * (1.0 - (idle - prevCpuIdle) / (total - prevCpuTotal));

            //Console.WriteLine($"CPU {percent:0.00}%");

            prevCpuIdle = idle;
            prevCpuTotal = total;

            return (float)percent / interval;
        }

        float GetLinuxRAM()
        {

            return File
            .ReadAllLines("/proc/meminfo")
            .Skip(1)
            .First()
            .Split(' ', StringSplitOptions.RemoveEmptyEntries)
            .Skip(1)
            .Select(ulong.Parse)
            .First() / 1024;

            //Console.WriteLine("Free " + freeMem);

            var pages = Syscall.sysconf(SysconfName._SC_PHYS_PAGES);
            var pageSize = Syscall.sysconf(SysconfName._SC_PAGESIZE);

            var ram = pages * pageSize / 1024.0f;

            Console.WriteLine($"RAM {ram:0.00}%");

            return ram;
        }

        public Node()
        {

            Id = System.Environment.MachineName;

            nic = NetworkInterface.GetAllNetworkInterfaces().Where(x => x.OperationalStatus == OperationalStatus.Up).First();
            networkSpeed = (float)(nic.Speed / 1048576.0);

            totalNetworkBytes = (ulong)nic.GetIPv4Statistics().BytesReceived + (ulong)nic.GetIPv4Statistics().BytesSent;

            Ip = nic.GetIPProperties().UnicastAddresses.First(x => x.Address.AddressFamily == AddressFamily.InterNetwork).Address.ToString();

            if (Environment.OSVersion.Platform == PlatformID.Win32NT)
            {

                using (ManagementObject Mo = new ManagementObject("Win32_Processor.DeviceID='CPU0'"))
                {
                    cpuClock = (uint)(Mo["CurrentClockSpeed"]);
                    cpuMaxClock = (uint)(Mo["MaxClockSpeed"]);
                }

                cpuCounter = new PerformanceCounter("Processor", "% Processor Time", "_Total");
                ramCounter = new PerformanceCounter("Memory", "Available MBytes");
            }


            timer = new System.Timers.Timer();
            timer.Elapsed += Timer_Elapsed;
            timer.Interval = 5000;
            timer.Start();
        }

        private void Timer_Elapsed(object? sender, ElapsedEventArgs e)
        {
            try
            {

                ulong ntb = 0;



                if (Environment.OSVersion.Platform == PlatformID.Win32NT)
                {                
                    ntb = (ulong)nic.GetIPv4Statistics().BytesReceived + (ulong)nic.GetIPv4Statistics().BytesSent;
                    Cpu = cpuCounter.NextValue();
                    Ram = ramCounter.NextValue();
                }
                else
                {
                    ntb = GetNetworkLinux();
                    Cpu = GetLinuxCPU();
                    Ram = GetLinuxRAM();
                }

                Network = (float)(((ntb - totalNetworkBytes) / 5.0) / nicSpeed);

                totalNetworkBytes = ntb;

                //Console.WriteLine("Net " + Network + " " + ntb);

                foreach (Job job in jobs)
                {
                    if (!job.Finished)
                    {
                        job.Start = job.Start;
                        job.Ram = (float)(job.Process.PeakWorkingSet64 / 1048576.0);
                    }
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }
        }
    }
}