using Microsoft.AspNetCore.Components;

namespace EgwCoreLib.Razor
{
    public partial class ProgressDisplay : IDisposable
    {
        #region Public Enums

        public enum ModalSize
        {
            Small,
            Medium,
            Large
        }

        #endregion Public Enums

        #region Public Properties

        /// <summary>
        /// Valore corrente
        /// </summary>
        [Parameter]
        public double CurrVal
        {
            get => actVal;
            set
            {
                actVal = value;
                startVal = value;
                isLoading = actVal < MaxVal;
            }
        }

        /// <summary>
        /// Dimensioni attese modale
        /// default: ModalSize.Medium
        /// </summary>
        [Parameter]
        public ModalSize DisplaySize { get; set; } = ModalSize.Medium;

        /// <summary>
        /// Tempo atteso per prossimo step
        /// default: 10000
        /// </summary>
        [Parameter]
        public int ExpTimeMSec { get; set; } = 10000;

        /// <summary>
        /// Valore massimo ammesso
        /// default: 100
        /// </summary>
        [Parameter]
        public double MaxVal { get; set; } = 100;

        /// <summary>
        /// Style modale
        /// default: card
        /// alternative: card alert-primary
        /// </summary>
        [Parameter]
        public string ModalCss { get; set; } = "card";

        /// <summary>
        /// Prossimo valore ammesso (fino al max)
        /// default: 100
        /// </summary>
        [Parameter]
        public double NextVal { get; set; } = 100;

        /// <summary>
        /// Style progressbar
        /// default: progress-bar progress-bar-striped progress-bar-animated
        /// </summary>
        [Parameter]
        public string ProgressCss { get; set; } = "progress-bar progress-bar-striped progress-bar-animated";

        /// <summary>
        /// Intervallo interno per refresh percentuale avanzamento
        /// default: 100ms
        /// </summary>
        [Parameter]
        public int RefreshInterval { get; set; } = 100;

        /// <summary>
        /// Indica se mostrare la percentuale vanzamento
        /// default: true
        /// </summary>
        [Parameter]
        public bool ShowPercent { get; set; } = true;

        /// <summary>
        /// Limite per anticipo slowdown (% della durata di ExpTimeMSec)
        /// </summary>
        [Parameter]
        public double SlowLimit { get; set; } = 0.5;

        /// <summary>
        /// Numero di secondi prima (rispetto valore ExpTimeMsec) da cui iniziare rallentamento
        /// </summary>
        private int slowWindowMSec
        {
            get => (int)(ExpTimeMSec * SlowLimit);
        }

        /// <summary>
        /// Titolo da mostrare (se "" NON lo mostra)
        /// </summary>
        [Parameter]
        public string Title { get; set; } = "Progress";

        #endregion Public Properties

        #region Public Methods

        public void Dispose()
        {
            uiTimer?.Dispose();
        }

        #endregion Public Methods

        #region Protected Properties

        protected string modalDialogCss
        {
            get
            {
                string answ = "modal-dialog";
                switch (DisplaySize)
                {
                    case ModalSize.Small:
                        answ = "modal-dialog modal-sm";
                        break;

                    case ModalSize.Large:
                        answ = "modal-dialog modal-xl";
                        break;

                    case ModalSize.Medium:
                    default:
                        break;
                }
                return answ;
            }
        }

        #endregion Protected Properties

        #region Protected Methods

        protected override async Task OnParametersSetAsync()
        {
            // salvo valori aggiornamento...
            if (ExpTimeMSec > 0)
            {
                lastUpdate = DateTime.Now;
                nextUpdate = lastUpdate.AddMilliseconds(ExpTimeMSec);
                await RefreshDisplay();
            }
            if (isLoading)
            {
                uiTimer?.Dispose();
                uiTimer = new PeriodicTimer(TimeSpan.FromMilliseconds(RefreshInterval));
                RunTimer();
            }
            else
            {
                uiTimer = null;
            }
        }

        #endregion Protected Methods

        #region Private Fields

        private PeriodicTimer? uiTimer = null;

        #endregion Private Fields

        #region Private Properties

        private double actVal { get; set; } = 100;
        private string currWidth { get; set; } = "";
        private string displayMsg { get; set; } = "Loading...";

        private bool isLoading { get; set; } = false;

        private DateTime lastUpdate { get; set; } = DateTime.Now.AddMinutes(-1);

        private DateTime nextUpdate { get; set; } = DateTime.Now;

        private double startVal { get; set; } = 100;

        #endregion Private Properties

        #region Private Methods

        private async Task RefreshDisplay()
        {
            currWidth = $"{(double)actVal / MaxVal:P0}";
            if (ShowPercent)
            {
                displayMsg = $"{actVal / MaxVal:P2}";
            }
            await InvokeAsync(StateHasChanged);
        }

        private async void RunTimer()
        {
            while (uiTimer != null && await uiTimer.WaitForNextTickAsync())
            {
                if (isLoading)
                {
                    DateTime adesso = DateTime.Now;
                    if (nextUpdate <= adesso.AddMilliseconds(slowWindowMSec))
                    {
                        nextUpdate = adesso.AddMilliseconds(RefreshInterval*2);
                    }
                    // calcolo delta ms...
                    var numMs = adesso.Subtract(lastUpdate).TotalMilliseconds;
                    var denMs = nextUpdate.Subtract(lastUpdate).TotalMilliseconds;
                    denMs = denMs > 0 ? denMs : 1;
                    // aggiorno display...
                    actVal = startVal + (NextVal - startVal) * (numMs / denMs);
                    await RefreshDisplay();
                }
            }
        }

        #endregion Private Methods
    }
}