// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename       : MediaScanViewModel.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : GUI view models.
//
// --[ Description ] ----------------------------------------------------------
//
//     View model and code for the media scan window.
//
// --[ License ] --------------------------------------------------------------
//
//     This program is free software: you can redistribute it and/or modify
//     it under the terms of the GNU General public License as
//     published by the Free Software Foundation, either version 3 of the
//     License, or (at your option) any later version.
//
//     This program is distributed in the hope that it will be useful,
//     but WITHOUT ANY WARRANTY; without even the implied warranty of
//     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//     GNU General public License for more details.
//
//     You should have received a copy of the GNU General public License
//     along with this program.  If not, see <http://www.gnu.org/licenses/>.
//
// ----------------------------------------------------------------------------
// Copyright © 2011-2022 Natalia Portillo
// ****************************************************************************/

namespace Aaru.Gui.ViewModels.Windows;

using System.Collections.ObjectModel;
using System.Reactive;
using System.Threading;
using System.Threading.Tasks;
using Aaru.Core;
using Aaru.Core.Devices.Scanning;
using Aaru.Devices;
using Avalonia.Controls;
using Avalonia.Media;
using Avalonia.Threading;
using MessageBox.Avalonia;
using MessageBox.Avalonia.Enums;
using OxyPlot;
using ReactiveUI;

public sealed class MediaScanViewModel : ViewModelBase
{
    readonly Window _view;
    string          _a;
    string          _avgSpeed;
    Color           _axesColor;
    string          _b;
    ulong           _blocks;
    ulong           _blocksToRead;
    string          _c;
    bool            _closeVisible;
    string          _d;
    string          _devicePath;
    string          _e;
    string          _f;
    Color           _lineColor;
    ScanResults     _localResults;
    string          _maxSpeed;
    double          _maxX;
    double          _maxY;
    string          _minSpeed;
    double          _minX;
    double          _minY;
    bool            _progress1Visible;
    string          _progress2Indeterminate;
    string          _progress2MaxValue;
    string          _progress2Text;
    string          _progress2Value;
    string          _progress2Visible;
    bool            _progressIndeterminate;
    double          _progressMaxValue;
    string          _progressText;
    double          _progressValue;
    bool            _progressVisible;
    bool            _resultsVisible;
    MediaScan       _scanner;
    bool            _startVisible;
    double          _stepsX;
    double          _stepsY;
    string          _stopEnabled;
    bool            _stopVisible;
    string          _totalTime;
    string          _unreadableSectors;

    public MediaScanViewModel(string devicePath, Window view)
    {
        _devicePath  = devicePath;
        _view        = view;
        StopVisible  = false;
        StartCommand = ReactiveCommand.Create(ExecuteStartCommand);
        CloseCommand = ReactiveCommand.Create(ExecuteCloseCommand);
        StopCommand  = ReactiveCommand.Create(ExecuteStopCommand);
        StartVisible = true;
        CloseVisible = true;
        BlockMapList = new ObservableCollection<(ulong block, double duration)>();
        ChartPoints  = new ObservableCollection<DataPoint>();
        StepsX       = double.NaN;
        StepsY       = double.NaN;
        AxesColor    = Colors.Black;
        LineColor    = Colors.Yellow;
    }

    public Color AxesColor
    {
        get => _axesColor;
        set => this.RaiseAndSetIfChanged(ref _axesColor, value);
    }

    public Color LineColor
    {
        get => _lineColor;
        set => this.RaiseAndSetIfChanged(ref _lineColor, value);
    }

    public ObservableCollection<(ulong block, double duration)> BlockMapList { get; }
    public ObservableCollection<DataPoint>                      ChartPoints  { get; }

    public ulong Blocks
    {
        get => _blocks;
        set => this.RaiseAndSetIfChanged(ref _blocks, value);
    }

    public string A
    {
        get => _a;
        set => this.RaiseAndSetIfChanged(ref _a, value);
    }

    public string B
    {
        get => _b;
        set => this.RaiseAndSetIfChanged(ref _b, value);
    }

    public string C
    {
        get => _c;
        set => this.RaiseAndSetIfChanged(ref _c, value);
    }

    public string D
    {
        get => _d;
        set => this.RaiseAndSetIfChanged(ref _d, value);
    }

    public string E
    {
        get => _e;
        set => this.RaiseAndSetIfChanged(ref _e, value);
    }

    public string F
    {
        get => _f;
        set => this.RaiseAndSetIfChanged(ref _f, value);
    }

    public string UnreadableSectors
    {
        get => _unreadableSectors;
        set => this.RaiseAndSetIfChanged(ref _unreadableSectors, value);
    }

    public string TotalTime
    {
        get => _totalTime;
        set => this.RaiseAndSetIfChanged(ref _totalTime, value);
    }

    public string AvgSpeed
    {
        get => _avgSpeed;
        set => this.RaiseAndSetIfChanged(ref _avgSpeed, value);
    }

    public string MaxSpeed
    {
        get => _maxSpeed;
        set => this.RaiseAndSetIfChanged(ref _maxSpeed, value);
    }

    public string MinSpeed
    {
        get => _minSpeed;
        set => this.RaiseAndSetIfChanged(ref _minSpeed, value);
    }

    public bool ProgressVisible
    {
        get => _progressVisible;
        set => this.RaiseAndSetIfChanged(ref _progressVisible, value);
    }

    public bool Progress1Visible
    {
        get => _progress1Visible;
        set => this.RaiseAndSetIfChanged(ref _progress1Visible, value);
    }

    public string ProgressText
    {
        get => _progressText;
        set => this.RaiseAndSetIfChanged(ref _progressText, value);
    }

    public double ProgressMaxValue
    {
        get => _progressMaxValue;
        set => this.RaiseAndSetIfChanged(ref _progressMaxValue, value);
    }

    public bool ProgressIndeterminate
    {
        get => _progressIndeterminate;
        set => this.RaiseAndSetIfChanged(ref _progressIndeterminate, value);
    }

    public double ProgressValue
    {
        get => _progressValue;
        set => this.RaiseAndSetIfChanged(ref _progressValue, value);
    }

    public bool StartVisible
    {
        get => _startVisible;
        set => this.RaiseAndSetIfChanged(ref _startVisible, value);
    }

    public bool CloseVisible
    {
        get => _closeVisible;
        set => this.RaiseAndSetIfChanged(ref _closeVisible, value);
    }

    public bool StopVisible
    {
        get => _stopVisible;
        set => this.RaiseAndSetIfChanged(ref _stopVisible, value);
    }

    public string StopEnabled
    {
        get => _stopEnabled;
        set => this.RaiseAndSetIfChanged(ref _stopEnabled, value);
    }

    public bool ResultsVisible
    {
        get => _resultsVisible;
        set => this.RaiseAndSetIfChanged(ref _resultsVisible, value);
    }

    public double MaxY
    {
        get => _maxY;
        set => this.RaiseAndSetIfChanged(ref _maxY, value);
    }

    public double MaxX
    {
        get => _maxX;
        set => this.RaiseAndSetIfChanged(ref _maxX, value);
    }

    public double MinY
    {
        get => _minY;
        set => this.RaiseAndSetIfChanged(ref _minY, value);
    }

    public double MinX
    {
        get => _minX;
        set => this.RaiseAndSetIfChanged(ref _minX, value);
    }

    public double StepsY
    {
        get => _stepsY;
        set => this.RaiseAndSetIfChanged(ref _stepsY, value);
    }

    public double StepsX
    {
        get => _stepsX;
        set => this.RaiseAndSetIfChanged(ref _stepsX, value);
    }

    public string Title { get; }

    public ReactiveCommand<Unit, Unit> StartCommand { get; }
    public ReactiveCommand<Unit, Unit> CloseCommand { get; }
    public ReactiveCommand<Unit, Unit> StopCommand  { get; }

    void ExecuteCloseCommand() => _view.Close();

    internal void ExecuteStopCommand() => _scanner?.Abort();

    void ExecuteStartCommand()
    {
        StopVisible     = true;
        StartVisible    = false;
        CloseVisible    = false;
        ProgressVisible = true;
        ResultsVisible  = true;
        ChartPoints.Clear();
        new Thread(DoWork).Start();
    }

    // TODO: Allow to save MHDD and ImgBurn log files
    async void DoWork()
    {
        if(_devicePath.Length == 2   &&
           _devicePath[1]     == ':' &&
           _devicePath[0]     != '/' &&
           char.IsLetter(_devicePath[0]))
            _devicePath = "\\\\.\\" + char.ToUpper(_devicePath[0]) + ':';

        var dev = Device.Create(_devicePath);

        if(dev is Devices.Remote.Device remoteDev)
            Statistics.AddRemote(remoteDev.RemoteApplication, remoteDev.RemoteVersion, remoteDev.RemoteOperatingSystem,
                                 remoteDev.RemoteOperatingSystemVersion, remoteDev.RemoteArchitecture);

        if(dev.Error)
        {
            await MessageBoxManager.
                  GetMessageBoxStandardWindow("Error", $"Error {dev.LastError} opening device.", ButtonEnum.Ok,
                                              Icon.Error).ShowDialog(_view);

            StopVisible     = false;
            StartVisible    = true;
            CloseVisible    = true;
            ProgressVisible = false;

            return;
        }

        Statistics.AddDevice(dev);

        _localResults                 =  new ScanResults();
        _scanner                      =  new MediaScan(null, null, _devicePath, dev, false);
        _scanner.ScanTime             += OnScanTime;
        _scanner.ScanUnreadable       += OnScanUnreadable;
        _scanner.UpdateStatus         += UpdateStatus;
        _scanner.StoppingErrorMessage += StoppingErrorMessage;
        _scanner.PulseProgress        += PulseProgress;
        _scanner.InitProgress         += InitProgress;
        _scanner.UpdateProgress       += UpdateProgress;
        _scanner.EndProgress          += EndProgress;
        _scanner.InitBlockMap         += InitBlockMap;
        _scanner.ScanSpeed            += ScanSpeed;

        ScanResults results = _scanner.Scan();

        await Dispatcher.UIThread.InvokeAsync(() =>
        {
            TotalTime = $"Took a total of {results.TotalTime} seconds ({results.ProcessingTime} processing commands).";

            AvgSpeed          = $"Average speed: {results.AvgSpeed:F3} MiB/sec.";
            MaxSpeed          = $"Fastest speed burst: {results.MaxSpeed:F3} MiB/sec.";
            MinSpeed          = $"Slowest speed burst: {results.MinSpeed:F3} MiB/sec.";
            A                 = $"{results.A} sectors took less than 3 ms.";
            B                 = $"{results.B} sectors took less than 10 ms but more than 3 ms.";
            C                 = $"{results.C} sectors took less than 50 ms but more than 10 ms.";
            D                 = $"{results.D} sectors took less than 150 ms but more than 50 ms.";
            E                 = $"{results.E} sectors took less than 500 ms but more than 150 ms.";
            F                 = $"{results.F} sectors took more than 500 ms.";
            UnreadableSectors = $"{results.UnreadableSectors.Count} sectors could not be read.";
        });

        // TODO: Show list of unreadable sectors
        /*
        if(results.UnreadableSectors.Count > 0)
            foreach(ulong bad in results.UnreadableSectors)
                string.Format("Sector {0} could not be read", bad);
*/

        // TODO: Show results
        /*
        
        if(results.SeekTotal != 0 || results.SeekMin != double.MaxValue || results.SeekMax != double.MinValue)
            
            string.Format("Testing {0} seeks, longest seek took {1:F3} ms, fastest one took {2:F3} ms. ({3:F3} ms average)",
                                 results.SeekTimes, results.SeekMax, results.SeekMin, results.SeekTotal / 1000);
                                 */

        Statistics.AddCommand("media-scan");

        dev.Close();
        await WorkFinished();
    }

    async void ScanSpeed(ulong sector, double currentSpeed) => await Dispatcher.UIThread.InvokeAsync(() =>
    {
        if(ChartPoints.Count == 0)
            ChartPoints.Add(new DataPoint(0, currentSpeed));

        ChartPoints.Add(new DataPoint(sector, currentSpeed));

        if(currentSpeed > MaxY)
            MaxY = currentSpeed + currentSpeed / 10d;
    });

    async void InitBlockMap(ulong blocks, ulong blockSize, ulong blocksToRead, ushort currentProfile) =>
        await Dispatcher.UIThread.InvokeAsync(() =>
        {
            Blocks        = blocks / blocksToRead;
            _blocksToRead = blocksToRead;

            MinX = 0;
            MinY = 0;

            switch(currentProfile)
            {
                case 0x0005: // CD and DDCD
                case 0x0008:
                case 0x0009:
                case 0x000A:
                case 0x0020:
                case 0x0021:
                case 0x0022:
                    if(blocks <= 360000)
                        MaxX = 360000;
                    else if(blocks <= 405000)
                        MaxX = 405000;
                    else if(blocks <= 445500)
                        MaxX = 445500;
                    else
                        MaxX = blocks;

                    StepsX = MaxX   / 10;
                    StepsY = 150    * 4;
                    MaxY   = StepsY * 12.5;

                    break;
                case 0x0010: // DVD SL
                case 0x0011:
                case 0x0012:
                case 0x0013:
                case 0x0014:
                case 0x0018:
                case 0x001A:
                case 0x001B:
                    MaxX   = 2298496;
                    StepsX = MaxX / 10;
                    StepsY = 1352.5;
                    MaxY   = StepsY * 18;

                    break;
                case 0x0015: // DVD DL
                case 0x0016:
                case 0x0017:
                case 0x002A:
                case 0x002B:
                    MaxX   = 4173824;
                    StepsX = MaxX / 10;
                    StepsY = 1352.5;
                    MaxY   = StepsY * 18;

                    break;
                case 0x0041:
                case 0x0042:
                case 0x0043:
                case 0x0040: // BD
                    if(blocks <= 12219392)
                        MaxX = 12219392;
                    else if(blocks <= 24438784)
                        MaxX = 24438784;
                    else if(blocks <= 48878592)
                        MaxX = 48878592;
                    else if(blocks <= 62500864)
                        MaxX = 62500864;
                    else
                        MaxX = blocks;

                    StepsX = MaxX / 10;
                    StepsY = 4394.5;
                    MaxY   = StepsY * 18;

                    break;
                case 0x0050: // HD DVD
                case 0x0051:
                case 0x0052:
                case 0x0053:
                case 0x0058:
                case 0x005A:
                    if(blocks <= 7361599)
                        MaxX = 7361599;
                    else if(blocks <= 16305407)
                        MaxX = 16305407;
                    else
                        MaxX = blocks;

                    StepsX = MaxX / 10;
                    StepsY = 4394.5;
                    MaxY   = StepsY * 8;

                    break;
                default:
                    MaxX   = blocks;
                    StepsX = MaxX / 10;
                    StepsY = 625;
                    MaxY   = StepsY;

                    break;
            }
        });

    async Task WorkFinished() => await Dispatcher.UIThread.InvokeAsync(() =>
    {
        StopVisible     = false;
        StartVisible    = true;
        CloseVisible    = true;
        ProgressVisible = false;
    });

    async void EndProgress() => await Dispatcher.UIThread.InvokeAsync(() =>
    {
        Progress1Visible = false;
    });

    async void UpdateProgress(string text, long current, long maximum) => await Dispatcher.UIThread.InvokeAsync(() =>
    {
        ProgressText          = text;
        ProgressIndeterminate = false;

        ProgressMaxValue = maximum;
        ProgressValue    = current;
    });

    async void InitProgress() => await Dispatcher.UIThread.InvokeAsync(() =>
    {
        Progress1Visible = true;
    });

    async void PulseProgress(string text) => await Dispatcher.UIThread.InvokeAsync(() =>
    {
        ProgressText          = text;
        ProgressIndeterminate = true;
    });

    async void StoppingErrorMessage(string text) => await Dispatcher.UIThread.InvokeAsync(action: async () =>
    {
        ProgressText = text;

        await MessageBoxManager.GetMessageBoxStandardWindow("Error", $"{text}", ButtonEnum.Ok, Icon.Error).
                                ShowDialog(_view);

        WorkFinished();
    });

    async void UpdateStatus(string text) => await Dispatcher.UIThread.InvokeAsync(() =>
    {
        ProgressText = text;
    });

    async void OnScanUnreadable(ulong sector) => await Dispatcher.UIThread.InvokeAsync(() =>
    {
        _localResults.Errored += _blocksToRead;
        UnreadableSectors     =  $"{_localResults.Errored} sectors could not be read.";
        BlockMapList.Add((sector / _blocksToRead, double.NaN));
    });

    async void OnScanTime(ulong sector, double duration) => await Dispatcher.UIThread.InvokeAsync(() =>
    {
        BlockMapList.Add((sector / _blocksToRead, duration));

        if(duration < 3)
            _localResults.A += _blocksToRead;
        else if(duration >= 3 &&
                duration < 10)
            _localResults.B += _blocksToRead;
        else if(duration >= 10 &&
                duration < 50)
            _localResults.C += _blocksToRead;
        else if(duration >= 50 &&
                duration < 150)
            _localResults.D += _blocksToRead;
        else if(duration >= 150 &&
                duration < 500)
            _localResults.E += _blocksToRead;
        else if(duration >= 500)
            _localResults.F += _blocksToRead;

        A = $"{_localResults.A} sectors took less than 3 ms.";
        B = $"{_localResults.B} sectors took less than 10 ms but more than 3 ms.";
        C = $"{_localResults.C} sectors took less than 50 ms but more than 10 ms.";
        D = $"{_localResults.D} sectors took less than 150 ms but more than 50 ms.";
        E = $"{_localResults.E} sectors took less than 500 ms but more than 150 ms.";
        F = $"{_localResults.F} sectors took more than 500 ms.";
    });
}