using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.IO;
using System.Linq;
using System.Threading;
using System.Windows.Input;
using AmebaPro3_ControlPanel.Services.Uart;
using AmebaPro3_ControlPanel.Utilities;

namespace AmebaPro3_ControlPanel.ViewModels;

public class UartConsoleViewModel : ConsolePanelViewModel
{
    private string? _selectedPort;
    private int _baudRate;
    private readonly PythonUartSession _uartSession;
    private bool _isConnecting;

    public UartConsoleViewModel(string title, int defaultBaudRate) : base(title)
    {
        _baudRate = defaultBaudRate;
        _uartSession = new PythonUartSession(GetUartBridgePath(), SynchronizationContext.Current);
        _uartSession.LineReceived += line => LogLines.Add(line);
        _uartSession.ErrorReceived += line => LogLines.Add($"[UART ERROR] {line}");
        _uartSession.Exited += OnSessionExited;

        ConnectCommand = new RelayCommand(_ => ConnectAsync(), _ => !IsConnected && !_isConnecting && !string.IsNullOrWhiteSpace(SelectedPort));
        DisconnectCommand = new RelayCommand(_ => Disconnect(), _ => IsConnected);
        OpenTeraTermCommand = new RelayCommand(_ => OpenTeraTerm(), _ => !string.IsNullOrWhiteSpace(SelectedPort));
    }

    public ObservableCollection<string> AvailablePorts { get; } = new();

    public string? SelectedPort
    {
        get => _selectedPort;
        set
        {
            if (SetProperty(ref _selectedPort, value))
            {
                (ConnectCommand as RelayCommand)?.RaiseCanExecuteChanged();
                (OpenTeraTermCommand as RelayCommand)?.RaiseCanExecuteChanged();
            }
        }
    }

    public int BaudRate
    {
        get => _baudRate;
        set => SetProperty(ref _baudRate, value);
    }

    public ICommand ConnectCommand { get; }

    public ICommand DisconnectCommand { get; }

    public ICommand OpenTeraTermCommand { get; }

    public void SetPorts(IEnumerable<string> ports)
    {
        AvailablePorts.Clear();
        foreach (var port in ports)
        {
            AvailablePorts.Add(port);
        }

        if (string.IsNullOrWhiteSpace(SelectedPort))
        {
            SelectedPort = AvailablePorts.FirstOrDefault();
        }
    }

    protected override void SendCurrentCommand(bool addToHistory)
    {
        if (string.IsNullOrWhiteSpace(CurrentCommand))
        {
            return;
        }

        var command = CurrentCommand.Trim();
        base.SendCurrentCommand(addToHistory);

        if (IsConnected)
        {
            _ = _uartSession.SendAsync(command);
        }
        else
        {
            LogLines.Add("[UART] Not connected.");
        }
    }

    private async void ConnectAsync()
    {
        if (_isConnecting || string.IsNullOrWhiteSpace(SelectedPort))
        {
            return;
        }

        _isConnecting = true;
        (ConnectCommand as RelayCommand)?.RaiseCanExecuteChanged();
        LogLines.Add($"[UART] Connecting to {SelectedPort} @ {BaudRate}...");

        var started = await _uartSession.StartAsync(SelectedPort, BaudRate);
        if (started)
        {
            IsConnected = true;
            LogLines.Add($"[UART] Connected to {SelectedPort} @ {BaudRate}.");
        }
        else
        {
            LogLines.Add("[UART] Failed to start session. Ensure Python + pyserial are installed.");
        }

        _isConnecting = false;
        (DisconnectCommand as RelayCommand)?.RaiseCanExecuteChanged();
        (ConnectCommand as RelayCommand)?.RaiseCanExecuteChanged();
    }

    private void Disconnect()
    {
        _ = DisconnectAsync();
    }

    private async System.Threading.Tasks.Task DisconnectAsync()
    {
        IsConnected = false;
        _isConnecting = false;
        (DisconnectCommand as RelayCommand)?.RaiseCanExecuteChanged();
        (ConnectCommand as RelayCommand)?.RaiseCanExecuteChanged();

        await _uartSession.StopAsync();
        LogLines.Add("[UART] Disconnected.");
    }

    private void OnSessionExited()
    {
        if (!IsConnected)
        {
            return;
        }

        IsConnected = false;
        _isConnecting = false;
        LogLines.Add("[UART] Session closed.");
        (DisconnectCommand as RelayCommand)?.RaiseCanExecuteChanged();
        (ConnectCommand as RelayCommand)?.RaiseCanExecuteChanged();
    }

    private void OpenTeraTerm()
    {
        if (TeraTermLauncher.TryLaunch(SelectedPort, BaudRate, out var message))
        {
            LogLines.Add($"[UART] {message}");
        }
        else
        {
            LogLines.Add($"[UART] {message}");
        }
    }

    private static string GetUartBridgePath()
    {
        return Path.Combine(AppContext.BaseDirectory, "Scripts", "uart_bridge.py");
    }
}