using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;


public partial class FullKeyboardForm : Form
{
    public string Caption { set => lblCaption.Text = value; }
    public bool ValueChanged { get; set; }
    public string Value { get; set; }
    public char PasswordChar { set => txtPreview.PasswordChar = txtInput.PasswordChar = value; }
    public FullKeyboardForm()
    {
        InitializeComponent();
    }
    public FullKeyboardForm(string currentString):this()
    {
        txtPreview.Text = currentString;
        Value=currentString;
    }
    private void FullKeyboardForm_Load(object sender, EventArgs e)
    {
        doubleCharButtons = Controls
            .Cast<Control>()
            .Where(c => c.Name.Contains("DoubleChar"))
            .Select(c => (Button)c)
            .ToList();
    }
    private void FullKeyboardForm_Shown(object sender, EventArgs e)
    {
        txtInput.Focus();
        txtInput.SelectAll();
    }
    public bool IsPassword
    {
        set
        {
            if (value)
                txtInput.PasswordChar = '*';
        }
    }

    bool isCaps = false;
    bool isShift = false;
    bool isCtrl = false;
    bool isAlt = false;
    private void btnCharKey_Click(object sender, EventArgs e)
    {
        if (sender is Button button)
        {
            string stringToAdd;
            if (!isCaps)
            {
                stringToAdd = button.Text.ToLower().Replace("&&", "&");
            }
            else
            {
                stringToAdd = button.Text.ToUpper().Replace("&&", "&");
            }
            InsertOneChar(stringToAdd);
        }
    }

    int selectionStartSaved = 0;
    void InsertOneChar(string s)
    {
        if (selectionStartSaved != txtInput.SelectionStart)
            selectionStartSaved = txtInput.SelectionStart;
        if (txtInput.SelectionLength > 0)
        {
            txtInput.Text = txtInput.Text.Remove(selectionStartSaved, txtInput.SelectionLength);
        }


        txtInput.Text = txtInput.Text.Insert(selectionStartSaved, s);
        selectionStartSaved = selectionStartSaved + s.Length;

        txtInput.Focus();
        txtInput.SelectionStart = selectionStartSaved;
        txtInput.SelectionLength = 0;
    }


    private void btnShift_Click(object sender, EventArgs e)
    {
        isShift = !isShift;
        foreach (var item in doubleCharButtons)
        {
            if (isShift)
            {
                btnShift1.Text = btnShift2.Text = "Shift";
                item.Text = item.Tag.ToString().Split(' ')[0];
            }
            else
            {
                btnShift1.Text = btnShift2.Text = "shift";
                item.Text = item.Tag.ToString().Split(' ')[1];
            }
        }
        
    }

    List<Button> doubleCharButtons;

    private void btnCapsLock_Click(object sender, EventArgs e)
    {
        isCaps = !isCaps;
        if (isCaps)
        {
            btnCapsLock.Text = "Caps Lock";
        }
        else
        {
            btnCapsLock.Text = "caps lock";
        }
    }

    private void btnTab_Click(object sender, EventArgs e)
    {
        InsertOneChar('\t'.ToString());
    }

    private void btnBack_Click(object sender, EventArgs e)
    {
        if (txtInput.Text.Length > 0 && (txtInput.SelectionStart > 0 || txtInput.SelectionLength>0))
        {
            if (selectionStartSaved != txtInput.SelectionStart)
                selectionStartSaved = txtInput.SelectionStart;

            if (txtInput.SelectionLength == 0)
            {
                txtInput.Text = txtInput.Text.Remove(txtInput.SelectionStart - 1, 1);
                selectionStartSaved = selectionStartSaved - 1;
                txtInput.Focus();
                txtInput.SelectionStart = selectionStartSaved;
                txtInput.SelectionLength = 0;
            }
            else
            {
                txtInput.Text = txtInput.Text.Remove(txtInput.SelectionStart, txtInput.SelectionLength);
                txtInput.Focus();
                txtInput.SelectionStart = selectionStartSaved;
                txtInput.SelectionLength = 0;
            }
        }

    }

    private void btnLeft_Click(object sender, EventArgs e)
    {
        txtInput.Focus();
        if (txtInput.SelectionStart > 0)
        {
            txtInput.SelectionStart -= 1;
        }
    }

    private void btnRight_Click(object sender, EventArgs e)
    {
        txtInput.Focus();
        if (txtInput.SelectionStart < txtInput.Text.Length)
        {
            txtInput.SelectionStart += 1;
        }
    }

    private void btnCtrl_Click(object sender, EventArgs e)
    {
        isCtrl = !isCtrl;
        if (isCtrl)
        {
            btnCtrl1.Text = btnCtrl2.Text= "Ctrl";
        }
        else
        {
            btnCtrl1.Text = btnCtrl2.Text = "ctrl";
        }
    }
    private void btnAlt_Click(object sender, EventArgs e)
    {
        isAlt = !isAlt;
        if (isAlt)
        {
            btnAlt1.Text = btnAlt2.Text = "Alt";
        }
        else
        {
            btnAlt1.Text = btnAlt2.Text = "alt";
        }
    }

    private void btnEnter_Click(object sender, EventArgs e)
    {
        if(isCtrl || isAlt)
        {
            InsertOneChar(Environment.NewLine);
        }
        else
        {
            
            if(Value != txtInput.Text)
            {
                Value= txtInput.Text;
                ValueChanged= true;
            }
            DialogResult = DialogResult.OK;
            Close();
        }
    }
    

    private void btnWin1_Click(object sender, EventArgs e)
    {
        // 模拟按下并释放 Windows 键
       SimulateInput.SimulateKey(SimulateInput.VK_LWIN);
    }

    private void btnUp_Click(object sender, EventArgs e)
    {
        txtInput.Focus();
        SimulateInput.SimulateKey(SimulateInput.VK_UP);
    }

    private void btnDown_Click(object sender, EventArgs e)
    {
        txtInput.Focus();
        SimulateInput.SimulateKey(SimulateInput.VK_DOWN);
    }

    private void btnExit_Click(object sender, EventArgs e)
    {
        DialogResult = DialogResult.Cancel;
        Close();
    }
}