using System.Drawing.Drawing2D;
using anjianjingling.Common;

namespace anjianjingling.Forms
{
    /// <summary>坐标取色器：置顶小窗，实时显示鼠标坐标与屏幕颜色，可复制坐标/颜色或写入日志。</summary>
    public sealed class PickerForm : Form
    {
        private const int MagZoom = 7;
        private const int SampleSize = 15;

        private readonly LogBus _log;
        private readonly System.Windows.Forms.Timer _timer = new() { Interval = 60 };
        private readonly Label _lblPos = new();
        private readonly Label _lblHex = new();
        private readonly Label _lblRgb = new();
        private readonly Panel _mag = new();
        private readonly Panel _swatch = new();
        private readonly Label _title = new();
        private readonly Label _btnClose = new();

        private Bitmap? _sample;
        private Point _cursor;
        private Color _color = Color.Black;
        private Point _dragOffset;
        private bool _dragging;

        public PickerForm(LogBus log)
        {
            _log = log;

            Text = "坐标取色器";
            FormBorderStyle = FormBorderStyle.None;
            ShowInTaskbar = false;
            TopMost = true;
            StartPosition = FormStartPosition.Manual;
            ClientSize = new Size(288, 188);
            BackColor = Color.FromArgb(30, 34, 42);
            Font = new Font("Microsoft YaHei UI", 9F);
            KeyPreview = true;

            var start = Cursor.Position;
            Location = new Point(
                Math.Max(0, Math.Min(Screen.PrimaryScreen!.WorkingArea.Right - Width - 24, start.X + 40)),
                Math.Max(0, Math.Min(Screen.PrimaryScreen!.WorkingArea.Bottom - Height - 24, start.Y + 40)));

            // 顶栏
            _title.Text = "  坐标取色器";
            _title.Dock = DockStyle.None;
            _title.SetBounds(0, 0, 240, 26);
            _title.TextAlign = ContentAlignment.MiddleLeft;
            _title.ForeColor = Color.FromArgb(220, 228, 240);
            _title.Font = new Font("Microsoft YaHei UI", 9F, FontStyle.Bold);
            _title.BackColor = Color.FromArgb(42, 48, 60);

            _btnClose.Text = "✕";
            _btnClose.SetBounds(ClientSize.Width - 26, 0, 26, 26);
            _btnClose.TextAlign = ContentAlignment.MiddleCenter;
            _btnClose.ForeColor = Color.FromArgb(200, 210, 225);
            _btnClose.BackColor = Color.FromArgb(42, 48, 60);
            _btnClose.Cursor = Cursors.Hand;
            _btnClose.Click += (s, e) => Close();
            _btnClose.MouseEnter += (s, e) => _btnClose.BackColor = Color.FromArgb(190, 70, 60);
            _btnClose.MouseLeave += (s, e) => _btnClose.BackColor = Color.FromArgb(42, 48, 60);

            // 放大镜
            _mag.SetBounds(10, 34, SampleSize * MagZoom, SampleSize * MagZoom);
            _mag.BackColor = Color.FromArgb(20, 24, 30);
            _mag.Paint += MagPaint;

            // 色块
            _swatch.SetBounds(124, 34, 62, 46);
            _swatch.Paint += (s, e) =>
            {
                e.Graphics.Clear(_color);
                using var pen = new Pen(Color.FromArgb(90, 98, 112));
                e.Graphics.DrawRectangle(pen, 0, 0, _swatch.Width - 1, _swatch.Height - 1);
            };

            // 文字
            _lblPos.SetBounds(124, 86, 160, 18);
            _lblHex.SetBounds(124, 106, 160, 18);
            _lblRgb.SetBounds(124, 126, 160, 18);
            foreach (var l in new[] { _lblPos, _lblHex, _lblRgb })
            {
                l.ForeColor = Color.FromArgb(214, 222, 235);
                l.Font = new Font("Consolas", 9.5F);
            }
            _lblPos.Text = "坐标 -";
            _lblHex.Text = "颜色 -";
            _lblRgb.Text = "RGB  -";

            // 按钮
            var bar = new FlowLayoutPanel
            {
                FlowDirection = FlowDirection.LeftToRight,
                WrapContents = false
            };
            bar.SetBounds(10, 150, 268, 30);
            bar.Controls.Add(MkBtn("复制坐标", () =>
                Copy(_cursor.X + ", " + _cursor.Y)));
            bar.Controls.Add(MkBtn("复制颜色", () =>
                Copy($"{_color.R:X2}{_color.G:X2}{_color.B:X2}")));
            bar.Controls.Add(MkBtn("写入日志", () =>
                _log.Write($"取色：坐标 ({_cursor.X}, {_cursor.Y})　颜色 #{_color.R:X2}{_color.G:X2}{_color.B:X2}")));

            Controls.AddRange(new Control[] { _mag, _swatch, _lblPos, _lblHex, _lblRgb, bar, _title, _btnClose });

            KeyDown += (s, e) => { if (e.KeyCode == Keys.Escape) Close(); };
            MouseDown += DragStart;
            _title.MouseDown += DragStart;
            MouseMove += DragMove;
            _title.MouseMove += DragMove;
            MouseUp += (s, e) => _dragging = false;

            _timer.Tick += (s, e) => Tick();
            _timer.Start();
            FormClosed += (s, e) => { _timer.Stop(); _sample?.Dispose(); };
        }

        private Button MkBtn(string text, Action onClick)
        {
            var b = new Button
            {
                Text = text, Width = 84, Height = 26, Margin = new Padding(0, 2, 4, 0),
                FlatStyle = FlatStyle.Flat, BackColor = Color.FromArgb(52, 60, 74),
                ForeColor = Color.FromArgb(222, 230, 242), Cursor = Cursors.Hand,
                Font = new Font("Microsoft YaHei UI", 8.5F)
            };
            b.FlatAppearance.BorderColor = Color.FromArgb(70, 80, 96);
            b.Click += (s, e) => onClick();
            return b;
        }

        private void Copy(string text)
        {
            try { Clipboard.SetText(text); _log.Write("已复制：" + text); } catch { }
        }

        private void DragStart(object? s, MouseEventArgs e)
        {
            if (e.Button != MouseButtons.Left) return;
            _dragging = true;
            _dragOffset = e.Location;
            if (s != _title && s != this) _dragOffset = new Point(e.X + (s as Control)!.Left, e.Y + (s as Control)!.Top + 26);
        }

        private void DragMove(object? s, MouseEventArgs e)
        {
            if (!_dragging) return;
            var screen = s == this ? PointToScreen(e.Location) : (s as Control)!.PointToScreen(e.Location);
            Location = new Point(screen.X - _dragOffset.X, screen.Y - _dragOffset.Y);
        }

        private void Tick()
        {
            if (IsDisposed) return;
            var p = Cursor.Position;
            if (p == _cursor && _sample != null) return;
            _cursor = p;

            try
            {
                int half = SampleSize / 2;
                _sample?.Dispose();
                _sample = new Bitmap(SampleSize, SampleSize);
                using (var g = Graphics.FromImage(_sample))
                    g.CopyFromScreen(p.X - half, p.Y - half, 0, 0, new Size(SampleSize, SampleSize));

                _color = _sample.GetPixel(half, half);
            }
            catch
            {
                return;
            }

            _lblPos.Text = $"坐标 {_cursor.X}, {_cursor.Y}";
            _lblHex.Text = $"颜色 #{_color.R:X2}{_color.G:X2}{_color.B:X2}";
            _lblRgb.Text = $"RGB  {_color.R}, {_color.G}, {_color.B}";
            _mag.Invalidate();
            _swatch.Invalidate();
        }

        private void MagPaint(object? s, PaintEventArgs e)
        {
            e.Graphics.Clear(Color.FromArgb(20, 24, 30));
            if (_sample == null) return;
            e.Graphics.InterpolationMode = InterpolationMode.NearestNeighbor;
            e.Graphics.PixelOffsetMode = PixelOffsetMode.Half;
            e.Graphics.DrawImage(_sample, new Rectangle(0, 0, _mag.Width, _mag.Height));

            // 准星
            int c = _mag.Width / 2;
            using var pen = new Pen(Color.FromArgb(220, 255, 80, 80)) { Width = 1 };
            e.Graphics.DrawLine(pen, c, 0, c, _mag.Height);
            e.Graphics.DrawLine(pen, 0, c, _mag.Width, c);
            using var inner = new Pen(Color.White) { Width = 1 };
            e.Graphics.DrawRectangle(inner, c - MagZoom / 2, c - MagZoom / 2, MagZoom, MagZoom);
        }

        protected override void OnPaint(PaintEventArgs e)
        {
            base.OnPaint(e);
            using var pen = new Pen(Color.FromArgb(64, 72, 86));
            e.Graphics.DrawRectangle(pen, 0, 0, ClientSize.Width - 1, ClientSize.Height - 1);
        }
    }
}