using System;
using System.Collections.Generic;
using System.Drawing;
using System.Globalization;
using System.Linq;
using System.Windows.Forms;
using CadParamPluging.Common;

namespace CadParamPluging.UI
{
    public class ParamDefinitionForm : Form
    {
        private readonly bool _isEdit;
        private readonly TextBox _txtKey;
        private readonly TextBox _txtLabel;
        private readonly ComboBox _cbType;
        private readonly CheckBox _chkRequired;
        private readonly TextBox _txtHint;
        private readonly TextBox _txtDefault;
        private readonly TextBox _txtMin;
        private readonly TextBox _txtMax;
        private readonly TextBox _txtEnumOptions;
        private readonly TextBox _txtGroup;
        private readonly NumericUpDown _numOrder;

        public ParamDefinition Result { get; private set; }

        public ParamDefinitionForm(string title, ParamDefinition initial, bool isEdit)
        {
            _isEdit = isEdit;

            Text = title;
            Size = new Size(520, 520);
            StartPosition = FormStartPosition.CenterParent;
            FormBorderStyle = FormBorderStyle.FixedDialog;
            MaximizeBox = false;
            MinimizeBox = false;
            ShowInTaskbar = false;

            var def = (initial ?? new ParamDefinition()).Clone();
            def.Normalize();

            var layout = new TableLayoutPanel
            {
                Dock = DockStyle.Fill,
                Padding = new Padding(10),
                ColumnCount = 2,
                RowCount = 12,
                AutoSize = true
            };
            layout.ColumnStyles.Add(new ColumnStyle(SizeType.AutoSize));
            layout.ColumnStyles.Add(new ColumnStyle(SizeType.Percent, 100f));

            _txtKey = new TextBox { Width = 260, Text = def.Key };
            _txtLabel = new TextBox { Width = 260, Text = def.Label };
            _cbType = new ComboBox { DropDownStyle = ComboBoxStyle.DropDownList, Width = 260 };
            _cbType.Items.AddRange(Enum.GetNames(typeof(ParamValueType)));
            _cbType.SelectedItem = def.Type.ToString();
            _cbType.SelectedIndexChanged += (_, __) => UpdateTypeUi();

            _chkRequired = new CheckBox { Text = "必填", Checked = def.Required, AutoSize = true };
            _txtHint = new TextBox { Width = 260, Text = def.Hint, Multiline = true, Height = 60, ScrollBars = ScrollBars.Vertical };
            _txtDefault = new TextBox { Width = 260, Text = def.DefaultValue };
            _txtMin = new TextBox { Width = 260, Text = def.Min };
            _txtMax = new TextBox { Width = 260, Text = def.Max };
            _txtEnumOptions = new TextBox { Width = 260, Height = 120, Multiline = true, ScrollBars = ScrollBars.Vertical };
            _txtEnumOptions.Text = string.Join(Environment.NewLine, def.EnumOptions ?? new List<string>());
            _txtGroup = new TextBox { Width = 260, Text = def.Group };
            _numOrder = new NumericUpDown { Width = 120, Minimum = -100000, Maximum = 100000, Value = def.Order };

            if (_isEdit)
            {
                _txtKey.ReadOnly = true;
            }

            var row = 0;
            layout.Controls.Add(new Label { Text = "Key(英文)", AutoSize = true, TextAlign = ContentAlignment.MiddleLeft }, 0, row);
            layout.Controls.Add(_txtKey, 1, row++);

            layout.Controls.Add(new Label { Text = "Label(中文)", AutoSize = true, TextAlign = ContentAlignment.MiddleLeft }, 0, row);
            layout.Controls.Add(_txtLabel, 1, row++);

            layout.Controls.Add(new Label { Text = "类型", AutoSize = true, TextAlign = ContentAlignment.MiddleLeft }, 0, row);
            layout.Controls.Add(_cbType, 1, row++);

            layout.Controls.Add(new Label { Text = "", AutoSize = true }, 0, row);
            layout.Controls.Add(_chkRequired, 1, row++);

            layout.Controls.Add(new Label { Text = "提示/填写方式", AutoSize = true, TextAlign = ContentAlignment.MiddleLeft }, 0, row);
            layout.Controls.Add(_txtHint, 1, row++);

            layout.Controls.Add(new Label { Text = "默认值", AutoSize = true, TextAlign = ContentAlignment.MiddleLeft }, 0, row);
            layout.Controls.Add(_txtDefault, 1, row++);

            layout.Controls.Add(new Label { Text = "最小值(数字)", AutoSize = true, TextAlign = ContentAlignment.MiddleLeft }, 0, row);
            layout.Controls.Add(_txtMin, 1, row++);

            layout.Controls.Add(new Label { Text = "最大值(数字)", AutoSize = true, TextAlign = ContentAlignment.MiddleLeft }, 0, row);
            layout.Controls.Add(_txtMax, 1, row++);

            layout.Controls.Add(new Label { Text = "枚举选项(每行一项)", AutoSize = true, TextAlign = ContentAlignment.MiddleLeft }, 0, row);
            layout.Controls.Add(_txtEnumOptions, 1, row++);

            layout.Controls.Add(new Label { Text = "分组", AutoSize = true, TextAlign = ContentAlignment.MiddleLeft }, 0, row);
            layout.Controls.Add(_txtGroup, 1, row++);

            layout.Controls.Add(new Label { Text = "排序", AutoSize = true, TextAlign = ContentAlignment.MiddleLeft }, 0, row);
            layout.Controls.Add(_numOrder, 1, row++);

            var btnPanel = new FlowLayoutPanel
            {
                Dock = DockStyle.Fill,
                FlowDirection = FlowDirection.RightToLeft,
                AutoSize = true
            };
            var btnCancel = new Button { Text = "取消", DialogResult = DialogResult.Cancel };
            var btnOk = new Button { Text = "确定" };
            btnOk.Click += (_, __) => OnOk();
            btnPanel.Controls.Add(btnCancel);
            btnPanel.Controls.Add(btnOk);

            layout.Controls.Add(btnPanel, 0, row);
            layout.SetColumnSpan(btnPanel, 2);

            Controls.Add(layout);
            AcceptButton = btnOk;
            CancelButton = btnCancel;

            UpdateTypeUi();
        }

        private void UpdateTypeUi()
        {
            var type = GetSelectedType();
            var showEnum = type == ParamValueType.Enum;
            _txtEnumOptions.Enabled = showEnum;

            var showMinMax = type == ParamValueType.Int || type == ParamValueType.Double;
            _txtMin.Enabled = showMinMax;
            _txtMax.Enabled = showMinMax;
        }

        private ParamValueType GetSelectedType()
        {
            var selected = _cbType.SelectedItem as string;
            if (Enum.TryParse(selected, out ParamValueType t))
            {
                return t;
            }

            return ParamValueType.String;
        }

        private void OnOk()
        {
            var key = (_txtKey.Text ?? string.Empty).Trim();
            var label = (_txtLabel.Text ?? string.Empty).Trim();

            if (key.Length == 0)
            {
                MessageBox.Show(this, "Key 不能为空。", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return;
            }

            if (!IsValidKey(key))
            {
                MessageBox.Show(this, "Key 格式不合法：必须以字母开头，仅允许字母/数字/下划线。", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return;
            }

            if (label.Length == 0)
            {
                MessageBox.Show(this, "Label 不能为空。", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return;
            }

            var type = GetSelectedType();

            var def = new ParamDefinition
            {
                Key = key,
                Label = label,
                Type = type,
                Required = _chkRequired.Checked,
                Hint = (_txtHint.Text ?? string.Empty).Trim(),
                DefaultValue = (_txtDefault.Text ?? string.Empty).Trim(),
                Min = (_txtMin.Text ?? string.Empty).Trim(),
                Max = (_txtMax.Text ?? string.Empty).Trim(),
                Group = (_txtGroup.Text ?? string.Empty).Trim(),
                Order = (int)_numOrder.Value,
                EnumOptions = ParseLines(_txtEnumOptions.Text)
            };
            def.Normalize();

            var err = ValidateDefinition(def);
            if (err != null)
            {
                MessageBox.Show(this, err, "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return;
            }

            Result = def;
            DialogResult = DialogResult.OK;
            Close();
        }

        private static List<string> ParseLines(string text)
        {
            if (string.IsNullOrWhiteSpace(text))
            {
                return new List<string>();
            }

            return text
                .Replace("\r\n", "\n")
                .Replace("\r", "\n")
                .Split(new[] { '\n' }, StringSplitOptions.RemoveEmptyEntries)
                .Select(s => (s ?? string.Empty).Trim())
                .Where(s => s.Length > 0)
                .ToList();
        }

        private static bool IsValidKey(string key)
        {
            if (string.IsNullOrWhiteSpace(key))
            {
                return false;
            }

            if (!char.IsLetter(key[0]))
            {
                return false;
            }

            foreach (var ch in key)
            {
                if (char.IsLetterOrDigit(ch) || ch == '_')
                {
                    continue;
                }
                return false;
            }

            return true;
        }

        private static string ValidateDefinition(ParamDefinition def)
        {
            if (def == null)
            {
                return "参数定义不能为空。";
            }

            if (def.Type == ParamValueType.Enum && (def.EnumOptions == null || def.EnumOptions.Count == 0))
            {
                return "Enum 类型必须提供至少 1 个枚举选项。";
            }

            if ((def.Type == ParamValueType.Int || def.Type == ParamValueType.Double) && (def.Min.Length > 0 || def.Max.Length > 0))
            {
                if (!TryParseDouble(def.Min, out var min, allowEmpty: true))
                {
                    return "最小值不是有效数字。";
                }

                if (!TryParseDouble(def.Max, out var max, allowEmpty: true))
                {
                    return "最大值不是有效数字。";
                }

                if (def.Min.Length > 0 && def.Max.Length > 0 && min > max)
                {
                    return "最小值不能大于最大值。";
                }
            }

            return null;
        }

        private static bool TryParseDouble(string text, out double value, bool allowEmpty)
        {
            value = 0;
            if (string.IsNullOrWhiteSpace(text))
            {
                return allowEmpty;
            }

            var s = text.Trim();
            if (double.TryParse(s, NumberStyles.Float, CultureInfo.InvariantCulture, out value))
            {
                return true;
            }

            return double.TryParse(s, NumberStyles.Float, CultureInfo.CurrentCulture, out value);
        }
    }
}