using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Windows.Forms;
using PKHeX.Core;
using static PKHeX.Core.MessageStrings;

namespace PKHeX.WinForms;

public sealed partial class SAV_EventFlags : Form
{
    private readonly EventWorkspace<IEventFlag37, ushort> Editor;
    private readonly Dictionary<int, NumericUpDown> WorkDict = [];
    private readonly Dictionary<int, int> FlagDict = [];

    private bool editing;

    public SAV_EventFlags(IEventFlag37 sav, GameVersion version)
    {
        InitializeComponent();
        WinFormsUtil.TranslateInterface(this, Main.CurrentLanguage);

        var editor = Editor = new EventWorkspace<IEventFlag37, ushort>(sav, version);
        DragEnter += Main_DragEnter;
        DragDrop += Main_DragDrop;

        editing = true;
        CB_Stats.Items.Clear();
        for (int i = 0; i < editor.Values.Length; i++)
            CB_Stats.Items.Add(i.ToString());

        dgv.SuspendLayout();
        TLP_Const.SuspendLayout();
        TLP_Const.Scroll += WinFormsUtil.PanelScroll;
        TLP_Const.Controls.Clear();
        AddFlagList(editor.Labels, editor.Flags);
        AddConstList(editor.Labels, editor.Values);

        dgv.ResumeLayout();
        TLP_Const.ResumeLayout();

        Text = $"{Text} ({version})";

        if (CB_Stats.Items.Count > 0)
        {
            CB_Stats.SelectedIndex = 0;
        }
        else
        {
            L_Stats.Visible = CB_Stats.Visible = MT_Stat.Visible = false;
            tabControl1.TabPages.Remove(GB_Constants);
        }
        NUD_Flag.Maximum = editor.Flags.Length - 1;
        NUD_Flag.Value = 0;
        c_CustomFlag.Checked = editor.Flags[0];
        editing = false;
    }

    private void B_Cancel_Click(object sender, EventArgs e)
    {
        Close();
    }

    private void B_Save_Click(object sender, EventArgs e)
    {
        Editor.Save();
        Close();
    }

    private void AddFlagList(EventLabelCollection list, bool[] values)
    {
        var labels = list.Flag;
        if (labels.Count == 0)
        {
            dgv.Visible = false;
            var research = new Label { Text = MsgResearchRequired, Name = "TLP_Flags_Research", ForeColor = Color.Red, AutoSize = true, Location = new Point(20, 20) };
            GB_Flags.Controls.Add(research);
            return;
        }

        var cFlag = new DataGridViewCheckBoxColumn
        {
            DisplayIndex = 0,
            Width = 20,
            SortMode = DataGridViewColumnSortMode.NotSortable,
        };

        var cLabel = new DataGridViewTextBoxColumn
        {
            DisplayIndex = 1,
            AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill,
            ReadOnly = true,
            SortMode = DataGridViewColumnSortMode.NotSortable,
        };

        cFlag.DefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleCenter;
        cLabel.DefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleLeft;

        dgv.Columns.Add(cFlag);
        dgv.Columns.Add(cLabel);

        var hideBelow = Main.Settings.Advanced.HideEventTypeBelow;
        labels = labels.Where(z => z.Type >= hideBelow).OrderByDescending(z => z.Type).ToList();
        dgv.Rows.Add(labels.Count);

        for (int i = 0; i < labels.Count; i++)
            FlagDict[labels[i].Index] = i;

        for (int i = 0; i < labels.Count; i++)
        {
            var (name, index, _) = labels[i];
            var cells = dgv.Rows[i].Cells;
            cells[0].Value = values[index];
            cells[1].Value = name;
        }
        dgv.CellValueChanged += (s, e) =>
        {
            if (e.ColumnIndex != 0 || e.RowIndex == -1)
                return;

            bool chk = (bool)dgv.Rows[e.RowIndex].Cells[0].Value;
            var index = labels[e.RowIndex].Index;
            values[index] = chk;
            if (NUD_Flag.Value == index)
                c_CustomFlag.Checked = chk;
        };
        dgv.CellMouseUp += (s, e) =>
        {
            if (e.RowIndex == -1)
                return;

            if (e.ColumnIndex == 0)
            {
                dgv.EndEdit();
                return;
            }

            if (e.ColumnIndex != 1)
                return;

            bool chk = (bool)dgv.Rows[e.RowIndex].Cells[0].Value;
            dgv.Rows[e.RowIndex].Cells[0].Value = !chk;
            var index = labels[e.RowIndex].Index;
            values[index] = !chk;
            if (NUD_Flag.Value == index)
                c_CustomFlag.Checked = !chk;
        };
    }

    private void AddConstList(EventLabelCollection list, ushort[] values)
    {
        var labels = list.Work;
        if (labels.Count == 0)
        {
            TLP_Const.Controls.Add(new Label { Text = MsgResearchRequired, Name = "TLP_Const_Research", ForeColor = Color.Red, AutoSize = true }, 0, 0);
            return;
        }

        var hide = Main.Settings.Advanced.HideEventTypeBelow;
        labels = labels.OrderByDescending(z => z.Type).ToList();
        for (var i = 0; i < labels.Count; i++)
        {
            var entry = labels[i];
            if (entry.Type < hide)
                break;
            var lbl = new Label { Text = entry.Name, Margin = Padding.Empty, AutoSize = true };
            var mtb = new NumericUpDown
            {
                Maximum = ushort.MaxValue,
                Minimum = ushort.MinValue,
                Margin = Padding.Empty,
                Width = 50,
            };

            var map = entry.PredefinedValues.Select(z => new ComboItem(z.Name, z.Value)).ToList();
            var cb = new ComboBox
            {
                Margin = Padding.Empty,
                Width = 150,
                DropDownStyle = ComboBoxStyle.DropDownList,
                BindingContext = BindingContext,
            };
            var font = cb.Font;
            cb.DropDownWidth = entry.PredefinedValues.Max(z => TextRenderer.MeasureText(z.Name, font).Width);
            cb.InitializeBinding();
            cb.DataSource = map;

            lbl.Click += (sender, e) => mtb.Value = 0;
            bool updating = false;
            mtb.ValueChanged += ChangeConstValue;
            void ChangeConstValue(object? sender, EventArgs e)
            {
                if (updating)
                    return;

                updating = true;
                var value = (ushort)mtb.Value;
                var (_, valueID) = map.Find(z => z.Value == value) ?? map[0];
                if (WinFormsUtil.GetIndex(cb) != valueID)
                    cb.SelectedValue = valueID;

                Editor.Values[entry.Index] = value;
                if (CB_Stats.SelectedIndex == entry.Index)
                    MT_Stat.Text = ((int)mtb.Value).ToString();
                updating = false;
            }
            cb.SelectedValueChanged += (o, args) =>
            {
                if (editing || updating)
                    return;
                var value = WinFormsUtil.GetIndex(cb);
                mtb.Value = value == NamedEventConst.CustomMagicValue ? 0 : value;
            };

            mtb.Value = values[entry.Index];
            if (mtb.Value == 0)
                ChangeConstValue(this, EventArgs.Empty);

            TLP_Const.Controls.Add(lbl, 0, i);
            TLP_Const.Controls.Add(cb, 1, i);
            TLP_Const.Controls.Add(mtb, 2, i);

            WorkDict.Add(entry.Index, mtb);
        }
    }

    private void ChangeCustomBool(object sender, EventArgs e)
    {
        if (editing)
            return;
        editing = true;
        var index = (int)NUD_Flag.Value;
        Editor.Flags[index] = c_CustomFlag.Checked;
        if (FlagDict.TryGetValue(index, out var rowIndex))
            dgv.Rows[rowIndex].Cells[0].Value = c_CustomFlag.Checked;
        editing = false;
    }

    private void ChangeCustomFlag(object sender, EventArgs e)
    {
        int flag = (int)NUD_Flag.Value;
        c_CustomFlag.Checked = Editor.Flags[flag];
    }

    private void ChangeCustomFlag(object sender, KeyEventArgs e) => ChangeCustomFlag(sender, (EventArgs)e);

    private void ChangeConstantIndex(object sender, EventArgs e)
    {
        var constants = Editor.Values;
        var index = CB_Stats.SelectedIndex;
        MT_Stat.Text = constants[index].ToString();
    }

    private void ChangeCustomConst(object sender, EventArgs e)
    {
        if (editing)
            return;
        editing = true;
        var index = CB_Stats.SelectedIndex;
        var parse = ushort.TryParse(MT_Stat.Text, out var value) ? value : (ushort)0;
        Editor.Values[index] = parse;
        if (WorkDict.TryGetValue(index, out var mtb))
            mtb.Value = parse;
        editing = false;
    }

    private void ChangeSAV(object sender, EventArgs e)
    {
        if (TB_NewSAV.Text.Length > 0 && TB_OldSAV.Text.Length > 0)
            DiffSaves();
    }

    private void OpenSAV(object sender, EventArgs e)
    {
        using var ofd = new OpenFileDialog();
        if (ofd.ShowDialog() == DialogResult.OK)
            LoadSAV(sender, ofd.FileName);
    }

    private void LoadSAV(object sender, string path)
    {
        var dest = sender == B_LoadOld ? TB_OldSAV : TB_NewSAV;
        dest.Text = path;
    }

    private void DiffSaves()
    {
        var diff = new EventBlockDiff<IEventFlag37, ushort>(TB_OldSAV.Text, TB_NewSAV.Text);
        if (diff.Message != EventWorkDiffCompatibility.Valid)
        {
            WinFormsUtil.Alert(diff.Message.GetMessage());
            return;
        }

        TB_IsSet.Text = string.Join(", ", diff.SetFlags.Select(z => $"{z:0000}"));
        TB_UnSet.Text = string.Join(", ", diff.ClearedFlags.Select(z => $"{z:0000}"));

        if (diff.WorkDiff.Count == 0)
        {
            WinFormsUtil.Alert("No Event Constant diff found.");
            return;
        }

        var promptCopy = WinFormsUtil.Prompt(MessageBoxButtons.YesNo, "Copy Event Constant diff to clipboard?");
        if (promptCopy == DialogResult.Yes)
            WinFormsUtil.SetClipboardText(string.Join(Environment.NewLine, diff.WorkDiff));
    }

    private static void Main_DragEnter(object? sender, DragEventArgs? e)
    {
        if (e?.Data is null)
            return;
        if (e.Data.GetDataPresent(DataFormats.FileDrop))
            e.Effect = DragDropEffects.Copy;
    }

    private void Main_DragDrop(object? sender, DragEventArgs? e)
    {
        if (e?.Data?.GetData(DataFormats.FileDrop) is not string[] { Length: not 0 } files)
            return;
        var dr = WinFormsUtil.Prompt(MessageBoxButtons.YesNo, Name, "Yes: Old Save" + Environment.NewLine + "No: New Save");
        var button = dr == DialogResult.Yes ? B_LoadOld : B_LoadNew;
        LoadSAV(button, files[0]);
    }
}