using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Windows.Forms;
using PKHeX.Core;
using PKHeX.Drawing.Misc;
using PKHeX.Drawing.PokeSprite;
using static PKHeX.Core.MessageStrings;

namespace PKHeX.WinForms.Controls;

public partial class BoxEditor : UserControl, ISlotViewer<PictureBox>
{
    public IList<PictureBox> SlotPictureBoxes { get; private set; } = [];
    public SaveFile SAV => M?.SE.SAV ?? throw new ArgumentNullException(nameof(SAV));

    public int BoxSlotCount { get; private set; }
    public SlotChangeManager? M { get; set; }
    public bool FlagIllegal { get; set; }
    public bool CanSetCurrentBox { get; set; }

    public BoxEdit Editor { get; set; } = null!;

    public BoxEditor()
    {
        InitializeComponent();
    }

    internal bool InitializeGrid()
    {
        var count = SAV.BoxSlotCount;
        var width = count / 5;
        var height = count / width;
        if (!BoxPokeGrid.InitializeGrid(width, height, SpriteUtil.Spriter))
            return false;
        RecenterControls();
        InitializeSlots();
        return true;
    }

    public void RecenterControls()
    {
        if (Width < BoxPokeGrid.Width)
            Width = BoxPokeGrid.Width;
        BoxPokeGrid.HorizontallyCenter(this);
        int p1 = CB_BoxSelect.Location.X;
        CB_BoxSelect.HorizontallyCenter(this);
        int p2 = CB_BoxSelect.Location.X;

        var delta = p2 - p1;
        if (delta == 0)
            return;

        B_BoxLeft.SetBounds(B_BoxLeft.Location.X + delta, 0, 0, 0, BoundsSpecified.X);
        B_BoxRight.SetBounds(B_BoxRight.Location.X + delta, 0, 0, 0, BoundsSpecified.X);
    }

    private void InitializeSlots()
    {
        SlotPictureBoxes = BoxPokeGrid.Entries;
        BoxSlotCount = SlotPictureBoxes.Count;
        foreach (var pb in SlotPictureBoxes)
        {
            pb.MouseEnter += (o, args) => BoxSlot_MouseEnter(pb, args);
            pb.MouseLeave += (o, args) => BoxSlot_MouseLeave(pb, args);
            pb.MouseClick += BoxSlot_MouseClick;
            pb.MouseMove += BoxSlot_MouseMove;
            pb.MouseDown += BoxSlot_MouseDown;
            pb.MouseUp += BoxSlot_MouseUp;

            pb.DragEnter += BoxSlot_DragEnter;
            pb.DragDrop += BoxSlot_DragDrop;
            pb.QueryContinueDrag += BoxSlot_QueryContinueDrag;
            pb.GiveFeedback += (sender, e) => e.UseDefaultCursors = false;
            pb.AllowDrop = true;
        }
    }

    public void NotifySlotOld(ISlotInfo previous)
    {
        if (previous is not SlotInfoBox b || b.Box != CurrentBox)
            return;

        var pb = SlotPictureBoxes[previous.Slot];
        pb.BackgroundImage = null;
    }

    public void NotifySlotChanged(ISlotInfo slot, SlotTouchType type, PKM pk)
    {
        int index = GetViewIndex(slot);
        if (index < 0)
            return;

        var pb = SlotPictureBoxes[index];
        SlotUtil.UpdateSlot(pb, slot, pk, SAV, FlagIllegal, type);
    }

    public int GetViewIndex(ISlotInfo slot)
    {
        if (slot is not SlotInfoBox b || b.Box != CurrentBox)
            return -1;
        return slot.Slot;
    }

    public ISlotInfo GetSlotData(PictureBox view)
    {
        int slot = GetSlot(view);
        return new SlotInfoBox(ViewIndex, slot);
    }

    private int GetSlot(PictureBox sender) => SlotPictureBoxes.IndexOf(sender);
    public int ViewIndex => CurrentBox;

    public bool ControlsVisible
    {
        get => CB_BoxSelect.Enabled;
        set => CB_BoxSelect.Enabled = CB_BoxSelect.Visible = B_BoxLeft.Visible = B_BoxRight.Visible = value;
    }

    public bool ControlsEnabled
    {
        get => CB_BoxSelect.Enabled;
        set => CB_BoxSelect.Enabled = B_BoxLeft.Enabled = B_BoxRight.Enabled = value;
    }

    public int CurrentBox
    {
        get => CB_BoxSelect.SelectedIndex;
        set
        {
            CB_BoxSelect.SelectedIndex = value;
            if (value < 0)
                return;
            Editor.LoadBox(value);
        }
    }

    public string CurrentBoxName => CB_BoxSelect.Text;

    public void Setup(SlotChangeManager m)
    {
        M = m;
        M.Boxes.Add(this);
        FlagIllegal = M.SE.FlagIllegal;
    }

    /// <summary>
    /// Updates the list of Box Names to select from, and selects the box index specified. If no box is specified, the previous index is used.
    /// </summary>
    /// <param name="box">Box to display after reload.</param>
    public void ResetBoxNames(int box = -1)
    {
        if (!SAV.HasBox)
            return;

        var currentIndex = CurrentBox;
        if (box < 0)
            box = currentIndex;

        var update = BoxUtil.GetBoxNames(SAV);
        var current = CB_BoxSelect.Items;
        if (!GetIsSame(update, current))
        {
            // try to keep list elements if same length
            if (update.Length == current.Count)
            {
                for (int i = 0; i < update.Length; i++)
                    current[i] = update[i];
            }
            else // rebuild completely
            {
                current.Clear();
                current.AddRange(update);
            }
        }

        box = Math.Clamp(box, 0, current.Count - 1);
        if (box != CurrentBox)
            CurrentBox = box;
    }

    private static bool GetIsSame(IReadOnlyList<string> a, IList b)
    {
        if (a.Count != b.Count)
            return false;
        for (int i = 0; i < a.Count; i++)
        {
            if (b[i] is not string s || s != a[i])
                return false;
        }
        return true;
    }

    public void ResetSlots()
    {
        Editor.Reload();
        int box = CurrentBox;
        BoxPokeGrid.SetBackground(SAV.WallpaperImage(box));
        M?.Hover.Stop();

        int index = box * SAV.BoxSlotCount;
        for (int i = 0; i < BoxSlotCount; i++)
        {
            var pb = SlotPictureBoxes[i];
            if (i >= SAV.BoxSlotCount || index + i >= SAV.SlotCount)
            {
                pb.Visible = false;
                continue;
            }
            pb.Visible = true;
            SlotUtil.UpdateSlot(pb, (SlotInfoBox)GetSlotData(pb), Editor[i], SAV, FlagIllegal);
        }

        if (M?.Env.Slots.Publisher.Previous is SlotInfoBox b && b.Box == CurrentBox)
            SlotPictureBoxes[b.Slot].BackgroundImage = SlotUtil.GetTouchTypeBackground(M.Env.Slots.Publisher.PreviousType);
    }

    public bool SaveBoxBinary()
    {
        var dr = WinFormsUtil.Prompt(MessageBoxButtons.YesNoCancel,
            MsgSaveBoxExportYes + Environment.NewLine +
            string.Format(MsgSaveBoxExportNo, CurrentBoxName, CurrentBox + 1) + Environment.NewLine +
            MsgSaveBoxExportCancel);

        if (dr == DialogResult.Yes)
        {
            using var sfd = new SaveFileDialog();
            sfd.Filter = "Box Data|*.bin";
            sfd.FileName = "pcdata.bin";
            if (sfd.ShowDialog() != DialogResult.OK)
                return false;
            File.WriteAllBytes(sfd.FileName, SAV.GetPCBinary());
            return true;
        }
        if (dr == DialogResult.No)
        {
            using var sfd = new SaveFileDialog();
            sfd.Filter = "Box Data|*.bin";
            sfd.FileName = $"boxdata {CurrentBoxName}.bin";
            if (sfd.ShowDialog() != DialogResult.OK)
                return false;
            File.WriteAllBytes(sfd.FileName, SAV.GetBoxBinary(CurrentBox));
            return true;
        }
        return false;
    }

    public void ClearEvents()
    {
        B_BoxRight.Click -= ClickBoxRight;
        B_BoxLeft.Click -= ClickBoxLeft;
        CB_BoxSelect.SelectedIndexChanged -= GetBox;
    }

    public void Reset()
    {
        ResetBoxNames();
        ResetSlots();
    }

    private void GetBox(object? sender, EventArgs e)
    {
        CurrentBox = CB_BoxSelect.SelectedIndex;
        if (SAV.CurrentBox != CurrentBox && CanSetCurrentBox)
            SAV.CurrentBox = CurrentBox;
        ResetSlots();
        M?.Hover.Stop();
    }

    private void ClickBoxLeft(object? sender, EventArgs e) => CurrentBox = Editor.MoveLeft(ModifierKeys == Keys.Control);
    private void ClickBoxRight(object? sender, EventArgs e) => CurrentBox = Editor.MoveRight(ModifierKeys == Keys.Control);

    // Drag & Drop Handling
    private void BoxSlot_MouseEnter(object? sender, EventArgs e) => M?.MouseEnter(sender, e);
    private void BoxSlot_MouseLeave(object? sender, EventArgs e) => M?.MouseLeave(sender, e);
    private void BoxSlot_MouseClick(object? sender, MouseEventArgs e) => M?.MouseClick(sender, e);
    private void BoxSlot_MouseUp(object? sender, MouseEventArgs e) => M?.MouseUp(sender, e);
    private void BoxSlot_MouseDown(object? sender, MouseEventArgs e) => M?.MouseDown(sender, e);
    private void BoxSlot_MouseMove(object? sender, MouseEventArgs e) => M?.MouseMove(sender, e);
    private void BoxSlot_DragEnter(object? sender, DragEventArgs e) => M?.DragEnter(sender, e);
    private void BoxSlot_QueryContinueDrag(object? sender, QueryContinueDragEventArgs e) => M?.QueryContinueDrag(sender, e);
    private void BoxSlot_DragDrop(object? sender, DragEventArgs e) => M?.DragDrop(sender, e);

    public bool InitializeFromSAV(SaveFile sav)
    {
        Editor = new BoxEdit(sav);
        bool result = InitializeGrid();

        int box = sav.CurrentBox;
        if ((uint)box >= sav.BoxCount)
            box = 0;

        // Display the Box Names
        ResetBoxNames(box);
        Editor.LoadBox(box);
        return result;
    }
}