using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;
using PKHeX.Core;
using PKHeX.Drawing.PokeSprite;
using PKHeX.WinForms.Properties;
using PKHeX.WinForms.Controls;
using static PKHeX.Core.MessageStrings;

namespace PKHeX.WinForms
{
    public partial class SAV_MysteryGiftDB : Form
    {
        private readonly PKMEditor PKME_Tabs;
        private readonly SaveFile SAV;
        private readonly SAVEditor BoxView;
        private readonly SummaryPreviewer ShowSet = new();

        public SAV_MysteryGiftDB(PKMEditor tabs, SAVEditor sav)
        {
            InitializeComponent();

            WinFormsUtil.TranslateInterface(this, Main.CurrentLanguage);

            SAV = sav.SAV;
            BoxView = sav;
            PKME_Tabs = tabs;

            // Preset Filters to only show PKM available for loaded save
            CB_FormatComparator.SelectedIndex = 3; // <=

            var grid = MysteryPokeGrid;
            var smallWidth = grid.Width;
            var smallHeight = grid.Height;
            grid.InitializeGrid(6, 11, SpriteUtil.Spriter);
            grid.SetBackground(Resources.box_wp_clean);
            var newWidth = grid.Width;
            var newHeight = grid.Height;
            var wdelta = newWidth - smallWidth;
            if (wdelta != 0)
                Width += wdelta;
            var hdelta = newHeight - smallHeight;
            if (hdelta != 0)
                Height += hdelta;

            PKXBOXES = grid.Entries.ToArray();

            // Enable Scrolling when hovered over
            foreach (var slot in PKXBOXES)
            {
                // Enable Click
                slot.MouseClick += (sender, e) =>
                {
                    if (ModifierKeys == Keys.Control)
                        ClickView(sender!, e);
                };

                slot.ContextMenuStrip = mnu;
                slot.MouseEnter += (o, args) => ShowHoverTextForSlot(slot, args);
            }

            Counter = L_Count.Text;
            Viewed = L_Viewed.Text;
            L_Viewed.Text = string.Empty; // invis for now
            L_Viewed.MouseEnter += (sender, e) => hover.SetToolTip(L_Viewed, L_Viewed.Text);

            // Load Data
            B_Search.Enabled = false;
            L_Count.Text = "Loading...";
            new Task(LoadDatabase).Start();

            CB_Format.Items[0] = MsgAny;
            CenterToParent();
        }

        private readonly PictureBox[] PKXBOXES;
        private readonly string DatabasePath = Main.MGDatabasePath;
        private List<MysteryGift> Results = new();
        private List<MysteryGift> RawDB = new();
        private int slotSelected = -1; // = null;
        private Image? slotColor;
        private const int RES_MAX = 66;
        private const int RES_MIN = 6;
        private readonly string Counter;
        private readonly string Viewed;
        private const int MAXFORMAT = PKX.Generation;

        private bool GetShiftedIndex(ref int index)
        {
            if (index >= RES_MAX)
                return false;
            index += SCR_Box.Value * RES_MIN;
            return index < Results.Count;
        }

        // Important Events
        private void ClickView(object sender, EventArgs e)
        {
            int index = GetSenderIndex(sender);
            if (index < 0)
                return;
            var temp = Results[index].ConvertToPKM(SAV);
            var pk = EntityConverter.ConvertToType(temp, SAV.PKMType, out var c);
            if (pk == null)
            {
                WinFormsUtil.Error(c.GetDisplayString(temp, SAV.PKMType));
                return;
            }
            SAV.AdaptPKM(pk);
            PKME_Tabs.PopulateFields(pk, false);
            slotSelected = index;
            slotColor = SpriteUtil.Spriter.View;
            UpdateSlotColor(SCR_Box.Value);
            L_Viewed.Text = string.Format(Viewed, Results[index].FileName);
        }

        private void ClickSavePK(object sender, EventArgs e)
        {
            int index = GetSenderIndex(sender);
            if (index < 0)
                return;
            var gift = Results[index];
            var pk = gift.ConvertToPKM(SAV);
            WinFormsUtil.SavePKMDialog(pk);
        }

        private void ClickSaveMG(object sender, EventArgs e)
        {
            int index = GetSenderIndex(sender);
            if (index < 0)
                return;
            var gift = Results[index];
            if (gift is not DataMysteryGift g) // e.g. WC3
            {
                WinFormsUtil.Alert(MsgExportWC3DataFail);
                return;
            }
            WinFormsUtil.ExportMGDialog(g, SAV.Version);
        }

        private int GetSenderIndex(object sender)
        {
            var pb = WinFormsUtil.GetUnderlyingControl<PictureBox>(sender);
            int index = Array.IndexOf(PKXBOXES, pb);
            if (index >= RES_MAX)
            {
                System.Media.SystemSounds.Exclamation.Play();
                return -1;
            }
            index += SCR_Box.Value*RES_MIN;
            if (index >= Results.Count)
            {
                System.Media.SystemSounds.Exclamation.Play();
                return -1;
            }
            return index;
        }

        private void PopulateComboBoxes()
        {
            // Set the Text
            CB_HeldItem.InitializeBinding();
            CB_Species.InitializeBinding();

            var Any = new ComboItem(MsgAny, -1);

            var DS_Species = new List<ComboItem>(GameInfo.SpeciesDataSource);
            DS_Species.RemoveAt(0);
            var filteredSpecies = DS_Species.Where(z => RawDB.Any(mg => mg.Species == z.Value)).ToList();
            filteredSpecies.Insert(0, Any);
            CB_Species.DataSource = filteredSpecies;

            var DS_Item = new List<ComboItem>(GameInfo.ItemDataSource);
            DS_Item.Insert(0, Any); CB_HeldItem.DataSource = DS_Item;

            // Set the Move ComboBoxes too..
            var DS_Move = new List<ComboItem>(GameInfo.MoveDataSource);
            DS_Move.RemoveAt(0); DS_Move.Insert(0, Any);
            {
                foreach (ComboBox cb in new[] { CB_Move1, CB_Move2, CB_Move3, CB_Move4 })
                {
                    cb.InitializeBinding();
                    cb.DataSource = new BindingSource(DS_Move, null);
                }
            }

            // Trigger a Reset
            ResetFilters(this, EventArgs.Empty);
            B_Search.Enabled = true;
        }

        private void ResetFilters(object sender, EventArgs e)
        {
            CHK_Shiny.Checked = CHK_IsEgg.Checked = true;
            CHK_Shiny.CheckState = CHK_IsEgg.CheckState = CheckState.Indeterminate;
            CB_HeldItem.SelectedIndex = 0;
            CB_Species.SelectedIndex = 0;

            CB_Move1.SelectedIndex = CB_Move2.SelectedIndex = CB_Move3.SelectedIndex = CB_Move4.SelectedIndex = 0;
            RTB_Instructions.Clear();

            if (sender != this)
                System.Media.SystemSounds.Asterisk.Play();
        }

        private void LoadDatabase()
        {
            var db = EncounterEvent.GetAllEvents();

            if (Main.Settings.MysteryDb.FilterUnavailableSpecies)
            {
                db = SAV switch
                {
                    SAV8LA => db.Where(z => z is WA8),
                    SAV8BS => db.Where(z => z is WB8),
                    SAV8SWSH => db.Where(z => ((PersonalInfoSWSH)PersonalTable.SWSH.GetFormEntry(z.Species, z.Form)).IsPresentInGame),
                    SAV7b => db.Where(z => z is WB7),
                    SAV7 => db.Where(z => z.Generation < 7 || z is WC7),
                    _ => db.Where(z => z.Generation <= SAV.Generation),
                };
            }

            RawDB = new List<MysteryGift>(db);
            foreach (var mg in RawDB)
                mg.GiftUsed = false;

            try
            {
                while (!IsHandleCreated) { }
                BeginInvoke(new MethodInvoker(delegate
                {
                    SetResults(RawDB);
                    PopulateComboBoxes();
                }));
            }
            catch { /* Window Closed? */ }
        }

        // IO Usage
        private void OpenDB(object sender, EventArgs e)
        {
            if (Directory.Exists(DatabasePath))
                Process.Start("explorer.exe", DatabasePath);
        }

        private void Menu_Export_Click(object sender, EventArgs e)
        {
            if (Results.Count == 0)
            { WinFormsUtil.Alert(MsgDBCreateReportFail); return; }

            if (DialogResult.Yes != WinFormsUtil.Prompt(MessageBoxButtons.YesNo, MsgDBExportResultsPrompt))
                return;

            using var fbd = new FolderBrowserDialog();
            if (DialogResult.OK != fbd.ShowDialog())
                return;

            string folder = fbd.SelectedPath;
            Directory.CreateDirectory(folder);

            foreach (var gift in Results.OfType<DataMysteryGift>()) // WC3 have no data
            {
                var fileName = Util.CleanFileName(gift.FileName);
                var path = Path.Combine(folder, fileName);
                var data = gift.Write();
                File.WriteAllBytes(path, data);
            }
        }

        // View Updates
        private void B_Search_Click(object sender, EventArgs e)
        {
            // Populate Search Query Result
            IEnumerable<MysteryGift> res = RawDB;

            int format = MAXFORMAT + 1 - CB_Format.SelectedIndex;

            switch (CB_FormatComparator.SelectedIndex)
            {
                case 0: /* Do nothing */                            break;
                case 1: res = res.Where(mg => mg.Generation >= format); break;
                case 2: res = res.Where(mg => mg.Generation == format); break;
                case 3: res = res.Where(mg => mg.Generation <= format); break;
            }

            // Primary Searchables
            int species = WinFormsUtil.GetIndex(CB_Species);
            int item = WinFormsUtil.GetIndex(CB_HeldItem);
            if (species != -1) res = res.Where(pk => pk.Species == species);
            if (item != -1) res = res.Where(pk => pk.HeldItem == item);

            // Secondary Searchables
            int move1 = WinFormsUtil.GetIndex(CB_Move1);
            int move2 = WinFormsUtil.GetIndex(CB_Move2);
            int move3 = WinFormsUtil.GetIndex(CB_Move3);
            int move4 = WinFormsUtil.GetIndex(CB_Move4);
            if (move1 != -1) res = res.Where(mg => mg.HasMove(move1));
            if (move2 != -1) res = res.Where(mg => mg.HasMove(move2));
            if (move3 != -1) res = res.Where(mg => mg.HasMove(move3));
            if (move4 != -1) res = res.Where(mg => mg.HasMove(move4));

            var shiny = CHK_Shiny.CheckState;
            if (shiny == CheckState.Checked) res = res.Where(pk => pk.IsShiny);
            else if (shiny == CheckState.Unchecked) res = res.Where(pk => !pk.IsShiny);

            var egg = CHK_IsEgg.CheckState;
            if (egg == CheckState.Checked) res = res.Where(pk => pk.IsEgg);
            else if (egg == CheckState.Unchecked) res = res.Where(pk => !pk.IsEgg);

            slotSelected = -1; // reset the slot last viewed

            if (RTB_Instructions.Lines.Any(line => line.Length > 0))
            {
                var filters = StringInstruction.GetFilters(RTB_Instructions.Lines).ToArray();
                BatchEditing.ScreenStrings(filters);
                res = res.Where(pkm => BatchEditing.IsFilterMatch(filters, pkm)); // Compare across all filters
            }

            var results = res.ToArray();
            if (results.Length == 0)
                WinFormsUtil.Alert(MsgDBSearchNone);

            SetResults(new List<MysteryGift>(results)); // updates Count Label as well.
            System.Media.SystemSounds.Asterisk.Play();
        }

        private void UpdateScroll(object sender, ScrollEventArgs e)
        {
            if (e.OldValue != e.NewValue)
                FillPKXBoxes(e.NewValue);
        }

        private void SetResults(List<MysteryGift> res)
        {
            Results = new List<MysteryGift>(res);
            ShowSet.Clear();

            SCR_Box.Maximum = (int)Math.Ceiling((decimal)Results.Count / RES_MIN);
            if (SCR_Box.Maximum > 0) SCR_Box.Maximum--;

            SCR_Box.Value = 0;
            FillPKXBoxes(0);

            L_Count.Text = string.Format(Counter, Results.Count);
        }

        private void FillPKXBoxes(int start)
        {
            if (Results.Count == 0)
            {
                for (int i = 0; i < RES_MAX; i++)
                {
                    PKXBOXES[i].Image = null;
                    PKXBOXES[i].BackgroundImage = null;
                }
                return;
            }
            int begin = start * RES_MIN;
            int end = Math.Min(RES_MAX, Results.Count - (start * RES_MIN));
            for (int i = 0; i < end; i++)
                PKXBOXES[i].Image = Results[i + begin].Sprite();
            for (int i = end; i < RES_MAX; i++)
                PKXBOXES[i].Image = null;
            UpdateSlotColor(start);
        }

        private void UpdateSlotColor(int start)
        {
            for (int i = 0; i < RES_MAX; i++)
                PKXBOXES[i].BackgroundImage = SpriteUtil.Spriter.Transparent;
            if (slotSelected != -1 && slotSelected >= RES_MIN * start && slotSelected < (RES_MIN * start) + RES_MAX)
                PKXBOXES[slotSelected - (start * RES_MIN)].BackgroundImage = slotColor ?? SpriteUtil.Spriter.View;
        }

        private void Menu_Import_Click(object sender, EventArgs e)
        {
            if (!BoxView.GetBulkImportSettings(out var clearAll, out var overwrite, out var noSetb))
                return;

            int box = BoxView.Box.CurrentBox;
            int ctr = SAV.LoadBoxes(Results, out var result, box, clearAll, overwrite, noSetb);
            if (ctr <= 0)
                return;

            BoxView.SetPKMBoxes();
            BoxView.UpdateBoxViewers();
            WinFormsUtil.Alert(result);
        }

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

        protected override void OnMouseWheel(MouseEventArgs e)
        {
            if (!MysteryPokeGrid.RectangleToScreen(MysteryPokeGrid.ClientRectangle).Contains(MousePosition))
                return;
            int oldval = SCR_Box.Value;
            int newval = oldval + (e.Delta < 0 ? 1 : -1);
            if (newval >= SCR_Box.Minimum && SCR_Box.Maximum >= newval)
                FillPKXBoxes(SCR_Box.Value = newval);
        }

        private void ChangeFormatFilter(object sender, EventArgs e)
        {
            if (CB_FormatComparator.SelectedIndex == 0)
            {
                CB_Format.Visible = false; // !any
                CB_Format.SelectedIndex = 0;
            }
            else
            {
                CB_Format.Visible = true;
                int index = MAXFORMAT - SAV.Generation + 1;
                CB_Format.SelectedIndex = index < CB_Format.Items.Count ? index : 0; // SAV generation (offset by 1 for "Any")
            }
        }

        private void ShowHoverTextForSlot(object sender, EventArgs e)
        {
            var pb = (PictureBox)sender;
            int index = Array.IndexOf(PKXBOXES, pb);
            if (!GetShiftedIndex(ref index))
                return;

            ShowSet.Show(pb, Results[index]);
        }
    }
}