using System;
using System.Collections.Generic;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Windows.Forms;
using static System.Windows.Forms.ListViewItem;
using System.ComponentModel;

namespace NethackHelper {
    public partial class ItemDisplay : UserControl {
        public const string UNIDENTIFIED = "[randomized]";
        public static readonly Color SELECTED_COLOR = Color.Black;
        public static readonly Color UNSELECTED_COLOR = Color.Gray;

        private static readonly Dictionary<ItemAttribute, Func<Item, string>> COLUMN_MAP = new() {
            [ItemAttribute.Name] = item => item.Name,
            [ItemAttribute.Cost] = item => item.Cost.ToString(),
            [ItemAttribute.Ink] = item => item.Ink.ToString(),
            [ItemAttribute.Appearance] = item => item.Appearance ?? UNIDENTIFIED,
        };

        [Browsable(false)]
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
        public Func<int, string> CostFormatter { get; set; } = cost => cost.ToString();

        [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
        public List<ItemDisplayColumn> Columns { get; set; } = new();

        private int[] GroupCosts { get; set; } = [];

        private Dictionary<string, string?> AppearanceMap { get; set; } = new();

        public ItemDisplay() {
            InitializeComponent();
            this.itemListView.ListViewItemSorter = Comparer<ListViewItem>.Create(CompareItems);
        }

        protected override void OnLoad(EventArgs e) {
            base.OnLoad(e);
            if (this.Columns != null) {
                this.itemListView.Columns.Clear();
                foreach (var column in this.Columns) {
                    this.itemListView.Columns.Add(column.Attribute.ToString(), column.Width);
                }
            }
        }

        public void DisplayItemList(ItemList itemList, IdentificationRecord? idRecord) {
            this.itemListView.Groups.Clear();
            this.itemListView.Items.Clear();
            this.AppearanceMap.Clear();

            this.GroupCosts = itemList.Items.Select(item => item.Cost).Distinct().Order().ToArray();
            var costDictionary = new Dictionary<int, ListViewGroup>();

            foreach (var cost in this.GroupCosts) {
                var group = new ListViewGroup(this.CostFormatter.Invoke(cost), HorizontalAlignment.Center);
                this.itemListView.Groups.Add(group);
                costDictionary.Add(cost, group);
            }

            foreach (var item in itemList.Items) {
                bool identified = false;
                ItemRecord record = default;
                if (idRecord != null) {
                    if (idRecord.TryGetValue(item.Name, out var identity)) {
                        record = identity;
                        identified = true;
                    }
                } else if (item.Appearance != null) {
                    record = new ItemRecord() {
                        Name = item.Name,
                        Appearance = item.Appearance,
                    };
                    identified = true;
                }

                AppearanceMap[item.Name] = record.Appearance;

                var columns = this.Columns.Select(col => COLUMN_MAP[col.Attribute].Invoke(item)).ToArray();

                var listViewItem = new ListViewItem(columns, costDictionary[item.Cost]);
                listViewItem.UseItemStyleForSubItems = false;
                var baseFont = new Font(this.itemListView.Font, FontStyle.Regular);
                var baseColor = UNSELECTED_COLOR;
                if (!identified) {
                    baseFont = new Font(baseFont, FontStyle.Bold);
                    baseColor = SELECTED_COLOR;
                }
                listViewItem.Checked = identified;
                listViewItem.Font = baseFont;
                listViewItem.ForeColor = baseColor;
                foreach (ListViewSubItem subItem in listViewItem.SubItems) {
                    subItem.Font = baseFont;
                    subItem.ForeColor = baseColor;
                }
                if (record.Appearance == null) {
                    var fontStyle = FontStyle.Italic;
                    if (!identified) {
                        fontStyle |= FontStyle.Bold;
                    }

                    for (var i = 0; i < this.Columns.Count; i++) {
                        if (this.Columns[i].Attribute == ItemAttribute.Appearance) {
                            listViewItem.SubItems[i].Font = new Font(baseFont, fontStyle);
                        }
                    }
                }
                this.itemListView.Items.Add(listViewItem);
            }
        }

        public IdentificationRecord Export() {
            List<ItemRecord> records = [];
            foreach (ListViewItem item in this.itemListView.Items) {
                if (item.Checked) {
                    string? appearance = this.AppearanceMap[item.Text];
                    records.Add(new() {
                        Name = item.Text,
                        Appearance = appearance,
                    });
                }
            }
            return new(records);
        }

        public void UpdateCostHeaders() {
            for (int i = 0; i < this.GroupCosts.Length; i++) {
                this.itemListView.Groups[i].Header = this.CostFormatter.Invoke(this.GroupCosts[i]);
            }
        }

        private void itemListView_MouseDoubleClick(object sender, MouseEventArgs e) {
            if (this.itemListView.SelectedItems.Count == 1) {
                var item = this.itemListView.SelectedItems[0];
                item.Checked = !item.Checked;
                var baseFont = item.Font;
                foreach (ListViewSubItem subItem in item.SubItems) {
                    if (item.Checked) {
                        if (subItem.Font.Italic) {
                            subItem.Font = new Font(baseFont, FontStyle.Italic);
                        } else {
                            subItem.Font = new Font(baseFont, FontStyle.Regular);
                        }
                        subItem.ForeColor = UNSELECTED_COLOR;
                    } else {
                        if (subItem.Font.Italic) {
                            subItem.Font = new Font(baseFont, FontStyle.Bold | FontStyle.Italic);
                        } else {
                            subItem.Font = new Font(baseFont, FontStyle.Bold | FontStyle.Regular);
                        }
                        subItem.ForeColor = SELECTED_COLOR;
                    }
                }
                this.itemListView.Sort();
            }
        }

        private static int CompareItems(ListViewItem a, ListViewItem b) {
            if (a.Checked != b.Checked) {
                return a.Checked.CompareTo(b.Checked);
            } else {
                return a.Text.CompareTo(b.Text);
            }
        }
    }

    [Serializable]
    public class ItemDisplayColumn {
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
        public ItemAttribute Attribute { get; set; }

        [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
        public int Width { get; set; }
    }
}