using System;
using System.Collections.ObjectModel;
using System.Linq;
using Xamarin.Essentials;
using Xamarin.Forms;

namespace Project1503
{
    public partial class InventoryPage : ContentPage
    {
        private ObservableCollection<InventoryItemModel> items;
        private ObservableCollection<HistoryItemModel> historyItems;

        // Add a property for filtering
        private string searchQuery;
        public string SearchQuery
        {
            get { return searchQuery; }
            set
            {
                searchQuery = value;
            }
        }

        public Command SearchCommand { get; set; }

        public InventoryPage()
        {
            InitializeComponent();

            items = LoadItemsFromPreferences();
            historyItems = LoadHistoryFromPreferences();
            listView.ItemsSource = items;

            // Initialize the search command
            SearchCommand = new Command<string>(UpdateSearchResults);
            BindingContext = this;
        }


        private ObservableCollection<InventoryItemModel> LoadItemsFromPreferences()
        {
            var serializedItems = Preferences.Get("inventoryItems", string.Empty);
            return string.IsNullOrWhiteSpace(serializedItems)
                ? new ObservableCollection<InventoryItemModel>()
                : Newtonsoft.Json.JsonConvert.DeserializeObject<ObservableCollection<InventoryItemModel>>(serializedItems);
        }

        private ObservableCollection<HistoryItemModel> LoadHistoryFromPreferences()
        {
            var serializedHistory = Preferences.Get("inventoryHistory", string.Empty);
            return string.IsNullOrWhiteSpace(serializedHistory)
                ? new ObservableCollection<HistoryItemModel>()
                : Newtonsoft.Json.JsonConvert.DeserializeObject<ObservableCollection<HistoryItemModel>>(serializedHistory);
        }

        private void SaveItemsToPreferences()
        {
            var serializedItems = Newtonsoft.Json.JsonConvert.SerializeObject(items);
            Preferences.Set("inventoryItems", serializedItems);
        }

        private void SaveHistoryToPreferences()
        {
            var serializedHistory = Newtonsoft.Json.JsonConvert.SerializeObject(historyItems);
            Preferences.Set("inventoryHistory", serializedHistory);
        }

        private void SaveHistoryItem(string action, InventoryItemModel item)
        {
            var historyItem = new HistoryItemModel
            {
                Action = action,
                ItemName = item.ItemName,
                TagNumber = item.TagNumber,
                ShelfNumber = item.ShelfNumber,
                Quantity = item.Quantity,
                Description = item.Description,
                DateAdded = DateTime.Now
            };

            historyItems.Add(historyItem);
            SaveHistoryToPreferences();
        }

        private void RemoveHistoryItem(InventoryItemModel item)
        {
            var historyItem = new HistoryItemModel
            {
                Action = "Delete",
                ItemName = item.ItemName,
                TagNumber = item.TagNumber,
                ShelfNumber = item.ShelfNumber,
                Quantity = item.Quantity,
                Description = item.Description,
                DateAdded = DateTime.Now
            };

            historyItems.Add(historyItem);
            SaveHistoryToPreferences();
        }

        private async void OnAddButtonClicked(object sender, EventArgs e)
        {
            // Prompt the user to enter details for the new item
            var itemName = await DisplayPromptAsync("Add Item", "Enter item name", maxLength: 50);
            if (string.IsNullOrWhiteSpace(itemName))
                return; // User canceled or entered an empty name

            var tagNumber = await DisplayPromptAsync("Add Item", "Enter tag number", maxLength: 20);
            var shelfNumber = await DisplayPromptAsync("Add Item", "Enter shelf number", maxLength: 20);
            var quantity = await DisplayPromptAsync("Add Item", "Enter quantity", maxLength: 20);
            var description = await DisplayPromptAsync("Add Item", "Enter description", maxLength: 100);

            var newItem = new InventoryItemModel
            {
                ItemName = itemName,
                TagNumber = tagNumber,
                ShelfNumber = shelfNumber,
                Quantity = quantity,
                Description = description,
                DateAdded = DateTime.Now
            };

            items.Add(newItem);
            SaveItemsToPreferences();

            SaveHistoryItem("Add", newItem);
        }

        private async void OnItemSelected(object sender, SelectedItemChangedEventArgs e)
        {
            if (e.SelectedItem == null)
                return;

            var selectedItem = (InventoryItemModel)e.SelectedItem;

            var result = await DisplayAlert("Item Details",
                $"Name: {selectedItem.ItemName}\n" +
                $"Tag Number: {selectedItem.TagNumber}\n" +
                $"Shelf Number: {selectedItem.ShelfNumber}\n" +
                $"Quantity: {selectedItem.Quantity}\n" +
                $"Description: {selectedItem.Description}\n" +
                $"Date of Addition: {selectedItem.DateAdded}",
                "Delete", "Cancel");

            if (result)
            {
                items.Remove(selectedItem);
                SaveItemsToPreferences();

                RemoveHistoryItem(selectedItem);
            }

            ((ListView)sender).SelectedItem = null;
        }
        private void UpdateSearchResults(string query)
        {
            SearchQuery = query;
            if (string.IsNullOrWhiteSpace(SearchQuery))
            {
                // Reset the list to show all items
                listView.ItemsSource = items;
            }
            else
            {
                // Filter items based on the search query
                var filteredItems = items.Where(item =>
                    item.ItemName.ToLower().Contains(SearchQuery.ToLower()) ||
                    item.TagNumber.ToLower().Contains(SearchQuery.ToLower()) ||
                    item.ShelfNumber.ToLower().Contains(SearchQuery.ToLower()) ||
                    item.Quantity.ToLower().Contains(SearchQuery.ToLower()) ||
                    item.Description.ToLower().Contains(SearchQuery.ToLower())
                ).ToList();

                listView.ItemsSource = new ObservableCollection<InventoryItemModel>(filteredItems);
            }
        }

    }

    public class InventoryItemModel
    {
        public string ItemName { get; set; }
        public string TagNumber { get; set; }
        public string ShelfNumber { get; set; }
        public string Quantity { get; set; }
        public string Description { get; set; }
        public DateTime DateAdded { get; set; }
    }
}