using Microsoft.AspNetCore.Components;
using Microsoft.AspNetCore.Components.Web.Virtualization;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Net;
using System.Text;
using System.Text.Json;
using System.Threading.Tasks;

namespace Neighbourhood.omg.lol.Models {
  public class State {
    public AccountResponseData? AccountInfo { get; set; }
    public AddressResponseList? AddressList { get; set; }

    public string? Name { get => AccountInfo?.Name; }
    public string? Email { get => AccountInfo?.Email; }
    public IEnumerable<string>? AddressNames { get => AddressList?.Select(a => a.Address); }
    public AddressResponseData? SelectedAddress { get; set; }
    public string? SelectedAddressName { get => SelectedAddress?.Address; }

    public List<Status>? Statuses { get; set; }
    public List<Pic>? Pics { get; set; }

    public List<Status>? CachedAddressStatuses { get; set; }
    public List<Pic>? CachedAddressPics { get; set; }
    public MarkupString? CachedAddressBio { get; set; }
    private string? _cachedAddress;
    public string? CachedAddress {
      get => _cachedAddress;
      set {
        if (_cachedAddress != value) {
          _cachedAddress = value;
          CachedAddressStatuses = new List<Status>();
          CachedAddressPics = new List<Pic>();
          CachedAddressBio = null;
        }
      }
    }

    public async Task PopulateAccountDetails(string token) {
      RestService api = new RestService(token);

      string accountJson = Preferences.Default.Get("accountdetails", string.Empty);
      string addressJson = Preferences.Default.Get("accountaddresses", string.Empty);
      string selectedAddressJson = Preferences.Default.Get("selectedaddress", string.Empty);

      if (!string.IsNullOrEmpty(accountJson)) AccountInfo = JsonSerializer.Deserialize<AccountResponseData>(accountJson);
      if (!string.IsNullOrEmpty(addressJson)) AddressList = JsonSerializer.Deserialize<AddressResponseList>(addressJson);
      if (!string.IsNullOrEmpty(selectedAddressJson)) SelectedAddress = JsonSerializer.Deserialize<AddressResponseData>(selectedAddressJson);

      // if we haven't got account info, attempt to retrieve it.
      if (AccountInfo == null) {
        AccountInfo = await api.AccountInfo();
        if (AccountInfo != null) {
          Preferences.Default.Set("accountdetails", JsonSerializer.Serialize(AccountInfo));
        }
      }

      // if we don't have the list of addresses, attempt to retrieve that.
      if (AddressList == null) {
        AddressList = await api.Addresses();
        if (AddressList != null) {
          Preferences.Default.Set("accountaddresses", JsonSerializer.Serialize(AddressList));
          SelectedAddress = AddressList.FirstOrDefault();
          Preferences.Default.Set("selectedaddress", JsonSerializer.Serialize(SelectedAddress));
        }
      }
    }

    public async Task RemoveAccountDetails() {
      Preferences.Default.Clear();
      AccountInfo = null;
      AddressList = null;
      SelectedAddress = null;
    }

    public async Task<MarkupString?> GetBio(string address, bool forceRefresh = false) {
      CachedAddress = address;
      if (forceRefresh || CachedAddressBio == null) {
        RestService api = new RestService();
        CachedAddressBio = await api.StatuslogBio(address);
      }
      return CachedAddressBio;
    }

    public async Task<List<Status>?> GetStatuses(bool forceRefresh = false) {
      RestService api = new RestService();
      if (forceRefresh || this.Statuses == null || this.Statuses.Count == 0) {
        this.Statuses = await api.StatuslogLatest();
      }
      return this.Statuses;
    }

    public async ValueTask<ItemsProviderResult<Status>> VirtualStatuses(ItemsProviderRequest request) {
      // TODO: request.cancellationToken
      var statuses = (await this.GetStatuses()) ?? new List<Status>();
      var numStatuses = Math.Min(request.Count, statuses.Count - request.StartIndex);
      return new ItemsProviderResult<Status>(statuses.Skip(request.StartIndex).Take(numStatuses), statuses.Count);
    }

    public async ValueTask<ItemsProviderResult<Status>> VirtualStatuses(ItemsProviderRequest request, string address) {
      // TODO: request.cancellationToken
      RestService api = new RestService();
      CachedAddressStatuses = (await api.Statuslog(address)) ?? new List<Status>();
      var numStatuses = Math.Min(request.Count, CachedAddressStatuses.Count - request.StartIndex);
      return new ItemsProviderResult<Status>(CachedAddressStatuses.Skip(request.StartIndex).Take(numStatuses), CachedAddressStatuses.Count);
    }

    public Func<ItemsProviderRequest, ValueTask<ItemsProviderResult<Status>>> VirtualStatusesFunc(string? address = null) {
      if (address == null) return VirtualStatuses;
      else {
        CachedAddress = address;
        return async (ItemsProviderRequest request) => await VirtualStatuses(request, CachedAddress);
      }
    }

    public async Task<List<Pic>?> GetPics(bool forceRefresh = false) {
      if(forceRefresh || this.Pics == null || this.Pics.Count == 0) {
        RestService api = new RestService();
        this.Pics = await api.SomePics();
      }
      return this.Pics;
    }

    public async ValueTask<ItemsProviderResult<Pic>> VirtualPics(ItemsProviderRequest request) {
      // TODO: request.cancellationToken
      var pics = (await this.GetPics()) ?? new List<Pic>();
      var numPics = Math.Min(request.Count, pics.Count - request.StartIndex);
      return new ItemsProviderResult<Pic>(pics.Skip(request.StartIndex).Take(numPics), pics.Count);
    }

    public async ValueTask<ItemsProviderResult<Pic>> VirtualPics(ItemsProviderRequest request, string address) {
      // TODO: request.cancellationToken
      RestService api = new RestService();
      CachedAddressPics = (await api.SomePics(address)) ?? new List<Pic>();
      var numPics = Math.Min(request.Count, CachedAddressPics.Count - request.StartIndex);
      return new ItemsProviderResult<Pic>(CachedAddressPics.Skip(request.StartIndex).Take(numPics), CachedAddressPics.Count);
    }

    public Func<ItemsProviderRequest, ValueTask<ItemsProviderResult<Pic>>> VirtualPicsFunc(string? address = null) {
      if (address == null) return VirtualPics;
      else {
        CachedAddress = address;
        return async (ItemsProviderRequest request) => await VirtualPics(request, CachedAddress);
      }
    }

    public async Task<long> FileSize(FileResult file) {
      using var fileStream = await file.OpenReadAsync();
      return fileStream.Length;
    }
    
    public async Task<string> Base64FromFile(FileResult file) {
      using var memoryStream = new MemoryStream();
      using var fileStream = await file.OpenReadAsync();
      await fileStream.CopyToAsync(memoryStream);
      byte[] bytes = memoryStream.ToArray();
      return Convert.ToBase64String(bytes);
    }

    public async Task RefreshStatuses() => await GetStatuses(forceRefresh: true);
    public async Task RefreshPics() => await GetPics(forceRefresh: true);
  }
}