using Microsoft.AspNetCore.Components;
using Blazored.LocalStorage;
using Blog3000.Shared;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Net.Http;
using Markdig.Extensions.Tables;
using Blog3000.Client.Services;
using System.Security.Cryptography;
using System.ComponentModel;
using System.Data;
using System.Net.Security;

namespace Blog3000.Client
{
    /// <summary>
    /// TODO: Add all localStorage Ops regarding BlogsPosts here
    /// - Updater
    /// - Topic-Fetcher
    /// - ...
    /// </summary>
    public class ViewStats : IDisposable
    {
        public static string DBKEY_PREFIX = "viewstats-";
        
        private readonly ILocalStorageService localStorage;
        private readonly NetworkStatus networkStatus;
        private readonly HttpClient httpClient;

        public ViewStats(ILocalStorageService ls, NetworkStatus ns, HttpClient http)
        {
            this.localStorage = ls;
            this.networkStatus = ns;
            this.httpClient = http;

            localStorage.Changed += LocalStorage_Changed;
        }


        public void Dispose()
        {
            localStorage.Changed -= LocalStorage_Changed;
        }


        public async Task AddPostView(string postId)
        {
            var unsentStats = await localStorage.GetItemAsync<Dictionary<string, int>>($"{DBKEY_PREFIX}local");
            unsentStats ??= new Dictionary<string, int>();
            unsentStats.Remove(postId);
            unsentStats.Add(postId, 1);
            await localStorage.SetItemAsync($"{DBKEY_PREFIX}local", unsentStats);
            _ = SyncViewStats();
        }

        public async Task<int> GetPostViewCount(string postId)
        {
            var remoteStats = await localStorage.GetItemAsync<Dictionary<string, int>>($"{DBKEY_PREFIX}remote");
            var unsentStats = await localStorage.GetItemAsync<Dictionary<string, int>>($"{DBKEY_PREFIX}local");

            int remoteCount = 0;
            remoteStats?.TryGetValue(postId, out remoteCount);
            int localCount = 0;
            unsentStats?.TryGetValue(postId, out localCount);

            return localCount + remoteCount;
        }

        /// <summary>
        /// Fetch a locally cached post. Optionally fetch images from remote.  Optionally fetch post from remote. 
        /// </summary>
        /// <param name="postId"></param>
        /// <param name="tryCacheImgs"></param>
        /// <param name="tryRemote"></param>
        /// <returns></returns>
        public async Task<bool> SyncViewStats()
        {
            if (!networkStatus.IsOnline)
            {
                System.Diagnostics.Debug.WriteLine("SyncViewStats: Offline, not syncing");
                return false;
            }

            var unsentStats = await localStorage.GetItemAsync<Dictionary<string, int>>($"{DBKEY_PREFIX}local");
            if ((unsentStats?.Count ?? 0) > 0)
            {
                try
                {
                    var newData = await httpClient.PostJsonAsync<Dictionary<string, int>>($"ViewStats", unsentStats);
                    await localStorage.RemoveItemAsync($"{DBKEY_PREFIX}local");
                    await localStorage.SetItemAsync<Dictionary<string, int>>($"{DBKEY_PREFIX}remote", newData);
                    System.Diagnostics.Debug.WriteLine("SyncViewStats: Stats synced");
                    return true;
                }
                catch (Exception ex)
                {
                    System.Diagnostics.Debug.WriteLine($"SyncViewStats: Sync failed: {ex.ToString()}");
                }
            }
            else
            {
                System.Diagnostics.Debug.WriteLine("SyncViewStats: UnsetStats empty, not sending, only fetching");
            }
            
            try
            {
                var newData = await httpClient.GetJsonAsync<Dictionary<string, int>>($"ViewStats");
                await localStorage.SetItemAsync<Dictionary<string, int>>($"{DBKEY_PREFIX}remote", newData);
                System.Diagnostics.Debug.WriteLine("SyncViewStats: Stats fetched");
                return true;
            }
            catch (Exception ex)
            {
                System.Diagnostics.Debug.WriteLine($"SyncViewStats: Fetch failed: {ex.ToString()}");
            }


            return false;
        }


        private void LocalStorage_Changed(object sender, ChangedEventArgs e)
        {
            if (e.Key.StartsWith(ViewStats.DBKEY_PREFIX)) Task.Run(() => {  
                //
            });
        }

    }





}