using Microsoft.AspNetCore.Components;
using Blog3000.Shared;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;

namespace Blog3000.Client.Pages
{
    public partial class Viewer: IDisposable
    {

       

        [Parameter]
        public string Id
        {
            get { return _id; }
            set
            {
                if (_id != value)
                {
                    _id = value;
                    idChanged?.Invoke(this, EventArgs.Empty);
                }
            }
        }
        private string _id;

        [Inject]
        private BlogDb BlogDb { get; set; }


        [Inject]
        private ViewStats ViewStats { get; set; }

        private BlogPost CurrentPost { get; set; }

        private string Status { get; set; }

        private int viewCount = 0;

        private event EventHandler idChanged;

        private Shared.MarkdownViewer.ImgRefRewriterDelegate imgRefRewriter;


        public void Dispose()
        {
            idChanged -= Viewer_idChanged;
        }


        protected override async Task OnInitializedAsync()
        {
            await RefreshData();
            idChanged += Viewer_idChanged;
        }


        private async void Viewer_idChanged(object sender, EventArgs e)
        {
            await RefreshData();
            this.StateHasChanged();
        }

        private async Task RefreshData() { 
            imgRefRewriter = (a, b) => {
                System.Diagnostics.Debug.WriteLine($"Rewrting {a}/{b}");
                try
                {
                    //var s = blogDb.FetchImage(Id, a);
                    //return "data:image/jpeg;base64, " + s;
                    return $"BlogPosts/{Id}/imgref/{a}";
                }
                catch(IOException ex)
                {
                    System.Diagnostics.Debug.WriteLine($"Error rewriting url {a}/{b}", ex);
                }
                return "";
              };

            Status = "Loading...";
            var (post, res) = await BlogDb.GetCachedPostAsync(Id, true, true);
            
            if (res == BlogDb.FetchStatus.OK)
            {
                try
                {
                    viewCount = await ViewStats.GetPostViewCount(Id);
                }
                catch(Exception ex)
                {
                    System.Diagnostics.Debug.WriteLine($"Can't get viewCount: ${ex.ToString()}");
                    viewCount = -1;

                }

                _ = ViewStats.AddPostView(Id);

                CurrentPost = post;
                Status = "";
            }
            else
            {
                CurrentPost = null;
                Status = res switch
                {
                    BlogDb.FetchStatus.NotFound => "Not found",
                    BlogDb.FetchStatus.NetError => "network error",
                    BlogDb.FetchStatus.Offline => "not cached local and network offline",
                    _ => "Unknown error"
                };
                Status = "Cannot view requested document: " + Status;               
            }            
        }

 
    }
}