blog3000/Blog3000/Client/Services/CacheStorage.cs

using Microsoft.JSInterop;
using Blog3000.Client.Utils;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace Blog3000.Client
{
    public abstract class CacheStorage
    {        
        private readonly string cacheId;
        private readonly IJSRuntime jsRuntime;
        private Task<bool> initedTask;


        public CacheStorage(IJSRuntime jsRuntime)
        {
            this.jsRuntime = jsRuntime;
            this.cacheId = GetCacheId();

            initedTask = jsRuntime.InvokePromise<bool>($"MyCacheStorage.Create", new object[] { cacheId });
            System.Diagnostics.Debug.WriteLine("CacheStorage init started");
        }


        public async Task Add(string url)
        {
            try
            {                
                await initedTask;
                await Task.Yield(); // Migitate 'Entry not found' problem?
                await jsRuntime.InvokePromiseAsync<bool>($"{cacheId}.Add", url);
                System.Diagnostics.Debug.WriteLine("Cache.Add done");
            }
            catch(Exception ex)
            {
                if (!ex.ToString().Contains("Entry was not found"))
                {
                    throw ex;
                }
                else System.Diagnostics.Debug.WriteLine("Cache.Add: Ignoring Entry not found problem!");
            }
        }


        public async Task AddAll(string[] urls)
        {
            // Work around bug in edge erroreneuosly reporting "Entry was not found" sometimge
            // although successful, Therefore we must request each file single
                        
            foreach (var u in urls)
            {
                await Task.Yield();
                await Add(u);             
            }
            
            //await Task.Yield();
            //await jsRuntime.InvokePromiseAsync<bool>($"{cacheId}.AddAll", urls);
            //System.Diagnostics.Debug.WriteLine("Cache.AddAll done");

        }


        public async Task Delete(string url)
        {
            await initedTask;
            await jsRuntime.InvokePromiseAsync<bool>($"{cacheId}.Delete", url);
            System.Diagnostics.Debug.WriteLine("Cache.Delete done");
        }


        public async Task<bool> AreCached(string[] filters)
        {
            await initedTask;
            var res = await jsRuntime.InvokePromiseAsync<bool>($"{cacheId}.AreCached", filters);
            System.Diagnostics.Debug.WriteLine($"Cache.AreCached {res} done");
            return res;
        }

        public async Task<string[]> MatchAll(string filter)
        {
            await initedTask;
            var res = await jsRuntime.InvokePromiseAsync<string[]>($"{cacheId}.MatchAll", filter);
            System.Diagnostics.Debug.WriteLine($"Cache.MatchAll {res?.Length ?? -1} done");
            return res;
        }

        protected abstract string GetCacheId();

    }
}