add languages endpoint

ref #379

src/FilterLists.Api/V1/Controllers/LanguagesController.cs

@@ -1,5 +1,6 @@
 using System.Threading.Tasks;
 using FilterLists.Data.Entities;
+using FilterLists.Services.Language;
 using FilterLists.Services.Seed;
 using FilterLists.Services.Seed.Models;
 using Microsoft.AspNetCore.Mvc;
@@ -9,9 +10,18 @@ namespace FilterLists.Api.V1.Controllers
 {
     public class LanguagesController : BaseController
     {
-        public LanguagesController(IMemoryCache memoryCache, SeedService seedService) : base(memoryCache, seedService)
-        {
-        }
+        private readonly LanguageService languageService;
+
+        public LanguagesController(IMemoryCache memoryCache, SeedService seedService, LanguageService languageService) :
+            base(memoryCache, seedService) => this.languageService = languageService;
+
+        [HttpGet]
+        public async Task<IActionResult> Index() =>
+            Json(await MemoryCache.GetOrCreate("LanguageService_Index", entry =>
+            {
+                entry.AbsoluteExpirationRelativeToNow = FourHoursFromNow;
+                return languageService.GetAllTargeted();
+            }));
 
         [HttpGet("seed")]
         public async Task<IActionResult> Seed() =>

src/FilterLists.Services/DependencyInjection/Extensions/ConfigureServicesCollection.cs

@@ -1,6 +1,7 @@
 using AutoMapper;
 using FilterLists.Data;
 using FilterLists.Services.FilterList;
+using FilterLists.Services.Language;
 using FilterLists.Services.Seed;
 using FilterLists.Services.Snapshot;
 using FilterLists.Services.Software;
@@ -23,6 +24,7 @@ public static void AddFilterListsApiServices(this IServiceCollection services, I
             services.TryAddScoped<FilterListService>();
             services.TryAddScoped<RuleService>();
             services.TryAddScoped<SoftwareService>();
+            services.TryAddScoped<LanguageService>();
             services.TryAddScoped<SeedService>();
             services.AddAutoMapper();
         }

src/FilterLists.Services/Language/LanguageService.cs

@@ -0,0 +1,27 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using AutoMapper;
+using AutoMapper.QueryableExtensions;
+using FilterLists.Data;
+using FilterLists.Services.Language.Models;
+using JetBrains.Annotations;
+using Microsoft.EntityFrameworkCore;
+
+namespace FilterLists.Services.Language
+{
+    [UsedImplicitly]
+    public class LanguageService : Service
+    {
+        public LanguageService(FilterListsDbContext dbContext, IConfigurationProvider mapConfig)
+            : base(dbContext, mapConfig)
+        {
+        }
+
+        public async Task<IEnumerable<LanguageDto>> GetAllTargeted() =>
+            await DbContext.Languages.Where(l => l.FilterListLanguages.Any())
+                           .OrderBy(s => s.Name)
+                           .ProjectTo<LanguageDto>(MapConfig)
+                           .ToListAsync();
+    }
+}

src/FilterLists.Services/Language/Models/LanguageDto.cs

@@ -0,0 +1,11 @@
+using JetBrains.Annotations;
+
+namespace FilterLists.Services.Language.Models
+{
+    [UsedImplicitly]
+    public class LanguageDto
+    {
+        public string Iso6391 { get; set; }
+        public string Name { get; set; }
+    }
+}