implemented services for data fetching

Diligent.WebAPI.Business/Services/FileService.cs

     public class FileService : IFileService
     {
         private readonly IConfiguration _configuration;
-        public FileService(IConfiguration configuration)
+        private readonly DatabaseContext _context;
+        public FileService(IConfiguration configuration, DatabaseContext context)
         {
             _configuration = configuration;
+            _context = context;
         }
         public async Task<string> GetCV(string fileName)
         {
             string base64 = Convert.ToBase64String(bytes);
             return base64;
         }
+
+        public async Task<IEnumerable<FileEntity>> GetAll()
+        {
+            return await _context.Files.ToListAsync();
+        }
     }
 }

Diligent.WebAPI.Business/Services/Interfaces/IFileService.cs

     {
         Task<string> GetCV(string fileName);
         Task UploadCV(string fileName,IFormFile file);
+        Task<IEnumerable<FileEntity>> GetAll();
     }
 }

Diligent.WebAPI.Business/Services/Interfaces/ITagService.cs

+
+using Diligent.WebAPI.Contracts.DTOs.Files;
+
+namespace Diligent.WebAPI.Business.Services.Interfaces
+{
+    public interface ITagService
+    {
+        Task<FileFiltersReturnDTO> GetFilters();
+    }
+}

Diligent.WebAPI.Business/Services/TagService.cs

+using Diligent.WebAPI.Contracts.DTOs.Files;
+
+namespace Diligent.WebAPI.Business.Services
+{
+    public class TagService : ITagService
+    {
+        private readonly DatabaseContext _databaseContext;
+
+        public TagService(DatabaseContext databaseContext)
+        {
+            _databaseContext = databaseContext;
+        }
+
+        public async Task<FileFiltersReturnDTO> GetFilters()
+        {
+            var categories = await _databaseContext.Categories.ToArrayAsync();
+            var tags = await _databaseContext.Tags.ToArrayAsync();
+            var extensions = await _databaseContext.Files
+                .Select(m => m.Extension).Distinct().ToArrayAsync();
+
+            return new FileFiltersReturnDTO
+            {
+                Categories = categories,
+                Tags = tags,
+                Extensions = extensions
+            };
+        }
+    }
+}

Diligent.WebAPI.Contracts/DTOs/Files/FileFiltersReturnDTO.cs

+using Diligent.WebAPI.Data.Entities;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Diligent.WebAPI.Contracts.DTOs.Files
+{
+    public class FileFiltersReturnDTO
+    {
+        public Category[] Categories { get; set; }
+        public Tag[] Tags { get; set; }
+        public string[] Extensions { get; set; }
+    }
+}

Diligent.WebAPI.Host/Controllers/V1/FilesController.cs

+namespace Diligent.WebAPI.Host.Controllers.V1
+{
+    [ApiVersion("1.0")]
+    [Route("v{version:apiVersion}/files")]
+    [ApiController]
+    public class FilesController : ControllerBase
+    {
+        private readonly IFileService _fileService;
+
+        public FilesController(IFileService fileService)
+        {
+            _fileService = fileService;
+        }
+
+        [HttpGet]
+        public async Task<IActionResult> GetAll() => Ok(await _fileService.GetAll());
+    }
+}

Diligent.WebAPI.Host/Controllers/V1/TagsController.cs

+namespace Diligent.WebAPI.Host.Controllers.V1
+{
+    [ApiVersion("1.0")]
+    [Route("v{version:apiVersion}/tags")]
+    [ApiController]
+    public class TagsController : ControllerBase
+    {
+        private readonly ITagService _tagService;
+
+        public TagsController(ITagService tagService)
+        {
+            _tagService = tagService;
+        }
+
+        [HttpGet]
+        public async Task<IActionResult> GetFileFilters() => Ok(await _tagService.GetFilters());
+    }
+}

Diligent.WebAPI.Host/Extensions/BusinessConfigurationExtension.cs

             services.AddScoped<ISaveImportedDataService, SaveImportedDataService>();
             services.AddScoped<IScreeningTestService, ScreeningTestService>();
             services.AddScoped<IFileService, FileService>();
+            services.AddScoped<ITagService, TagService>();
         }
 
         /// <summary>