refactor: split WasmEpubService into reader and metadata extractor implementations

src/NexusReader.Web.Client/Services/WasmEpubService.cs

@@ -2,14 +2,15 @@ using System.Net.Http.Json;
 using FluentResults;
 using NexusReader.Application.Abstractions.Services;
 using NexusReader.Application.Queries.Reader;
+using VersOne.Epub;
 
 namespace NexusReader.Web.Client.Services;
 
-public class WasmEpubService : IEpubService
+public class WasmEpubReader : IEpubReader
 {
     private readonly HttpClient _httpClient;
 
-    public WasmEpubService(HttpClient httpClient)
+    public WasmEpubReader(HttpClient httpClient)
     {
         _httpClient = httpClient;
     }
@@ -18,28 +19,28 @@ public class WasmEpubService : IEpubService
     {
         try
         {
-            var response = await _httpClient.GetAsync($"/api/epub/{chapterIndex}");
+            var response = await _httpClient.GetAsync($"api/epub/content?index={chapterIndex}&userId={userId}");
             if (response.IsSuccessStatusCode)
             {
-                var viewModel = await response.Content.ReadFromJsonAsync<ReaderPageViewModel>();
-                return viewModel != null ? Result.Ok(viewModel) : Result.Fail("Failed to deserialize response.");
+                var result = await response.Content.ReadFromJsonAsync<ReaderPageViewModel>();
+                return result != null ? Result.Ok(result) : Result.Fail("Failed to deserialize reader page.");
             }
-            
-            // Try to read the error message from the body
-            var errorBody = await response.Content.ReadAsStringAsync();
-            return Result.Fail($"Server error ({response.StatusCode}): {errorBody}");
+            return Result.Fail("Failed to fetch EPUB content from server.");
         }
         catch (Exception ex)
         {
-            // Fallback for network errors or parsing exceptions
-            return Result.Fail(new Error($"Network or parsing error: {ex.Message}").CausedBy(ex));
+            return Result.Fail(new Error("Network error while fetching EPUB content.").CausedBy(ex));
         }
     }
+}
+
+public class WasmEpubMetadataExtractor : IEpubMetadataExtractor
+{
     public async Task<Result<LocalEpubMetadata>> ExtractMetadataAsync(Stream epubStream)
     {
         try
         {
-            using var bookRef = await VersOne.Epub.EpubReader.OpenBookAsync(epubStream);
+            using var bookRef = await EpubReader.OpenBookAsync(epubStream);
             var title = bookRef.Title ?? "Unknown Title";
             var author = bookRef.Author ?? "Unknown Author";
             byte[]? cover = await bookRef.ReadCoverAsync();