Add --reimport and --reprocess-reactions CLI modes

Add flags to reimport all data from archived files or selectively
reprocess reactions. Also replace EnsureCreatedAsync with explicit
database/table existence checks for safer initialization.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/DiscordArchiveManager/Data/DiscordArchiveContext.cs

@@ -111,7 +111,13 @@ public class DiscordArchiveContext : DbContext
                 .WithMany(m => m.Reactions)
                 .HasForeignKey(e => e.MessageId)
                 .OnDelete(DeleteBehavior.Cascade);
+            entity.HasOne(e => e.User)
+                .WithMany(u => u.Reactions)
+                .HasForeignKey(e => e.UserId)
+                .OnDelete(DeleteBehavior.Restrict);
             entity.HasIndex(e => e.MessageId);
+            entity.HasIndex(e => e.UserId);
+            entity.HasIndex(e => new { e.MessageId, e.EmojiName, e.UserId }).IsUnique();
         });
 
         // Mention configuration

src/DiscordArchiveManager/Models/Entities/Reaction.cs

@@ -19,9 +19,14 @@ public class Reaction
     [MaxLength(256)]
     public string EmojiName { get; set; } = null!;
 
-    public int Count { get; set; }
+    [Required]
+    [MaxLength(32)]
+    public string UserId { get; set; } = null!;
 
     // Navigation properties
     [ForeignKey(nameof(MessageId))]
     public Message Message { get; set; } = null!;
+
+    [ForeignKey(nameof(UserId))]
+    public User User { get; set; } = null!;
 }

src/DiscordArchiveManager/Models/Entities/User.cs

@@ -22,4 +22,5 @@ public class User
     public ICollection<UserSnapshot> Snapshots { get; set; } = new List<UserSnapshot>();
     public ICollection<Message> Messages { get; set; } = new List<Message>();
     public ICollection<Mention> Mentions { get; set; } = new List<Mention>();
+    public ICollection<Reaction> Reactions { get; set; } = new List<Reaction>();
 }

src/DiscordArchiveManager/Program.cs

@@ -1,6 +1,8 @@
 using DiscordArchiveManager.Data;
 using DiscordArchiveManager.Services;
 using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Storage;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
@@ -32,11 +34,23 @@ var inputDirectory = config["Paths:InputDirectory"] ?? "/app/input";
 var archiveDirectory = config["Paths:ArchiveDirectory"] ?? "/app/archive";
 var imageDirectory = config["Paths:ImageDirectory"] ?? "/app/images";
 
+var reprocessReactions = args.Contains("--reprocess-reactions");
+var reimport = args.Contains("--reimport");
+
 logger.LogInformation("Discord Archive Manager starting...");
 logger.LogInformation("Input directory: {Path}", inputDirectory);
 logger.LogInformation("Archive directory: {Path}", archiveDirectory);
 logger.LogInformation("Image directory: {Path}", imageDirectory);
 
+if (reimport)
+{
+    logger.LogInformation("Mode: Reimport all data from archive");
+}
+else if (reprocessReactions)
+{
+    logger.LogInformation("Mode: Reprocess reactions from archive");
+}
+
 // Ensure directories exist
 Directory.CreateDirectory(inputDirectory);
 Directory.CreateDirectory(archiveDirectory);
@@ -46,17 +60,46 @@ Directory.CreateDirectory(imageDirectory);
 using (var scope = host.Services.CreateScope())
 {
     var context = scope.ServiceProvider.GetRequiredService<DiscordArchiveContext>();
-    logger.LogInformation("Ensuring database exists and applying migrations...");
-    await context.Database.EnsureCreatedAsync();
+    logger.LogInformation("Ensuring database schema exists...");
+
+    // Get the database creator for more control
+    var creator = context.GetService<IRelationalDatabaseCreator>()!;
+
+    if (!await creator.ExistsAsync())
+    {
+        logger.LogError("Database does not exist. Please create it first.");
+        return;
+    }
+
+    if (!await creator.HasTablesAsync())
+    {
+        logger.LogInformation("Creating database tables...");
+        await creator.CreateTablesAsync();
+    }
+
     logger.LogInformation("Database ready.");
 }
 
-// Process files
+// Process files or reprocess reactions
 using (var scope = host.Services.CreateScope())
 {
     var importService = scope.ServiceProvider.GetRequiredService<JsonImportService>();
     var archiveService = scope.ServiceProvider.GetRequiredService<ArchiveService>();
 
+    if (reimport)
+    {
+        logger.LogInformation("Reimporting all data from archived files...");
+        var (success, errors) = await importService.ReimportFromArchiveAsync(archiveDirectory, imageDirectory);
+        logger.LogInformation("Reimport complete. Imported: {Success}, Errors: {Errors}", success, errors);
+    }
+    else if (reprocessReactions)
+    {
+        logger.LogInformation("Reprocessing reactions from archived files...");
+        var added = await importService.ReprocessReactionsAsync(archiveDirectory);
+        logger.LogInformation("Reprocessing complete. Added {Count} reactions.", added);
+    }
+    else
+    {
         var files = archiveService.GetExportFiles(inputDirectory).ToList();
 
         if (files.Count == 0)
@@ -96,5 +139,6 @@ using (var scope = host.Services.CreateScope())
                 successCount, skipCount, errorCount);
         }
     }
+}
 
 logger.LogInformation("Discord Archive Manager finished.");

src/DiscordArchiveManager/Services/ArchiveService.cs

@@ -28,8 +28,8 @@ public class ArchiveService
         var jsonDirectory = Path.GetDirectoryName(jsonFilePath)!;
         var filesDirectory = GetFilesDirectoryPath(jsonFilePath);
 
-        // Create archive subdirectory based on date
-        var archiveSubdir = DateTime.Now.ToString("yyyy-MM-dd");
+        // Create archive subdirectory based on export date from filename
+        var archiveSubdir = GetExportDateFromFilename(jsonFileName) ?? DateTime.Now.ToString("yyyy-MM-dd");
         var archivePath = Path.Combine(archiveRoot, archiveSubdir);
         Directory.CreateDirectory(archivePath);
 
@@ -152,6 +152,26 @@ public class ArchiveService
         }
     }
 
+    /// <summary>
+    /// Extracts the export date from a filename like "2026-01-20.json".
+    /// Returns null if the filename doesn't match the expected pattern.
+    /// </summary>
+    private static string? GetExportDateFromFilename(string filename)
+    {
+        var nameWithoutExtension = Path.GetFileNameWithoutExtension(filename);
+        if (DateTime.TryParseExact(nameWithoutExtension, "yyyy-MM-dd", null, System.Globalization.DateTimeStyles.None, out _))
+        {
+            return nameWithoutExtension;
+        }
+        // Handle filenames with suffix like "2026-01-20_1.json"
+        var parts = nameWithoutExtension.Split('_');
+        if (parts.Length > 0 && DateTime.TryParseExact(parts[0], "yyyy-MM-dd", null, System.Globalization.DateTimeStyles.None, out _))
+        {
+            return parts[0];
+        }
+        return null;
+    }
+
     /// <summary>
     /// Moves a file, falling back to copy+delete for cross-device moves.
     /// </summary>

src/DiscordArchiveManager/Services/JsonImportService.cs

@@ -72,20 +72,32 @@ public class JsonImportService
                 // Upsert Channel
                 await UpsertChannelAsync(export.Channel, export.Guild.Id);
 
-                // Process messages
+                // Process messages - save after each to isolate any issues
                 var processedCount = 0;
                 foreach (var message in export.Messages)
+                {
+                    try
                     {
                         if (await ProcessMessageAsync(message, export.Channel.Id, jsonFilePath, imageRoot))
                         {
+                            await _context.SaveChangesAsync();
                             processedCount++;
                         }
                     }
+                    catch (DbUpdateException ex) when (ex.InnerException is Microsoft.Data.SqlClient.SqlException sqlEx && sqlEx.Number == 2601)
+                    {
+                        // Duplicate key - log and continue
+                        _logger.LogWarning("Duplicate key error for message {MessageId}, skipping: {Error}",
+                            message.Id, sqlEx.Message);
+                        _context.ChangeTracker.Clear();
+                        // Re-upsert guild and channel as they were cleared
+                        await UpsertGuildAsync(export.Guild);
+                        await UpsertChannelAsync(export.Channel, export.Guild.Id);
+                    }
+                }
 
                 _logger.LogInformation("Processed {Count} new messages", processedCount);
 
-                await _context.SaveChangesAsync();
-
                 // Archive the file
                 var archivePath = _archiveService.ArchiveExport(jsonFilePath, archiveRoot);
 
@@ -106,6 +118,9 @@ public class JsonImportService
             catch (Exception ex)
             {
                 await transaction.RollbackAsync();
+                _context.ChangeTracker.Clear(); // Clear tracked entities to prevent cascading failures
+                _processedMessages.Clear(); // Clear the session tracking
+                _addedReactions.Clear();
                 _logger.LogError(ex, "Error processing file, rolled back transaction: {Path}", jsonFilePath);
                 throw;
             }