Merge branch 'codex/mail-categories-v1'

Wino.Services/DatabaseService.cs

@@ -49,6 +49,8 @@ public class DatabaseService : IDatabaseService
     {
         await Task.WhenAll(
             Connection.CreateTableAsync<MailCopy>(),
+            Connection.CreateTableAsync<MailCategory>(),
+            Connection.CreateTableAsync<MailCategoryAssignment>(),
             Connection.CreateTableAsync<MailItemFolder>(),
             Connection.CreateTableAsync<MailAccount>(),
             Connection.CreateTableAsync<AccountContact>(),
@@ -226,6 +228,12 @@ SET {nameof(KeyboardShortcut.Action)} =
         await Connection.ExecuteAsync("CREATE INDEX IF NOT EXISTS IX_MailCopy_MessageId ON MailCopy(MessageId)").ConfigureAwait(false);
         await Connection.ExecuteAsync("CREATE INDEX IF NOT EXISTS IX_MailCopy_FolderId_IsRead ON MailCopy(FolderId, IsRead)").ConfigureAwait(false);
         await Connection.ExecuteAsync("CREATE INDEX IF NOT EXISTS IX_MailCopy_CreationDate ON MailCopy(CreationDate)").ConfigureAwait(false);
+        await Connection.ExecuteAsync("CREATE INDEX IF NOT EXISTS IX_MailCategory_MailAccountId ON MailCategory(MailAccountId)").ConfigureAwait(false);
+        await Connection.ExecuteAsync("CREATE INDEX IF NOT EXISTS IX_MailCategory_MailAccountId_Name ON MailCategory(MailAccountId, Name)").ConfigureAwait(false);
+        await Connection.ExecuteAsync("CREATE INDEX IF NOT EXISTS IX_MailCategory_MailAccountId_IsFavorite ON MailCategory(MailAccountId, IsFavorite)").ConfigureAwait(false);
+        await Connection.ExecuteAsync("CREATE INDEX IF NOT EXISTS IX_MailCategoryAssignment_MailCategoryId ON MailCategoryAssignment(MailCategoryId)").ConfigureAwait(false);
+        await Connection.ExecuteAsync("CREATE INDEX IF NOT EXISTS IX_MailCategoryAssignment_MailCopyUniqueId ON MailCategoryAssignment(MailCopyUniqueId)").ConfigureAwait(false);
+        await Connection.ExecuteAsync("CREATE UNIQUE INDEX IF NOT EXISTS IX_MailCategoryAssignment_Category_MailCopy ON MailCategoryAssignment(MailCategoryId, MailCopyUniqueId)").ConfigureAwait(false);
 
         await Connection.ExecuteAsync("CREATE INDEX IF NOT EXISTS IX_MailItemFolder_MailAccountId ON MailItemFolder(MailAccountId)").ConfigureAwait(false);
         await Connection.ExecuteAsync("CREATE INDEX IF NOT EXISTS IX_MailItemFolder_MailAccountId_RemoteFolderId ON MailItemFolder(MailAccountId, RemoteFolderId)").ConfigureAwait(false);

Wino.Services/FolderService.cs

@@ -22,6 +22,7 @@ namespace Wino.Services;
 public class FolderService : BaseDatabaseService, IFolderService
 {
     private readonly IAccountService _accountService;
+    private readonly IMailCategoryService _mailCategoryService;
     private readonly ILogger _logger = Log.ForContext<FolderService>();
 
     private readonly SpecialFolderType[] gmailCategoryFolderTypes =
@@ -34,9 +35,11 @@ public class FolderService : BaseDatabaseService, IFolderService
     ];
 
     public FolderService(IDatabaseService databaseService,
-                           IAccountService accountService) : base(databaseService)
+                           IAccountService accountService,
+                           IMailCategoryService mailCategoryService) : base(databaseService)
     {
         _accountService = accountService;
+        _mailCategoryService = mailCategoryService;
     }
 
     public async Task ChangeStickyStatusAsync(Guid folderId, bool isSticky)
@@ -269,6 +272,9 @@ public class FolderService : BaseDatabaseService, IFolderService
             }
         }
 
+        var favoriteCategories = await GetFavoriteCategoryMenuItemsAsync(mailAccount, folders, accountMenuItem).ConfigureAwait(false);
+        preparedFolderMenuItems.AddRange(favoriteCategories);
+
         // Only add category folder if it's Gmail.
         if (mailAccount.ProviderType == MailProviderType.Gmail) preparedFolderMenuItems.Add(categoryFolderMenuItem);
 
@@ -309,9 +315,62 @@ public class FolderService : BaseDatabaseService, IFolderService
             preparedFolderMenuItems.Add(menuItem);
         }
 
+        var favoriteCategories = await GetMergedFavoriteCategoryMenuItemsAsync(holdingAccounts, allAccountFolders, mergedAccountFolderMenuItem.Parameter).ConfigureAwait(false);
+        preparedFolderMenuItems.AddRange(favoriteCategories);
+
         return preparedFolderMenuItems;
     }
 
+    private async Task<IEnumerable<IMenuItem>> GetFavoriteCategoryMenuItemsAsync(MailAccount account, IEnumerable<IMailItemFolder> handlingFolders, IMenuItem parentMenuItem)
+    {
+        var favoriteCategories = await _mailCategoryService.GetFavoriteCategoriesAsync(account.Id).ConfigureAwait(false);
+
+        if (!favoriteCategories.Any())
+            return [];
+
+        var availableFolders = handlingFolders
+            .Where(a => a.IsMoveTarget)
+            .Cast<IMailItemFolder>()
+            .ToList();
+
+        return favoriteCategories
+            .Select(category => (IMenuItem)new MailCategoryMenuItem(category, account, availableFolders, parentMenuItem))
+            .ToList();
+    }
+
+    private async Task<IEnumerable<IMenuItem>> GetMergedFavoriteCategoryMenuItemsAsync(IEnumerable<MailAccount> holdingAccounts, IEnumerable<IEnumerable<MailItemFolder>> allAccountFolders, MergedInbox mergedInbox)
+    {
+        var categoriesByAccount = new List<(MailAccount Account, List<MailCategory> Categories)>();
+
+        foreach (var account in holdingAccounts)
+        {
+            var categories = await _mailCategoryService.GetFavoriteCategoriesAsync(account.Id).ConfigureAwait(false);
+            if (categories.Any())
+            {
+                categoriesByAccount.Add((account, categories));
+            }
+        }
+
+        if (!categoriesByAccount.Any())
+            return [];
+
+        var handlingFolders = allAccountFolders
+            .SelectMany(a => a)
+            .Where(a => a.IsMoveTarget)
+            .Cast<IMailItemFolder>()
+            .ToList();
+
+        return categoriesByAccount
+            .SelectMany(a => a.Categories)
+            .GroupBy(a => NormalizeCategoryName(a.Name), StringComparer.OrdinalIgnoreCase)
+            .Select(group => (IMenuItem)new MergedMailCategoryMenuItem(group.ToList(), handlingFolders, mergedInbox))
+            .OrderBy(item => ((MergedMailCategoryMenuItem)item).FolderName, StringComparer.CurrentCultureIgnoreCase)
+            .ToList();
+    }
+
+    private static string NormalizeCategoryName(string name)
+        => name?.Trim() ?? string.Empty;
+
     private HashSet<SpecialFolderType> FindCommonFolders(List<List<MailItemFolder>> lists)
     {
         var allSpecialTypesExceptOther = Enum.GetValues<SpecialFolderType>().Cast<SpecialFolderType>().Where(a => a != SpecialFolderType.Other).ToList();

Wino.Services/MailCategoryService.cs

@@ -0,0 +1,358 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using CommunityToolkit.Mvvm.Messaging;
+using Wino.Core.Domain.Entities.Mail;
+using Wino.Core.Domain.Interfaces;
+using Wino.Core.Domain.Models.Accounts;
+using Wino.Messaging.Client.Accounts;
+using Wino.Messaging.UI;
+
+namespace Wino.Services;
+
+public class MailCategoryService : BaseDatabaseService, IMailCategoryService
+{
+    public MailCategoryService(IDatabaseService databaseService) : base(databaseService)
+    {
+    }
+
+    public Task<List<MailCategory>> GetCategoriesAsync(Guid accountId)
+        => Connection.QueryAsync<MailCategory>(
+            $"SELECT * FROM {nameof(MailCategory)} WHERE {nameof(MailCategory.MailAccountId)} = ? ORDER BY {nameof(MailCategory.IsFavorite)} DESC, {nameof(MailCategory.Name)} COLLATE NOCASE",
+            accountId);
+
+    public Task<List<MailCategory>> GetFavoriteCategoriesAsync(Guid accountId)
+        => Connection.QueryAsync<MailCategory>(
+            $"SELECT * FROM {nameof(MailCategory)} WHERE {nameof(MailCategory.MailAccountId)} = ? AND {nameof(MailCategory.IsFavorite)} = 1 ORDER BY {nameof(MailCategory.Name)} COLLATE NOCASE",
+            accountId);
+
+    public Task<MailCategory> GetCategoryAsync(Guid categoryId)
+        => Connection.FindAsync<MailCategory>(categoryId);
+
+    public async Task<bool> CategoryNameExistsAsync(Guid accountId, string name, Guid? excludedCategoryId = null)
+    {
+        var normalizedName = NormalizeCategoryName(name);
+        if (string.IsNullOrWhiteSpace(normalizedName))
+            return false;
+
+        var sql = $"SELECT COUNT(*) FROM {nameof(MailCategory)} WHERE {nameof(MailCategory.MailAccountId)} = ? AND lower(trim({nameof(MailCategory.Name)})) = ?";
+        var parameters = new List<object> { accountId, normalizedName.ToLowerInvariant() };
+
+        if (excludedCategoryId.HasValue)
+        {
+            sql += $" AND {nameof(MailCategory.Id)} <> ?";
+            parameters.Add(excludedCategoryId.Value);
+        }
+
+        return await Connection.ExecuteScalarAsync<int>(sql, parameters.ToArray()).ConfigureAwait(false) > 0;
+    }
+
+    public async Task<MailCategory> CreateCategoryAsync(MailCategory category)
+    {
+        category.Id = category.Id == Guid.Empty ? Guid.NewGuid() : category.Id;
+        category.Name = NormalizeCategoryName(category.Name);
+
+        await Connection.InsertAsync(category, typeof(MailCategory)).ConfigureAwait(false);
+        NotifyCategoryStructureChanged(category.MailAccountId);
+
+        return category;
+    }
+
+    public async Task UpdateCategoryAsync(MailCategory category)
+    {
+        category.Name = NormalizeCategoryName(category.Name);
+
+        await Connection.UpdateAsync(category, typeof(MailCategory)).ConfigureAwait(false);
+        NotifyCategoryStructureChanged(category.MailAccountId);
+    }
+
+    public async Task DeleteCategoryAsync(Guid categoryId)
+    {
+        var category = await GetCategoryAsync(categoryId).ConfigureAwait(false);
+        if (category == null)
+            return;
+
+        await Connection.ExecuteAsync($"DELETE FROM {nameof(MailCategoryAssignment)} WHERE {nameof(MailCategoryAssignment.MailCategoryId)} = ?", categoryId).ConfigureAwait(false);
+        await Connection.DeleteAsync<MailCategory>(categoryId).ConfigureAwait(false);
+
+        NotifyCategoryStructureChanged(category.MailAccountId);
+    }
+
+    public async Task DeleteCategoriesAsync(Guid accountId)
+    {
+        var categories = await GetCategoriesAsync(accountId).ConfigureAwait(false);
+
+        if (categories.Count == 0)
+            return;
+
+        var categoryIds = categories.Select(a => a.Id).ToList();
+        var placeholders = string.Join(",", categoryIds.Select(_ => "?"));
+        var deleteAssignmentsSql = $"DELETE FROM {nameof(MailCategoryAssignment)} WHERE {nameof(MailCategoryAssignment.MailCategoryId)} IN ({placeholders})";
+
+        await Connection.ExecuteAsync(deleteAssignmentsSql, categoryIds.Cast<object>().ToArray()).ConfigureAwait(false);
+        await Connection.Table<MailCategory>().DeleteAsync(a => a.MailAccountId == accountId).ConfigureAwait(false);
+
+        NotifyCategoryStructureChanged(accountId);
+    }
+
+    public async Task ToggleFavoriteAsync(Guid categoryId, bool isFavorite)
+    {
+        var category = await GetCategoryAsync(categoryId).ConfigureAwait(false);
+        if (category == null || category.IsFavorite == isFavorite)
+            return;
+
+        category.IsFavorite = isFavorite;
+        await Connection.UpdateAsync(category, typeof(MailCategory)).ConfigureAwait(false);
+
+        NotifyCategoryStructureChanged(category.MailAccountId);
+    }
+
+    public async Task UpdateRemoteIdAsync(Guid categoryId, string remoteId)
+    {
+        var category = await GetCategoryAsync(categoryId).ConfigureAwait(false);
+        if (category == null)
+            return;
+
+        category.RemoteId = remoteId;
+        await Connection.UpdateAsync(category, typeof(MailCategory)).ConfigureAwait(false);
+    }
+
+    public async Task ReplaceCategoriesAsync(Guid accountId, IEnumerable<MailCategory> categories)
+    {
+        var existingCategories = await GetCategoriesAsync(accountId).ConfigureAwait(false);
+        var existingByRemoteId = existingCategories
+            .Where(a => !string.IsNullOrWhiteSpace(a.RemoteId))
+            .ToDictionary(a => a.RemoteId, StringComparer.OrdinalIgnoreCase);
+        var existingByName = existingCategories
+            .GroupBy(a => NormalizeCategoryName(a.Name), StringComparer.OrdinalIgnoreCase)
+            .ToDictionary(a => a.Key, a => a.First(), StringComparer.OrdinalIgnoreCase);
+
+        var incomingCategories = categories?.ToList() ?? [];
+        var preservedIds = new HashSet<Guid>();
+
+        foreach (var incoming in incomingCategories)
+        {
+            incoming.MailAccountId = accountId;
+            incoming.Id = incoming.Id == Guid.Empty ? Guid.NewGuid() : incoming.Id;
+            incoming.Name = NormalizeCategoryName(incoming.Name);
+
+            MailCategory existing = null;
+
+            if (!string.IsNullOrWhiteSpace(incoming.RemoteId) && existingByRemoteId.TryGetValue(incoming.RemoteId, out var byRemote))
+            {
+                existing = byRemote;
+            }
+            else if (existingByName.TryGetValue(incoming.Name, out var byName))
+            {
+                existing = byName;
+            }
+
+            if (existing == null)
+            {
+                await Connection.InsertAsync(incoming, typeof(MailCategory)).ConfigureAwait(false);
+                preservedIds.Add(incoming.Id);
+            }
+            else
+            {
+                incoming.Id = existing.Id;
+                incoming.IsFavorite = existing.IsFavorite;
+                await Connection.UpdateAsync(incoming, typeof(MailCategory)).ConfigureAwait(false);
+                preservedIds.Add(existing.Id);
+            }
+        }
+
+        var categoryIdsToDelete = existingCategories
+            .Where(a => !preservedIds.Contains(a.Id))
+            .Select(a => a.Id)
+            .ToList();
+
+        if (categoryIdsToDelete.Count > 0)
+        {
+            var placeholders = string.Join(",", categoryIdsToDelete.Select(_ => "?"));
+            await Connection.ExecuteAsync(
+                $"DELETE FROM {nameof(MailCategoryAssignment)} WHERE {nameof(MailCategoryAssignment.MailCategoryId)} IN ({placeholders})",
+                categoryIdsToDelete.Cast<object>().ToArray()).ConfigureAwait(false);
+
+            foreach (var categoryId in categoryIdsToDelete)
+            {
+                await Connection.DeleteAsync<MailCategory>(categoryId).ConfigureAwait(false);
+            }
+        }
+
+        NotifyCategoryStructureChanged(accountId);
+    }
+
+    public async Task ReplaceMailAssignmentsAsync(Guid accountId, Guid mailCopyUniqueId, IEnumerable<string> categoryNames)
+    {
+        var normalizedNames = categoryNames?
+            .Select(NormalizeCategoryName)
+            .Where(a => !string.IsNullOrWhiteSpace(a))
+            .Distinct(StringComparer.OrdinalIgnoreCase)
+            .ToList() ?? [];
+
+        var availableCategories = await GetCategoriesAsync(accountId).ConfigureAwait(false);
+        var categoryIds = availableCategories
+            .Where(a => normalizedNames.Contains(NormalizeCategoryName(a.Name), StringComparer.OrdinalIgnoreCase))
+            .Select(a => a.Id)
+            .ToHashSet();
+
+        var existingAssignments = await Connection.QueryAsync<MailCategoryAssignment>(
+            $"SELECT * FROM {nameof(MailCategoryAssignment)} WHERE {nameof(MailCategoryAssignment.MailCopyUniqueId)} = ?",
+            mailCopyUniqueId).ConfigureAwait(false);
+
+        var assignmentsToDelete = existingAssignments.Where(a => !categoryIds.Contains(a.MailCategoryId)).ToList();
+        var existingIds = existingAssignments.Select(a => a.MailCategoryId).ToHashSet();
+        var assignmentsToAdd = categoryIds.Where(a => !existingIds.Contains(a)).ToList();
+
+        foreach (var assignment in assignmentsToDelete)
+        {
+            await Connection.DeleteAsync<MailCategoryAssignment>(assignment.Id).ConfigureAwait(false);
+        }
+
+        foreach (var categoryId in assignmentsToAdd)
+        {
+            await Connection.InsertAsync(new MailCategoryAssignment
+            {
+                Id = Guid.NewGuid(),
+                MailCategoryId = categoryId,
+                MailCopyUniqueId = mailCopyUniqueId
+            }, typeof(MailCategoryAssignment)).ConfigureAwait(false);
+        }
+
+        WeakReferenceMessenger.Default.Send(new RefreshUnreadCountsMessage(accountId));
+    }
+
+    public async Task AssignCategoryAsync(Guid categoryId, IEnumerable<Guid> mailCopyUniqueIds)
+    {
+        var uniqueIds = mailCopyUniqueIds?.Distinct().ToList() ?? [];
+        if (uniqueIds.Count == 0)
+            return;
+
+        var category = await GetCategoryAsync(categoryId).ConfigureAwait(false);
+        if (category == null)
+            return;
+
+        var placeholders = string.Join(",", uniqueIds.Select(_ => "?"));
+        var query = $"SELECT * FROM {nameof(MailCategoryAssignment)} WHERE {nameof(MailCategoryAssignment.MailCategoryId)} = ? AND {nameof(MailCategoryAssignment.MailCopyUniqueId)} IN ({placeholders})";
+        var existingAssignments = await Connection.QueryAsync<MailCategoryAssignment>(
+            query,
+            [categoryId, .. uniqueIds.Cast<object>()]).ConfigureAwait(false);
+        var existingUniqueIds = existingAssignments.Select(a => a.MailCopyUniqueId).ToHashSet();
+
+        foreach (var uniqueId in uniqueIds.Where(a => !existingUniqueIds.Contains(a)))
+        {
+            await Connection.InsertAsync(new MailCategoryAssignment
+            {
+                Id = Guid.NewGuid(),
+                MailCategoryId = categoryId,
+                MailCopyUniqueId = uniqueId
+            }, typeof(MailCategoryAssignment)).ConfigureAwait(false);
+        }
+
+        WeakReferenceMessenger.Default.Send(new RefreshUnreadCountsMessage(category.MailAccountId));
+    }
+
+    public async Task UnassignCategoryAsync(Guid categoryId, IEnumerable<Guid> mailCopyUniqueIds)
+    {
+        var uniqueIds = mailCopyUniqueIds?.Distinct().ToList() ?? [];
+        if (uniqueIds.Count == 0)
+            return;
+
+        var category = await GetCategoryAsync(categoryId).ConfigureAwait(false);
+        if (category == null)
+            return;
+
+        var placeholders = string.Join(",", uniqueIds.Select(_ => "?"));
+        await Connection.ExecuteAsync(
+            $"DELETE FROM {nameof(MailCategoryAssignment)} WHERE {nameof(MailCategoryAssignment.MailCategoryId)} = ? AND {nameof(MailCategoryAssignment.MailCopyUniqueId)} IN ({placeholders})",
+            [categoryId, .. uniqueIds.Cast<object>()]).ConfigureAwait(false);
+
+        WeakReferenceMessenger.Default.Send(new RefreshUnreadCountsMessage(category.MailAccountId));
+    }
+
+    public async Task<List<MailCategory>> GetCategoriesForMailAsync(Guid accountId, IEnumerable<Guid> mailCopyUniqueIds)
+    {
+        var uniqueIds = mailCopyUniqueIds?.Distinct().ToList() ?? [];
+        if (uniqueIds.Count == 0)
+            return [];
+
+        var placeholders = string.Join(",", uniqueIds.Select(_ => "?"));
+        var sql = $"SELECT DISTINCT MailCategory.* FROM {nameof(MailCategory)} " +
+                  $"INNER JOIN {nameof(MailCategoryAssignment)} ON {nameof(MailCategory)}.{nameof(MailCategory.Id)} = {nameof(MailCategoryAssignment)}.{nameof(MailCategoryAssignment.MailCategoryId)} " +
+                  $"WHERE {nameof(MailCategory)}.{nameof(MailCategory.MailAccountId)} = ? AND {nameof(MailCategoryAssignment)}.{nameof(MailCategoryAssignment.MailCopyUniqueId)} IN ({placeholders}) " +
+                  $"ORDER BY {nameof(MailCategory.Name)} COLLATE NOCASE";
+
+        return await Connection.QueryAsync<MailCategory>(
+            sql,
+            [accountId, .. uniqueIds.Cast<object>()]).ConfigureAwait(false);
+    }
+
+    public async Task<List<Guid>> GetAssignedCategoryIdsForAllAsync(IEnumerable<Guid> mailCopyUniqueIds)
+    {
+        var uniqueIds = mailCopyUniqueIds?.Distinct().ToList() ?? [];
+        if (uniqueIds.Count == 0)
+            return [];
+
+        var placeholders = string.Join(",", uniqueIds.Select(_ => "?"));
+        var sql = $"SELECT {nameof(MailCategoryAssignment.MailCategoryId)} " +
+                  $"FROM {nameof(MailCategoryAssignment)} " +
+                  $"WHERE {nameof(MailCategoryAssignment.MailCopyUniqueId)} IN ({placeholders}) " +
+                  $"GROUP BY {nameof(MailCategoryAssignment.MailCategoryId)} " +
+                  $"HAVING COUNT(DISTINCT {nameof(MailCategoryAssignment.MailCopyUniqueId)}) = ?";
+
+        return await Connection.QueryScalarsAsync<Guid>(
+            sql,
+            [.. uniqueIds.Cast<object>(), uniqueIds.Count]).ConfigureAwait(false);
+    }
+
+    public async Task<List<string>> GetCategoryNamesForMailAsync(Guid mailCopyUniqueId)
+    {
+        var sql = $"SELECT {nameof(MailCategory.Name)} " +
+                  $"FROM {nameof(MailCategory)} " +
+                  $"INNER JOIN {nameof(MailCategoryAssignment)} ON {nameof(MailCategory)}.{nameof(MailCategory.Id)} = {nameof(MailCategoryAssignment.MailCategoryId)} " +
+                  $"WHERE {nameof(MailCategoryAssignment.MailCopyUniqueId)} = ? " +
+                  $"ORDER BY {nameof(MailCategory.Name)} COLLATE NOCASE";
+
+        return await Connection.QueryScalarsAsync<string>(sql, mailCopyUniqueId).ConfigureAwait(false);
+    }
+
+    public async Task<List<MailCopy>> GetMailCopiesForCategoryAsync(Guid categoryId)
+    {
+        var sql = $"SELECT {nameof(MailCopy)}.* " +
+                  $"FROM {nameof(MailCopy)} " +
+                  $"INNER JOIN {nameof(MailCategoryAssignment)} ON {nameof(MailCopy)}.{nameof(MailCopy.UniqueId)} = {nameof(MailCategoryAssignment.MailCopyUniqueId)} " +
+                  $"WHERE {nameof(MailCategoryAssignment.MailCategoryId)} = ?";
+
+        return await Connection.QueryAsync<MailCopy>(sql, categoryId).ConfigureAwait(false);
+    }
+
+    public Task<List<UnreadCategoryCountResult>> GetUnreadCategoryCountResultsAsync(IEnumerable<Guid> accountIds)
+    {
+        var accountIdList = accountIds?.Distinct().ToList() ?? [];
+        if (accountIdList.Count == 0)
+            return Task.FromResult(new List<UnreadCategoryCountResult>());
+
+        var placeholders = string.Join(",", accountIdList.Select(_ => "?"));
+        var sql =
+            $"SELECT MailCategory.{nameof(MailCategory.Id)} as {nameof(UnreadCategoryCountResult.CategoryId)}, " +
+            $"MailCategory.{nameof(MailCategory.MailAccountId)} as {nameof(UnreadCategoryCountResult.AccountId)}, " +
+            $"COUNT(DISTINCT MailCopy.{nameof(MailCopy.UniqueId)}) as {nameof(UnreadCategoryCountResult.UnreadItemCount)} " +
+            $"FROM {nameof(MailCategory)} " +
+            $"INNER JOIN {nameof(MailCategoryAssignment)} ON {nameof(MailCategory)}.{nameof(MailCategory.Id)} = {nameof(MailCategoryAssignment)}.{nameof(MailCategoryAssignment.MailCategoryId)} " +
+            $"INNER JOIN {nameof(MailCopy)} ON {nameof(MailCategoryAssignment)}.{nameof(MailCategoryAssignment.MailCopyUniqueId)} = {nameof(MailCopy)}.{nameof(MailCopy.UniqueId)} " +
+            $"WHERE MailCategory.{nameof(MailCategory.MailAccountId)} IN ({placeholders}) AND MailCopy.{nameof(MailCopy.IsRead)} = 0 " +
+            $"GROUP BY MailCategory.{nameof(MailCategory.Id)}";
+
+        return Connection.QueryAsync<UnreadCategoryCountResult>(sql, accountIdList.Cast<object>().ToArray());
+    }
+
+    private void NotifyCategoryStructureChanged(Guid accountId)
+    {
+        WeakReferenceMessenger.Default.Send(new AccountsMenuRefreshRequested(false));
+        WeakReferenceMessenger.Default.Send(new RefreshUnreadCountsMessage(accountId));
+    }
+
+    private static string NormalizeCategoryName(string name)
+        => name?.Trim() ?? string.Empty;
+}

Wino.Services/MailService.cs

@@ -32,6 +32,7 @@ public class MailService : BaseDatabaseService, IMailService
     private readonly IMimeFileService _mimeFileService;
     private readonly IPreferencesService _preferencesService;
     private readonly ISentMailReceiptService _sentMailReceiptService;
+    private readonly IMailCategoryService _mailCategoryService;
 
     private readonly ILogger _logger = Log.ForContext<MailService>();
 
@@ -42,7 +43,8 @@ public class MailService : BaseDatabaseService, IMailService
                        ISignatureService signatureService,
                        IMimeFileService mimeFileService,
                        IPreferencesService preferencesService,
-                       ISentMailReceiptService sentMailReceiptService) : base(databaseService)
+                       ISentMailReceiptService sentMailReceiptService,
+                       IMailCategoryService mailCategoryService) : base(databaseService)
     {
         _folderService = folderService;
         _contactService = contactService;
@@ -51,6 +53,7 @@ public class MailService : BaseDatabaseService, IMailService
         _mimeFileService = mimeFileService;
         _preferencesService = preferencesService;
         _sentMailReceiptService = sentMailReceiptService;
+        _mailCategoryService = mailCategoryService;
     }
 
     public async Task<(MailCopy draftMailCopy, string draftBase64MimeMessage)> CreateDraftAsync(Guid accountId, DraftCreationOptions draftCreationOptions)
@@ -171,7 +174,9 @@ public class MailService : BaseDatabaseService, IMailService
     private static (string Query, object[] Parameters) BuildMailFetchQuery(MailListInitializationOptions options)
     {
         var sql = new StringBuilder();
-        sql.Append("SELECT MailCopy.* FROM MailCopy INNER JOIN MailItemFolder ON MailCopy.FolderId = MailItemFolder.Id");
+        sql.Append(options.IsCategoryView
+            ? "SELECT DISTINCT MailCopy.* FROM MailCopy INNER JOIN MailItemFolder ON MailCopy.FolderId = MailItemFolder.Id INNER JOIN MailCategoryAssignment ON MailCopy.UniqueId = MailCategoryAssignment.MailCopyUniqueId"
+            : "SELECT MailCopy.* FROM MailCopy INNER JOIN MailItemFolder ON MailCopy.FolderId = MailItemFolder.Id");
 
         var whereClauses = new List<string>();
         var parameters = new List<object>();
@@ -181,6 +186,13 @@ public class MailService : BaseDatabaseService, IMailService
         whereClauses.Add($"MailCopy.FolderId IN ({folderPlaceholders})");
         parameters.AddRange(options.Folders.Select(f => (object)f.Id));
 
+        if (options.IsCategoryView)
+        {
+            var categoryPlaceholders = string.Join(",", options.CategoryIds.Select(_ => "?"));
+            whereClauses.Add($"MailCategoryAssignment.MailCategoryId IN ({categoryPlaceholders})");
+            parameters.AddRange(options.CategoryIds.Select(a => (object)a));
+        }
+
         // Filter type
         switch (options.FilterType)
         {
@@ -338,7 +350,7 @@ public class MailService : BaseDatabaseService, IMailService
     {
         List<MailCopy> mails;
 
-        if (options.PreFetchMailCopies != null)
+        if (options.PreFetchMailCopies != null && !options.IsCategoryView)
         {
             mails = ApplyOptionsToPreFetchedMails(options);
         }
@@ -398,7 +410,7 @@ public class MailService : BaseDatabaseService, IMailService
         mails.RemoveAll(m => m.AssignedAccount == null || m.AssignedFolder == null);
         await _sentMailReceiptService.PopulateReceiptStatesAsync(mails).ConfigureAwait(false);
 
-        if (!options.CreateThreads || mails.Count == 0)
+        if (!options.CreateThreads || mails.Count == 0 || options.IsCategoryView)
             return [.. mails];
 
         // 6. Expand threads: one batch query for all sibling mails across all threads.
@@ -727,6 +739,7 @@ public class MailService : BaseDatabaseService, IMailService
         _logger.Debug("Deleting mail {Id} from folder {FolderName}", mailCopy.Id, mailCopy.AssignedFolder.FolderName);
 
         await Connection.DeleteAsync<MailCopy>(mailCopy.UniqueId).ConfigureAwait(false);
+        await Connection.ExecuteAsync("DELETE FROM MailCategoryAssignment WHERE MailCopyUniqueId = ?", mailCopy.UniqueId).ConfigureAwait(false);
 
         // If there are no more copies exists of the same mail, delete the MIME file as well.
         var isMailExists = await IsMailExistsAsync(mailCopy.Id).ConfigureAwait(false);
@@ -965,6 +978,7 @@ public class MailService : BaseDatabaseService, IMailService
             mailCopy.UniqueId = existingCopyItem.UniqueId;
 
             await UpdateMailAsync(mailCopy).ConfigureAwait(false);
+            await ReplaceMailCategoriesForPackageAsync(accountId, mailCopy, package).ConfigureAwait(false);
             await _sentMailReceiptService.TrackSentMailAsync(mailCopy, mimeMessage).ConfigureAwait(false);
             await _sentMailReceiptService.ProcessIncomingReceiptAsync(mailCopy, mimeMessage).ConfigureAwait(false);
 
@@ -981,6 +995,7 @@ public class MailService : BaseDatabaseService, IMailService
             }
 
             await InsertMailAsync(mailCopy).ConfigureAwait(false);
+            await ReplaceMailCategoriesForPackageAsync(accountId, mailCopy, package).ConfigureAwait(false);
             await _sentMailReceiptService.TrackSentMailAsync(mailCopy, mimeMessage).ConfigureAwait(false);
             await _sentMailReceiptService.ProcessIncomingReceiptAsync(mailCopy, mimeMessage).ConfigureAwait(false);
 
@@ -1017,6 +1032,11 @@ public class MailService : BaseDatabaseService, IMailService
         await _contactService.SaveAddressInformationAsync(contacts).ConfigureAwait(false);
     }
 
+    private Task ReplaceMailCategoriesForPackageAsync(Guid accountId, MailCopy mailCopy, NewMailItemPackage package)
+        => package?.CategoryNames == null
+            ? Task.CompletedTask
+            : _mailCategoryService.ReplaceMailAssignmentsAsync(accountId, mailCopy.UniqueId, package.CategoryNames);
+
     private async Task<MimeMessage> CreateDraftMimeAsync(MailAccount account, DraftCreationOptions draftCreationOptions, MailAccountAlias selectedAlias)
     {
         // This unique id is stored in mime headers for Wino to identify remote message with local copy.

Wino.Services/ServicesContainerSetup.cs

@@ -20,6 +20,7 @@ public static class ServicesContainerSetup
 
         services.AddTransient<ICalendarService, CalendarService>();
         services.AddTransient<IMailService, MailService>();
+        services.AddTransient<IMailCategoryService, MailCategoryService>();
         services.AddTransient<ISentMailReceiptService, SentMailReceiptService>();
         services.AddTransient<IFolderService, FolderService>();
         services.AddTransient<IAccountService, AccountService>();