Implement "Everyone is friends" toggle: add global friends functionality with server settings and UI integration

DorkNet.Server/Services/RelationshipQueries.cs

@@ -0,0 +1,62 @@
+using DorkNet.Server.Data;
+using DorkNet.Server.Data.Entities;
+using Microsoft.EntityFrameworkCore;
+
+namespace DorkNet.Server.Services;
+
+/// <summary>
+/// Effective-friend resolution that honors the
+/// <see cref="ServerSettingsEntity.GlobalFriendsEnabled"/> toggle.
+///
+/// When the toggle is ON, every account on the server is treated as a
+/// friend of every other account WITHOUT writing any relationship rows —
+/// the friend graph is synthesized at read time. This keeps a small private
+/// server frictionless (no searching + manual friend requests) and reverts
+/// instantly when the toggle flips off, since nothing was persisted.
+///
+/// Blocked relationships still suppress the pairing, and the system/coach
+/// account (<see cref="SystemAccountId"/>) is never offered as a friend.
+///
+/// Live propagation: flipping the toggle broadcasts
+/// <c>PushNotificationId.RelationshipsInvalid</c>, which the 2020 watch
+/// handles by calling <c>Relationships.RefreshList</c> — a full re-fetch of
+/// <c>api/relationships/v2/get</c> — so connected players see the change
+/// without relogging (verified against the readable March decompile:
+/// <c>RecNet/Relationships.txt → OnRelationshipsInvalid → RefreshList</c>).
+/// </summary>
+public static class RelationshipQueries
+{
+    /// <summary>Coach/system account seeded at startup (Player.Id = 1).
+    /// Excluded from the global-friends set so it never shows up as a
+    /// friend in anyone's list.</summary>
+    public const long SystemAccountId = 1;
+
+    /// <summary>The effective friend ids for <paramref name="me"/>. With the
+    /// global-friends toggle off this is the real Friend graph; with it on
+    /// it's every other (non-system, non-blocked) account.</summary>
+    public static async Task<List<long>> EffectiveFriendIdsAsync(
+        DorkNetDbContext db, ServerSettingsService settings, long me)
+    {
+        if (!await settings.IsGlobalFriendsEnabledAsync())
+        {
+            return await db.Relationships
+                .Where(r => r.Status == RelationshipStatus.Friend &&
+                            (r.RequesterId == me || r.TargetId == me))
+                .Select(r => r.RequesterId == me ? r.TargetId : r.RequesterId)
+                .ToListAsync();
+        }
+
+        // Global friends: everyone except myself, the system account, and
+        // anyone in a Blocked relationship with me (either direction).
+        var blocked = await db.Relationships
+            .Where(r => r.Status == RelationshipStatus.Blocked &&
+                        (r.RequesterId == me || r.TargetId == me))
+            .Select(r => r.RequesterId == me ? r.TargetId : r.RequesterId)
+            .ToListAsync();
+
+        return await db.Players
+            .Where(p => p.Id != me && p.Id != SystemAccountId && !blocked.Contains(p.Id))
+            .Select(p => p.Id)
+            .ToListAsync();
+    }
+}

DorkNet.Server/Services/ServerSettingsService.cs

@@ -48,6 +48,26 @@ public class ServerSettingsService(DorkNetDbContext db)
         return existing;
     }
 
+    /// <summary>When true, every account is treated as a friend of every
+    /// other account (synthesized at read time — no relationship rows are
+    /// written). See <see cref="ServerSettingsEntity.GlobalFriendsEnabled"/>
+    /// and <see cref="RelationshipQueries"/>.</summary>
+    public async Task<bool> IsGlobalFriendsEnabledAsync()
+    {
+        var row = await db.ServerSettings.AsNoTracking()
+            .FirstOrDefaultAsync(s => s.Id == RowId);
+        return row?.GlobalFriendsEnabled ?? false;
+    }
+
+    public async Task<ServerSettingsEntity> SetGlobalFriendsEnabledAsync(bool enabled)
+    {
+        var existing = await GetTrackedRowAsync();
+        existing.GlobalFriendsEnabled = enabled;
+        existing.UpdatedAt = DateTime.UtcNow;
+        await db.SaveChangesAsync();
+        return existing;
+    }
+
     public async Task<WeeklyChallengeSettings> GetWeeklyChallengesAsync()
     {
         var row = await GetAsync();