From af1b14b0d2a889e3bdfbe2f08dac0cf0ef4922f5 Mon Sep 17 00:00:00 2001
From: gokhoal <doggeybag.z@gmail.com>
Date: Wed, 10 Jun 2026 22:46:40 +0200
Subject: [PATCH] endpoint de creation de discussion

---
 .../CreatePrivateDiscussionEndpoint.cs        | 83 +++++++++++++++++++
 1 file changed, 83 insertions(+)
 create mode 100644 Knots/Endpoints/Discussion/CreatePrivateDiscussionEndpoint.cs

diff --git a/Knots/Endpoints/Discussion/CreatePrivateDiscussionEndpoint.cs b/Knots/Endpoints/Discussion/CreatePrivateDiscussionEndpoint.cs
new file mode 100644
index 0000000..3c43958
--- /dev/null
+++ b/Knots/Endpoints/Discussion/CreatePrivateDiscussionEndpoint.cs
@@ -0,0 +1,83 @@
+using FastEndpoints;
+using Knots.DTO.Discussion;
+using Knots.Models;
+using Microsoft.EntityFrameworkCore;
+using System.Security.Claims;
+
+namespace Knots.Endpoints.Discussion;
+
+public class CreatePrivateDiscussionEndpoint(KnotsDbContext db)
+    : Endpoint<CreatePrivateDiscussionRequest, GetDiscussionDto>
+{
+    public override void Configure()
+    {
+        Post("/discussions/private");
+    }
+
+    public override async Task HandleAsync(CreatePrivateDiscussionRequest req, CancellationToken ct)
+    {
+        int currentUserId = int.Parse(User.FindFirstValue(ClaimTypes.NameIdentifier)!);
+
+        // 1. retrouver l'utilisateur cible par son nom
+        Models.User? target = await db.Users
+            .SingleOrDefaultAsync(u => u.Username == req.Username, ct);
+
+        if (target is null)
+        {
+            await SendNotFoundAsync(ct);   // utilisateur introuvable
+            return;
+        }
+
+        if (target.Id == currentUserId)
+        {
+            await SendErrorsAsync(400, ct); // pas de discussion avec soi-même
+            return;
+        }
+
+        // 2. vérifier qu'une discussion privée entre les deux n'existe pas déjà
+        Models.Discussion? existing = await db.Discussions
+            .Where(d => d.GroupId == null
+                && d.UserDiscussions.Any(ud => ud.UserId == currentUserId)
+                && d.UserDiscussions.Any(ud => ud.UserId == target.Id))
+            .FirstOrDefaultAsync(ct);
+
+        if (existing is not null)
+        {
+            await SendOkAsync(new GetDiscussionDto
+            {
+                Id = existing.Id,
+                IsGroup = false,
+                Name = target.Username!,
+                MembersCount = null
+            }, ct);
+            return;
+        }
+
+        // 3. créer la discussion + les deux participants
+        Models.Discussion discussion = new()
+        {
+            IsGroup = false,
+            UserDiscussions =
+            [
+                new UserDiscussion { UserId = currentUserId },
+                new UserDiscussion { UserId = target.Id }
+            ]
+        };
+
+        db.Discussions.Add(discussion);
+        await db.SaveChangesAsync(ct);
+
+        await SendOkAsync(new GetDiscussionDto
+        {
+            Id = discussion.Id,
+            IsGroup = false,
+            Name = target.Username!,
+            MembersCount = null
+        }, ct);
+    }
+}
+
+public class CreatePrivateDiscussionRequest
+{
+    public string Username { get; set; } = "";
+}
\ No newline at end of file