messages implemented

app/Models/Conversation.php

@@ -0,0 +1,117 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\Relations\HasMany;
+use Illuminate\Database\Eloquent\Relations\HasOne;
+use Illuminate\Database\Eloquent\Relations\BelongsToMany;
+
+/**
+ * @property int         $id
+ * @property string      $type        direct|group
+ * @property string|null $title
+ * @property int         $created_by
+ * @property \Carbon\Carbon|null $last_message_at
+ * @property \Carbon\Carbon $created_at
+ * @property \Carbon\Carbon $updated_at
+ */
+class Conversation extends Model
+{
+    use HasFactory;
+
+    protected $fillable = [
+        'type',
+        'title',
+        'created_by',
+        'last_message_at',
+    ];
+
+    protected $casts = [
+        'last_message_at' => 'datetime',
+    ];
+
+    // ── Relationships ────────────────────────────────────────────────────────
+
+    public function creator(): BelongsTo
+    {
+        return $this->belongsTo(User::class, 'created_by');
+    }
+
+    public function participants(): BelongsToMany
+    {
+        return $this->belongsToMany(User::class, 'conversation_participants')
+            ->withPivot(['role', 'last_read_at', 'is_muted', 'is_archived', 'is_pinned', 'pinned_at', 'joined_at', 'left_at'])
+            ->wherePivotNull('left_at');
+    }
+
+    public function allParticipants(): HasMany
+    {
+        return $this->hasMany(ConversationParticipant::class);
+    }
+
+    public function messages(): HasMany
+    {
+        return $this->hasMany(Message::class)->orderBy('created_at');
+    }
+
+    public function latestMessage(): HasOne
+    {
+        return $this->hasOne(Message::class)->whereNull('deleted_at')->latestOfMany();
+    }
+
+    // ── Helpers ─────────────────────────────────────────────────────────────
+
+    public function isDirect(): bool
+    {
+        return $this->type === 'direct';
+    }
+
+    public function isGroup(): bool
+    {
+        return $this->type === 'group';
+    }
+
+    /**
+     * Find an existing direct conversation between exactly two users, or null.
+     */
+    public static function findDirect(int $userA, int $userB): ?self
+    {
+        return self::query()
+            ->where('type', 'direct')
+            ->whereHas('allParticipants', fn ($q) => $q->where('user_id', $userA)->whereNull('left_at'))
+            ->whereHas('allParticipants', fn ($q) => $q->where('user_id', $userB)->whereNull('left_at'))
+            ->whereRaw(
+                '(select count(*) from conversation_participants'
+                .' where conversation_participants.conversation_id = conversations.id'
+                .' and left_at is null) = 2'
+            )
+            ->first();
+    }
+
+    /**
+     * Compute unread count for a given participant.
+     */
+    public function unreadCountFor(int $userId): int
+    {
+        $participant = $this->allParticipants()
+            ->where('user_id', $userId)
+            ->first();
+
+        if (! $participant) {
+            return 0;
+        }
+
+        $query = $this->messages()
+            ->whereNull('deleted_at')
+            ->where('sender_id', '!=', $userId);
+
+        if ($participant->last_read_at) {
+            $query->where('created_at', '>', $participant->last_read_at);
+        }
+
+        return $query->count();
+    }
+}