feat: add loa requests

This commit adds a feature that allows users to request periods of inactivity from their managers. This is effectively known as a leave of absence.

The commit also introduces new permissions and migrations, therefore, you'll need to adapt your database according to these changes.

app/Absence.php

@@ -2,6 +2,8 @@
 
 namespace App;
 
+use App\Exceptions\AbsenceNotActionableException;
+use Illuminate\Database\Eloquent\Casts\Attribute;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
@@ -25,4 +27,99 @@ class Absence extends Model
     {
         return $this->belongsTo('App\User', 'requesterID', 'id');
     }
+
+
+    /**
+     * Determines whether this model can be setApproved(), setDeclined() or setCancelled()
+     *
+     * @param bool $toCancel Switch the check to cancellability check
+     * @return bool
+     */
+    public function isActionable(bool $toCancel = false): bool
+    {
+        if ($toCancel)
+        {
+            return in_array($this->getRawOriginal('status'), ['PENDING', 'APPROVED']);
+        }
+
+        return $this->getRawOriginal('status') == 'PENDING';
+    }
+
+
+    /**
+     * Sets the Absence's status as approved
+     *
+     * @return Absence
+     * @throws AbsenceNotActionableException
+     */
+    public function setApproved(): Absence
+    {
+        if ($this->isActionable())
+        {
+            return tap($this)->update([
+                'status' => 'APPROVED'
+            ]);
+        }
+
+        throw new AbsenceNotActionableException('This absence is not actionable!');
+    }
+
+
+    /**
+     * Sets the absence's status as declined
+     *
+     * @return Absence
+     * @throws AbsenceNotActionableException
+     */
+    public function setDeclined(): Absence
+    {
+        if ($this->isActionable()) {
+            return tap($this)->update([
+                'status' => 'DECLINED'
+            ]);
+        }
+
+        throw new AbsenceNotActionableException('This absence is not actionable!');
+    }
+
+
+    /**
+     * Sets the absence's status as cancelled
+     *
+     * @return Absence
+     * @throws AbsenceNotActionableException Thrown when the switch to this status would be invalid
+     */
+    public function setCancelled(): Absence
+    {
+        if ($this->isActionable(true)) {
+            return tap($this)->update([
+                'status' => 'CANCELLED'
+            ]);
+        }
+
+        throw new AbsenceNotActionableException('This absence is not actionable!');
+    }
+
+    /**
+     * Sets the absence's status as ended
+     *
+     * @return Absence
+     */
+    public function setEnded(): Absence
+    {
+        return tap($this)->update([
+            'status' => 'ENDED'
+        ]);
+    }
+
+
+    // Look out when retrieving this value;
+    //If you need the unaltered version of it, either adapt to its formatting or call getRawOriginal()
+    protected function status(): Attribute {
+        return Attribute::make(
+            get: fn($value) => ucfirst(strtolower($value))
+        );
+    }
+
 }
+