Feat: Adds multi currency support (#88)

app/Actions/EnsureCostBasisAddedToSale.php

@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Actions;
+
+use App\Models\Transaction;
+use Illuminate\Database\Eloquent\Model;
+
+class EnsureCostBasisAddedToSale
+{
+    public function __invoke(Model $model, callable $next)
+    {
+        // cost basis is required for sales to calculate realized gains
+        if ($model->transaction_type == 'SELL') {
+
+            $average_cost_basis = Transaction::where([
+                'portfolio_id' => $model->portfolio_id,
+                'symbol' => $model->symbol,
+                'transaction_type' => 'BUY',
+            ])->whereDate('date', '<=', $model->date)
+                ->average('cost_basis');
+
+            $model->cost_basis = $average_cost_basis ?? 0;
+        }
+
+        return $next($model);
+    }
+}