Feat: Adds multi currency support (#88)

app/Casts/BaseCurrency.php

@@ -0,0 +1,46 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Casts;
+
+use App\Models\Currency;
+use Illuminate\Contracts\Database\Eloquent\CastsAttributes;
+use Illuminate\Database\Eloquent\Model;
+
+class BaseCurrency implements CastsAttributes
+{
+    /**
+     * Cast the given value to user's display currency
+     *
+     * @param  array<string, mixed>  $attributes
+     */
+    public function get(Model $model, string $key, mixed $value, array $attributes): mixed
+    {
+
+        return (float) $value;
+    }
+
+    /**
+     * Prepare the given value for storage in base currency
+     *
+     * @param  array<string, mixed>  $attributes
+     */
+    public function set(Model $model, string $key, mixed $value, array $attributes): mixed
+    {
+
+        // for market data and transactions the `currency` attribute is available...
+        // but for dividends and other types, need to make sure `market_data` is loaded
+        if (is_null($model?->currency)) {
+
+            $model->loadMarketData();
+        }
+
+        return Currency::convert(
+            (float) $value,
+            $model?->currency ?? $model->market_data?->currency,
+            config('investbrain.base_currency'),
+            $model?->date
+        );
+    }
+}