adds fallback capability to market data providers

app/Interfaces/MarketData/FallbackInterface.php

@@ -0,0 +1,42 @@
+<?php
+
+namespace App\Interfaces\MarketData;
+
+use Illuminate\Support\Facades\Log;
+
+class FallbackInterface
+{
+
+    protected string $latest_error;
+
+    public function __call($method, $arguments)
+    {
+
+        $providers = explode(',', config('investbrain.provider', 'yahoo'));
+        
+        foreach ($providers as $provider) {
+
+            $provider = trim($provider);
+
+            try {
+
+                if (!in_array($provider, array_keys(config('investbrain.interfaces', [])))) {
+
+                    throw new \Exception("Provider [{$provider}] is not a valid market data interface.");
+                }
+
+                $provider_class_name = config("investbrain.interfaces.$provider");
+
+                return app()->make($provider_class_name)->$method(...$arguments);
+
+            } catch (\Throwable $e) {
+                
+                $this->latest_error = $e->getMessage();
+
+                Log::warning("Failed calling method {$method} ({$provider}): {$this->latest_error}");
+            }
+        }
+
+        throw new \Exception("Could not get market data: {$this->latest_error}");
+    }
+}

app/Providers/AppServiceProvider.php

@@ -11,16 +11,9 @@ class AppServiceProvider extends ServiceProvider
      */
     public function register(): void
     {
-        if (!in_array(
-            $interface = config('investbrain.default', 'yahoo'), 
-            array_keys(config('investbrain.interfaces', []))
-        )) {
-            throw new \Exception("Error: '$interface' is not a valid market data interface.");
-        }
-        
         $this->app->bind(
             \App\Interfaces\MarketData\MarketDataInterface::class,
-            config("investbrain.interfaces.$interface")
+            \App\Interfaces\MarketData\FallbackInterface::class
         );
     }