refactor: extract AbstractLlmPredictionProvider for shared boilerplate

Anthropic, Gemini, and OpenAi providers each repeated: API-key gate,
chronological price-list building, response validation
(direction/confidence/reasoning), TrendDirection::tryFrom, confidence
cap at 85, and the top-level try/catch + Log::error.

Now in AbstractLlmPredictionProvider:
- LLM_MAX_CONFIDENCE constant
- buildPriceList(Collection) helper
- buildPrediction(input, ?source) — handles direction validation,
  confidence cap, model construction
- defaultPrompt(priceList) — shared by Gemini and OpenAi
- Default predict() flow (apiKey + callProvider + buildPrediction +
  try/catch). Gemini and OpenAi only implement apiKey() and
  callProvider(). Anthropic overrides predict() because of its
  multi-phase web-search + forced-tool flow but reuses the helpers.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/Services/LlmPrediction/OpenAiPredictionProvider.php

@@ -2,112 +2,61 @@
 
 namespace App\Services\LlmPrediction;
 
-use App\Enums\PredictionSource;
-use App\Enums\TrendDirection;
-use App\Models\BrentPrice;
-use App\Models\PricePrediction;
-use App\Services\ApiLogger;
-use Illuminate\Support\Collection;
 use Illuminate\Support\Facades\Http;
 use Illuminate\Support\Facades\Log;
-use Throwable;
 
-class OpenAiPredictionProvider implements OilPredictionProvider
+class OpenAiPredictionProvider extends AbstractLlmPredictionProvider
 {
-    private const int LLM_MAX_CONFIDENCE = 85;
-
-    public function __construct(
-        private readonly ApiLogger $apiLogger,
-    ) {}
-
-    public function predict(Collection $prices): ?PricePrediction
+    protected function apiKey(): ?string
     {
-        if (! config('services.openai.api_key')) {
-            return null;
-        }
-
-        $priceList = $prices->sortBy('date')
-            ->map(fn (BrentPrice $p) => $p->date->toDateString().': $'.$p->price_usd)
-            ->implode("\n");
+        return config('services.openai.api_key');
+    }
 
+    protected function callProvider(string $apiKey, string $priceList): ?array
+    {
         $url = 'https://api.openai.com/v1/chat/completions';
 
-        try {
-            $response = $this->apiLogger->send('openai', 'POST', $url, fn () => Http::timeout(15)
-                ->withToken(config('services.openai.api_key'))
-                ->post($url, [
-                    'model' => config('services.openai.model', 'gpt-4o-mini'),
-                    'response_format' => [
-                        'type' => 'json_schema',
-                        'json_schema' => [
-                            'name' => 'oil_prediction',
-                            'strict' => true,
-                            'schema' => [
-                                'type' => 'object',
-                                'properties' => [
-                                    'direction' => ['type' => 'string', 'enum' => ['rising', 'falling', 'flat']],
-                                    'confidence' => ['type' => 'integer'],
-                                    'reasoning' => ['type' => 'string'],
-                                ],
-                                'required' => ['direction', 'confidence', 'reasoning'],
-                                'additionalProperties' => false,
+        $response = $this->apiLogger->send('openai', 'POST', $url, fn () => Http::timeout(15)
+            ->withToken($apiKey)
+            ->post($url, [
+                'model' => config('services.openai.model', 'gpt-4o-mini'),
+                'response_format' => [
+                    'type' => 'json_schema',
+                    'json_schema' => [
+                        'name' => 'oil_prediction',
+                        'strict' => true,
+                        'schema' => [
+                            'type' => 'object',
+                            'properties' => [
+                                'direction' => ['type' => 'string', 'enum' => ['rising', 'falling', 'flat']],
+                                'confidence' => ['type' => 'integer'],
+                                'reasoning' => ['type' => 'string'],
                             ],
+                            'required' => ['direction', 'confidence', 'reasoning'],
+                            'additionalProperties' => false,
                         ],
                     ],
-                    'messages' => [[
-                        'role' => 'user',
-                        'content' => $this->prompt($priceList),
-                    ]],
-                ]));
+                ],
+                'messages' => [[
+                    'role' => 'user',
+                    'content' => $this->defaultPrompt($priceList),
+                ]],
+            ]));
 
-            if (! $response->successful()) {
-                Log::error('OpenAiPredictionProvider: request failed', ['status' => $response->status()]);
-
-                return null;
-            }
-
-            $data = json_decode($response->json('choices.0.message.content') ?? '{}', true);
-
-            if (! isset($data['direction'], $data['confidence'], $data['reasoning'])) {
-                Log::error('OpenAiPredictionProvider: unexpected response format', ['data' => $data]);
-
-                return null;
-            }
-
-            $direction = TrendDirection::tryFrom($data['direction']);
-
-            if ($direction === null) {
-                Log::error('OpenAiPredictionProvider: invalid direction', ['direction' => $data['direction']]);
-
-                return null;
-            }
-
-            return new PricePrediction([
-                'predicted_for' => now()->toDateString(),
-                'source' => PredictionSource::Llm,
-                'direction' => $direction,
-                'confidence' => min((int) $data['confidence'], self::LLM_MAX_CONFIDENCE),
-                'reasoning' => $data['reasoning'],
-                'generated_at' => now(),
-            ]);
-        } catch (Throwable $e) {
-            Log::error('OpenAiPredictionProvider: predict failed', ['error' => $e->getMessage()]);
+        if (! $response->successful()) {
+            Log::error(self::class.': request failed', ['status' => $response->status()]);
 
             return null;
         }
-    }
 
-    private function prompt(string $priceList): string
-    {
-        return <<<PROMPT
-            You are analyzing Brent crude oil price data for a UK fuel price alert service.
-            Predict the short-term direction over the next 3–5 days.
+        $data = json_decode($response->json('choices.0.message.content') ?? '{}', true);
 
-            Recent Brent crude prices (USD/barrel):
-            {$priceList}
+        if (! isset($data['direction'], $data['confidence'], $data['reasoning'])) {
+            Log::error(self::class.': unexpected response format', ['data' => $data]);
 
-            Respond with direction (rising, falling, or flat), a confidence score (0–85),
-            and a one-sentence reasoning.
-            PROMPT;
+            return null;
+        }
+
+        return $data;
     }
 }