feat: add LLM prediction providers with structured output support

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-07 14:42:44 +01:00
parent e9612666e3
commit 6a80c11f38
18 changed files with 1101 additions and 484 deletions
--- a/app/Services/LlmPrediction/GeminiPredictionProvider.php
+++ b/app/Services/LlmPrediction/GeminiPredictionProvider.php
@@ -0,0 +1,111 @@
+<?php
+
+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 GeminiPredictionProvider implements OilPredictionProvider
+{
+    private const int LLM_MAX_CONFIDENCE = 85;
+
+    public function __construct(
+        private readonly ApiLogger $apiLogger,
+    ) {}
+
+    public function predict(Collection $prices): ?PricePrediction
+    {
+        if (! config('services.gemini.api_key')) {
+            return null;
+        }
+
+        $priceList = $prices->sortBy('date')
+            ->map(fn (BrentPrice $p) => $p->date->toDateString().': $'.$p->price_usd)
+            ->implode("\n");
+
+        $model = config('services.gemini.model', 'gemini-2.0-flash');
+        $url = "https://generativelanguage.googleapis.com/v1beta/models/{$model}:generateContent";
+
+        try {
+            $response = $this->apiLogger->send('gemini', 'POST', $url, fn () => Http::timeout(15)
+                ->withQueryParameters(['key' => config('services.gemini.api_key')])
+                ->post($url, [
+                    'contents' => [[
+                        'parts' => [['text' => $this->prompt($priceList)]],
+                    ]],
+                    'generationConfig' => [
+                        'responseMimeType' => 'application/json',
+                        'responseSchema' => [
+                            'type' => 'OBJECT',
+                            'properties' => [
+                                'direction' => [
+                                    'type' => 'STRING',
+                                    'enum' => ['rising', 'falling', 'flat'],
+                                ],
+                                'confidence' => ['type' => 'INTEGER'],
+                                'reasoning' => ['type' => 'STRING'],
+                            ],
+                            'required' => ['direction', 'confidence', 'reasoning'],
+                        ],
+                    ],
+                ]));
+
+            if (! $response->successful()) {
+                Log::error('GeminiPredictionProvider: request failed', ['status' => $response->status()]);
+
+                return null;
+            }
+
+            $text = $response->json('candidates.0.content.parts.0.text') ?? '';
+            $data = json_decode($text, true);
+
+            if (! isset($data['direction'], $data['confidence'], $data['reasoning'])) {
+                Log::error('GeminiPredictionProvider: unexpected response format', ['text' => $text]);
+
+                return null;
+            }
+
+            $direction = TrendDirection::tryFrom($data['direction']);
+
+            if ($direction === null) {
+                Log::error('GeminiPredictionProvider: 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('GeminiPredictionProvider: predict failed', ['error' => $e->getMessage()]);
+
+            return null;
+        }
+    }
+
+    private function prompt(string $priceList): string
+    {
+        return <<<PROMPT
+            You are analyzing Brent crude oil price data for a UK fuel price alert service.
+            Predict the short-term direction over the next 3–5 days.
+
+            Recent Brent crude prices (USD/barrel):
+            {$priceList}
+
+            Respond with direction (rising, falling, or flat), a confidence score (0–85),
+            and a one-sentence reasoning.
+            PROMPT;
+    }
+}