refactor: split oil price ingestion and prediction into separate services + commands

- BrentPriceFetcher owns ingestion (fetchFromEia / fetchFromFred, each throws on failure) - BrentPricePredictor owns prediction and marks latest brent_prices row as generated - oil:fetch command tries EIA, falls back to FRED, fails loudly if both fail - oil:predict command prompts if latest price already has a prediction; --force bypasses - add prediction_generated_at column to brent_prices - delete OilPriceService (replaced by the two focused services)
2026-04-14 16:59:43 +01:00
parent 1a0381265e
commit 486f0e689c
10 changed files with 415 additions and 306 deletions
--- a/app/Services/BrentPricePredictor.php
+++ b/app/Services/BrentPricePredictor.php
@@ -0,0 +1,135 @@
+<?php
+
+namespace App\Services;
+
+use App\Enums\PredictionSource;
+use App\Enums\TrendDirection;
+use App\Models\BrentPrice;
+use App\Models\PricePrediction;
+use App\Services\LlmPrediction\OilPredictionProvider;
+use Illuminate\Support\Collection;
+use Illuminate\Support\Facades\Log;
+
+final class BrentPricePredictor
+{
+    private const float EWMA_ALPHA = 0.3;
+
+    private const float EWMA_THRESHOLD_PCT = 1.5;
+
+    private const int EWMA_MAX_CONFIDENCE = 65;
+
+    private const int EWMA_MIN_ROWS = 14;
+
+    public function __construct(
+        private readonly OilPredictionProvider $provider,
+    ) {}
+
+    /**
+     * Return the latest BrentPrice row, or null if none exists.
+     */
+    public function latestPrice(): ?BrentPrice
+    {
+        return BrentPrice::orderBy('date', 'desc')->first();
+    }
+
+    /**
+     * Generate EWMA + LLM predictions, store them, and flag the latest
+     * brent_prices row as having a prediction generated.
+     */
+    public function generatePrediction(): ?PricePrediction
+    {
+        $prices = BrentPrice::orderBy('date', 'desc')->limit(30)->get();
+
+        if ($prices->count() < self::EWMA_MIN_ROWS) {
+            Log::warning('BrentPricePredictor: not enough price data', [
+                'rows' => $prices->count(),
+            ]);
+
+            return null;
+        }
+
+        $ewma = $this->generateEwmaPrediction($prices);
+
+        if ($ewma !== null) {
+            PricePrediction::create($ewma->toArray());
+        }
+
+        $llm = $this->provider->predict($prices);
+
+        if ($llm !== null) {
+            PricePrediction::create($llm->toArray());
+        }
+
+        $result = $llm ?? $ewma;
+
+        if ($result !== null) {
+            $prices->first()->forceFill(['prediction_generated_at' => now()])->save();
+        }
+
+        return $result;
+    }
+
+    public function generateEwmaPrediction(Collection $prices): ?PricePrediction
+    {
+        $chronological = $prices->sortBy('date')->pluck('price_usd')->values()->all();
+
+        if (count($chronological) < self::EWMA_MIN_ROWS) {
+            return null;
+        }
+
+        $ewma3 = $this->computeEwma(array_slice($chronological, -3));
+        $ewma7 = $this->computeEwma(array_slice($chronological, -7));
+
+        $changePct = (($ewma3 - $ewma7) / $ewma7) * 100;
+
+        [$direction, $confidence] = match (true) {
+            $changePct >= self::EWMA_THRESHOLD_PCT => [
+                TrendDirection::Rising,
+                $this->ewmaConfidence($changePct),
+            ],
+            $changePct <= -self::EWMA_THRESHOLD_PCT => [
+                TrendDirection::Falling,
+                $this->ewmaConfidence(abs($changePct)),
+            ],
+            default => [TrendDirection::Flat, 50],
+        };
+
+        $reasoning = sprintf(
+            '3-day EWMA ($%.2f) vs 7-day EWMA ($%.2f): %.2f%% %s.',
+            $ewma3,
+            $ewma7,
+            abs($changePct),
+            $direction === TrendDirection::Flat ? 'difference (flat)' : $direction->value,
+        );
+
+        return new PricePrediction([
+            'predicted_for' => now()->toDateString(),
+            'source' => PredictionSource::Ewma,
+            'direction' => $direction,
+            'confidence' => $confidence,
+            'reasoning' => $reasoning,
+            'generated_at' => now(),
+        ]);
+    }
+
+    /**
+     * @param  float[]  $prices  Chronological (oldest first).
+     */
+    private function computeEwma(array $prices): float
+    {
+        $ema = $prices[0];
+
+        foreach (array_slice($prices, 1) as $price) {
+            $ema = self::EWMA_ALPHA * $price + (1 - self::EWMA_ALPHA) * $ema;
+        }
+
+        return round($ema, 4);
+    }
+
+    private function ewmaConfidence(float $changePct): int
+    {
+        $scaled = min($changePct / 5.0, 1.0) * self::EWMA_MAX_CONFIDENCE;
+
+        return (int) round(max(30, $scaled));
+    }
+}