feat: FuelPriceService with OAuth token caching

Also extend Pest TestCase to Unit tests and guard MySQL-only migration
DDL (composite PK + PARTITION BY) behind a driver check so in-memory
SQLite tests can run migrations cleanly.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/Services/FuelPriceService.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace App\Services;
+
+use Illuminate\Support\Facades\Cache;
+use Illuminate\Support\Facades\Http;
+
+class FuelPriceService
+{
+    private const TOKEN_CACHE_KEY = 'fuel_finder_access_token';
+
+    public function __construct(
+        private readonly StationTaggingService $taggingService,
+    ) {}
+
+    public function getAccessToken(): string
+    {
+        return Cache::remember(self::TOKEN_CACHE_KEY, 3540, function (): string {
+            $response = Http::timeout(10)
+                ->post(config('services.fuel_finder.base_url').'/oauth/generate_access_token', [
+                    'client_id'     => config('services.fuel_finder.client_id'),
+                    'client_secret' => config('services.fuel_finder.client_secret'),
+                ]);
+
+            return $response->json('data.access_token');
+        });
+    }
+}

database/migrations/2026_04_03_172841_create_station_prices_table.php

@@ -12,7 +12,9 @@ return new class extends Migration
      */
     public function up(): void
     {
-        Schema::create('station_prices', function (Blueprint $table): void {
+        $isMysql = DB::getDriverName() === 'mysql';
+
+        Schema::create('station_prices', function (Blueprint $table) use ($isMysql): void {
             $table->bigIncrements('id');
             $table->string('station_id', 64);
             $table->string('fuel_type', 20);
@@ -21,13 +23,16 @@ return new class extends Migration
             $table->dateTime('price_reported_at');
             $table->dateTime('recorded_at');
 
-            // Composite PK required for MySQL range partitioning
+            // Composite PK required for MySQL range partitioning (not supported by SQLite)
+            if ($isMysql) {
                 $table->primary(['id', 'price_effective_at']);
+            }
             $table->index(['station_id', 'fuel_type', 'price_effective_at']);
             $table->index('price_effective_at');
         });
 
-        // Monthly partitions 2026–2027 + MAXVALUE catch-all
+        // Monthly partitions 2026–2027 + MAXVALUE catch-all (MySQL only)
+        if ($isMysql) {
             DB::statement("ALTER TABLE station_prices
                 PARTITION BY RANGE (YEAR(price_effective_at) * 100 + MONTH(price_effective_at)) (
                     PARTITION p202601 VALUES LESS THAN (202602),
@@ -57,6 +62,7 @@ return new class extends Migration
                     PARTITION pFuture VALUES LESS THAN MAXVALUE
                 )");
         }
+    }
 
     /**
      * Reverse the migrations.

tests/Pest.php

@@ -16,7 +16,7 @@ use Tests\TestCase;
 
 pest()->extend(TestCase::class)
  // ->use(RefreshDatabase::class)
-    ->in('Feature');
+    ->in('Feature', 'Unit');
 
 /*
 |--------------------------------------------------------------------------

tests/Unit/Services/FuelPriceServiceTest.php

@@ -0,0 +1,40 @@
+<?php
+
+use App\Services\FuelPriceService;
+use App\Services\StationTaggingService;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Support\Facades\Cache;
+use Illuminate\Support\Facades\Http;
+
+uses(RefreshDatabase::class);
+
+beforeEach(function (): void {
+    $this->service = new FuelPriceService(new StationTaggingService());
+});
+
+it('fetches and caches an access token', function (): void {
+    Http::fake([
+        '*/oauth/generate_access_token' => Http::response([
+            'data' => [
+                'access_token' => 'test-token-abc',
+                'expires_in'   => 3600,
+            ],
+        ]),
+    ]);
+
+    $token = $this->service->getAccessToken();
+
+    expect($token)->toBe('test-token-abc');
+    expect(Cache::get('fuel_finder_access_token'))->toBe('test-token-abc');
+});
+
+it('returns cached token without hitting API', function (): void {
+    Cache::put('fuel_finder_access_token', 'cached-token', 3540);
+
+    Http::fake();
+
+    $token = $this->service->getAccessToken();
+
+    expect($token)->toBe('cached-token');
+    Http::assertNothingSent();
+});