chore: initial commit of existing codebase

app/Services/PurchaseStageService.php

@@ -0,0 +1,50 @@
+<?php
+
+namespace App\Services;
+
+use App\Models\PurchaseRequest;
+
+class PurchaseStageService
+{
+    const STAGES = [
+        'draft', 'gm_approval', 'rfq', 'quoting',
+        'comparison', 'lpo', 'receiving', 'payment', 'complete',
+    ];
+
+    public function advance(PurchaseRequest $request): void
+    {
+        $current = array_search($request->stage, self::STAGES);
+        if ($current === false || $current === count(self::STAGES) - 1) {
+            return;
+        }
+        $request->update(['stage' => self::STAGES[$current + 1]]);
+    }
+
+    public function setStage(PurchaseRequest $request, string $stage): void
+    {
+        abort_unless(in_array($stage, self::STAGES), 422, 'Invalid stage');
+        $request->update(['stage' => $stage]);
+    }
+
+    public function stageIndex(string $stage): int
+    {
+        $idx = array_search($stage, self::STAGES);
+        return $idx === false ? 0 : $idx;
+    }
+
+    public function stageLabel(string $stage): string
+    {
+        return match ($stage) {
+            'draft'       => 'Purchase Request',
+            'gm_approval' => 'GM Signature',
+            'rfq'         => 'Select Suppliers',
+            'quoting'     => 'Awaiting Quotes',
+            'comparison'  => 'Quote Comparison',
+            'lpo'         => 'LPO Issued',
+            'receiving'   => 'Receiving Materials',
+            'payment'     => 'Payment',
+            'complete'    => 'Complete',
+            default       => ucfirst($stage),
+        };
+    }
+}