alrahma_sunday_school_api/docs/project-design/INVENTORY_IMPROVEMENT_IMPLEMENTATION_SUMMARY.md

Inventory System Improvement — Implementation Summary

Overview

This implementation applies the first three sprints of the inventory improvement plan:

1. Stabilize Inventory Data — Make movement ledger the source of truth
2. Movement and Audit Cleanup — Append-only ledger with void/correction support
3. Procurement Integration — Link purchase orders to inventory movements
4. Low-Stock and Reorder Workflow — New endpoints and features

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Changes Made

Phase 1: Stabilize Inventory Data

1. Quantity removed from item updates

• app/Http/Requests/Inventory/InventoryItemUpdateRequest.php: Removed quantity from validatable fields. Stock changes must go through movements (adjust, audit, etc.).
• app/Services/Inventory/InventoryItemService.php: filterItemData() now only includes quantity during creation ($lockedType === null), not during updates.
• app/Http/Requests/Inventory/InventoryItemStoreRequest.php: Strengthened validation — type uses in:classroom,book,office,kitchen, condition uses in:good,needs_repair,need_replace,cannot_find, category_id checks exists:inventory_categories,id.

2. Append-only movement ledger with void/correction

New migration: 2026_06_11_074503_add_inventory_movement_audit_fields.php

Adds to inventory_movements:

• voided_at (timestamp) — when the movement was voided
• voided_by (bigint) — user who voided it
• void_reason (varchar 255) — reason for voiding
• corrects_movement_id (bigint) — links a correction to the original movement
• source_type / source_id (varchar/bigint) — polymorphic source reference

app/Models/InventoryMovement.php: Added fillable fields, casts, scopes (notVoided, voided), and relationships (voidedBy, correctsMovement, corrections).

app/Services/Inventory/InventoryMovementService.php:

Method	Status	Notes
create()	⚠️ Deprecated	Still works, but marked @deprecated. Use recordMovement() instead.
update()	⚠️ Deprecated	Still works. Prevents editing voided movements.
delete()	⚠️ Deprecated	Prevents deleting movements that have corrections.
bulkDelete()	⚠️ Deprecated	Same prevention for corrections.
recordMovement()	✅ Primary method	Append-only, creates initial movement automatically.
voidMovement()	✅ NEW	Marks original as voided + creates reverse correction.
correctMovement()	✅ NEW	Adds an adjusting entry linked to the original.
recalcQuantity()	✅ Updated	Excludes voided movements from sum calculations.
reconcile()	✅ NEW	Compares stored quantity vs movement sum, reports discrepancies.

3. Reconciliation command

app/Console/Commands/InventoryReconcile.php: php artisan inventory:reconcile with --school-year and --fix options.

Phase 2: Movement and Audit Cleanup

Void and correction API endpoints

app/Http/Controllers/Api/Inventory/InventoryMovementController.php:

• POST movements/{id}/void — requires reason
• POST movements/{id}/correct — requires qty_change and reason

Both require authentication and return appropriate success/error responses.

Phase 3: Procurement Integration

1. inventory_item_id on purchase_order_items

New migration: 2026_06_11_074642_add_inventory_item_id_to_purchase_order_items.php

Adds inventory_item_id (unsigned int, nullable) to purchase_order_items with an index. This allows linking PO items to inventory items.

app/Models/PurchaseOrderItem.php: Added inventory_item_id to $fillable.

2. PurchaseOrderReceiveService links to inventory

app/Services/PurchaseOrders/PurchaseOrderReceiveService.php:

• Injects InventoryMovementService
• On receiving PO items with inventory_item_id set, creates an inventory movement via recordMovement()
• Continues to update legacy supplies.qty_on_hand for backward compatibility

Phase 4: Low-Stock and Reorder Workflow

New database fields

New migration: 2026_06_11_074621_add_inventory_item_reorder_fields.php

Adds to inventory_items:

• preferred_supplier_id, last_purchase_price, average_unit_cost
• reorder_point, reorder_quantity, lead_time_days
• barcode, qr_code, asset_tag

app/Models/InventoryItem.php: Added fillable fields, casts, relationships (preferredSupplier), and scopes (lowStock, outOfStock).

app/Http/Resources/Inventory/InventoryItemResource.php: Exposes all new fields.

New API endpoints

app/Http/Controllers/Api/Inventory/InventoryController.php:

Method	Endpoint	Description
lowStock()	GET inventory/low-stock	Lists items where quantity <= reorder_point
reorderSuggestions()	GET inventory/reorder-suggestions	Calculates suggested order quantities
reorderRequest()	POST inventory/items/{id}/reorder-request	Single item reorder info
stockStatus()	GET inventory/stock-status	All items with status: ok/low_stock/out_of_stock
dashboard()	GET inventory/dashboard	Summary counts by type, low stock, out of stock, etc.

All routes are registered under api/v1/inventory/ in routes/api.php.

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Database Migrations

Migration	Description
2026_06_11_074503_add_inventory_movement_audit_fields	Adds void/correction fields to movements
2026_06_11_074621_add_inventory_item_reorder_fields	Adds reorder/supplier/barcode fields to items
2026_06_11_074642_add_inventory_item_id_to_purchase_order_items	Links PO items to inventory items

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Key Backward Compatibility Notes

1. Existing endpoints remain unchanged. GET/POST/PATCH/DELETE inventory/items, inventory/movements, and all summary/distribution endpoints continue to work with the same payloads.

2. Old create/update/delete movement methods work as before, but are marked @deprecated. They still enforce new guards (e.g., cannot edit voided movements, cannot delete movements with corrections).

3. Purchase order receiving continues to update supplies.qty_on_hand for legacy support. The new inventory movement is added alongside, not instead.

4. Voided movements are excluded from quantity calculations by default. Existing reports that call recalcQuantity() automatically benefit.

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Console Commands

# Check for discrepancies between stored quantity and movement sum
php artisan inventory:reconcile

# With --fix to auto-correct discrepancies
php artisan inventory:reconcile --fix

# For a specific school year
php artisan inventory:reconcile --school-year=2025-2026

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API Reference

New Endpoints

GET  /api/v1/inventory/low-stock
GET  /api/v1/inventory/reorder-suggestions
POST /api/v1/inventory/items/{id}/reorder-request
GET  /api/v1/inventory/stock-status?type=book
GET  /api/v1/inventory/dashboard?school_year=2025-2026
POST /api/v1/inventory/movements/{id}/void     { reason: "..." }
POST /api/v1/inventory/movements/{id}/correct  { qty_change: -5, reason: "..." }