initial inventory service

pkg/inventory/memory_service.go

@@ -0,0 +1,47 @@
+package inventory
+
+import (
+	"errors"
+	"sync"
+)
+
+type MemoryInventoryService struct {
+	warehouses map[LocationID]*Warehouse
+	mu         sync.RWMutex
+}
+
+func NewMemoryInventoryService() *MemoryInventoryService {
+	return &MemoryInventoryService{
+		warehouses: make(map[LocationID]*Warehouse),
+	}
+}
+
+func (s *MemoryInventoryService) AddWarehouse(warehouse *Warehouse) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.warehouses[warehouse.ID] = warehouse
+}
+
+func (s *MemoryInventoryService) GetInventory(sku SKU, locationID LocationID) (*InventoryItem, error) {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	warehouse, ok := s.warehouses[locationID]
+	if !ok {
+		return nil, errors.New("warehouse not found")
+	}
+
+	for _, item := range warehouse.Inventory {
+		if item.SKU == sku {
+			return &item, nil
+		}
+	}
+	return nil, errors.New("sku not found in warehouse")
+}
+
+func (s *MemoryInventoryService) ReserveInventory(req ...ReserveRequest) error {
+	// We'll implement the reservation logic using Lua script execution here
+
+	// For now, let's just return an error indicating it's not implemented
+	return errors.New("reservation not implemented yet")
+}

pkg/inventory/redis_service.go

@@ -0,0 +1,107 @@
+package inventory
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+
+	"github.com/redis/go-redis/v9"
+)
+
+type RedisInventoryService struct {
+	client     *redis.Client
+	ctx        context.Context
+	luaScripts map[string]*redis.Script
+}
+
+func NewRedisInventoryService(client *redis.Client, ctx context.Context) (*RedisInventoryService, error) {
+	rdb := client
+
+	// Ping Redis to check connection
+	_, err := rdb.Ping(ctx).Result()
+	if err != nil {
+		return nil, err
+	}
+
+	return &RedisInventoryService{
+		client:     rdb,
+		ctx:        ctx,
+		luaScripts: make(map[string]*redis.Script),
+	}, nil
+}
+
+func (s *RedisInventoryService) LoadLuaScript(key string) error {
+	// Get the script from Redis
+	script, err := s.client.Get(s.ctx, key).Result()
+	if err != nil {
+		return err
+	}
+
+	// Load the script into the luaScripts cache
+	s.luaScripts[key] = redis.NewScript(script)
+	return nil
+}
+
+func (s *RedisInventoryService) AddWarehouse(warehouse *Warehouse) error {
+	// Convert warehouse to Redis-friendly format
+	data := map[string]interface{}{
+		"id":        string(warehouse.ID),
+		"name":      warehouse.Name,
+		"inventory": warehouse.Inventory,
+	}
+
+	// Store in Redis with a key pattern like "warehouse:<ID>"
+	key := "warehouse:" + string(warehouse.ID)
+	_, err := s.client.HMSet(s.ctx, key, data).Result()
+	return err
+}
+
+func (s *RedisInventoryService) GetInventory(sku SKU, locationID LocationID) (*InventoryItem, error) {
+	// Get the warehouse from Redis
+	key := "warehouse:" + string(locationID)
+	result, err := s.client.HGetAll(s.ctx, key).Result()
+	if err != nil {
+		return nil, err
+	}
+
+	// Parse the inventory items
+	var inventoryItems []InventoryItem
+	for _, itemData := range result {
+		var item InventoryItem
+		if err := json.Unmarshal([]byte(itemData), &item); err == nil {
+			inventoryItems = append(inventoryItems, item)
+		}
+	}
+
+	// Find the requested SKU
+	for _, item := range inventoryItems {
+		if item.SKU == sku {
+			return &item, nil
+		}
+	}
+
+	return nil, errors.New("sku not found in warehouse")
+}
+
+func (s *RedisInventoryService) ReserveInventory(req ReserveRequest) error {
+	return nil
+	// Get the Lua script from Redis
+	// key := "lua:reserve_inventory"
+	// script, err := s.client.Get(s.ctx, key).Result()
+	// if err != nil {
+	// 	return err
+	// }
+
+	// luaScript := redis.NewScript(script)
+
+	// // Prepare arguments for the Lua script
+	// args := []interface{}{
+	// 	string(req.LocationID),
+	// 	string(req.SKU),
+	// 	req.Quantity,
+	// }
+
+	// // Execute the Lua script
+	// cmd := s.client.Eval(s.ctx, luaScript, len(args), args...)
+	//return err
+}

pkg/inventory/types.go

@@ -0,0 +1,30 @@
+package inventory
+
+import "time"
+
+type SKU string
+
+type LocationID string
+
+type InventoryItem struct {
+	SKU        SKU
+	Quantity   int
+	LastUpdate time.Time
+}
+
+type Warehouse struct {
+	ID        LocationID
+	Name      string
+	Inventory []InventoryItem
+}
+
+type InventoryService interface {
+	GetInventory(sku SKU, locationID LocationID) (uint32, error)
+	ReserveInventory(req ...ReserveRequest) error
+}
+
+type ReserveRequest struct {
+	SKU        SKU
+	LocationID LocationID
+	Quantity   uint32
+}