# Go Cart Actor

A distributed cart management system using the actor model pattern.

## Prerequisites

- Go 1.24.2+
- Protocol Buffers compiler (`protoc`)
- protoc-gen-go and protoc-gen-go-grpc plugins

### Installing Protocol Buffers

On Windows:
```powershell
winget install protobuf
```

On macOS:
```bash
brew install protobuf
```

On Linux:
```bash
# Ubuntu/Debian
sudo apt install protobuf-compiler

# Or download from: https://github.com/protocolbuffers/protobuf/releases
```

### Installing Go protobuf plugin

```bash
go install google.golang.org/protobuf/cmd/protoc-gen-go@latest
go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@latest
```

## Working with Protocol Buffers

### Generating Go code from proto files

After modifying any proto (`proto/messages.proto`, `proto/cart_actor.proto`, `proto/control_plane.proto`), regenerate the Go code (all three share the unified `messages` package):

```bash
cd proto
protoc --go_out=. --go_opt=paths=source_relative \
       --go-grpc_out=. --go-grpc_opt=paths=source_relative \
       messages.proto cart_actor.proto control_plane.proto
```

### Protocol Buffer Messages

The `proto/messages.proto` file defines the following message types:

- `AddRequest` - Add items to cart (includes quantity, sku, country, optional storeId)
- `SetCartRequest` - Set entire cart contents
- `AddItem` - Complete item information for cart
- `RemoveItem` - Remove item from cart
- `ChangeQuantity` - Update item quantity
- `SetDelivery` - Configure delivery options
- `SetPickupPoint` - Set pickup location
- `PickupPoint` - Pickup point details
- `RemoveDelivery` - Remove delivery option
- `CreateCheckoutOrder` - Initiate checkout
- `OrderCreated` - Order creation response

### Building the project

```bash
go build .
```

### Running tests

```bash
go test ./...
```

## Important Notes

- Always regenerate protobuf Go code after modifying any `.proto` files (messages/cart_actor/control_plane)
- The generated `messages.pb.go` file should not be edited manually
- Make sure your PATH includes the protoc-gen-go binary location (usually `$GOPATH/bin`)