Files
go-cart-actor/cmd/cart/mutation_remove_item.go
matst80 9fc3871e84 better
2025-10-13 15:39:41 +02:00

45 lines
1.1 KiB
Go

package main
import (
"fmt"
messages "git.tornberg.me/go-cart-actor/pkg/messages"
)
// mutation_remove_item.go
//
// Registers the RemoveItem mutation.
//
// Behavior:
// - Removes the cart line whose local cart line Id == payload.Id
// - If no such line exists returns an error
// - Recalculates cart totals (WithTotals)
//
// Notes:
// - This removes only the line item; any deliveries referencing the removed
// item are NOT automatically adjusted (mirrors prior logic). If future
// semantics require pruning delivery.item_ids you can extend this handler.
// - If multiple lines somehow shared the same Id (should not happen), only
// the first match would be removed—data integrity relies on unique line Ids.
func RemoveItem(g *CartGrain, m *messages.RemoveItem) error {
if m == nil {
return fmt.Errorf("RemoveItem: nil payload")
}
targetID := int(m.Id)
index := -1
for i, it := range g.Items {
if it.Id == targetID {
index = i
break
}
}
if index == -1 {
return fmt.Errorf("RemoveItem: item id %d not found", m.Id)
}
g.Items = append(g.Items[:index], g.Items[index+1:]...)
return nil
}