package main

import (
	"fmt"

	messages "git.tornberg.me/go-cart-actor/pkg/messages"
)

// mutation_set_pickup_point.go
//
// Registers the SetPickupPoint mutation using the generic mutation registry.
//
// Semantics (mirrors original switch-based implementation):
//   - Locate the delivery with Id == payload.DeliveryId
//   - Set (or overwrite) its PickupPoint with the provided data
//   - Does NOT alter pricing or taxes (so no totals recalculation required)
//
// Validation / Error Handling:
//   - If payload is nil -> error
//   - If DeliveryId not found -> error
//
// Concurrency:
//   - Relies on the existing expectation that higher-level mutation routing
//     serializes Apply() calls per grain; if stricter guarantees are needed,
//     a delivery-level lock could be introduced later.
//
// Future Extensions:
//   - Validate pickup point fields (country code, zip format, etc.)
//   - Track history / audit of pickup point changes
//   - Trigger delivery price adjustments (which would then require WithTotals()).
func init() {
	RegisterMutation[messages.SetPickupPoint](
		"SetPickupPoint",
		func(g *CartGrain, m *messages.SetPickupPoint) error {
			if m == nil {
				return fmt.Errorf("SetPickupPoint: nil payload")
			}

			for _, d := range g.Deliveries {
				if d.Id == int(m.DeliveryId) {
					d.PickupPoint = &messages.PickupPoint{
						Id:      m.Id,
						Name:    m.Name,
						Address: m.Address,
						City:    m.City,
						Zip:     m.Zip,
						Country: m.Country,
					}
					return nil
				}
			}
			return fmt.Errorf("SetPickupPoint: delivery id %d not found", m.DeliveryId)
		},
		// No WithTotals(): pickup point does not change pricing / tax.
	)
}