package printjob

import (
	"fmt"

	"printer.backend/internal/model"
)

// CollectImageRefs returns all order images in job order (orders, then images within each order).
func CollectImageRefs(orders []model.Order) []model.PrintJobImageRef {
	var refs []model.PrintJobImageRef
	for _, o := range orders {
		for _, img := range o.Images {
			refs = append(refs, model.PrintJobImageRef{
				OrderID: o.ID,
				ImageID: img.ID,
			})
		}
	}
	return refs
}

// AssignSlots maps images to layout slots (at most one image per slot).
func AssignSlots(refs []model.PrintJobImageRef, preview model.LayoutPreview) []model.PrintJobSlotAssignment {
	limit := len(preview.Positions)
	if len(refs) < limit {
		limit = len(refs)
	}
	out := make([]model.PrintJobSlotAssignment, 0, limit)
	for i := 0; i < limit; i++ {
		out = append(out, model.PrintJobSlotAssignment{
			Slot:     i,
			Image:    refs[i],
			Position: preview.Positions[i],
		})
	}
	return out
}

// Summary builds validation and slot assignments for a print job.
func Summary(orders []model.Order, preview model.LayoutPreview) model.PrintJobSummary {
	refs := CollectImageRefs(orders)
	slots := preview.Count
	imageCount := len(refs)
	overflow := imageCount > slots

	var warning string
	if overflow {
		warning = fmt.Sprintf(
			"%d Bilder für %d Item-Positionen: %d Bilder werden nicht platziert",
			imageCount, slots, imageCount-slots,
		)
	}

	return model.PrintJobSummary{
		ImageCount:    imageCount,
		SlotCount:     slots,
		ImageOverflow: overflow,
		Warning:       warning,
		Assignments:   AssignSlots(refs, preview),
		Preview:       preview,
	}
}