package graph

import (
	"slices"
	"strings"
	"sync"

	"git.novox.be/novox/mesh-sdk/go/catalogue"
	"git.novox.be/novox/mesh-sdk/go/seatlist"
)

// bootstrappedReads are the reader capabilities `seat:<seat>` of the bootstrapped seats: the embedded files' own, so
// computed once.
var bootstrappedReads = sync.OnceValue(func() []string {
	var out []string
	for _, d := range seatlist.Bootstrapped() {
		out = append(out, catalogue.ReadSeat+d.Seat)
	}
	return out
})

// MissingReads is catalogue.MissingManifestReads with every need of a bootstrapped seat counted as read (novox/hq ADR 0614
// §4, ADR 0636 §2): every reader of the seat list holds the bootstrapped seats from its start, before it has read the list,
// so a manifest naming one is read by every node-engine whatever its statement names. Without it an engine whose statement
// was made before its list was in use states no seat, and the node-engine's own build naming mesh-catalog is held on the
// very engine that would state it (issue 1966). The assigner's capability hold and the indexer's hold both judge with it,
// so the rule is one.
func MissingReads(needs, stated []string) []string {
	boot := bootstrappedReads()
	missing := slices.DeleteFunc(catalogue.MissingManifestReads(needs, stated), func(n string) bool {
		return strings.HasPrefix(n, catalogue.ReadSeat) && slices.Contains(boot, n)
	})
	if len(missing) == 0 {
		return nil
	}
	return missing
}