package activator

import (
	"errors"

	"github.com/carlosframework/platform/internal/registry"
)

// errClaimsNoGenerations refuses a claims-on swap whose claim runtime cannot
// start a generation of its own (ClaimRuntime.Generations and Pins). It is
// returned before anything is raised, stopped or spawned.
var errClaimsNoGenerations = errors.New("swap: claims are on and the claim runtime cannot start a generation of its own")

// claimsSwapRefusal is the guard every claims-backed swap (work that is not
// hostwrite.Legacy) meets before its side effects: before the admission
// runs inside the work, before an overlap raises the parent, before a hold
// stops its incumbent (final review F9, index P2-9). On this base it always
// refuses. A runtime without Generations and Pins gets
// errClaimsNoGenerations, as before. One with both still meets the closed
// isolated launch (ErrClaimIsolationUnavailable, as the admission's
// refusal: NoOwnership, so the attempt is abandoned, never failed). The
// booleans stay for plan 5; they alone never open this guard.
//
// overlap names the one exception, and it is a test seam: claimSpawn, the
// stand-in for a working isolated launch, lets an overlap through to its
// claims-on spawn. Only this package's tests set it (no production file
// assigns it; TestClaimSpawnIsATestSeam checks that), so production always
// refuses here. A hold has no stand-in: its pinned wake would run the
// closed claims launch itself, so it is refused even then.
func (a *Service) claimsSwapRefusal(overlap bool) error {
	if r := a.cfg.Claims; r == nil || !r.Generations || !r.Pins {
		return errClaimsNoGenerations
	}
	if overlap && a.claimSpawn != nil {
		return nil
	}
	return claimAdmission(ErrClaimIsolationUnavailable, false)
}

// claimGenAt is generation n's handle for a claims-on spawn: the generation
// sockets where the row has them, and the canonical socket (with a real
// number) where it does not.
func (a *Service) claimGenAt(rt registry.Route, n uint64) Gen {
	if gp, ok := a.backend.(genPather); ok {
		if g, ok := gp.GenPaths(rt, n); ok {
			return g
		}
	}
	return Gen{N: n, Socket: rt.Socket, Control: rt.Socket + ".control"}
}