package buscompose

import "slices"

// **The lease write's grants** (novox/hq ADR 0582 clause 3, issue 774). Composed with Records.LeaseCut, the list takes
// from the controller its write of the lease's key and every update, purge and delete of the lease's bucket, and gives
// the grants part the key `holder`, which it creates naming itself and deletes at a hand-back (clause 5). Whatever the
// records, the bus module's tools account may read and update the lease's bucket, for the tool that removes and
// restores its expiry; no other bucket's.

// leaseStream is the lease bucket's stream.
var leaseStream = "KV_" + LeaseBucket

// LeaseHolderWrite is the grants part's write of the lease's one key, from the cut.
func LeaseHolderWrite() string { return "$KV." + LeaseBucket + "." + leaseKey }

// LeaseCutDenied are the controller's subjects of the lease's bucket that its `$JS.API.>` reaches and the cut refuses:
// the bucket's update (its expiry), purge and delete, and a message's delete (the key's last value).
func LeaseCutDenied() []string {
	return []string{"$JS.API.STREAM.UPDATE." + leaseStream, "$JS.API.STREAM.PURGE." + leaseStream,
		"$JS.API.STREAM.DELETE." + leaseStream, "$JS.API.STREAM.MSG.DELETE." + leaseStream}
}

// LeaseExpiryGrants are the bus module's tools account's read and update of the lease's bucket, for its expiry.
func LeaseExpiryGrants() []string {
	return []string{"$JS.API.STREAM.INFO." + leaseStream, "$JS.API.STREAM.UPDATE." + leaseStream}
}

// writesTheLease is the controller holding the lease, or, from the cut, the grants part writing its key holder alone.
func writesTheLease(p Principal, pattern string) bool {
	if p.Kind == KindController {
		return true
	}
	return p.Kind == KindModule && p.Module == GrantsModule && p.LeaseCut && pattern == LeaseHolderWrite()
}

// setsLeaseExpiry is the bus module's tools account updating the lease's bucket: the writers table's one exemption from
// stream definitions being the controller's beside ASSIGNMENTS' removal (ADR 0582 clause 3).
func setsLeaseExpiry(p Principal, pattern string) bool {
	return p.Kind == KindProcess && len(p.Removes) > 0 && slices.Contains(LeaseExpiryGrants(), pattern)
}