package moves

import (
	"time"

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

// AbortAfter is how long a Phase 1 move may stay preparing before it aborts
// itself (spec §7.11: "a move whose readiness never comes aborts itself
// after a bound, so an unreachable target never needs a human"; Plan 5
// ruling K18). §13 pages an operator at 60 minutes with no promotable round;
// the abort comes at six hours. The console's sweep (Plan 5 Task 7) CASes
// provision.MoveGuardedAbort when AbortDue says so; nothing here writes.
const AbortAfter = 6 * time.Hour

// AbortDue reports whether rec's move is due its automatic abort at now: a
// Phase 1 move (not legacy) still preparing, AbortAfter or more after the
// later of its RequestedAt and its ReadyAt.
//
// The bound is measured from max(RequestedAt, ReadyAt) (ruling K18), not
// from Move.UpdatedAt, which every record write stamps and so says nothing
// about readiness. Today a preparing move has no ReadyAt (nothing demotes a
// ready move to preparing), so the bound runs from the request; taking the
// later of the two keeps it right should a demotion ever stamp one. A ready
// move is not due: readiness came, and the cut is the operator's (or the
// automatic cut's). A move with no request time is never due: there is no
// evidence to measure from.
func AbortDue(rec provision.Record, now time.Time) bool {
	m := rec.Move
	if m == nil || m.Legacy() || m.State != provision.MovePreparing || m.RequestedAt.IsZero() {
		return false
	}
	return !now.Before(PreparingSince(m).Add(AbortAfter))
}

// PreparingSince is where a preparing move's clocks run from: the later of
// its RequestedAt and its ReadyAt (ruling K18). The six-hour abort (AbortDue)
// and the console's 60-minute page (§13) both measure from it, so the two
// can never disagree about how long a move has prepared (Plan 6 preflight
// L29).
func PreparingSince(m *provision.MoveState) time.Time {
	from := m.RequestedAt
	if m.ReadyAt != nil && m.ReadyAt.After(from) {
		from = *m.ReadyAt
	}
	return from
}