package link

import (
	"context"
	"errors"
	"strings"

	"github.com/nats-io/nats.go"
	"github.com/nats-io/nats.go/jetstream"

	"github.com/novox/mesh-controller/internal/broker"
)

// The kinds of ask, as the queue says them. **The kind decides the queue** (novox/hq ADR 0406 §3): a delivery build is on
// the seat's own queue, taken before any check; a check of a pull request marked ready is on the second; every other
// check on the third. Nothing orders the asks any more: a builder takes from the queues in that order, and the check
// queues keep one request a pull request. The reordering of one queue by moving asks to its tail, with its pause of the
// worker, its look every two seconds and its second copies, is gone (issue 558 is answered by the streams).
const (
	KindDelivery = "delivery"
	KindCheck    = "check"
)

// KindOf is an ask's kind: a check for a pull request's check — a recheck the merge tool asks included —
// a dry run, or an ask nothing could be read from; a delivery for any other build.
func KindOf(r BuildRequest) string {
	if r.ID == "" || r.Check != nil || r.DryRun {
		return KindCheck
	}
	return KindDelivery
}

// DeleteAsk removes a waiting or dead ask from the queue it is in, at its sequence. Says the sequence it removed, 0 when
// it was not there any more: taken and settled, or replaced by a newer request for its pull request.
func DeleteAsk(_ context.Context, js *broker.JetStream, seat string, ask QueuedAsk) (uint64, error) {
	stream := ask.Stream
	if stream == "" {
		worker, _ := broker.HolderConsumerFor("", "", broker.DeclaredSeat{Name: seat, Accepts: []string{"build"}})
		stream = worker.Stream
	}
	err := js.Context().DeleteMsg(stream, ask.Seq)
	switch {
	case err == nil:
		return ask.Seq, nil
	case errors.Is(err, nats.ErrMsgNotFound) || errors.Is(err, jetstream.ErrMsgNotFound) ||
		strings.Contains(err.Error(), "no message found"):
		return 0, nil
	}
	return 0, err
}