package hostops

import (
	"context"
	"sort"

	"github.com/carlosframework/platform/internal/hostactors"
	"github.com/carlosframework/platform/internal/hostclaim"
)

func (a ProductionAuthority) StartDeleteClaim(ctx context.Context, before hostclaim.Observed, r Record, by string) (hostclaim.Observed, error) {
	if err := a.StartDelete(ctx, before, r); err != nil {
		return hostclaim.Observed{}, err
	}
	admission, err := a.admission(ctx, r.Holder.Account, r.Holder.App)
	if err != nil {
		return hostclaim.Observed{}, err
	}
	if admission.Value.Op == nil || admission.Value.Op.Kind != "deleting" || admission.Value.Op.Intent["host"] != r.Holder.Host {
		return hostclaim.Observed{}, ErrIdentity
	}
	id := admission.Value.Op.ID
	regions, boxes, err := a.Inventory(ctx, before)
	if err != nil {
		return hostclaim.Observed{}, err
	}
	roster, err := a.Directory.Read(ctx)
	if err != nil {
		return hostclaim.Observed{}, err
	}
	poolSet := map[string]bool{}
	for _, box := range roster.Roster.Boxes {
		if box.Namespace == a.Namespace {
			poolSet[box.Pool] = true
		}
	}
	var pools []string
	for pool := range poolSet {
		pools = append(pools, pool)
	}
	sort.Strings(pools)
	scope := hostactors.Scope{Namespace: a.Namespace, Regions: regions, Pools: pools, Participants: before.Claim.Op.Participants, ConsoleID: a.ConsoleID}
	if err = a.StartDelete(ctx, before, r); err != nil {
		return hostclaim.Observed{}, err
	}
	// Ruling 86: a delete passes the completion box it verified dead.
	fenced, err := a.completionFence(ctx, before.Claim)
	if err != nil {
		return hostclaim.Observed{}, err
	}
	return a.startHeldClaim(ctx, before, id, scope, func() error {
		if err := a.StartDelete(ctx, before, r); err != nil {
			return err
		}
		fresh, err := a.admission(ctx, r.Holder.Account, r.Holder.App)
		if err != nil {
			return err
		}
		if fresh.Value.AppID != admission.Value.AppID || fresh.Value.State != "closed" || fresh.Value.Op == nil || fresh.Value.Op.ID != id || fresh.Value.Op.Kind != "deleting" || fresh.Value.Op.Intent["host"] != r.Holder.Host {
			return ErrPending
		}
		return nil
	}, hostclaim.BeginDelete(id, by, r.ETag, a.Now(), regions, boxes, fenced))
}