package host

import (
	"context"
	"encoding/json"
	"strings"

	"github.com/carlosframework/platform/internal/hostactors"
	"github.com/carlosframework/platform/internal/hostbox"
	"github.com/carlosframework/platform/internal/hostevidence"
	"github.com/carlosframework/platform/internal/release"
)

func readMigrationStop(ctx context.Context, store release.Store, directory hostactors.Directory, launches *hostbox.LaunchJournal, inventory *hostbox.StopInventoryDB, launch hostbox.LaunchInventory) (StopResult, error) {
	target := launch.Target
	in, err := inventory.ReadExactStopInventory(ctx, target)
	if err != nil {
		return StopResult{}, err
	}
	journal, err := launches.ReadStopKernelJournal(ctx, target)
	if err != nil {
		return StopResult{}, err
	}
	if err := legacyJournalProof(store, directory)(ctx, launch, in, journal); err != nil {
		return StopResult{}, err
	}
	roster, err := directory.Read(ctx)
	if err != nil {
		return StopResult{}, err
	}
	actor, ok := roster.Roster.Boxes[target.Box]
	if !ok || actor.Enrollment != target.Enrollment {
		return StopResult{}, hostbox.ErrLegacyJournalProof
	}
	prefix := strings.TrimSuffix(stopEvidenceKey(target.Host, target.Op, target.Box, ""), ".json")
	keys, err := store.List(ctx, prefix)
	if err != nil {
		return StopResult{}, err
	}
	wanted := StopReceipt{Host: target.Host, Incarnation: target.Incarnation, InstallationStamp: target.Stamp, WriterSession: target.Session, Box: target.Box, Enrollment: target.Enrollment, BootID: target.BootID, ControllerID: target.ControllerID, OperationID: target.Op, Region: target.Region, Binding: in.DirectoryRevision, InventorySHA256: digestStop(in), LocalJournalSHA256: digestStop(journal)}
	for _, key := range keys {
		if !strings.HasPrefix(key, prefix) || !strings.HasSuffix(key, ".json") {
			continue
		}
		raw, _, err := store.Get(ctx, key)
		if err != nil {
			return StopResult{}, err
		}
		signature, _, err := store.Get(ctx, key+".sig")
		if err != nil {
			continue
		}
		if hostevidence.Verify(actor.CensusPublicKey, key, raw, signature) != nil {
			continue
		}
		var p StopReceipt
		if json.Unmarshal(raw, &p) != nil || p.V != 1 || p.Kind != "stopped" || p.ID == "" || p.FenceID == "" || p.ClaimGen == 0 || p.ObservedBootID == "" || p.EvidenceAt.IsZero() || len(p.CgroupIdentities) == 0 || p.RequestLimitNS != int64(hostbox.RequestLimit) || key != prefix+p.ID+".json" || legacyJournalProofMatch(p) != legacyJournalProofMatch(wanted) || p.Phase != target.Phase || p.ObligationID != target.ObligationID {
			continue
		}
		numeral, ok := receiptRosterRevision(p.DirectoryRevision)
		if !ok {
			continue
		}
		target.FenceID, target.ClaimGen, target.ClaimETag, target.RosterRevision = p.FenceID, p.ClaimGen, p.ClaimETag, numeral
		return StopResult{Target: target, Key: key, Digest: digestRawStop(raw), Bytes: raw, EvidenceAt: p.EvidenceAt}, nil
	}
	return StopResult{}, hostbox.ErrLegacyJournalProof
}