package host

import (
	"context"
	"crypto/ed25519"
	"os"
	"time"

	"github.com/carlosframework/platform/internal/historyreadback"
	"github.com/carlosframework/platform/internal/hostactors"
	"github.com/carlosframework/platform/internal/hostfloor"
	"github.com/carlosframework/platform/internal/release"
)

type historyReadbackPublisher struct {
	directory  hostactors.Directory
	enrollment hostfloor.Enrollment
	key        func() (ed25519.PrivateKey, error)
	now        func() time.Time
}

func (p historyReadbackPublisher) publish(ctx context.Context, b release.HistoryBinding, snapshot func(context.Context) (release.HistoryMigrationStatus, error)) error {
	observed, err := p.directory.Read(ctx)
	if err != nil {
		return err
	}
	box, ok := observed.Roster.Boxes[p.enrollment.Box]
	if !ok || box.Enrollment != p.enrollment.Enrollment || p.enrollment.InstanceID == "" || box.Cloud.InstanceID != p.enrollment.InstanceID || p.key == nil || p.now == nil {
		return os.ErrPermission
	}
	key, err := p.key()
	if err != nil {
		return err
	}
	scope := historyreadback.Scope{Bucket: p.directory.Bucket, Box: p.enrollment.Box, Enrollment: p.enrollment.Enrollment, Binding: b}
	return historyreadback.Respond(ctx, p.directory, scope, key, p.now(), snapshot)
}

func publishRootHistoryReadback(ctx context.Context, store release.Store, b release.HistoryBinding, snapshot func(context.Context) (release.HistoryMigrationStatus, error)) error {
	ctx, cancel := context.WithTimeout(ctx, 5*time.Second)
	defer cancel()
	rr, err := readProductionRosterRow(ctx, store, os.Getenv)
	if err != nil {
		return err
	}
	p := historyReadbackPublisher{directory: rr.directory, enrollment: rr.enrollment, key: func() (ed25519.PrivateKey, error) { return readClaimEvidenceKey("/etc/carlos/host-evidence.key") }, now: time.Now}
	return p.publish(ctx, b, snapshot)
}