package host

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

	"github.com/carlosframework/platform/internal/release"
	"github.com/carlosframework/platform/internal/rootstate"
)

type rootHistoryMaintenance struct {
	readback   func(context.Context, release.HistoryBinding, func(context.Context) (release.HistoryMigrationStatus, error)) error
	history    *release.RootHistory
	store      release.Store
	source     *proofBindingSource
	checks     rootRestartChecks
	pub        func() (ed25519.PublicKey, error)
	projection func() (rootstate.Store, error)
	now        func() time.Time
}

func (m rootHistoryMaintenance) run(ctx context.Context, b release.HistoryBinding) error {
	resolveContext := func(ctx context.Context, want release.HistoryBinding) (string, error) {
		_, got, _, err := m.source.unitBinding(ctx, want.Host)
		if err != nil {
			return "", err
		}
		if got.Route.Account != want.Account || got.Route.App != want.App {
			return "", os.ErrPermission
		}
		return got.Source, nil
	}
	resolve := func(want release.HistoryBinding) (string, error) { return resolveContext(ctx, want) }
	sources := release.HistoryRecoverySources{}
	defer func() {
		projection, err := m.projection()
		if err == nil {
			err = m.history.ProjectMigrationStatus(projection, b, resolve, sources)
			projection.Close()
		}
		if err != nil {
			log.Print(err)
		}
		if m.readback != nil {
			err := m.readback(ctx, b, func(readbackCtx context.Context) (release.HistoryMigrationStatus, error) {
				readbackResolve := func(want release.HistoryBinding) (string, error) { return resolveContext(readbackCtx, want) }
				return m.history.MigrationStatusWithSources(b, readbackResolve, sources)
			})
			if err != nil {
				log.Print(err)
			}
		}
	}()
	unresolved, err := m.checks.copyRecoveryHistory(m.history, b)
	sources.Known, sources.Unresolved = err == nil, unresolved
	if err != nil {
		return err
	}
	pub, err := m.pub()
	if err != nil {
		return err
	}
	now := m.now()
	if err := m.history.ReceiveReconstruction(ctx, m.store, pub, b, now, resolve); err != nil {
		return err
	}
	if err := m.history.ReceiveRecoveryRetirements(ctx, m.store, pub, b, now, resolve); err != nil {
		return err
	}
	return checkUnresolvedRecoveries(m.history, unresolved)
}