//go:build linux && rootrunner

package host

import (
	"encoding/json"
	"os"
	"sort"
	"strconv"
	"strings"
	"testing"

	"github.com/carlosframework/platform/internal/lease/leasetest"
)

type lifecycleRemoteCheckpoint struct {
	Boot, Snapshot string
	Objects        []seedRebootObject
}

func lifecycleSaveBucket(t *testing.T, model *leasetest.VersionedBucket) {
	t.Helper()
	boot, err := os.ReadFile("/proc/sys/kernel/random/boot_id")
	lifecycleCheck(t, "checkpoint boot", err)
	saved := lifecycleRemoteCheckpoint{Boot: strings.TrimSpace(string(boot)), Snapshot: model.Snapshot()}
	versions, err := model.ListVersions(t.Context(), "data", "")
	lifecycleCheck(t, "checkpoint versions", err)
	for _, version := range versions {
		object := seedRebootObject{Version: version}
		if !version.DeleteMarker {
			object.Body, err = model.GetVersion(t.Context(), "data", version.Key, version.VersionID)
			lifecycleCheck(t, "checkpoint bytes", err)
		}
		saved.Objects = append(saved.Objects, object)
	}
	raw, err := json.Marshal(saved)
	lifecycleCheck(t, "checkpoint JSON", err)
	lifecycleCheck(t, "checkpoint remote service", os.WriteFile(lifecycleHome+"/remote.json", raw, 0600))
}

func lifecycleRestoreBucket(t *testing.T, model *leasetest.VersionedBucket) {
	t.Helper()
	raw, err := os.ReadFile(lifecycleHome + "/remote.json")
	lifecycleCheck(t, "read remote checkpoint", err)
	var saved lifecycleRemoteCheckpoint
	lifecycleCheck(t, "decode remote checkpoint", json.Unmarshal(raw, &saved))
	boot, err := os.ReadFile("/proc/sys/kernel/random/boot_id")
	lifecycleCheck(t, "read reboot identity", err)
	if saved.Boot == "" || saved.Boot == strings.TrimSpace(string(boot)) {
		t.Fatal("lifecycle runner did not reboot")
	}
	sort.Slice(saved.Objects, func(i, j int) bool {
		a, _ := strconv.Atoi(strings.TrimPrefix(saved.Objects[i].Version.VersionID, "v"))
		b, _ := strconv.Atoi(strings.TrimPrefix(saved.Objects[j].Version.VersionID, "v"))
		return a < b
	})
	next := 1
	for _, object := range saved.Objects {
		n, err := strconv.Atoi(strings.TrimPrefix(object.Version.VersionID, "v"))
		lifecycleCheck(t, "version number", err)
		for next < n {
			id := model.Put("data", "checkpoint-gap", nil)
			lifecycleCheck(t, "preserve version gap", model.DeleteVersion(t.Context(), "data", "checkpoint-gap", id))
			next++
		}
		var id string
		if object.Version.DeleteMarker {
			id = model.BareDelete("data", object.Version.Key)
		} else {
			id = model.Put("data", object.Version.Key, object.Body)
		}
		if id != object.Version.VersionID {
			t.Fatal("remote version identity changed", id, object.Version.VersionID)
		}
		next++
	}
	if model.Snapshot() != saved.Snapshot {
		t.Fatal("remote state changed across reboot")
	}
}