//go:build linux && rootrunner

package host

import (
	"encoding/json"
	"errors"
	"os"
	"os/exec"
	"strings"
	"testing"

	"github.com/carlosframework/platform/internal/controlsock"
	"github.com/carlosframework/platform/internal/hostguard"
	"github.com/carlosframework/platform/internal/rootstate"
)

const lifecycleCrashPath = "/var/lib/carlos-claims/lifecycle-crash"

func lifecycleCrash(t *testing.T, point string) {
	t.Helper()
	if os.Getenv("PLAN14_LIFECYCLE_CRASH") != point {
		return
	}
	if _, err := os.Stat(lifecycleCrashPath); err == nil {
		return
	} else if !errors.Is(err, os.ErrNotExist) {
		t.Fatal(err)
	}
	state, err := rootstate.Open("/var/lib/carlos-claims", false, false)
	lifecycleCheck(t, "crash checkpoint store", err)
	lifecycleCheck(t, "durable crash checkpoint", state.Write("lifecycle-crash", []byte(point)))
	os.Exit(86)
}

type lifecycleCrashStore struct {
	rootstate.Store
	t *testing.T
}

func (s lifecycleCrashStore) Write(name string, body []byte) error {
	if err := s.Store.Write(name, body); err != nil {
		return err
	}
	if name != lifecycleHost+".json" {
		return nil
	}
	var r struct {
		Installation hostguard.RootInstallation
		Retired      []hostguard.Captured
		Barrier      *hostguard.FenceTarget
		State        struct {
			ActiveStamp uint64 `json:"active_stamp"`
		}
	}
	if err := json.Unmarshal(body, &r); err != nil {
		return err
	}
	if r.Barrier != nil {
		lifecycleCrash(s.t, "handover")
	}
	if r.State.ActiveStamp == 0 && r.Installation.Stamp != 0 && len(r.Retired) != 0 {
		lifecycleCrash(s.t, "retirement")
	}
	return nil
}

func lifecycleControlFaults(t *testing.T) {
	original := openClaimRootAuthority
	openClaimRootAuthority = func() (rootstate.Store, error) {
		s, err := original()
		if err != nil {
			return nil, err
		}
		return lifecycleCrashStore{s, t}, nil
	}
	t.Cleanup(func() { openClaimRootAuthority = original })
}

func lifecycleStartControl(t *testing.T, endpoint string) func() {
	t.Helper()
	raw, err := unitsFS.ReadFile("units/carlos-instance-control.service")
	lifecycleCheck(t, "controller template", err)
	var lines []string
	for _, line := range strings.Split(string(raw), "\n") {
		key, _, _ := strings.Cut(line, "=")
		if key == "ExecStart" || key == "Requires" || key == "After" {
			continue
		}
		lines = append(lines, line)
	}
	lines = append(lines, "[Service]", "ExecStart=/opt/carlos/carlos -test.run=^TestPlan14LifecycleControlProcessPayload$ -test.v -test.timeout=12m", "Environment=PLAN14_LIFECYCLE_CONTROL=1", "Environment=PLAN14_LIFECYCLE_CRASH="+os.Getenv("PLAN14_LIFECYCLE_CRASH"), "Environment=CARLOS_S3_ENDPOINT="+endpoint, "ReadWritePaths=/data /opt/carlos /var/lib/carlos-claims /var/lib/carlos-release /sys/fs/cgroup "+lifecycleHome, "RestrictAddressFamilies=", "RestrictAddressFamilies=AF_UNIX AF_INET", "MemoryMax=512M", "StandardOutput=append:"+lifecycleHome+"/controller.log", "StandardError=append:"+lifecycleHome+"/controller.log")
	path := "/run/systemd/system/carlos-instance-control.service"
	f, err := os.OpenFile(path, os.O_CREATE|os.O_EXCL|os.O_WRONLY, 0644)
	lifecycleCheck(t, "exclusive controller unit", err)
	_, err = f.WriteString(strings.Join(lines, "\n"))
	f.Close()
	lifecycleCheck(t, "controller unit", err)
	out, err := exec.Command("systemctl", "daemon-reload").CombinedOutput()
	lifecycleCheck(t, string(out), err)
	start := func() {
		exec.Command("systemctl", "stop", "carlos-instance-control.service").Run()
		os.Remove("/run/carlos-control/lifecycle-ready")
		os.Remove(controlsock.Path)
		out, err := exec.Command("systemctl", "start", "carlos-instance-control.service").CombinedOutput()
		lifecycleCheck(t, string(out), err)
	}
	t.Cleanup(func() {
		exec.Command("systemctl", "stop", "carlos-instance-control.service").Run()
		os.Remove(path)
		exec.Command("systemctl", "daemon-reload").Run()
		body, _ := os.ReadFile(lifecycleHome + "/controller.log")
		t.Logf("controller log: %s", body)
	})
	start()
	return start
}