package daemon

import (
	"encoding/json"
	"errors"
	"fmt"
	"net"
	"os"
	"path/filepath"
	"runtime"
	"strings"
	"syscall"
	"testing"
	"time"

	"github.com/kunchenguid/no-mistakes/internal/ipc"
	"github.com/kunchenguid/no-mistakes/internal/paths"
)

type failingRenameError string

func (e failingRenameError) Error() string { return string(e) }

func writeDaemonPIDRecord(t *testing.T, path string, record daemonPIDFile) {
	t.Helper()
	data, err := json.Marshal(record)
	if err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(path, data, 0o644); err != nil {
		t.Fatal(err)
	}
}

func TestWaitForDaemonStopKeepsArtifactsWhenKillFails(t *testing.T) {
	tmpDir, err := os.MkdirTemp("", "dtest")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	p := paths.WithRoot(tmpDir)
	if err := p.EnsureDirs(); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(p.PIDFile(), []byte("999999"), 0o644); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(p.Socket(), []byte("still-there"), 0o644); err != nil {
		t.Fatal(err)
	}

	originalHealthCheck := daemonHealthCheck
	daemonHealthCheck = func(*paths.Paths) (bool, error) {
		return true, nil
	}
	defer func() {
		daemonHealthCheck = originalHealthCheck
	}()

	started := time.Now()
	err = waitForDaemonStop(p)
	if err == nil {
		t.Fatal("expected waitForDaemonStop to fail when kill fails")
	}
	if time.Since(started) < 5*time.Second {
		t.Fatalf("waitForDaemonStop returned too early after %v", time.Since(started))
	}
	if _, err := os.Stat(p.PIDFile()); err != nil {
		t.Fatalf("expected pid file to remain after failed kill, got err=%v", err)
	}
	if _, err := os.Stat(p.Socket()); err != nil {
		t.Fatalf("expected socket file to remain after failed kill, got err=%v", err)
	}
}

func TestDaemonStartTimeoutDefaultsToLongerWindowOnWindows(t *testing.T) {
	t.Setenv("NM_TEST_DAEMON_START_TIMEOUT", "")
	oldGOOS := runtimeGOOS
	runtimeGOOS = "windows"
	t.Cleanup(func() { runtimeGOOS = oldGOOS })

	if got := daemonStartTimeout(); got != 15*time.Second {
		t.Fatalf("daemonStartTimeout() = %v, want 15s", got)
	}
}

func TestEnsureDaemonDoesNotStartWhenHealthCheckTimesOut(t *testing.T) {
	tmpDir, err := os.MkdirTemp("", "dtest")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	p := paths.WithRoot(tmpDir)
	timeoutErr := fmt.Errorf("dial ipc: %w", &ipc.ConnectTimeoutError{
		SocketPath:      p.Socket(),
		TimeoutDuration: 25 * time.Millisecond,
		Err:             errors.New("dial timeout"),
	})

	originalHealthCheck := daemonHealthCheck
	daemonHealthCheck = func(*paths.Paths) (bool, error) {
		return false, timeoutErr
	}
	defer func() {
		daemonHealthCheck = originalHealthCheck
	}()

	originalStart := daemonStart
	started := false
	daemonStart = func(*paths.Paths) error {
		started = true
		return nil
	}
	defer func() {
		daemonStart = originalStart
	}()

	startedAt := time.Now()
	err = EnsureDaemon(p)
	elapsed := time.Since(startedAt)
	if err == nil {
		t.Fatal("EnsureDaemon returned nil for timed-out daemon socket")
	}
	if elapsed > 250*time.Millisecond {
		t.Fatalf("EnsureDaemon took %v, want fast failure", elapsed)
	}
	if started {
		t.Fatal("EnsureDaemon started a daemon after a connect timeout")
	}
	if !strings.Contains(err.Error(), p.Socket()) {
		t.Fatalf("EnsureDaemon error = %q, want socket path %q", err.Error(), p.Socket())
	}
}

func TestIsRunningFailsFastWhenSocketAcceptsButDoesNotRespond(t *testing.T) {
	if runtime.GOOS == "windows" {
		t.Skip("unix socket setup is platform-specific")
	}

	tmpDir, err := os.MkdirTemp("", "dtest")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	p := paths.WithRoot(tmpDir)
	if err := p.EnsureDirs(); err != nil {
		t.Fatal(err)
	}
	ln, err := net.Listen("unix", p.Socket())
	if err != nil {
		t.Fatal(err)
	}
	defer ln.Close()

	accepted := make(chan net.Conn, 1)
	go func() {
		conn, err := ln.Accept()
		if err != nil {
			return
		}
		accepted <- conn
	}()
	t.Cleanup(func() {
		select {
		case conn := <-accepted:
			_ = conn.Close()
		default:
		}
	})

	type result struct {
		alive bool
		err   error
	}
	done := make(chan result, 1)
	go func() {
		alive, err := IsRunning(p)
		done <- result{alive: alive, err: err}
	}()

	select {
	case got := <-done:
		if got.alive {
			t.Fatal("silent socket must not be reported running")
		}
		if got.err == nil {
			t.Fatal("expected a clear health-check error from silent socket")
		}
	case <-time.After(time.Second):
		t.Fatal("IsRunning hung on a silent daemon socket")
	}
}

func TestIsRunningSurfacesExistingDeadSocket(t *testing.T) {
	if runtime.GOOS == "windows" {
		t.Skip("unix socket setup is platform-specific")
	}

	tmpDir, err := os.MkdirTemp("", "dtest")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	p := paths.WithRoot(tmpDir)
	if err := p.EnsureDirs(); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(p.Socket(), []byte("dead"), 0o644); err != nil {
		t.Fatal(err)
	}

	alive, err := IsRunning(p)
	if alive {
		t.Fatal("dead socket must not be reported running")
	}
	if err == nil || !strings.Contains(err.Error(), "connect to daemon socket") {
		t.Fatalf("err = %v, want clear dead-socket connection error", err)
	}
}

func TestStopDetachedDaemonFallsBackToPIDWhenSocketIsBroken(t *testing.T) {
	if runtime.GOOS == "windows" {
		t.Skip("unix socket setup is platform-specific")
	}

	tmpDir, err := os.MkdirTemp("", "dtest")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	p := paths.WithRoot(tmpDir)
	if err := p.EnsureDirs(); err != nil {
		t.Fatal(err)
	}
	const pid = 424242
	startedAt := time.Date(2026, 4, 20, 10, 0, 0, 0, time.UTC)
	writeDaemonPIDRecord(t, p.PIDFile(), daemonPIDFile{PID: pid, StartedAt: startedAt})
	ln, err := net.Listen("unix", p.Socket())
	if err != nil {
		t.Fatal(err)
	}
	defer ln.Close()

	originalDial := daemonDial
	daemonDial = func(string) (*ipc.Client, error) {
		return nil, fmt.Errorf("transient ipc failure")
	}
	defer func() {
		daemonDial = originalDial
	}()
	originalProcessRunning := daemonProcessRunning
	runningChecks := 0
	daemonProcessRunning = func(checkPID int) (bool, error) {
		if checkPID != pid {
			t.Fatalf("processRunning pid = %d, want %d", checkPID, pid)
		}
		runningChecks++
		return runningChecks == 1, nil
	}
	defer func() {
		daemonProcessRunning = originalProcessRunning
	}()
	originalProcessStartTime := daemonProcessStartTime
	daemonProcessStartTime = func(checkPID int) (time.Time, error) {
		if checkPID != pid {
			t.Fatalf("processStartTime pid = %d, want %d", checkPID, pid)
		}
		return startedAt, nil
	}
	defer func() {
		daemonProcessStartTime = originalProcessStartTime
	}()
	originalKillPID := daemonKillPID
	killedPID := 0
	daemonKillPID = func(killPID int) error {
		killedPID = killPID
		return nil
	}
	defer func() {
		daemonKillPID = originalKillPID
	}()

	if err := stopDetachedDaemon(p); err != nil {
		t.Fatalf("expected stopDetachedDaemon to stop live pid when IPC dial fails, got %v", err)
	}
	if killedPID != pid {
		t.Fatalf("expected pid fallback to kill pid %d, got %d", pid, killedPID)
	}
	if runningChecks == 0 {
		t.Fatal("expected pid fallback to check process state")
	}
	if _, statErr := os.Stat(p.PIDFile()); !os.IsNotExist(statErr) {
		t.Fatalf("expected pid file to be removed after PID fallback, got err=%v", statErr)
	}
	if _, statErr := os.Stat(p.Socket()); !os.IsNotExist(statErr) {
		t.Fatalf("expected socket file to be removed after PID fallback, got err=%v", statErr)
	}
}

func TestStopDetachedDaemonRejectsStalePIDFallback(t *testing.T) {
	if runtime.GOOS == "windows" {
		t.Skip("unix socket setup is platform-specific")
	}

	tmpDir, err := os.MkdirTemp("", "dtest")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	p := paths.WithRoot(tmpDir)
	if err := p.EnsureDirs(); err != nil {
		t.Fatal(err)
	}
	writeDaemonPIDRecord(t, p.PIDFile(), daemonPIDFile{PID: os.Getpid(), StartedAt: time.Now().Add(-24 * time.Hour)})
	ln, err := net.Listen("unix", p.Socket())
	if err != nil {
		t.Fatal(err)
	}
	defer ln.Close()

	originalDial := daemonDial
	daemonDial = func(string) (*ipc.Client, error) {
		return nil, fmt.Errorf("transient ipc failure")
	}
	defer func() {
		daemonDial = originalDial
	}()
	originalKillPID := daemonKillPID
	killCalled := false
	daemonKillPID = func(int) error {
		killCalled = true
		return nil
	}
	defer func() {
		daemonKillPID = originalKillPID
	}()

	err = stopDetachedDaemon(p)
	if err == nil {
		t.Fatal("expected stale pid fallback to fail")
	}
	if killCalled {
		t.Fatal("expected stale pid fallback to avoid killing the process")
	}
	if _, statErr := os.Stat(p.PIDFile()); statErr != nil {
		t.Fatalf("expected pid file to remain after rejected pid fallback, got err=%v", statErr)
	}
	if _, statErr := os.Stat(p.Socket()); statErr != nil {
		t.Fatalf("expected socket file to remain after rejected pid fallback, got err=%v", statErr)
	}
}

func TestStopDetachedDaemonRejectsUnrelatedLiveProcessPIDFallback(t *testing.T) {
	if runtime.GOOS == "windows" {
		t.Skip("unix socket setup is platform-specific")
	}

	tmpDir, err := os.MkdirTemp("", "dtest")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	p := paths.WithRoot(tmpDir)
	if err := p.EnsureDirs(); err != nil {
		t.Fatal(err)
	}
	writeDaemonPIDRecord(t, p.PIDFile(), daemonPIDFile{PID: os.Getpid(), StartedAt: time.Now()})
	ln, err := net.Listen("unix", p.Socket())
	if err != nil {
		t.Fatal(err)
	}
	defer ln.Close()

	originalDial := daemonDial
	daemonDial = func(string) (*ipc.Client, error) {
		return nil, fmt.Errorf("transient ipc failure")
	}
	defer func() {
		daemonDial = originalDial
	}()
	originalProcessStartTime := daemonProcessStartTime
	daemonProcessStartTime = func(checkPID int) (time.Time, error) {
		if checkPID != os.Getpid() {
			t.Fatalf("processStartTime pid = %d, want %d", checkPID, os.Getpid())
		}
		return time.Now().Add(-time.Hour), nil
	}
	defer func() {
		daemonProcessStartTime = originalProcessStartTime
	}()
	originalKillPID := daemonKillPID
	killCalled := false
	daemonKillPID = func(int) error {
		killCalled = true
		return nil
	}
	defer func() {
		daemonKillPID = originalKillPID
	}()

	err = stopDetachedDaemon(p)
	if err == nil {
		t.Fatal("expected unrelated live process pid fallback to fail")
	}
	if killCalled {
		t.Fatal("expected unrelated live process pid fallback to avoid killing the process")
	}
	if _, statErr := os.Stat(p.PIDFile()); statErr != nil {
		t.Fatalf("expected pid file to remain after rejected pid fallback, got err=%v", statErr)
	}
	if _, statErr := os.Stat(p.Socket()); statErr != nil {
		t.Fatalf("expected socket file to remain after rejected pid fallback, got err=%v", statErr)
	}
}

// TestValidateDaemonPIDFallback_RefusesToKillOwnProcess covers the crash
// behind an intermittent Windows CI hang: helpers_test.go's startTestDaemon
// runs the daemon in-process via a goroutine (daemon.RunWithResources), so
// the pid file it writes records the test binary's own pid. If the daemon
// doesn't confirm a graceful stop before waitForDaemonStop's deadline, the
// PID-kill fallback must never target that pid - doing so kills the test
// binary itself (SIGKILL on the current process), which surfaces as the
// whole package crashing with no per-test PASS/FAIL output rather than a
// normal test failure. The pid file record here is otherwise fully valid
// (matching StartedAt) to prove the self-pid guard fires before, and
// independent of, the record/staleness checks.
func TestValidateDaemonPIDFallback_RefusesToKillOwnProcess(t *testing.T) {
	tmpDir, err := os.MkdirTemp("", "dtest")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	p := paths.WithRoot(tmpDir)
	if err := p.EnsureDirs(); err != nil {
		t.Fatal(err)
	}
	startedAt := time.Now()
	writeDaemonPIDRecord(t, p.PIDFile(), daemonPIDFile{PID: os.Getpid(), StartedAt: startedAt})

	originalProcessStartTime := daemonProcessStartTime
	daemonProcessStartTime = func(checkPID int) (time.Time, error) {
		if checkPID != os.Getpid() {
			t.Fatalf("processStartTime pid = %d, want %d", checkPID, os.Getpid())
		}
		return startedAt, nil
	}
	defer func() {
		daemonProcessStartTime = originalProcessStartTime
	}()

	err = validateDaemonPIDFallback(p, os.Getpid())
	if err == nil {
		t.Fatal("expected validateDaemonPIDFallback to refuse killing our own pid")
	}
	if !strings.Contains(err.Error(), "our own pid") {
		t.Fatalf("err = %v, want a clear self-kill refusal", err)
	}
}

func TestValidateDaemonPIDFallback_RejectsLegacyPIDFileForReusedPID(t *testing.T) {
	tmpDir, err := os.MkdirTemp("", "dtest")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	p := paths.WithRoot(tmpDir)
	if err := p.EnsureDirs(); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(p.PIDFile(), []byte(fmt.Sprintf("%d", os.Getpid())), 0o644); err != nil {
		t.Fatal(err)
	}

	old := daemonProcessStartTime
	daemonProcessStartTime = func(checkPID int) (time.Time, error) {
		if checkPID != os.Getpid() {
			t.Fatalf("processStartTime pid = %d, want %d", checkPID, os.Getpid())
		}
		return time.Now().Add(-time.Hour), nil
	}
	t.Cleanup(func() {
		daemonProcessStartTime = old
	})

	err = validateDaemonPIDFallback(p, os.Getpid())
	if err == nil {
		t.Fatal("expected legacy pid fallback to reject reused pid")
	}
}

func TestValidateDaemonPIDFallback_RejectsLegacyPIDFileTouchedNearLivePID(t *testing.T) {
	tmpDir, err := os.MkdirTemp("", "dtest")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	p := paths.WithRoot(tmpDir)
	if err := p.EnsureDirs(); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(p.PIDFile(), []byte(fmt.Sprintf("%d", os.Getpid())), 0o644); err != nil {
		t.Fatal(err)
	}
	mtime := time.Date(2026, 4, 20, 10, 0, 0, 0, time.UTC)
	if err := os.Chtimes(p.PIDFile(), mtime, mtime); err != nil {
		t.Fatal(err)
	}

	oldStartTime := daemonProcessStartTime
	oldHealth := daemonHealthCheck
	daemonProcessStartTime = func(checkPID int) (time.Time, error) {
		if checkPID != os.Getpid() {
			t.Fatalf("processStartTime pid = %d, want %d", checkPID, os.Getpid())
		}
		return mtime.Add(time.Second), nil
	}
	daemonHealthCheck = func(*paths.Paths) (bool, error) {
		return false, nil
	}
	t.Cleanup(func() {
		daemonProcessStartTime = oldStartTime
		daemonHealthCheck = oldHealth
	})

	err = validateDaemonPIDFallback(p, os.Getpid())
	if err == nil {
		t.Fatal("expected legacy pid fallback to reject timestamp-only matches")
	}
}

func TestWaitForProcessExitRetriesTransientInspectionErrors(t *testing.T) {
	originalProcessRunning := daemonProcessRunning
	checks := 0
	daemonProcessRunning = func(pid int) (bool, error) {
		if pid != 4242 {
			t.Fatalf("daemonProcessRunning pid = %d, want 4242", pid)
		}
		checks++
		switch checks {
		case 1:
			return false, fmt.Errorf("transient failure")
		case 2:
			return true, nil
		default:
			return false, nil
		}
	}
	t.Cleanup(func() {
		daemonProcessRunning = originalProcessRunning
	})

	waitForProcessExit(4242, 50*time.Millisecond)

	if checks < 3 {
		t.Fatalf("waitForProcessExit stopped after %d checks, want at least 3", checks)
	}
}

func TestCurrentDaemonPIDRecord_UsesProcessStartTime(t *testing.T) {
	want := time.Date(2026, 4, 20, 10, 0, 0, 0, time.UTC)
	now := want.Add(10 * time.Second)

	record, err := currentDaemonPIDRecord(func(pid int) (time.Time, error) {
		if pid != os.Getpid() {
			t.Fatalf("processStartTime pid = %d, want %d", pid, os.Getpid())
		}
		return want, nil
	}, func() time.Time {
		return now
	})
	if err != nil {
		t.Fatalf("currentDaemonPIDRecord returned error: %v", err)
	}
	if record.PID != os.Getpid() {
		t.Fatalf("record pid = %d, want %d", record.PID, os.Getpid())
	}
	if !record.StartedAt.Equal(want) {
		t.Fatalf("record started_at = %v, want %v", record.StartedAt, want)
	}
}

func TestWriteDaemonPIDFile_LeavesExistingFileUntouchedOnRenameFailure(t *testing.T) {
	tmpDir := t.TempDir()
	path := filepath.Join(tmpDir, "daemon.pid")
	original := []byte("old-data")
	if err := os.WriteFile(path, original, 0o644); err != nil {
		t.Fatal(err)
	}

	oldRename := renameDaemonPIDFile
	renameDaemonPIDFile = func(_, _ string) error {
		return failingRenameError("rename failed")
	}
	t.Cleanup(func() {
		renameDaemonPIDFile = oldRename
	})

	err := writeDaemonPIDFile(path, daemonPIDFile{PID: 12345, StartedAt: time.Date(2026, 4, 20, 10, 0, 0, 0, time.UTC)})
	if err == nil {
		t.Fatal("expected writeDaemonPIDFile to fail when rename fails")
	}
	data, readErr := os.ReadFile(path)
	if readErr != nil {
		t.Fatalf("read pid file: %v", readErr)
	}
	if string(data) != string(original) {
		t.Fatalf("pid file changed after failed atomic write: got %q want %q", string(data), string(original))
	}
	matches, globErr := filepath.Glob(filepath.Join(tmpDir, "daemon.pid.tmp-*"))
	if globErr != nil {
		t.Fatalf("glob temp files: %v", globErr)
	}
	if len(matches) != 0 {
		t.Fatalf("expected temp files to be cleaned up, got %v", matches)
	}
}

func TestStopDetachedDaemonRemovesArtifactsForDeadPID(t *testing.T) {
	if runtime.GOOS == "windows" {
		t.Skip("unix socket setup is platform-specific")
	}

	tmpDir, err := os.MkdirTemp("", "dtest")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	p := paths.WithRoot(tmpDir)
	if err := p.EnsureDirs(); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(p.PIDFile(), []byte("999999"), 0o644); err != nil {
		t.Fatal(err)
	}
	fd, err := syscall.Socket(syscall.AF_UNIX, syscall.SOCK_STREAM, 0)
	if err != nil {
		t.Fatal(err)
	}
	addr := &syscall.SockaddrUnix{Name: p.Socket()}
	if err := syscall.Bind(fd, addr); err != nil {
		_ = syscall.Close(fd)
		t.Fatal(err)
	}
	if err := syscall.Close(fd); err != nil {
		t.Fatal(err)
	}

	originalDial := daemonDial
	daemonDial = func(string) (*ipc.Client, error) {
		return nil, fmt.Errorf("transient ipc failure")
	}
	defer func() {
		daemonDial = originalDial
	}()

	if err := stopDetachedDaemon(p); err != nil {
		t.Fatalf("expected stopDetachedDaemon to clean stale artifacts, got %v", err)
	}
	if _, statErr := os.Stat(p.PIDFile()); !os.IsNotExist(statErr) {
		t.Fatalf("expected stale pid file to be removed, got err=%v", statErr)
	}
	if _, statErr := os.Stat(p.Socket()); !os.IsNotExist(statErr) {
		t.Fatalf("expected stale socket file to be removed, got err=%v", statErr)
	}
}

func TestStaleDaemonArtifactsKeepsPIDForLiveProcessWithoutSocket(t *testing.T) {
	tmpDir, err := os.MkdirTemp("", "dtest")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	p := paths.WithRoot(tmpDir)
	if err := p.EnsureDirs(); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(p.PIDFile(), []byte(fmt.Sprintf("%d", os.Getpid())), 0o644); err != nil {
		t.Fatal(err)
	}

	stale, err := staleDaemonArtifacts(p)
	if err != nil {
		t.Fatalf("staleDaemonArtifacts returned error: %v", err)
	}
	if stale {
		t.Fatal("expected live pid without socket to be treated as non-stale")
	}
}

func TestStaleDaemonArtifactsKeepsRegularEndpointFileForLiveProcess(t *testing.T) {
	tmpDir, err := os.MkdirTemp("", "dtest")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	p := paths.WithRoot(tmpDir)
	if err := p.EnsureDirs(); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(p.PIDFile(), []byte(fmt.Sprintf("%d", os.Getpid())), 0o644); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(p.Socket(), []byte("127.0.0.1:1234\ntoken\n"), 0o600); err != nil {
		t.Fatal(err)
	}

	original := daemonEndpointUsesRegularFile
	daemonEndpointUsesRegularFile = func() bool { return true }
	defer func() {
		daemonEndpointUsesRegularFile = original
	}()

	stale, err := staleDaemonArtifacts(p)
	if err != nil {
		t.Fatalf("staleDaemonArtifacts returned error: %v", err)
	}
	if stale {
		t.Fatal("expected live pid with regular endpoint file to be treated as non-stale")
	}
}

func TestStopDetachedDaemonKeepsArtifactsWhenPIDMissingButDaemonLooksLive(t *testing.T) {
	if runtime.GOOS == "windows" {
		t.Skip("unix socket setup is platform-specific")
	}

	tmpDir, err := os.MkdirTemp("", "dtest")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	p := paths.WithRoot(tmpDir)
	if err := p.EnsureDirs(); err != nil {
		t.Fatal(err)
	}
	ln, err := net.Listen("unix", p.Socket())
	if err != nil {
		t.Fatal(err)
	}
	defer ln.Close()

	originalDial := daemonDial
	daemonDial = func(string) (*ipc.Client, error) {
		return nil, fmt.Errorf("transient ipc failure")
	}
	defer func() {
		daemonDial = originalDial
	}()
	err = stopDetachedDaemon(p)
	if err == nil {
		t.Fatal("expected stopDetachedDaemon to fail without a pid file")
	}
	if _, statErr := os.Stat(p.Socket()); statErr != nil {
		t.Fatalf("expected socket file to remain when daemon looks live, got err=%v", statErr)
	}
	if _, statErr := os.Stat(p.PIDFile()); !os.IsNotExist(statErr) {
		t.Fatalf("expected pid file to remain missing, got err=%v", statErr)
	}
}

func TestStaleDaemonArtifactsRejectsNonPositivePID(t *testing.T) {
	tests := []struct {
		name string
		pid  string
	}{
		{name: "zero", pid: "0"},
		{name: "negative", pid: "-1"},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			tmpDir, err := os.MkdirTemp("", "dtest")
			if err != nil {
				t.Fatal(err)
			}
			defer os.RemoveAll(tmpDir)

			p := paths.WithRoot(tmpDir)
			if err := p.EnsureDirs(); err != nil {
				t.Fatal(err)
			}
			if err := os.WriteFile(p.PIDFile(), []byte(tt.pid), 0o644); err != nil {
				t.Fatal(err)
			}

			called := false
			original := daemonProcessRunning
			daemonProcessRunning = func(int) (bool, error) {
				called = true
				return false, nil
			}
			defer func() {
				daemonProcessRunning = original
			}()

			_, err = staleDaemonArtifacts(p)
			if err == nil {
				t.Fatal("expected invalid pid error")
			}
			if !strings.Contains(err.Error(), "invalid") {
				t.Fatalf("error = %q, want invalid pid error", err)
			}
			if called {
				t.Fatal("expected invalid pid to avoid process probe")
			}
		})
	}
}

func TestReadPIDNoFile(t *testing.T) {
	tmpDir, err := os.MkdirTemp("", "dtest")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	p := paths.WithRoot(tmpDir)
	_, err = ReadPID(p)
	if err == nil {
		t.Error("expected error when no PID file")
	}
}

// TestWaitForDaemonStopNeverKillsOwnPIDWhenHealthCheckOnlyErrors reproduces
// the full path behind the Windows CI hang end to end: a daemon that never
// confirms a graceful stop (health check errors on every poll, as observed
// on Windows where a closed loopback listener doesn't fail pending/racing
// connections as immediately as a Unix domain socket unlink does) combined
// with a pid file that records our own pid (the shape startTestDaemon in
// internal/cli/helpers_test.go produces, since it runs the daemon in-process
// via a goroutine). waitForDaemonStop must give up with an error instead of
// ever calling daemonKillPID against the current process.
func TestWaitForDaemonStopNeverKillsOwnPIDWhenHealthCheckOnlyErrors(t *testing.T) {
	tmpDir, err := os.MkdirTemp("", "dtest")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	p := paths.WithRoot(tmpDir)
	if err := p.EnsureDirs(); err != nil {
		t.Fatal(err)
	}
	startedAt := time.Now()
	writeDaemonPIDRecord(t, p.PIDFile(), daemonPIDFile{PID: os.Getpid(), StartedAt: startedAt})
	if err := os.WriteFile(p.Socket(), []byte("still-there"), 0o644); err != nil {
		t.Fatal(err)
	}

	originalHealthCheck := daemonHealthCheck
	daemonHealthCheck = func(*paths.Paths) (bool, error) {
		return false, errors.New("connect to daemon socket timed out")
	}
	defer func() {
		daemonHealthCheck = originalHealthCheck
	}()
	originalProcessStartTime := daemonProcessStartTime
	daemonProcessStartTime = func(checkPID int) (time.Time, error) {
		return startedAt, nil
	}
	defer func() {
		daemonProcessStartTime = originalProcessStartTime
	}()
	originalKillPID := daemonKillPID
	killCalled := false
	daemonKillPID = func(int) error {
		killCalled = true
		return nil
	}
	defer func() {
		daemonKillPID = originalKillPID
	}()

	err = waitForDaemonStop(p)
	if err == nil {
		t.Fatal("expected waitForDaemonStop to fail rather than kill our own pid")
	}
	if !strings.Contains(err.Error(), "our own pid") {
		t.Fatalf("err = %v, want a clear self-kill refusal", err)
	}
	if killCalled {
		t.Fatal("waitForDaemonStop must never kill its own process")
	}
}

func TestWaitForDaemonStopDoesNotTreatHealthCheckErrorsAsStopped(t *testing.T) {
	tmpDir, err := os.MkdirTemp("", "dtest")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	p := paths.WithRoot(tmpDir)
	if err := p.EnsureDirs(); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(p.PIDFile(), []byte("999999"), 0o644); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(p.Socket(), []byte("still-there"), 0o644); err != nil {
		t.Fatal(err)
	}

	originalHealthCheck := daemonHealthCheck
	daemonHealthCheck = func(*paths.Paths) (bool, error) {
		return false, errors.New("transient ipc failure")
	}
	defer func() {
		daemonHealthCheck = originalHealthCheck
	}()

	started := time.Now()
	err = waitForDaemonStop(p)
	if err == nil {
		t.Fatal("expected waitForDaemonStop to fail when health checks only error")
	}
	if time.Since(started) < 5*time.Second {
		t.Fatalf("waitForDaemonStop returned too early after %v", time.Since(started))
	}
	if _, err := os.Stat(p.PIDFile()); err != nil {
		t.Fatalf("expected pid file to remain after health-check errors, got err=%v", err)
	}
	if _, err := os.Stat(p.Socket()); err != nil {
		t.Fatalf("expected socket file to remain after health-check errors, got err=%v", err)
	}
}

func TestWaitForDaemonStopRejectsStalePIDBeforeKill(t *testing.T) {
	tmpDir, err := os.MkdirTemp("", "dtest")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	p := paths.WithRoot(tmpDir)
	if err := p.EnsureDirs(); err != nil {
		t.Fatal(err)
	}
	writeDaemonPIDRecord(t, p.PIDFile(), daemonPIDFile{PID: os.Getpid(), StartedAt: time.Now().Add(-24 * time.Hour)})
	if err := os.WriteFile(p.Socket(), []byte("still-there"), 0o644); err != nil {
		t.Fatal(err)
	}

	originalHealthCheck := daemonHealthCheck
	daemonHealthCheck = func(*paths.Paths) (bool, error) {
		return true, nil
	}
	defer func() {
		daemonHealthCheck = originalHealthCheck
	}()
	originalProcessStartTime := daemonProcessStartTime
	daemonProcessStartTime = func(checkPID int) (time.Time, error) {
		if checkPID != os.Getpid() {
			t.Fatalf("processStartTime pid = %d, want %d", checkPID, os.Getpid())
		}
		return time.Now(), nil
	}
	defer func() {
		daemonProcessStartTime = originalProcessStartTime
	}()
	originalKillPID := daemonKillPID
	killCalled := false
	daemonKillPID = func(int) error {
		killCalled = true
		return nil
	}
	defer func() {
		daemonKillPID = originalKillPID
	}()

	started := time.Now()
	err = waitForDaemonStop(p)
	if err == nil {
		t.Fatal("expected waitForDaemonStop to fail for stale pid")
	}
	if time.Since(started) < 5*time.Second {
		t.Fatalf("waitForDaemonStop returned too early after %v", time.Since(started))
	}
	if killCalled {
		t.Fatal("expected stale pid to avoid killing the process")
	}
	if _, err := os.Stat(p.PIDFile()); err != nil {
		t.Fatalf("expected pid file to remain after rejected kill, got err=%v", err)
	}
	if _, err := os.Stat(p.Socket()); err != nil {
		t.Fatalf("expected socket file to remain after rejected kill, got err=%v", err)
	}
}

func TestReadPIDInvalid(t *testing.T) {
	tmpDir, err := os.MkdirTemp("", "dtest")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	p := paths.WithRoot(tmpDir)
	os.WriteFile(filepath.Join(tmpDir, "daemon.pid"), []byte("notanumber"), 0o644)
	_, err = ReadPID(p)
	if err == nil {
		t.Error("expected error for invalid PID content")
	}
}

func TestReadPIDRejectsNonPositiveValues(t *testing.T) {
	tests := []struct {
		name string
		pid  string
	}{
		{name: "zero", pid: "0"},
		{name: "negative", pid: "-1"},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			tmpDir, err := os.MkdirTemp("", "dtest")
			if err != nil {
				t.Fatal(err)
			}
			defer os.RemoveAll(tmpDir)

			p := paths.WithRoot(tmpDir)
			if err := os.WriteFile(filepath.Join(tmpDir, "daemon.pid"), []byte(tt.pid), 0o644); err != nil {
				t.Fatal(err)
			}

			_, err = ReadPID(p)
			if err == nil {
				t.Fatal("expected invalid pid error")
			}
			if !strings.Contains(err.Error(), "invalid") {
				t.Fatalf("error = %q, want invalid pid error", err)
			}
		})
	}
}