//go:build windows

package main

import (
	"bufio"
	"context"
	"fmt"
	"io"
	"os"
	"os/exec"
	"sync"
	"syscall"
	"testing"
	"time"
)

func TestNativeProcessHelper(t *testing.T) {
	if os.Getenv("AP_OWNED_HELPER") != "1" {
		t.Skip("helper child only")
	}
	fmt.Fprintln(os.Stdout, "READY")
	io.Copy(io.Discard, os.Stdin)
	os.Exit(0)
}
func startOwnedHelper(t *testing.T) (uint32, func()) {
	t.Helper()
	exe, err := os.Executable()
	if err != nil {
		t.Fatal(err)
	}
	ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
	cmd := exec.CommandContext(ctx, exe, "-test.run=^TestNativeProcessHelper$")
	cmd.Env = append(os.Environ(), "AP_OWNED_HELPER=1")
	cmd.SysProcAttr = &syscall.SysProcAttr{CreationFlags: 0x08000000}
	input, err := cmd.StdinPipe()
	if err != nil {
		cancel()
		t.Fatal(err)
	}
	output, err := cmd.StdoutPipe()
	if err != nil {
		input.Close()
		cancel()
		t.Fatal(err)
	}
	if err = cmd.Start(); err != nil {
		input.Close()
		cancel()
		t.Fatal(err)
	}
	var once sync.Once
	stop := func() { once.Do(func() { input.Close(); cmd.Wait(); cancel() }) }
	t.Cleanup(stop)
	line, err := bufio.NewReader(output).ReadString('\n')
	if err != nil || line != "READY\n" {
		t.Fatalf("owned helper did not start: %v", err)
	}
	return uint32(cmd.Process.Pid), stop
}
func requireNativeProcesses(t *testing.T) {
	t.Helper()
	if os.Getenv("AP_NATIVE_PROCESSES") != "1" {
		t.Skip("opt-in, test-owned children only; never enumerates other processes")
	}
}
func TestNativeOwnedProcessRightsIdentityAndLifetime(t *testing.T) {
	requireNativeProcesses(t)
	pid, stop := startOwnedHelper(t)
	backend := newWindowsBackend()
	// The system-wide enumerator is intentionally NEVER called in native tests.
	backend.list = func() ([]procInfo, error) { return []procInfo{{PID: pid, Name: "OwnedHelper.exe"}}, nil }
	snap, err := backend.Snapshot()
	if err != nil || len(snap.Processes) != 1 {
		t.Fatalf("owned snapshot failed: %v", err)
	}
	p := snap.Processes[0]
	defer backend.Close(&p)
	if p.Key.Created == 0 || p.RSS == 0 || p.Name == "" || !p.Waitable {
		t.Fatal("incomplete owned-process metadata")
	}
	alive, err := backend.Alive(&p)
	if err != nil || !alive {
		t.Fatal("live helper not recognized", err)
	}
	if err = setPrio(p.Handle, p.PID, p.Prio); err == nil {
		t.Fatal("snapshot handle unexpectedly grants SET_INFORMATION")
	}
	original := p.Prio
	bad := p
	bad.Key.Created++
	if err = backend.SetPriority(&bad, PriorityClassHigh); err == nil {
		t.Fatal("identity mismatch did not prevent write")
	}
	now, err := backend.Priority(&p)
	if err != nil || now != original {
		t.Fatal("identity check changed priority")
	}
	if err = backend.SetPriority(&p, PriorityClassBelowNormal); err != nil {
		t.Fatal(err)
	}
	now, err = backend.Priority(&p)
	if err != nil || now != PriorityClassBelowNormal {
		t.Fatal("owned priority write not observed", err)
	}
	// Do not request REALTIME in native tests. The child is about to terminate.
	stop()
	alive, err = backend.Alive(&p)
	if err != nil || alive {
		t.Fatal("signaled process handle not recognized as exited", err)
	}
}
func TestNativeControllerRestoresOwnedChild(t *testing.T) {
	requireNativeProcesses(t)
	pid, _ := startOwnedHelper(t)
	backend := newWindowsBackend()
	backend.list = func() ([]procInfo, error) { return []procInfo{{PID: pid, Name: "OwnedHelper.exe"}}, nil }
	initial, err := backend.inspect(procInfo{PID: pid})
	if err != nil {
		t.Fatal(err)
	}
	defer backend.Close(&initial)
	// Establish a known, non-realtime baseline on this test-owned child.
	if err = backend.SetPriority(&initial, PriorityClassBelowNormal); err != nil {
		t.Fatal(err)
	}
	c := newController(backend, 1, 0, false, time.Minute)
	r := c.Step()
	if len(r.Errors) != 0 {
		c.Shutdown()
		t.Fatal(r.Errors)
	}
	actual, err := backend.Priority(&initial)
	if err != nil || actual != PriorityClassHigh {
		c.Shutdown()
		t.Fatal("promotion failed", err)
	}
	r = c.Shutdown()
	if r.Unrestored != 0 || len(r.Errors) != 0 {
		t.Fatal(r)
	}
	actual, err = backend.Priority(&initial)
	if err != nil || actual != PriorityClassBelowNormal {
		t.Fatal("baseline not restored", err)
	}
}