// SPDX-License-Identifier: GPL-3.0-or-later

package ebpfsource

import (
	"bytes"
	"encoding/binary"
	"testing"
)

func TestDecodeExecSample(t *testing.T) {
	raw := execEventRaw{PID: 42, PPID: 7, UID: 1000}
	copyCString(raw.ParentComm[:], "nginx")
	copyCString(raw.Filename[:], "/bin/bash")
	copyCString(raw.Arg1[:], "-c")
	copyCString(raw.Arg2[:], "id")
	var sample bytes.Buffer
	if err := binary.Write(&sample, binary.NativeEndian, raw); err != nil {
		t.Fatal(err)
	}

	event, err := decodeExecSample(sample.Bytes())
	if err != nil {
		t.Fatal(err)
	}
	if event.PID != 42 || event.PPID != 7 || event.UID != 1000 ||
		event.ParentComm != "nginx" || event.Filename != "/bin/bash" ||
		len(event.Argv) != 2 || event.Argv[0] != "-c" || event.Argv[1] != "id" {
		t.Fatalf("unexpected event: %#v", event)
	}
}

func TestDecodeExecSampleRejectsWrongSize(t *testing.T) {
	if _, err := decodeExecSample([]byte{1, 2, 3}); err == nil {
		t.Fatal("expected size error")
	}
}

func TestCStringStopsAtNUL(t *testing.T) {
	if got := cString([]int8{'a', 'b', 0, 'c'}); got != "ab" {
		t.Fatalf("got %q", got)
	}
}

func copyCString(destination []int8, value string) {
	for index, char := range []byte(value) {
		if index >= len(destination)-1 {
			break
		}
		destination[index] = int8(char)
	}
}