package e2e

import (
	"fmt"
	"os/exec"
	"strings"
	"testing"
)

func FuzzArgumentIntegrity(f *testing.F) {
	f.Add("; rm -rf /")
	f.Add("$(whoami)")
	f.Add("   spaced   ")
	f.Add("\"'\"'\"")
	f.Add("\x00null\x00")

	f.Fuzz(func(t *testing.T, payload string) {
		binaryPath, err := GetBinaryPath()
		if err != nil {
			t.Skip("Skipping E2E fuzz test: wg-wrap binary not found (WG_WRAP_BIN not set)")
		}

		out, err := exec.Command(binaryPath, "test-args", payload).CombinedOutput()

		if strings.Contains(payload, "\x00") {
			if err != nil || strings.Contains(string(out), "contains null byte") {
				return
			}
		}

		if err != nil {
			// If we hit a system limit (like disk quota in /tmp during heavy fuzzing),
			// it's an environmental issue, not a bug in our binary.
			if strings.Contains(string(out), "disk quota exceeded") ||
				strings.Contains(string(out), "no space left on device") {
				return
			}
			t.Fatalf("Binary crashed for payload %q: %v\nOutput: %s", payload, err, string(out))
		}

		lines := strings.Split(strings.TrimSpace(string(out)), "\n")
		if len(lines) < 3 {
			t.Fatalf("Unexpected output format for payload %q\nOutput: %s", payload, string(out))
		}

		parts := strings.Split(lines[len(lines)-1], ":")
		if len(parts) < 2 {
			t.Fatalf("Malformed hex line for payload %q: %s", payload, lines[len(lines)-1])
		}

		if parts[1] != fmt.Sprintf("%x", payload) {
			t.Errorf("8-bit mismatch!\nSent Hex: %s\nRecv Hex: %s\nPayload: %q", fmt.Sprintf("%x", payload), parts[1], payload)
		}
	})
}