package e2e

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

// TestCrashRecovery verifies that wg-wrap can recover from a "dirty" state
// where a previous run crashed, leaving behind stale PID and pin files.
func TestCrashRecovery(t *testing.T) {
	binaryPath, err := GetBinaryPath()
	if err != nil {
		t.Skipf("Skipping test: %v", err)
	}

	tmpRuntimeDir := t.TempDir()
	tmpConfigDir := t.TempDir()
	profile := "crash-test"

	// Setup a valid profile config
	profilesDir := filepath.Join(tmpConfigDir, "wg-wrap", "profiles")
	if err := os.MkdirAll(profilesDir, 0755); err != nil {
		t.Fatal(err)
	}
	profileConfPath := filepath.Join(profilesDir, profile+".conf")
	conf := `[Interface]
Address = 10.0.0.2/24
PrivateKey = 0000000000000000000000000000000000000000000000000000000000000000
[Peer]
PublicKey = 0000000000000000000000000000000000000000000000000000000000000000
AllowedIPs = 0.0.0.0/0
Endpoint = 1.1.1.1:51820
`
	if err := os.WriteFile(profileConfPath, []byte(conf), 0644); err != nil {
		t.Fatal(err)
	}

	// 1. Simulate a "Crash" by creating stale state manually.
	// We create a pin file and some PID files for processes that aren't actually running.
	nsPath := filepath.Join(tmpRuntimeDir, "profiles", profile+".ns")
	profilesRuntimeDir := filepath.Join(tmpRuntimeDir, "profiles")
	if err := os.MkdirAll(profilesRuntimeDir, 0755); err != nil {
		t.Fatal(err)
	}

	if err := os.WriteFile(nsPath, []byte("stale-pin"), 0644); err != nil {
		t.Fatal(err)
	}

	pidsDir := filepath.Join(tmpRuntimeDir, "profiles", profile, "pids")
	if err := os.MkdirAll(pidsDir, 0755); err != nil {
		t.Fatal(err)
	}
	// Create a fake PID file for a process that likely doesn't exist (PID 1234567)
	if err := os.WriteFile(filepath.Join(pidsDir, "1234567"), []byte(""), 0644); err != nil {
		t.Fatal(err)
	}

	// 2. Try to run wg-wrap.
	// It should see the stale PID, prune it, realize the namespace is actually dead,
	// and start a fresh tunnel.
	cmd := exec.Command(binaryPath, "--profile", profile, "--", "ls")
	cmd.Env = append(os.Environ(),
		fmt.Sprintf("XDG_RUNTIME_DIR=%s", tmpRuntimeDir),
		fmt.Sprintf("XDG_CONFIG_HOME=%s", tmpConfigDir),
	)

	out, err := cmd.CombinedOutput()
	if err != nil {
		t.Fatalf("wg-wrap failed to recover from stale state: %v\nOutput: %s", err, string(out))
	}

	// 3. Verify it actually started a tunnel (it should have printed "Initializing...")
	if !strings.Contains(string(out), "Initializing WireGuard tunnel") {
		t.Errorf("Expected wg-wrap to initialize a new tunnel, but it didn't. Output: %s", string(out))
	}
}