package aerotun

import (
	"fmt"
	"net"
	"reflect"
	"strings"
	"testing"
)

func TestDefaultRoutePreservesUnderlayAndRollsBack(t *testing.T) {
	for _, fail := range []bool{false, true} {
		t.Run(fmt.Sprint(fail), func(t *testing.T) {
			var calls []string
			r := routeManager{run: func(a ...string) ([]byte, error) {
				cmd := strings.Join(a, " ")
				calls = append(calls, cmd)
				if strings.Contains(cmd, "route get") {
					return []byte(`[{"dev":"eth0","gateway":"192.0.2.1"}]`), nil
				}
				if strings.Contains(cmd, "show exact") {
					return []byte(`[]`), nil
				}
				if fail && strings.Contains(cmd, "add 128.") {
					return nil, fmt.Errorf("route conflict")
				}
				return nil, nil
			}}
			err := r.install("aerotun0", net.ParseIP("203.0.113.10"))
			if (err != nil) != fail {
				t.Fatalf("unexpected result: %v", err)
			}
			if !fail {
				r.cleanup()
			}
			want := []string{"-j -4 route get 203.0.113.10", "-j -4 route show exact 203.0.113.10/32", "-4 route add 203.0.113.10/32 via 192.0.2.1 dev eth0", "-4 route add 0.0.0.0/1 dev aerotun0", "-4 route add 128.0.0.0/1 dev aerotun0"}
			if !fail {
				want = append(want, "-4 route del 128.0.0.0/1 dev aerotun0")
			}
			want = append(want, "-4 route del 0.0.0.0/1 dev aerotun0", "-4 route del 203.0.113.10/32 via 192.0.2.1 dev eth0")
			if !reflect.DeepEqual(calls, want) {
				t.Fatalf("route operations:\n%v\nwant:\n%v", calls, want)
			}
		})
	}
}
func TestValidateConfig(t *testing.T) {
	base := TunnelInstance{Name: "aerotun0", Mode: "client", LocalAddress: "10.99.0.1/24", PeerAddress: "10.99.0.2/24", RemoteEndpoint: "192.0.2.1:51830", PSK: testPSK}
	if err := validateConfig(&base); err != nil {
		t.Fatal(err)
	}
	for _, mutate := range []func(*TunnelInstance){func(c *TunnelInstance) { c.Name = "lo"; c.Mode = "invalid" }, func(c *TunnelInstance) { c.PSK = "short" }, func(c *TunnelInstance) { c.MTU = 65535 }, func(c *TunnelInstance) { c.RemoteEndpoint = "" }, func(c *TunnelInstance) { c.LocalAddress = "bad" }, func(c *TunnelInstance) { c.PeerAddress = c.LocalAddress }, func(c *TunnelInstance) { c.Mode = "server"; c.DefaultRoute = true }} {
		c := base
		mutate(&c)
		if err := validateConfig(&c); err == nil {
			t.Fatalf("invalid config accepted: %+v", c)
		}
	}
}

func TestDefaultRouteLeavesExistingEndpointRoute(t *testing.T) {
	var changes []string
	r := routeManager{run: func(a ...string) ([]byte, error) {
		cmd := strings.Join(a, " ")
		if strings.Contains(cmd, "route get") {
			return []byte(`[{"dev":"eth0","gateway":"192.0.2.1"}]`), nil
		}
		if strings.Contains(cmd, "show exact") {
			return []byte(`[{"dst":"203.0.113.10/32","dev":"eth0"}]`), nil
		}
		changes = append(changes, cmd)
		return nil, nil
	}}
	if err := r.install("aerotun0", net.ParseIP("203.0.113.10")); err != nil {
		t.Fatal(err)
	}
	r.cleanup()
	for _, cmd := range changes {
		if strings.Contains(cmd, "203.0.113.10") {
			t.Fatalf("modified pre-existing endpoint route: %s", cmd)
		}
	}
	if len(changes) != 4 {
		t.Fatalf("expected two additions and two deletions: %v", changes)
	}
}