package wireguard

import (
	"errors"
	"net"
	"testing"

	"github.com/golang/mock/gomock"
	"github.com/qdm12/gluetun/internal/netlink"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func Test_Wireguard_addAddresses(t *testing.T) {
	t.Parallel()

	ipNetOne := &net.IPNet{IP: net.IPv4(1, 2, 3, 4), Mask: net.IPv4Mask(255, 255, 255, 255)}
	ipNetTwo := &net.IPNet{IP: net.ParseIP("::1234"), Mask: net.CIDRMask(64, 128)}

	newLink := func() netlink.Link {
		linkAttrs := netlink.NewLinkAttrs()
		linkAttrs.Name = "a_bridge"
		return &netlink.Bridge{
			LinkAttrs: linkAttrs,
		}
	}

	errDummy := errors.New("dummy")

	testCases := map[string]struct {
		link      netlink.Link
		addrs     []*net.IPNet
		wgBuilder func(ctrl *gomock.Controller, link netlink.Link) *Wireguard
		err       error
	}{
		"success": {
			link:  newLink(),
			addrs: []*net.IPNet{ipNetOne, ipNetTwo},
			wgBuilder: func(ctrl *gomock.Controller, link netlink.Link) *Wireguard {
				netLinker := NewMockNetLinker(ctrl)
				firstCall := netLinker.EXPECT().
					AddrAdd(link, &netlink.Addr{IPNet: ipNetOne}).
					Return(nil)
				netLinker.EXPECT().
					AddrAdd(link, &netlink.Addr{IPNet: ipNetTwo}).
					Return(nil).After(firstCall)
				return &Wireguard{
					netlink: netLinker,
					settings: Settings{
						IPv6: ptrTo(true),
					},
				}
			},
		},
		"first add error": {
			link:  newLink(),
			addrs: []*net.IPNet{ipNetOne, ipNetTwo},
			wgBuilder: func(ctrl *gomock.Controller, link netlink.Link) *Wireguard {
				netLinker := NewMockNetLinker(ctrl)
				netLinker.EXPECT().
					AddrAdd(link, &netlink.Addr{IPNet: ipNetOne}).
					Return(errDummy)
				return &Wireguard{
					netlink: netLinker,
					settings: Settings{
						IPv6: ptrTo(true),
					},
				}
			},
			err: errors.New("dummy: when adding address 1.2.3.4/32 to link a_bridge"),
		},
		"second add error": {
			link:  newLink(),
			addrs: []*net.IPNet{ipNetOne, ipNetTwo},
			wgBuilder: func(ctrl *gomock.Controller, link netlink.Link) *Wireguard {
				netLinker := NewMockNetLinker(ctrl)
				firstCall := netLinker.EXPECT().
					AddrAdd(link, &netlink.Addr{IPNet: ipNetOne}).
					Return(nil)
				netLinker.EXPECT().
					AddrAdd(link, &netlink.Addr{IPNet: ipNetTwo}).
					Return(errDummy).After(firstCall)
				return &Wireguard{
					netlink: netLinker,
					settings: Settings{
						IPv6: ptrTo(true),
					},
				}
			},
			err: errors.New("dummy: when adding address ::1234/64 to link a_bridge"),
		},
		"ignore IPv6": {
			link:  newLink(),
			addrs: []*net.IPNet{ipNetTwo},
			wgBuilder: func(ctrl *gomock.Controller, link netlink.Link) *Wireguard {
				return &Wireguard{
					settings: Settings{
						IPv6: ptrTo(false),
					},
				}
			},
		},
	}

	for name, testCase := range testCases {
		testCase := testCase
		t.Run(name, func(t *testing.T) {
			t.Parallel()
			ctrl := gomock.NewController(t)

			wg := testCase.wgBuilder(ctrl, testCase.link)

			err := wg.addAddresses(testCase.link, testCase.addrs)

			if testCase.err != nil {
				require.Error(t, err)
				assert.Equal(t, testCase.err.Error(), err.Error())
			} else {
				require.NoError(t, err)
			}
		})
	}
}