// Copyright 2022 CNI authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package ip

import (
	"net"

	. "github.com/onsi/ginkgo/v2"
	. "github.com/onsi/gomega"
)

var _ = Describe("CIDR functions", func() {
	It("NextIP", func() {
		testCases := []struct {
			ip     net.IP
			nextIP net.IP
		}{
			{
				[]byte{192, 0, 2},
				nil,
			},
			{
				net.ParseIP("192.168.0.1"),
				net.IPv4(192, 168, 0, 2).To4(),
			},
			{
				net.ParseIP("192.168.0.255"),
				net.IPv4(192, 168, 1, 0).To4(),
			},
			{
				net.ParseIP("0.1.0.5"),
				net.IPv4(0, 1, 0, 6).To4(),
			},
			{
				net.ParseIP("AB12::123"),
				net.ParseIP("AB12::124"),
			},
			{
				net.ParseIP("AB12::FFFF"),
				net.ParseIP("AB12::1:0"),
			},
			{
				net.ParseIP("0::123"),
				net.ParseIP("0::124"),
			},
		}

		for _, test := range testCases {
			ip := NextIP(test.ip)

			Expect(ip).To(Equal(test.nextIP))
		}
	})

	It("PrevIP", func() {
		testCases := []struct {
			ip     net.IP
			prevIP net.IP
		}{
			{
				[]byte{192, 0, 2},
				nil,
			},
			{
				net.ParseIP("192.168.0.2"),
				net.IPv4(192, 168, 0, 1).To4(),
			},
			{
				net.ParseIP("192.168.1.0"),
				net.IPv4(192, 168, 0, 255).To4(),
			},
			{
				net.ParseIP("0.1.0.5"),
				net.IPv4(0, 1, 0, 4).To4(),
			},
			{
				net.ParseIP("AB12::123"),
				net.ParseIP("AB12::122"),
			},
			{
				net.ParseIP("AB12::1:0"),
				net.ParseIP("AB12::FFFF"),
			},
			{
				net.ParseIP("0::124"),
				net.ParseIP("0::123"),
			},
		}

		for _, test := range testCases {
			ip := PrevIP(test.ip)

			Expect(ip).To(Equal(test.prevIP))
		}
	})

	It("Cmp", func() {
		testCases := []struct {
			a      net.IP
			b      net.IP
			result int
		}{
			{
				net.ParseIP("192.168.0.2"),
				nil,
				-2,
			},
			{
				net.ParseIP("192.168.0.2"),
				[]byte{192, 168, 5},
				-2,
			},
			{
				net.ParseIP("192.168.0.2"),
				net.ParseIP("AB12::123"),
				-2,
			},
			{
				net.ParseIP("192.168.0.2"),
				net.ParseIP("192.168.0.5"),
				-1,
			},
			{
				net.ParseIP("192.168.0.2"),
				net.ParseIP("192.168.0.5").To4(),
				-1,
			},
			{
				net.ParseIP("192.168.0.10"),
				net.ParseIP("192.168.0.5"),
				1,
			},
			{
				net.ParseIP("192.168.0.10"),
				net.ParseIP("192.168.0.10"),
				0,
			},
			{
				net.ParseIP("192.168.0.10"),
				net.ParseIP("192.168.0.10").To4(),
				0,
			},
			{
				net.ParseIP("AB12::122"),
				net.ParseIP("AB12::123"),
				-1,
			},
			{
				net.ParseIP("AB12::210"),
				net.ParseIP("AB12::123"),
				1,
			},
			{
				net.ParseIP("AB12::210"),
				net.ParseIP("AB12::210"),
				0,
			},
		}

		for _, test := range testCases {
			result := Cmp(test.a, test.b)

			Expect(result).To(Equal(test.result))
		}
	})

	It("Network", func() {
		testCases := []struct {
			ipNet  *net.IPNet
			result *net.IPNet
		}{
			{
				nil,
				nil,
			},
			{
				&net.IPNet{
					IP:   nil,
					Mask: net.IPv4Mask(255, 255, 255, 0),
				},
				nil,
			},
			{
				&net.IPNet{
					IP:   net.IPv4(192, 168, 0, 1),
					Mask: nil,
				},
				nil,
			},
			{
				&net.IPNet{
					IP:   net.ParseIP("AB12::123"),
					Mask: net.IPv4Mask(255, 255, 255, 0),
				},
				nil,
			},
			{
				&net.IPNet{
					IP:   net.IPv4(192, 168, 0, 100).To4(),
					Mask: net.CIDRMask(120, 128),
				},
				&net.IPNet{
					IP:   net.IPv4(192, 168, 0, 0).To4(),
					Mask: net.CIDRMask(120, 128),
				},
			},
			{
				&net.IPNet{
					IP:   net.IPv4(192, 168, 0, 100),
					Mask: net.CIDRMask(24, 32),
				},
				&net.IPNet{
					IP:   net.IPv4(192, 168, 0, 0).To4(),
					Mask: net.CIDRMask(24, 32),
				},
			},
			{
				&net.IPNet{
					IP:   net.ParseIP("AB12::123"),
					Mask: net.CIDRMask(120, 128),
				},
				&net.IPNet{
					IP:   net.ParseIP("AB12::100"),
					Mask: net.CIDRMask(120, 128),
				},
			},
		}

		for _, test := range testCases {
			result := Network(test.ipNet)

			Expect(result).To(Equal(test.result))
		}
	})
})