// Copyright 2018 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package enode

import (
	"bytes"
	"crypto/ecdsa"
	"math/big"
	"net"
	"reflect"
	"strings"
	"testing"
	"testing/quick"
)

var parseNodeTests = []struct {
	rawurl     string
	wantError  string
	wantResult *Node
}{
	{
		rawurl:    "http://foobar",
		wantError: `invalid URL scheme, want "enode"`,
	},
	{
		rawurl:    "enode://01010101@123.124.125.126:3",
		wantError: `invalid node ID (wrong length, want 128 hex chars)`,
	},
	// Complete nodes with IP address.
	{
		rawurl:    "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439@hostname:3",
		wantError: `invalid IP address`,
	},
	{
		rawurl:    "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439@127.0.0.1:foo",
		wantError: `invalid port`,
	},
	{
		rawurl:    "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439@127.0.0.1:3?discport=foo",
		wantError: `invalid discport in query`,
	},
	{
		rawurl: "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439@127.0.0.1:52150",
		wantResult: NewV4(
			hexPubkey("1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439"),
			net.IP{0x7f, 0x0, 0x0, 0x1},
			52150,
			52150,
		),
	},
	{
		rawurl: "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439@[::]:52150",
		wantResult: NewV4(
			hexPubkey("1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439"),
			net.ParseIP("::"),
			52150,
			52150,
		),
	},
	{
		rawurl: "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439@[2001:db8:3c4d:15::abcd:ef12]:52150",
		wantResult: NewV4(
			hexPubkey("1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439"),
			net.ParseIP("2001:db8:3c4d:15::abcd:ef12"),
			52150,
			52150,
		),
	},
	{
		rawurl: "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439@127.0.0.1:52150?discport=22334",
		wantResult: NewV4(
			hexPubkey("1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439"),
			net.IP{0x7f, 0x0, 0x0, 0x1},
			52150,
			22334,
		),
	},
	// Incomplete nodes with no address.
	{
		rawurl: "1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439",
		wantResult: NewV4(
			hexPubkey("1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439"),
			nil, 0, 0,
		),
	},
	{
		rawurl: "enode://1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439",
		wantResult: NewV4(
			hexPubkey("1dd9d65c4552b5eb43d5ad55a2ee3f56c6cbc1c64a5c8d659f51fcd51bace24351232b8d7821617d2b29b54b81cdefb9b3e9c37d7fd5f63270bcc9e1a6f6a439"),
			nil, 0, 0,
		),
	},
	// Invalid URLs
	{
		rawurl:    "01010101",
		wantError: `invalid node ID (wrong length, want 128 hex chars)`,
	},
	{
		rawurl:    "enode://01010101",
		wantError: `invalid node ID (wrong length, want 128 hex chars)`,
	},
	{
		// This test checks that errors from url.Parse are handled.
		rawurl:    "://foo",
		wantError: `parse ://foo: missing protocol scheme`,
	},
}

func hexPubkey(h string) *ecdsa.PublicKey {
	k, err := parsePubkey(h)
	if err != nil {
		panic(err)
	}
	return k
}

func TestParseNode(t *testing.T) {
	for _, test := range parseNodeTests {
		n, err := ParseV4(test.rawurl)
		if test.wantError != "" {
			if err == nil {
				t.Errorf("test %q:\n  got nil error, expected %#q", test.rawurl, test.wantError)
				continue
			} else if err.Error() != test.wantError {
				t.Errorf("test %q:\n  got error %#q, expected %#q", test.rawurl, err.Error(), test.wantError)
				continue
			}
		} else {
			if err != nil {
				t.Errorf("test %q:\n  unexpected error: %v", test.rawurl, err)
				continue
			}
			if !reflect.DeepEqual(n, test.wantResult) {
				t.Errorf("test %q:\n  result mismatch:\ngot:  %#v\nwant: %#v", test.rawurl, n, test.wantResult)
			}
		}
	}
}

func TestNodeString(t *testing.T) {
	for i, test := range parseNodeTests {
		if test.wantError == "" && strings.HasPrefix(test.rawurl, "enode://") {
			str := test.wantResult.String()
			if str != test.rawurl {
				t.Errorf("test %d: Node.String() mismatch:\ngot:  %s\nwant: %s", i, str, test.rawurl)
			}
		}
	}
}

func TestHexID(t *testing.T) {
	ref := ID{0, 0, 0, 0, 0, 0, 0, 128, 106, 217, 182, 31, 165, 174, 1, 67, 7, 235, 220, 150, 66, 83, 173, 205, 159, 44, 10, 57, 42, 161, 26, 188}
	id1 := HexID("0x00000000000000806ad9b61fa5ae014307ebdc964253adcd9f2c0a392aa11abc")
	id2 := HexID("00000000000000806ad9b61fa5ae014307ebdc964253adcd9f2c0a392aa11abc")

	if id1 != ref {
		t.Errorf("wrong id1\ngot  %v\nwant %v", id1[:], ref[:])
	}
	if id2 != ref {
		t.Errorf("wrong id2\ngot  %v\nwant %v", id2[:], ref[:])
	}
}

func TestID_textEncoding(t *testing.T) {
	ref := ID{
		0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10,
		0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x20,
		0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x30,
		0x31, 0x32,
	}
	hex := "0102030405060708091011121314151617181920212223242526272829303132"

	text, err := ref.MarshalText()
	if err != nil {
		t.Fatal(err)
	}
	if !bytes.Equal(text, []byte(hex)) {
		t.Fatalf("text encoding did not match\nexpected: %s\ngot:      %s", hex, text)
	}

	id := new(ID)
	if err := id.UnmarshalText(text); err != nil {
		t.Fatal(err)
	}
	if *id != ref {
		t.Fatalf("text decoding did not match\nexpected: %s\ngot:      %s", ref, id)
	}
}

func TestNodeID_distcmp(t *testing.T) {
	distcmpBig := func(target, a, b ID) int {
		tbig := new(big.Int).SetBytes(target[:])
		abig := new(big.Int).SetBytes(a[:])
		bbig := new(big.Int).SetBytes(b[:])
		return new(big.Int).Xor(tbig, abig).Cmp(new(big.Int).Xor(tbig, bbig))
	}
	if err := quick.CheckEqual(DistCmp, distcmpBig, nil); err != nil {
		t.Error(err)
	}
}

// The random tests is likely to miss the case where a and b are equal,
// this test checks it explicitly.
func TestNodeID_distcmpEqual(t *testing.T) {
	base := ID{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}
	x := ID{15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0}
	if DistCmp(base, x, x) != 0 {
		t.Errorf("DistCmp(base, x, x) != 0")
	}
}

func TestNodeID_logdist(t *testing.T) {
	logdistBig := func(a, b ID) int {
		abig, bbig := new(big.Int).SetBytes(a[:]), new(big.Int).SetBytes(b[:])
		return new(big.Int).Xor(abig, bbig).BitLen()
	}
	if err := quick.CheckEqual(LogDist, logdistBig, nil); err != nil {
		t.Error(err)
	}
}

// The random tests is likely to miss the case where a and b are equal,
// this test checks it explicitly.
func TestNodeID_logdistEqual(t *testing.T) {
	x := ID{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}
	if LogDist(x, x) != 0 {
		t.Errorf("LogDist(x, x) != 0")
	}
}