<?php

declare(strict_types=1);

namespace Ramsey\Uuid\Test\Provider\Node;

use Ramsey\Uuid\Exception\InvalidArgumentException;
use Ramsey\Uuid\Exception\NodeException;
use Ramsey\Uuid\Provider\Node\SystemNodeProvider;
use Ramsey\Uuid\Test\TestCase;
use phpmock\spy\Spy;

use function array_shift;
use function array_walk;
use function gettype;
use function is_array;
use function strlen;
use function vsprintf;

use const GLOB_NOSORT;

/**
 * Tests for the SystemNodeProvider class
 *
 * The class under test make use of various native functions who's output is
 * dictated by which environment PHP runs on. Instead of having to run these
 * tests on each of these environments, the related functions are mocked. The
 * following functions are concerned:
 *
 * - glob
 * - constant
 * - passthru
 * - file_get_contents
 * - ini_get
 *
 * On Linux systems `glob` would normally provide one or more paths were mac
 * address can be retrieved (using `file_get_contents`). On non-linux systems,
 * or when the `glob` fails, `passthru` is used to read the mac address from the
 * command for the relevant environment as provided by `constant('PHP_OS')`.
 *
 * Please note that, in order to have robust tests, (the output of) these
 * functions should ALWAYS be mocked and the amount of times each function
 * should be run should ALWAYS be specified.
 *
 * This will make the tests more verbose but also more bullet-proof.
 */
class SystemNodeProviderTest extends TestCase
{
    private const MOCK_GLOB = 'glob';
    private const MOCK_CONSTANT = 'constant';
    private const MOCK_PASSTHRU = 'passthru';
    private const MOCK_FILE_GET_CONTENTS = 'file_get_contents';
    private const MOCK_INI_GET = 'ini_get';
    private const MOCK_IS_READABLE = 'is_readable';

    private const PROVIDER_NAMESPACE = 'Ramsey\\Uuid\\Provider\\Node';

    /**
     * @var Spy[]
     */
    private $functionProxies = [];

    /**
     * @runInSeparateProcess
     * @preserveGlobalState disabled
     * @dataProvider provideValidNetStatOutput
     */
    public function testGetNodeReturnsSystemNodeFromMacAddress(string $netstatOutput, string $expected): void
    {
        /* Arrange mocks for native functions */
        $this->arrangeMockFunctions(
            null,
            null,
            function () use ($netstatOutput): void {
                echo $netstatOutput;
            },
            'NOT LINUX',
            'nothing disabled'
        );

        /* Act upon the system under test */
        $provider = new SystemNodeProvider();
        $node = $provider->getNode();

        /* Assert the result match expectations */
        $this->assertMockFunctions(null, null, ['netstat -ie 2>&1'], ['PHP_OS'], ['disable_functions']);

        $this->assertSame($expected, $node->toString());

        $message = vsprintf(
            'Node should be a hexadecimal string of 12 characters. Actual node: %s (length: %s)',
            [$node->toString(), strlen($node->toString()),]
        );
        $this->assertMatchesRegularExpression('/^[A-Fa-f0-9]{12}$/', $node->toString(), $message);
    }

    /**
     * @runInSeparateProcess
     * @preserveGlobalState disabled
     * @dataProvider provideInvalidNetStatOutput
     */
    public function testGetNodeShouldNotReturnsSystemNodeForInvalidMacAddress(string $netstatOutput): void
    {
        /* Arrange */
        $this->arrangeMockFunctions(
            null,
            null,
            function () use ($netstatOutput): void {
                echo $netstatOutput;
            },
            'NOT LINUX',
            'nothing disabled'
        );

        /* Act */
        $exception = null;
        $provider = new SystemNodeProvider();

        try {
            $provider->getNode();
        } catch (NodeException $exception) {
            // do nothing
        }

        /* Assert */
        $this->assertMockFunctions(null, null, ['netstat -ie 2>&1'], ['PHP_OS'], ['disable_functions']);
        $this->assertInstanceOf(NodeException::class, $exception);
    }

    /**
     * @runInSeparateProcess
     * @preserveGlobalState disabled
     * @dataProvider provideNotationalFormats
     */
    public function testGetNodeReturnsNodeStrippedOfNotationalFormatting(string $formatted, string $expected): void
    {
        /* Arrange */
        $this->arrangeMockFunctions(
            null,
            null,
            function () use ($formatted): void {
                echo "\n{$formatted}\n";
            },
            'NOT LINUX',
            'nothing disabled'
        );

        /* Act */
        $provider = new SystemNodeProvider();
        $node = $provider->getNode();

        /* Assert */
        $this->assertMockFunctions(null, null, ['netstat -ie 2>&1'], ['PHP_OS'], ['disable_functions']);

        $this->assertSame($expected, $node->toString());
    }

    /**
     * @runInSeparateProcess
     * @preserveGlobalState disabled
     * @dataProvider provideInvalidNotationalFormats
     */
    public function testGetNodeDoesNotAcceptIncorrectNotationalFormatting(string $formatted): void
    {
        /* Arrange */
        $this->arrangeMockFunctions(
            null,
            null,
            function () use ($formatted): void {
                echo "\n{$formatted}\n";
            },
            'NOT LINUX',
            'nothing disabled'
        );

        /* Act */
        $exception = null;
        $provider = new SystemNodeProvider();

        try {
            $provider->getNode();
        } catch (NodeException $exception) {
            // do nothing
        }

        /* Assert */
        $this->assertMockFunctions(null, null, ['netstat -ie 2>&1'], ['PHP_OS'], ['disable_functions']);
        $this->assertInstanceOf(NodeException::class, $exception);
    }

    /**
     * @runInSeparateProcess
     * @preserveGlobalState disabled
     */
    public function testGetNodeReturnsFirstMacAddressFound(): void
    {
        /* Arrange */
        $this->arrangeMockFunctions(
            null,
            null,
            function (): void {
                echo "\nAA-BB-CC-DD-EE-FF\n00-11-22-33-44-55\nFF-11-EE-22-DD-33\n";
            },
            'NOT LINUX',
            'nothing disabled'
        );

        /* Act */
        $provider = new SystemNodeProvider();
        $node = $provider->getNode();

        /* Assert */
        $this->assertMockFunctions(null, null, ['netstat -ie 2>&1'], ['PHP_OS'], ['disable_functions']);

        $this->assertSame('aabbccddeeff', $node->toString());
    }

    /**
     * @runInSeparateProcess
     * @preserveGlobalState disabled
     */
    public function testGetNodeReturnsFalseWhenNodeIsNotFound(): void
    {
        /* Arrange */
        $this->arrangeMockFunctions(
            null,
            null,
            function (): void {
                echo 'some string that does not match the mac address';
            },
            'NOT LINUX',
            'nothing disabled'
        );

        /* Act */
        $exception = null;
        $provider = new SystemNodeProvider();

        try {
            $provider->getNode();
        } catch (NodeException $exception) {
            // do nothing
        }

        /* Assert */
        $this->assertMockFunctions(null, null, ['netstat -ie 2>&1'], ['PHP_OS'], ['disable_functions']);
        $this->assertInstanceOf(NodeException::class, $exception);
    }

    /**
     * @runInSeparateProcess
     * @preserveGlobalState disabled
     */
    public function testGetNodeWillNotExecuteSystemCallIfFailedFirstTime(): void
    {
        /* Arrange */
        $this->arrangeMockFunctions(
            null,
            null,
            function (): void {
                echo 'some string that does not match the mac address';
            },
            'NOT LINUX',
            'nothing disabled'
        );

        /* Act */
        $exception1 = null;
        $exception2 = null;
        $provider = new SystemNodeProvider();

        try {
            $provider->getNode();
        } catch (NodeException $exception1) {
            // do nothing
        }

        try {
            $provider->getNode();
        } catch (NodeException $exception2) {
            // do nothing
        }

        /* Assert */
        $this->assertMockFunctions(null, null, ['netstat -ie 2>&1'], ['PHP_OS'], ['disable_functions']);
        $this->assertInstanceOf(NodeException::class, $exception1);
        $this->assertInstanceOf(NodeException::class, $exception2);
    }

    /**
     * @runInSeparateProcess
     * @preserveGlobalState disabled
     * @dataProvider provideCommandPerOs
     */
    public function testGetNodeGetsNetworkInterfaceConfig(string $os, string $command): void
    {
        /* Arrange */
        $this->arrangeMockFunctions(
            'whatever',
            ['mock address path'],
            'whatever',
            $os,
            'nothing disabled',
            true
        );

        /* Act */
        $exception = null;
        $provider = new SystemNodeProvider();

        try {
            $provider->getNode();
        } catch (NodeException $exception) {
            // do nothing
        }

        /* Assert */
        $globBodyAssert = null;
        $fileGetContentsAssert = null;
        $isReadableAssert = null;
        if ($os === 'Linux') {
            $globBodyAssert = [['/sys/class/net/*/address', GLOB_NOSORT]];
            $fileGetContentsAssert = ['mock address path'];
            $isReadableAssert = $fileGetContentsAssert;
        }
        $this->assertMockFunctions(
            $fileGetContentsAssert,
            $globBodyAssert,
            [$command],
            ['PHP_OS'],
            ['disable_functions'],
            $isReadableAssert
        );

        $this->assertInstanceOf(NodeException::class, $exception);
    }

    /**
     * @runInSeparateProcess
     * @preserveGlobalState disabled
     */
    public function testGetNodeReturnsSameNodeUponSubsequentCalls(): void
    {
        /* Arrange */
        $this->arrangeMockFunctions(
            null,
            null,
            function (): void {
                echo "\nAA-BB-CC-DD-EE-FF\n";
            },
            'NOT LINUX',
            'nothing disabled'
        );

        /* Act */
        $provider = new SystemNodeProvider();
        $node = $provider->getNode();
        $node2 = $provider->getNode();

        /* Assert */
        $this->assertMockFunctions(null, null, ['netstat -ie 2>&1'], ['PHP_OS'], ['disable_functions']);

        $this->assertSame($node->toString(), $node2->toString());
    }

    /**
     * @runInSeparateProcess
     * @preserveGlobalState disabled
     */
    public function testSubsequentCallsToGetNodeDoNotRecallIfconfig(): void
    {
        /* Arrange */
        $this->arrangeMockFunctions(
            null,
            null,
            function (): void {
                echo "\nAA-BB-CC-DD-EE-FF\n";
            },
            'NOT LINUX',
            'nothing disabled'
        );

        /* Act */
        $provider = new SystemNodeProvider();
        $node = $provider->getNode();
        $node2 = $provider->getNode();

        /* Assert */
        $this->assertMockFunctions(null, null, ['netstat -ie 2>&1'], ['PHP_OS'], ['disable_functions']);

        $this->assertSame($node->toString(), $node2->toString());
    }

    /**
     * @runInSeparateProcess
     * @preserveGlobalState disabled
     * @dataProvider provideCommandPerOs
     */
    public function testCallGetsysfsOnLinux(string $os, string $command): void
    {
        /* Arrange */
        $this->arrangeMockFunctions(
            function () {
                static $macs = ["00:00:00:00:00:00\n", "01:02:03:04:05:06\n"];

                return array_shift($macs);
            },
            ['mock address path 1', 'mock address path 2'],
            function (): void {
                echo "\n01-02-03-04-05-06\n";
            },
            $os,
            'nothing disabled',
            true
        );

        /* Act */
        $provider = new SystemNodeProvider();
        $node = $provider->getNode();

        /* Assert */
        $fileGetContentsAssert = null;
        $globBodyAssert = null;
        $passthruBodyAssert = [$command];
        $constantBodyAssert = ['PHP_OS'];
        $iniGetDisableFunctionsAssert = ['disable_functions'];
        $isReadableAssert = null;

        if ($os === 'Linux') {
            $fileGetContentsAssert = [['mock address path 1'], ['mock address path 2']];
            $globBodyAssert = [['/sys/class/net/*/address', GLOB_NOSORT]];
            $passthruBodyAssert = null;
            $constantBodyAssert = ['PHP_OS'];
            $iniGetDisableFunctionsAssert = null;
            $isReadableAssert = $fileGetContentsAssert;
        }
        $this->assertMockFunctions(
            $fileGetContentsAssert,
            $globBodyAssert,
            $passthruBodyAssert,
            $constantBodyAssert,
            $iniGetDisableFunctionsAssert,
            $isReadableAssert
        );

        $this->assertSame('010203040506', $node->toString());
    }

    /**
     * @runInSeparateProcess
     * @preserveGlobalState disabled
     */
    public function testCallGetsysfsOnLinuxWhenGlobReturnsFalse(): void
    {
        /* Arrange */
        $this->arrangeMockFunctions(
            null,
            false,
            function (): void {
                echo "\n01-02-03-04-05-06\n";
            },
            'Linux',
            'nothing disabled'
        );

        /* Act */
        $provider = new SystemNodeProvider();
        $node = $provider->getNode();

        /* Assert */
        $this->assertMockFunctions(
            null,
            [['/sys/class/net/*/address', GLOB_NOSORT]],
            ['netstat -ie 2>&1'],
            ['PHP_OS'],
            ['disable_functions']
        );

        $this->assertSame('010203040506', $node->toString());
    }

    /**
     * @runInSeparateProcess
     * @preserveGlobalState disabled
     */
    public function testCallGetsysfsOnLinuxWhenGlobReturnsEmptyArray(): void
    {
        /* Arrange */
        $this->arrangeMockFunctions(
            null,
            [],
            function (): void {
                echo "\n01-02-03-04-05-06\n";
            },
            'Linux',
            'nothing disabled'
        );

        /* Act */
        $provider = new SystemNodeProvider();
        $node = $provider->getNode();

        /* Assert */
        $this->assertMockFunctions(
            null,
            [['/sys/class/net/*/address', GLOB_NOSORT]],
            ['netstat -ie 2>&1'],
            ['PHP_OS'],
            ['disable_functions']
        );

        $this->assertSame('010203040506', $node->toString());
    }

    /**
     * @runInSeparateProcess
     * @preserveGlobalState disabled
     */
    public function testCallGetsysfsOnLinuxWhenGlobFilesAreNotReadable(): void
    {
        /* Arrange */
        $this->arrangeMockFunctions(
            null,
            ['mock address path 1', 'mock address path 2'],
            function (): void {
                echo "\n01-02-03-04-05-06\n";
            },
            'Linux',
            'nothing disabled',
            false
        );

        /* Act */
        $provider = new SystemNodeProvider();
        $node = $provider->getNode();

        /* Assert */
        $this->assertMockFunctions(
            null,
            [['/sys/class/net/*/address', GLOB_NOSORT]],
            ['netstat -ie 2>&1'],
            ['PHP_OS'],
            ['disable_functions'],
            ['mock address path 1', 'mock address path 2']
        );

        $this->assertSame('010203040506', $node->toString());
    }

    /**
     * @runInSeparateProcess
     * @preserveGlobalState disabled
     */
    public function testGetNodeReturnsFalseWhenPassthruIsDisabled(): void
    {
        /* Arrange */
        $this->arrangeMockFunctions(
            null,
            null,
            null,
            'NOT LINUX',
            'PASSTHRU,some_other_function'
        );

        /* Act */
        $exception = null;
        $provider = new SystemNodeProvider();

        try {
            $provider->getNode();
        } catch (NodeException $exception) {
            // do nothing
        }

        /* Assert */
        $this->assertMockFunctions(
            null,
            null,
            null,
            ['PHP_OS'],
            ['disable_functions']
        );

        $this->assertInstanceOf(NodeException::class, $exception);
    }

    /**
     * Replaces the return value for functions with the given value or callback.
     *
     * @param callback|mixed|null $fileGetContentsBody
     * @param callback|mixed|null $globBody
     * @param callback|mixed|null $passthruBody
     * @param callback|mixed|null $constantBody
     * @param callback|mixed|null $iniGetDisableFunctionsBody
     * @param callback|mixed|null $isReadableBody
     */
    private function arrangeMockFunctions(
        $fileGetContentsBody,
        $globBody,
        $passthruBody,
        $constantBody,
        $iniGetDisableFunctionsBody,
        $isReadableBody = true
    ): void {
        $mockFunction = [
            self::MOCK_FILE_GET_CONTENTS => $fileGetContentsBody,
            self::MOCK_GLOB => $globBody,
            self::MOCK_PASSTHRU => $passthruBody,
            self::MOCK_CONSTANT => $constantBody,
            self::MOCK_INI_GET => $iniGetDisableFunctionsBody,
            self::MOCK_IS_READABLE => $isReadableBody,
        ];

        array_walk($mockFunction, function ($body, $key): void {
            if (!is_callable($body)) {
                $body = function () use ($body) {
                    return $body;
                };
            }

            $spy = new Spy(self::PROVIDER_NAMESPACE, $key, $body);
            $spy->enable();

            $this->functionProxies[$key] = $spy;
        });
    }

    /**
     * Verifies that each function was called exactly once for each assert given.
     *
     * Provide a NULL to assert a function is never called.
     *
     * @param array<int, string>|array<int, array<int,string>>|null $fileGetContentsAssert
     * @param array<int, array<int, int|string>>|null $globBodyAssert
     * @param array<int, string>|array<int, array<int,string>>|null $passthruBodyAssert
     * @param array<int, string>|array<int, array<int,string>>|null $constantBodyAssert
     * @param array<int, string>|array<int, array<int,string>>|null $iniGetDisableFunctionsAssert
     * @param array<int, string>|array<int, array<int,string>>|null $isReadableAssert
     */
    private function assertMockFunctions(
        ?array $fileGetContentsAssert,
        ?array $globBodyAssert,
        ?array $passthruBodyAssert,
        ?array $constantBodyAssert,
        ?array $iniGetDisableFunctionsAssert,
        ?array $isReadableAssert = null
    ): void {
        $mockFunctionAsserts = [
            self::MOCK_FILE_GET_CONTENTS => $fileGetContentsAssert,
            self::MOCK_GLOB => $globBodyAssert,
            self::MOCK_PASSTHRU => $passthruBodyAssert,
            self::MOCK_CONSTANT => $constantBodyAssert,
            self::MOCK_INI_GET => $iniGetDisableFunctionsAssert,
            self::MOCK_IS_READABLE => $isReadableAssert,
        ];

        array_walk($mockFunctionAsserts, function ($asserts, $key): void {
            if ($asserts === null) {
                // Assert the function was never invoked.
                $this->assertEmpty($this->functionProxies[$key]->getInvocations());
            } elseif (is_array($asserts)) {
                // Assert there was at least one invocation for this function.
                $this->assertNotEmpty($this->functionProxies[$key]->getInvocations());

                $invokedArgs = [];
                foreach ($this->functionProxies[$key]->getInvocations() as $invocation) {
                    $invokedArgs[] = $invocation->getArguments();
                }

                foreach ($asserts as $assert) {
                    // Assert these args were used to invoke the function.
                    $assert = is_array($assert) ? $assert : [$assert];
                    $this->assertContains($assert, $invokedArgs);
                }
            } else {
                $error = vsprintf(
                    'Given parameter for %s must be an array or NULL, "%s" given.',
                    [$key, gettype($asserts)]
                );

                throw new InvalidArgumentException($error);
            }
        });
    }

    /**
     * Provides the command that should be executed per supported OS
     *
     * @phpcsSuppress SlevomatCodingStandard.TypeHints.ReturnTypeHint.MissingTraversableTypeHintSpecification
     */
    public function provideCommandPerOs(): array
    {
        return [
            'windows' => ['Windows', 'ipconfig /all 2>&1'],
            'mac' => ['Darwhat', 'ifconfig 2>&1'],
            'linux' => ['Linux', 'netstat -ie 2>&1'],
            'freebsd' => ['FreeBSD', 'netstat -i -f link 2>&1'],
            'anything_else' => ['someotherxyz', 'netstat -ie 2>&1'],
            'Linux when `glob` fails' => ['LIN', 'netstat -ie 2>&1'],
        ];
    }

    /**
     * Values that are NOT parsed to a mac address by the class under test
     *
     * @phpcsSuppress SlevomatCodingStandard.TypeHints.ReturnTypeHint.MissingTraversableTypeHintSpecification
     */
    public function provideInvalidNetStatOutput(): array
    {
        return [
            'Not an octal value' => [
                "The program 'netstat' is currently not installed. " .
                "You can install it by typing:\nsudo apt install net-tools\n",
            ],
            'One character too short' => ["\nA-BB-CC-DD-EE-FF\n"],
            'One tuple too short' => ["\nBB-CC-DD-EE-FF\n"],
            'With colon, with linebreak, without space' => ["\n:AA-BB-CC-DD-EE-FF\n"],
            'With colon, without linebreak, with space' => [' : AA-BB-CC-DD-EE-FF'],
            'With colon, without linebreak, without space' => [':AA-BB-CC-DD-EE-FF'],
            'Without colon, without linebreak, without space' => ['AA-BB-CC-DD-EE-FF'],
            'Without leading linebreak' => ["AA-BB-CC-DD-EE-FF\n"],
            'Without leading whitespace' => ['AA-BB-CC-DD-EE-FF '],
            'Without trailing linebreak' => ["\nAA-BB-CC-DD-EE-FF"],
            'Without trailing whitespace' => [' AA-BB-CC-DD-EE-FF'],
            'All zero MAC address' => ['00-00-00-00-00-00'],
        ];
    }

    /**
     * Provides notations that the class under test should NOT attempt to strip
     *
     * @phpcsSuppress SlevomatCodingStandard.TypeHints.ReturnTypeHint.MissingTraversableTypeHintSpecification
     */
    public function provideInvalidNotationalFormats(): array
    {
        return [
            ['01:23-45-67-89-ab'],
            ['01:23:45-67-89-ab'],
            ['01:23:45:67-89-ab'],
            ['01:23:45:67:89-ab'],
            ['01-23:45:67:89:ab'],
            ['01-23-45:67:89:ab'],
            ['01-23-45-67:89:ab'],
            ['01-23-45-67-89:ab'],
            ['00:00:00:00:00:00'],
        ];
    }

    /**
     * Provides mac addresses that the class under test should strip notational format from
     *
     * @phpcsSuppress SlevomatCodingStandard.TypeHints.ReturnTypeHint.MissingTraversableTypeHintSpecification
     */
    public function provideNotationalFormats(): array
    {
        return [
            ['01-23-45-67-89-ab', '0123456789ab'],
            ['01:23:45:67:89:ab', '0123456789ab'],
        ];
    }

    /**
     * Values that are parsed to a mac address by the class under test
     *
     * @phpcsSuppress SlevomatCodingStandard.TypeHints.ReturnTypeHint.MissingTraversableTypeHintSpecification
     */
    public function provideValidNetStatOutput(): array
    {
        return [
            /* Full output of related command */
            'Full output - Linux' => [<<<'TXT'
                Kernel Interface table
                docker0   Link encap:Ethernet  HWaddr 01:23:45:67:89:ab
                          inet addr:172.17.0.1  Bcast:0.0.0.0  Mask:255.255.0.0
                          UP BROADCAST MULTICAST  MTU:1500  Metric:1
                          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
                          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
                          collisions:0 txqueuelen:0
                          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

                enp3s0    Link encap:Ethernet  HWaddr fe:dc:ba:98:76:54
                          inet addr:10.0.0.1  Bcast:10.0.0.255  Mask:255.255.255.0
                          inet6 addr: ffee::ddcc:bbaa:9988:7766/64 Scope:Link
                          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
                          RX packets:943077 errors:0 dropped:0 overruns:0 frame:0
                          TX packets:2168039 errors:0 dropped:0 overruns:0 carrier:0
                          collisions:0 txqueuelen:1000
                          RX bytes:748596414 (748.5 MB)  TX bytes:2930448282 (2.9 GB)

                lo        Link encap:Local Loopback
                          inet addr:127.0.0.1  Mask:255.0.0.0
                          inet6 addr: ::1/128 Scope:Host
                          UP LOOPBACK RUNNING  MTU:65536  Metric:1
                          RX packets:8302 errors:0 dropped:0 overruns:0 frame:0
                          TX packets:8302 errors:0 dropped:0 overruns:0 carrier:0
                          collisions:0 txqueuelen:1000
                          RX bytes:1094983 (1.0 MB)  TX bytes:1094983 (1.0 MB)
TXT
                , '0123456789ab',
            ],
            'Full output - MacOS' => [<<<'TXT'
                lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
                    options=1203<RXCSUM,TXCSUM,TXSTATUS,SW_TIMESTAMP>
                    inet 127.0.0.1 netmask 0xff000000
                    inet6 ::1 prefixlen 128
                    inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1
                    nd6 options=201<PERFORMNUD,DAD>
                gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280
                stf0: flags=0<> mtu 1280
                EHC29: flags=0<> mtu 0
                XHC20: flags=0<> mtu 0
                EHC26: flags=0<> mtu 0
                aa0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
                    options=10b<RXCSUM,TXCSUM,VLAN_HWTAGGING,AV>
                    ether 00:00:00:00:00:00
                    status: active
                en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
                    options=10b<RXCSUM,TXCSUM,VLAN_HWTAGGING,AV>
                    ether 10:dd:b1:b4:e4:8e
                    inet6 fe80::c70:76f5:aa1:5db1%en0 prefixlen 64 secured scopeid 0x7
                    inet 10.53.8.112 netmask 0xfffffc00 broadcast 10.53.11.255
                    nd6 options=201<PERFORMNUD,DAD>
                    media: autoselect (1000baseT <full-duplex>)
                    status: active
                en1: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
                    ether ec:35:86:38:c8:c2
                    inet6 fe80::aa:d44f:5f5f:7fd4%en1 prefixlen 64 secured scopeid 0x8
                    inet 10.53.17.196 netmask 0xfffffc00 broadcast 10.53.19.255
                    nd6 options=201<PERFORMNUD,DAD>
                    media: autoselect
                    status: active
                p2p0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 2304
                    ether 0e:35:86:38:c8:c2
                    media: autoselect
                    status: inactive
                awdl0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1484
                    ether ea:ab:ae:25:f5:d0
                    inet6 fe80::e8ab:aeff:fe25:f5d0%awdl0 prefixlen 64 scopeid 0xa
                    nd6 options=201<PERFORMNUD,DAD>
                    media: autoselect
                    status: active
                en2: flags=8963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
                    options=60<TSO4,TSO6>
                    ether 32:00:18:9b:dc:60
                    media: autoselect <full-duplex>
                    status: inactive
                en3: flags=8963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
                    options=60<TSO4,TSO6>
                    ether 32:00:18:9b:dc:61
                    media: autoselect <full-duplex>
                    status: inactive
                bridge0: flags=8822<BROADCAST,SMART,SIMPLEX,MULTICAST> mtu 1500
                    options=63<RXCSUM,TXCSUM,TSO4,TSO6>
                    ether 32:00:18:9b:dc:60
                    Configuration:
                        id 0:0:0:0:0:0 priority 0 hellotime 0 fwddelay 0
                        maxage 0 holdcnt 0 proto stp maxaddr 100 timeout 1200
                        root id 0:0:0:0:0:0 priority 0 ifcost 0 port 0
                        ipfilter disabled flags 0x2
                    member: en2 flags=3<LEARNING,DISCOVER>
                            ifmaxaddr 0 port 11 priority 0 path cost 0
                    member: en3 flags=3<LEARNING,DISCOVER>
                            ifmaxaddr 0 port 12 priority 0 path cost 0
                    media: <unknown type>
                    status: inactive
                utun0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 2000
                    options=6403<RXCSUM,TXCSUM,CHANNEL_IO,PARTIAL_CSUM,ZEROINVERT_CSUM>
                    inet6 fe80::57c6:d692:9d41:d28f%utun0 prefixlen 64 scopeid 0xe
                    nd6 options=201<PERFORMNUD,DAD>
TXT
                , '10ddb1b4e48e',
            ],
            'Full output - Window' => [<<<'TXT'
                Windows IP Configuration

                   Host Name . . . . . . . . . . . . : MSEDGEWIN10
                   Primary Dns Suffix  . . . . . . . :
                   Node Type . . . . . . . . . . . . : Hybrid
                   IP Routing Enabled. . . . . . . . : No
                   WINS Proxy Enabled. . . . . . . . : No
                   DNS Suffix Search List. . . . . . : network.lan

                Some kind of adapter:

                   Connection-specific DNS Suffix  . : network.foo
                   Description . . . . . . . . . . . : Some Adapter
                   Physical Address. . . . . . . . . : 00-00-00-00-00-00

                Ethernet adapter Ethernet:

                   Connection-specific DNS Suffix  . : network.lan
                   Description . . . . . . . . . . . : Intel(R) PRO/1000 MT Desktop Adapter
                   Physical Address. . . . . . . . . : 08-00-27-B8-42-C6
                   DHCP Enabled. . . . . . . . . . . : Yes
                   Autoconfiguration Enabled . . . . : Yes
                   Link-local IPv6 Address . . . . . : fe80::606a:ae33:7ce1:b5e9%3(Preferred)
                   IPv4 Address. . . . . . . . . . . : 10.0.2.15(Preferred)
                   Subnet Mask . . . . . . . . . . . : 255.255.255.0
                   Lease Obtained. . . . . . . . . . : Tuesday, January 30, 2018 11:25:31 PM
                   Lease Expires . . . . . . . . . . : Wednesday, January 31, 2018 11:25:27 PM
                   Default Gateway . . . . . . . . . : 10.0.2.2
                   DHCP Server . . . . . . . . . . . : 10.0.2.2
                   DHCPv6 IAID . . . . . . . . . . . : 34078759
                   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-21-40-72-3F-08-00-27-B8-42-C6
                   DNS Servers . . . . . . . . . . . : 10.0.2.3
                   NetBIOS over Tcpip. . . . . . . . : Enabled

                Tunnel adapter isatap.network.lan:

                   Media State . . . . . . . . . . . : Media disconnected
                   Connection-specific DNS Suffix  . : network.lan
                   Description . . . . . . . . . . . : Microsoft ISATAP Adapter
                   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
                   DHCP Enabled. . . . . . . . . . . : No
                   Autoconfiguration Enabled . . . . : Yes
TXT
                , '080027b842c6',
            ],
            'Full output - FreeBSD' => [<<<'TXT'
                Name    Mtu Network       Address              Ipkts Ierrs Idrop    Opkts Oerrs  Coll
                aa0       0 <Link#0>      00:00:00:00:00:00        0     0     0        0     0     0
                em0    1500 <Link#1>      08:00:27:71:a1:00    65514     0     0    42918     0     0
                em1    1500 <Link#2>      08:00:27:d0:60:a0     1199     0     0      535     0     0
                lo0   16384 <Link#3>      lo0                      4     0     0        4     0     0
TXT
                , '08002771a100',
            ],

            /* The single line that is relevant */
            'Linux  - single line' => ["\ndocker0   Link encap:Ethernet  HWaddr 01:23:45:67:89:ab\n", '0123456789ab'],
            'MacOS  - Single line ' => ["\nether 10:dd:b1:b4:e4:8e\n", '10ddb1b4e48e'],
            'Window - single line' => ["\nPhysical Address. . . . . . . . . : 08-00-27-B8-42-C6\n", '080027b842c6'],

            /* Minimal subsets of the single line to show the differences */
            'with colon, with linebreak, with space' => ["\n : AA-BB-CC-DD-EE-FF\n", 'aabbccddeeff'],
            'without colon, with linebreak, with space' => ["\n AA-BB-CC-DD-EE-FF \n", 'aabbccddeeff'],
            'without colon, with linebreak, without space' => ["\nAA-BB-CC-DD-EE-FF\n", 'aabbccddeeff'],
            'without colon, without linebreak, with space' => [' AA-BB-CC-DD-EE-FF ', 'aabbccddeeff'],

            /* Other accepted variations */
            'Actual mac - 1' => ["\n52:54:00:14:91:69\n", '525400149169'],
            'Actual mac - 2' => ["\n00:16:3e:a9:73:f0\n", '00163ea973f0'],
            'FF:FF:FF:FF:FF:FF' => ["\nFF:FF:FF:FF:FF:FF\n", 'ffffffffffff'],

            /* Incorrect variations that are also accepted */
            'Too long -- extra character' => ["\nABC-01-23-45-67-89\n", 'bc0123456789'],
            'Too long -- extra tuple' => ["\n01-AA-BB-CC-DD-EE-FF\n", '01aabbccddee'],
        ];
    }
}