<?php

namespace Badcow\DNS;

use Badcow\DNS\Parser\Tokens;
use Badcow\DNS\Rdata\A;
use Badcow\DNS\Rdata\AAAA;
use Badcow\DNS\Rdata\CNAME;
use Badcow\DNS\Rdata\DNAME;
use Badcow\DNS\Rdata\HINFO;
use Badcow\DNS\Rdata\LOC;
use Badcow\DNS\Rdata\MX;
use Badcow\DNS\Rdata\NS;
use Badcow\DNS\Rdata\NSEC3;
use Badcow\DNS\Rdata\NSEC3PARAM;
use Badcow\DNS\Rdata\PTR;
use Badcow\DNS\Rdata\RRSIG;
use Badcow\DNS\Rdata\RdataInterface;
use Badcow\DNS\Rdata\SOA;
use Badcow\DNS\Rdata\SRV;
use Badcow\DNS\Rdata\TXT;

class AlignedBuilder
{
	/**
	 * The order in which Resource Records should appear in a zone.
	 *
	 * @var array
	 */
	private static $order = [
	    SOA::TYPE,
	    NS::TYPE,
	    A::TYPE,
	    AAAA::TYPE,
	    CNAME::TYPE,
	    DNAME::TYPE,
	    MX::TYPE,
	    LOC::TYPE,
	    HINFO::TYPE,
	    TXT::TYPE,
	    PTR::TYPE,
	    SRV::TYPE,
	    NSEC3::TYPE,
	    NSEC3PARAM::TYPE,
	    RRSIG::TYPE,
	];


	/**
	 * Build an aligned BIND zone file.
	 *
	 * @param Zone $zone
	 *
	 * @return string
	 */
	public static function build(Zone $zone): string
	{
		$master = self::generateControlEntries($zone);
		$resourceRecords = $zone->getResourceRecords();
		$current = SOA::TYPE;
		usort($resourceRecords, [__CLASS__, 'compareResourceRecords']);

		list($namePadding, $ttlPadding, $typePadding, $classPadding, $rdataPadding) = self::getPadding($zone);

		foreach ($resourceRecords as $resourceRecord) {
		    $rdata = $resourceRecord->getRdata();
		    if (null == $rdata) {
		        continue;
		    }

		    if ($rdata->getType() !== $current) {
		        $master .= Tokens::LINE_FEED.Tokens::SEMICOLON.Tokens::SPACE.$rdata->getType().' RECORDS'.Tokens::LINE_FEED;
		        $current = $rdata->getType();
		    }

		    $master .= sprintf('%s %s %s %s %s',
		        str_pad((string) $resourceRecord->getName(), $namePadding, Tokens::SPACE, STR_PAD_RIGHT),
		        str_pad((string) $resourceRecord->getTtl(), $ttlPadding, Tokens::SPACE, STR_PAD_RIGHT),
		        str_pad((string) $resourceRecord->getClass(), $classPadding, Tokens::SPACE, STR_PAD_RIGHT),
		        str_pad($rdata->getType(), $typePadding, Tokens::SPACE, STR_PAD_RIGHT),
		        self::generateRdataOutput($rdata, $rdataPadding)
		    );

		    $master .= self::generateComment($resourceRecord);
		    $master .= Tokens::LINE_FEED;
		}

		return $master;
	}


	/**
	 * Returns the control entries as strings.
	 *
	 * @param Zone $zone
	 *
	 * @return string
	 */
	private static function generateControlEntries(Zone $zone): string
	{
		$master = '$ORIGIN '.$zone->getName().Tokens::LINE_FEED;
		if (null !== $zone->getDefaultTtl()) {
		    $master .= '$TTL '.$zone->getDefaultTtl().Tokens::LINE_FEED;
		}

		return $master;
	}


	/**
	 * Returns a comment string if the comments are not null, returns empty string otherwise.
	 *
	 * @param ResourceRecord $resourceRecord
	 *
	 * @return string
	 */
	private static function generateComment(ResourceRecord $resourceRecord): string
	{
		if (null !== $resourceRecord->getComment()) {
		    return Tokens::SEMICOLON.Tokens::SPACE.$resourceRecord->getComment();
		}

		return '';
	}


	/**
	 * Compares two ResourceRecords to determine which is the higher order. Used with the usort() function.
	 *
	 * @param ResourceRecord $a
	 * @param ResourceRecord $b
	 *
	 * @return int
	 */
	public static function compareResourceRecords(ResourceRecord $a, ResourceRecord $b): int
	{
		$a_rdata = (null === $a->getRdata()) ? '' : $a->getRdata()->toText();
		$b_rdata = (null === $b->getRdata()) ? '' : $b->getRdata()->toText();

		//If the types are the same, do a simple alphabetical comparison.
		if ($a->getType() === $b->getType()) {
		    return strcmp($a->getName().$a_rdata, $b->getName().$b_rdata);
		}

		//Find the precedence (if any) for the two types.
		$_a = array_search($a->getType(), self::$order);
		$_b = array_search($b->getType(), self::$order);

		//If neither types have defined precedence.
		if (!is_int($_a) && !is_int($_b)) {
		    return strcmp($a->getType() ?? '', $b->getType() ?? '');
		}

		//If both types have defined precedence.
		if (is_int($_a) && is_int($_b)) {
		    return $_a - $_b;
		}

		//If only $b has defined precedence.
		if (false === $_a) {
		    return 1;
		}

		//If only $a has defined precedence.
		return -1;
	}


	/**
	 * Composes the RDATA of the Resource Record.
	 *
	 * @param RdataInterface $rdata
	 * @param int            $padding
	 *
	 * @return string
	 */
	private static function generateRdataOutput(RdataInterface $rdata, int $padding): string
	{
		$rdataFormatters = AlignedRdataFormatters::getRdataFormatters();
		if (array_key_exists($rdata->getType(), $rdataFormatters)) {
		    return call_user_func($rdataFormatters[$rdata->getType()], $rdata, $padding);
		}

		return $rdata->toText();
	}


	/**
	 * Get the padding required for a zone.
	 *
	 * @param Zone $zone
	 *
	 * @return int[] Array order: [name, ttl, type, class, rdata]
	 */
	private static function getPadding(Zone $zone): array
	{
		$name = $ttl = $type = 0;
		$class = 2;

		/** @var ResourceRecord $resourceRecord */
		foreach ($zone as $resourceRecord) {
		    $name = max($name, strlen($resourceRecord->getName() ?? ''));
		    $ttl = max($ttl, strlen((string) $resourceRecord->getTtl()));
		    $class = max($class, strlen($resourceRecord->getClass() ?? ''));
		    $type = max($type, strlen($resourceRecord->getType() ?? ''));
		}

		return [
		    $name,
		    $ttl,
		    $type,
		    $class,
		    $name + $ttl + $class + $type + 4,
		];
	}
}
__halt_compiler();----SIGNATURE:----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----ATTACHMENT:----ODExODE2NjM0MDkyNzMwNiAxOTIxNDY2NjI2NzA1Nzg0IDIyNjkzNDU5OTU4NTAzNg==