<?php
/*
** Zabbix
** Copyright (C) 2001-2021 Zabbix SIA
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** This program 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 General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
**/


class CHostImporter extends CImporter {

	/**
	 * @var array		a list of host IDs which were created or updated to create an interface cache for those hosts
	 */
	protected $processedHostIds = [];

	/**
	 * Import hosts.
	 *
	 * @param array $hosts
	 *
	 * @throws Exception
	 */
	public function import(array $hosts) {
		$hostsToCreate = [];
		$hostsToUpdate = [];
		$templateLinkage = [];
		$tmpls_to_clear = [];

		foreach ($hosts as $host) {
			/*
			 * Save linked templates for 2 purposes:
			 *  - save linkages to add in case if 'create new' linkages is checked;
			 *  - calculate missing linkages in case if 'delete missing' is checked.
			 */
			if (!empty($host['templates'])) {
				foreach ($host['templates'] as $template) {
					$templateId = $this->referencer->resolveTemplate($template['name']);
					if (!$templateId) {
						throw new Exception(_s('Template "%1$s" for host "%2$s" does not exist.', $template['name'], $host['host']));
					}
					$templateLinkage[$host['host']][] = ['templateid' => $templateId];
				}
			}
			unset($host['templates']);

			$host = $this->resolveHostReferences($host);

			if (array_key_exists('hostid', $host) && ($this->options['hosts']['updateExisting']
					|| $this->options['process_hosts'])) {
				$hostsToUpdate[] = $host;
			}
			else if ($this->options['hosts']['createMissing']) {
				if (array_key_exists('hostid', $host)) {
					throw new Exception(_s('Host "%1$s" already exists.', $host['host']));
				}

				$hostsToCreate[] = $host;
			}
		}

		// Get template linkages to unlink and clear.
		if ($hostsToUpdate && $this->options['templateLinkage']['deleteMissing']) {
			// Get already linked templates.
			$db_template_links = API::Host()->get([
				'output' => ['hostids'],
				'selectParentTemplates' => ['hostid'],
				'hostids' => zbx_objectValues($hostsToUpdate, 'hostid'),
				'preservekeys' => true
			]);

			foreach ($db_template_links as &$db_template_link) {
				$db_template_link = zbx_objectValues($db_template_link['parentTemplates'], 'templateid');
			}
			unset($db_template_link);

			foreach ($hostsToUpdate as $host) {
				if (array_key_exists($host['host'], $templateLinkage)) {
					$tmpls_to_clear[$host['hostid']] = array_diff($db_template_links[$host['hostid']],
						zbx_objectValues($templateLinkage[$host['host']], 'templateid')
					);
				}
				else {
					$tmpls_to_clear[$host['hostid']] = $db_template_links[$host['hostid']];
				}
			}
		}

		// create/update hosts
		if ($this->options['hosts']['createMissing'] && $hostsToCreate) {
			$newHostIds = API::Host()->create($hostsToCreate);
			foreach ($newHostIds['hostids'] as $hnum => $hostId) {
				$hostHost = $hostsToCreate[$hnum]['host'];
				$this->processedHostIds[$hostHost] = $hostId;

				$this->referencer->addHostRef($hostHost, $hostId);

				if ($this->options['templateLinkage']['createMissing'] && !empty($templateLinkage[$hostHost])) {
					API::Template()->massAdd([
						'hosts' => ['hostid' => $hostId],
						'templates' => $templateLinkage[$hostHost]
					]);
				}
			}
		}

		if ($hostsToUpdate) {
			if ($this->options['hosts']['updateExisting']) {
				$hostsToUpdate = $this->addInterfaceIds($hostsToUpdate);

				API::Host()->update($hostsToUpdate);
			}

			foreach ($hostsToUpdate as $host) {
				$this->processedHostIds[$host['host']] = $host['hostid'];

				// Drop existing template linkages if 'delete missing' selected.
				if (array_key_exists($host['hostid'], $tmpls_to_clear) && $tmpls_to_clear[$host['hostid']]) {
					API::Host()->massRemove([
						'hostids' => [$host['hostid']],
						'templateids_clear' => $tmpls_to_clear[$host['hostid']]
					]);
				}

				// Make new template linkages.
				if ($this->options['templateLinkage']['createMissing'] && !empty($templateLinkage[$host['host']])) {
					API::Template()->massAdd([
						'hosts' => $host,
						'templates' => $templateLinkage[$host['host']]
					]);
				}
			}
		}

		// create interfaces cache interface_ref->interfaceid
		$dbInterfaces = API::HostInterface()->get([
			'hostids' => $this->processedHostIds,
			'output' => API_OUTPUT_EXTEND
		]);

		foreach ($hosts as $host) {
			if (isset($this->processedHostIds[$host['host']])) {
				foreach ($host['interfaces'] as $interface) {
					$hostId = $this->processedHostIds[$host['host']];

					if (!isset($this->referencer->interfacesCache[$hostId])) {
						$this->referencer->interfacesCache[$hostId] = [];
					}

					foreach ($dbInterfaces as $dbInterface) {
						if ($hostId == $dbInterface['hostid']
								&& $dbInterface['ip'] == $interface['ip']
								&& $dbInterface['dns'] == $interface['dns']
								&& $dbInterface['useip'] == $interface['useip']
								&& $dbInterface['port'] == $interface['port']
								&& $dbInterface['type'] == $interface['type']
								&& $dbInterface['main'] == $interface['main']
								&& (!isset($interface['bulk']) || $dbInterface['bulk'] == $interface['bulk'])) {
							$refName = $interface['interface_ref'];
							$this->referencer->interfacesCache[$hostId][$refName] = $dbInterface['interfaceid'];
						}
					}
				}
			}
		}
	}

	/**
	 * Get a list of created or updated host IDs.
	 *
	 * @return array
	 */
	public function getProcessedHostIds() {
		return $this->processedHostIds;
	}

	/**
	 * Change all references in host to database ids.
	 *
	 * @throws Exception
	 *
	 * @param array $host
	 *
	 * @return array
	 */
	protected function resolveHostReferences(array $host) {
		foreach ($host['groups'] as $gnum => $group) {
			$groupId = $this->referencer->resolveGroup($group['name']);
			if (!$groupId) {
				throw new Exception(_s('Group "%1$s" for host "%2$s" does not exist.', $group['name'], $host['host']));
			}
			$host['groups'][$gnum] = ['groupid' => $groupId];
		}

		if (isset($host['proxy'])) {
			if (empty($host['proxy'])) {
				$proxyId = 0;
			}
			else {
				$proxyId = $this->referencer->resolveProxy($host['proxy']['name']);
				if (!$proxyId) {
					throw new Exception(_s('Proxy "%1$s" for host "%2$s" does not exist.', $host['proxy']['name'], $host['host']));
				}
			}

			$host['proxy_hostid'] = $proxyId;
		}

		if ($hostId = $this->referencer->resolveHost($host['host'])) {
			$host['hostid'] = $hostId;

			if (array_key_exists('macros', $host)) {
				foreach ($host['macros'] as &$macro) {
					if ($hostMacroId = $this->referencer->resolveMacro($hostId, $macro['macro'])) {
						$macro['hostmacroid'] = $hostMacroId;
					}
				}
				unset($macro);
			}
		}


		return $host;
	}

	/**
	 * For existing hosts we need to set an interfaceid for existing interfaces or they will be added.
	 *
	 * @param array $xmlHosts    hosts from XML for which interfaces will be added
	 *
	 * @return array
	 */
	protected function addInterfaceIds(array $xmlHosts) {
		$dbInterfaces = API::HostInterface()->get([
			'hostids' => zbx_objectValues($xmlHosts, 'hostid'),
			'output' => API_OUTPUT_EXTEND,
			'preservekeys' => true
		]);

		// build lookup maps for:
		// - interfaces per host
		// - default (primary) interface ids per host per interface type
		$dbHostInterfaces = [];
		$dbHostMainInterfaceIds = [];

		foreach ($dbInterfaces as $dbInterface) {
			$dbHostId = $dbInterface['hostid'];

			$dbHostInterfaces[$dbHostId][] = $dbInterface;
			if ($dbInterface['main'] == INTERFACE_PRIMARY) {
				$dbHostMainInterfaceIds[$dbHostId][$dbInterface['type']] = $dbInterface['interfaceid'];
			}
		}

		foreach ($xmlHosts as &$xmlHost) {
			// if interfaces in XML are empty then do not touch existing interfaces
			if (!$xmlHost['interfaces']) {
				unset($xmlHost['interfaces']);
				continue;
			}

			$xmlHostId = $xmlHost['hostid'];

			$currentDbHostMainInterfaceIds = isset($dbHostMainInterfaceIds[$xmlHostId])
				? $dbHostMainInterfaceIds[$xmlHostId]
				: [];

			$reusedInterfaceIds = [];

			foreach ($xmlHost['interfaces'] as &$xmlHostInterface) {
				$xmlHostInterfaceType = $xmlHostInterface['type'];

				// check if an existing interfaceid from current host can be reused
				// in case there is default (primary) interface in current host with same type
				if ($xmlHostInterface['main'] == INTERFACE_PRIMARY
						&& isset($currentDbHostMainInterfaceIds[$xmlHostInterfaceType])) {
					$dbHostInterfaceId = $currentDbHostMainInterfaceIds[$xmlHostInterfaceType];

					$xmlHostInterface['interfaceid'] = $dbHostInterfaceId;
					$reusedInterfaceIds[$dbHostInterfaceId] = true;
				}
			}
			unset($xmlHostInterface);

			// loop through all interfaces of current host and take interfaceids from ones that
			// match completely, ignoring hosts from XML with set interfaceids and ignoring hosts
			// from DB with reused interfaceids
			foreach ($xmlHost['interfaces'] as &$xmlHostInterface) {
				foreach ($dbHostInterfaces[$xmlHostId] as $dbHostInterface) {
					$dbHostInterfaceId = $dbHostInterface['interfaceid'];

					if (!isset($xmlHostInterface['interfaceid']) && !isset($reusedInterfaceIds[$dbHostInterfaceId])
							&& $dbHostInterface['ip'] == $xmlHostInterface['ip']
							&& $dbHostInterface['dns'] == $xmlHostInterface['dns']
							&& $dbHostInterface['useip'] == $xmlHostInterface['useip']
							&& $dbHostInterface['port'] == $xmlHostInterface['port']
							&& $dbHostInterface['type'] == $xmlHostInterface['type']
							&& (!isset($xmlHostInterface['bulk'])
								|| $dbHostInterface['bulk'] == $xmlHostInterface['bulk'])) {
						$xmlHostInterface['interfaceid'] = $dbHostInterfaceId;
						$reusedInterfaceIds[$dbHostInterfaceId] = true;
						break;
					}
				}
			}
			unset($xmlHostInterface);
		}
		unset($xmlHost);

		return $xmlHosts;
	}
}
