<?php

class InstanceConfig {

	static function createInstanceConfigTable() {
		DB::getPDO()->execSql("
			create table if not exists `CRM_INSTANCE_CONFIG` (
				`id` int(11) not null AUTO_INCREMENT,
				`namespace` varchar(255) NOT NULL DEFAULT '',
				`rootNamespace` varchar(255) NOT NULL DEFAULT '',
				`idInstanceBase` int(11) NOT NULL DEFAULT 0,
				`_createdAt` datetime NOT NULL,
				UNIQUE KEY `namespace` (`namespace`),
				KEY `rootNamespace` (`rootNamespace`),
				PRIMARY KEY (`id`)
			) ENGINE=MyISAM  DEFAULT CHARSET=latin2
		");
	}

	static function getInstanceTable($namespace) { // @returns tableName with struct { pk, idInstance, _createdAt }
		$conf = self::getInstanceConfig($namespace);
		if (!empty($conf['idInstanceBase'])) return "CRM__#INSTANCE_TABLE__{$conf['idInstanceBase']}";

		$rootNs = $conf['rootNamespace'];
		$rootConf = self::getInstanceConfig($rootNs);
		$instanceTableName = "CRM__#INSTANCE_TABLE__{$rootConf['id']}";
		if (!empty($rootConf['idInstance'])) {
			$affected = DB::getPDO()->update("CRM_INSTANCE_CONFIG", 'rootNamespace', $rootNs, [
				'idInstanceBase' => $rootConf['id']
			]);
			return $instanceTableName;
		}

		// TODO: fetch primaryKeyType - TODO: store primaryKey and primaryKeyType in SystemObject item
		$pkType = 'int';
		DB::getPDO()->exec("
			CREATE TABLE IF NOT EXISTS `{$instanceTableName}` (
				`pk` int(11) NOT NULL COMMENT 'primary key'
				, `idInstance` int(11) NOT NULL
				, `_createdAt` datetime NOT NULL
				, KEY `pk` (`pk`)
				, KEY `idInstance` (`idInstance`)
			) ENGINE=MyISAM DEFAULT CHARSET=latin2 COMMENT='{$rootNs} #INSTANCE';
		");
		$affected = DB::getPDO()->update("CRM_INSTANCE_CONFIG", 'rootNamespace', $rootNs, [
			'idInstanceBase' => $rootConf['id']
		]);
		return $instanceTableName;
	}

	static function getInstanceConfig($namespace) { // @returns { id, namespace, rootNamespace, idInstanceBase, _createdAt }
		try {
			$conf = self::fetchInstanceConfig($namespace);
		} catch (Exception $e) {
			self::createInstanceConfigTable();
			// TODO:?: `_tableInstalled` tinyint(1) not null default 0,
			$conf = self::fetchInstanceConfig($namespace);
		}
		if (!$conf) {
			$id = DB::getPDO()->insert("CRM_INSTANCE_CONFIG", [
				'namespace' => $namespace,
				'rootNamespace' => self::getRootNamespace($namespace),
				'_createdAt' => 'NOW()',
			]);
			$conf = self::fetchInstanceConfig($namespace);
		}
		if (!$conf) throw new Exception("Instance not found in config table '{$namespace}'");
		return $conf;
	}

	static function fetchInstanceConfig($namespace) {
		return DB::getPDO()->fetchFirst("
			select c.*
			from `CRM_INSTANCE_CONFIG` c
			where c.namespace = :namespace
		", [
			':namespace' => $namespace
		]);
	}

	static function getRootNamespace($namespace) { // TODO: works only for relative urls! - mv to Acl->getRootNamespace
		Lib::loadClass('SchemaFactory');
		try {
			$objectItem = SchemaFactory::loadDefaultObject('SystemObject')->getItem($namespace);
		} catch (Exception $e) {
			throw new Exception("Object not installed '{$namespace}'");
		}
		if (!$objectItem['isStructInstalled']) throw new Exception("Object structure not installed '{$namespace}'");

		if ($objectItem['idDatabase'] != DB::getPDO()->getZasobId()) {
			if ('StorageAcl' === $objectItem['_type']) {
				DBG::log("getRootNamespace...");
				return $objectItem['namespace'];
			}
			else {
				throw new Exception("Only default_db supported"); // TODO: support more Sources
			}
		}

		return "default_db/{$objectItem['_rootTableName']}";
	}

	static function getNamespaceSiblings($namespace) {
		return array_map(function ($row) {
			return $row['namespace'];
		}, DB::getPDO()->fetchAll("
			select s.namespace
			from CRM_INSTANCE_CONFIG c
				join CRM_INSTANCE_CONFIG s on ( s.rootNamespace = c.rootNamespace and s.namespace != c.rootNamespace )
			where c.namespace = :namespace
		", [
			'namespace' => $namespace
		]));
	}

	static function getFeatureNamespaces($namespace, $pk) {
		$instanceTable = self::getInstanceTable($namespace);
		return array_map(function ($row) {
			return $row['namespace'];
		}, DB::getPDO()->fetchAll("
			select c.namespace
			from `{$instanceTable}` i
				join `CRM_INSTANCE_CONFIG` c on ( c.id = i.idInstance )
			where i.pk = :pk
		", [
			'pk' => $pk,
		]));
	}

}