<?php
namespace EesyLDAP;


/**
 * @property-read bool $loaded
 */
class Schema {

  /**
   * CN=SubSchema Entry object
   * @var Entry
   */
  protected $entry;

  /**
   * LDAP connection
   * @var Ldap
   */
  protected $ldap;

  /**
   * Some syntax OID constants
   */
  public const SYNTAX_BOOLEAN = '1.3.6.1.4.1.1466.115.121.1.7';
  public const SYNTAX_DIRECTORY_STRING = '1.3.6.1.4.1.1466.115.121.1.15';
  public const SYNTAX_DISTINGUISHED_NAME = '1.3.6.1.4.1.1466.115.121.1.12';
  public const SYNTAX_INTEGER = '1.3.6.1.4.1.1466.115.121.1.27';
  public const SYNTAX_JPEG = '1.3.6.1.4.1.1466.115.121.1.28';
  public const SYNTAX_NUMERIC_STRING = '1.3.6.1.4.1.1466.115.121.1.36';
  public const SYNTAX_OID = '1.3.6.1.4.1.1466.115.121.1.38';
  public const SYNTAX_OCTET_STRING = '1.3.6.1.4.1.1466.115.121.1.40';

  /**
  * Map SubSchema entry attributes to schema entry type
  *
  * @var array<string,string>
  */
  protected static $attributes_to_entry_types = array(
    'attributeTypes'   => 'Attribute',
    'matchingRules'    => 'MatchingRule',
    'matchingRuleUse'  => 'MatchingRuleUse',
    'objectClasses'    => 'ObjectClass',
    'ldapSyntaxes'     => 'Syntax',
  );

  /**
   * Loaded schema entries ordered by type
   * @var array<string,array<string,Schema\SchemaEntry>>
   */
  protected $entries = array();

  /**
   * Loaded schema entries mapped with their OID
   * @var array<string,Schema\SchemaEntry>
   */
  protected $oids = array();

  /**
   * Loaded telltale
   * @var bool
   */
  protected $loaded = false;

  /**
   * Constructor
   * @param Ldap $ldap The LDAP connection
   * @param Entry $entry The cn=SubSchema LDAP entry object
   * @return void
   */
  public function __construct(&$ldap, &$entry) {
    $this -> ldap = $ldap;
    $this -> entry = $entry;
    $this -> parse();
    $this -> loaded = true;
  }

  /**
   * Magic method to get schema key
   * @param string $key
   * @return mixed
   * @throws \EesyLDAP\InvalidPropertyException
   */
  public function __get($key) {
    switch ($key) {
      case 'loaded':
        return $this -> loaded;
    }
    throw new \EesyLDAP\InvalidPropertyException(
      "Invalid property '$key' requested on '".get_called_class()."'"
    );
  }

  /**
   * Load schema from provided LDAP connection
   * @param Ldap $ldap
   * @param bool|null $raise
   * @return Schema|false Schema object on success, false on error
   */
  public static function load(&$ldap, $raise=null) {
    $entry = $ldap->get_entry(
      'cn=SubSchema', '(objectclass=*)',
      array_keys(self :: $attributes_to_entry_types)
    );
    if (!$entry instanceof Entry)
      return $ldap->error('Fail to load cn=SubSchema entry', $raise);
    return new Schema($ldap, $entry);
  }

  /**
   * Parse SubSchema entry attributes values
   * @return void
   */
  protected function parse() {
    foreach (self :: $attributes_to_entry_types as $attr => $type) {
      $type_name = strtolower($type);
      foreach($this -> entry -> get_raw_values($attr, array(), true) as $value) {
        // @phpstan-ignore-next-line
        $entry = call_user_func("\\EesyLDAP\\Schema\\$type::parse", $value);
        if (!$entry instanceof Schema\SchemaEntry) {
          $this -> ldap -> error("Fail to parse %s schema value: %s", null, $attr, $value);
          continue;
        }
        $oid = $entry->oid;
        if ($type != 'MatchingRuleUse') {
          if (array_key_exists($oid, $this->oids)) {
            $this -> ldap -> error(
              "Duplicate OID %s found in schema: %s / %s", null, $oid, $this->oids[$oid], $entry);
            continue;
          }
          $this->oids[$oid] = $entry;
        }

        if (!array_key_exists($type_name, $this -> entries))
          $this -> entries[$type_name] = array();
        $name = $entry->name;
        if (array_key_exists($name, $this -> entries[$type_name])) {
          $this -> ldap -> error(
            "Duplicate %s schema entry %s found: %s / %s",
            null, $type, $name, $this -> entries[$type_name][$name], $entry
          );
          continue;
        }
        $this -> entries[$type_name][$name] = $entry;
      }
    }
  }

  /**
   * Get a schema entry by type and name/oid
   * @param string $type
   * @param string $name_or_oid
   * @return Schema\SchemaEntry|false
   */
  protected function _get_entry($type, $name_or_oid) {
    if (
      array_key_exists($name_or_oid, $this -> oids)
      && is_a($this -> oids[$name_or_oid], "\\EesyLDAP\\Schema\\$type")
    )
      return $this -> oids[$name_or_oid];
    $type_name = strtolower($type);
    if (!array_key_exists($type_name, $this -> entries))
      return false;
    foreach($this -> entries[$type_name] as $attr)
      if ($attr->is_me($name_or_oid))
        return $attr;
    return false;
  }

  /**
   * Get an attribute by name or oid
   * @param string $name_or_oid
   * @return Schema\Attribute|false
   */
  public function attribute($name_or_oid) {
    // @phpstan-ignore-next-line
    return $this -> _get_entry('Attribute', $name_or_oid);
  }

  /**
   * Get an objectclass by name or oid
   * @param string $name_or_oid
   * @return \EesyLDAP\Schema\ObjectClass|false
   */
  public function objectclass($name_or_oid) {
    // @phpstan-ignore-next-line
    return $this -> _get_entry('ObjectClass', $name_or_oid);
  }

  /**
   * Get a matching rule by name or oid
   * @param string $name_or_oid
   * @return Schema\MatchingRule|false
   */
  public function matching_rule($name_or_oid) {
    // @phpstan-ignore-next-line
    return $this -> _get_entry('MatchingRule', $name_or_oid);
  }

  /**
   * Get a matching rule use by name or oid
   * @param string $name_or_oid
   * @return Schema\MatchingRuleUse|false
   */
  public function matching_rule_use($name_or_oid) {
    // @phpstan-ignore-next-line
    return $this -> _get_entry('MatchingRuleUse', $name_or_oid);
  }

  /**
   * Get a syntax by name or oid
   * @param string $name_or_oid
   * @return Schema\Syntax|false
   */
  public function syntax($name_or_oid) {
    // @phpstan-ignore-next-line
    return $this -> _get_entry('Syntax', $name_or_oid);
  }

  /**
   * Check if given objectclass have the specified attribute
   * @param string $attr The attribute name
   * @param string|array<string> $objectclasses List of objectclass
   * @return bool
   */
  public function has_attribute($attr, ...$objectclasses) {
    foreach($objectclasses as $objectclass) {
      if (is_array($objectclass)) {
        if (call_user_func_array(array($this, 'has_attribute'), array_merge(array($attr), $objectclass)))
          return true;
        continue;
      }
      $oc = $this -> objectclass($objectclass);
      if (!$oc)
        continue;
      if ($oc->has_attribute($attr))
        return true;
    }
    return false;
  }

}