Imported code from old repository

CloudObjects/SDK/COIDParser.php

@@ -0,0 +1,152 @@
+<?php
+
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+ 
+namespace CloudObjects\SDK;
+
+use ML\IRI\IRI;
+
+/**
+ * The COIDParser can be used to validate COIDs and extract information.
+ */
+class COIDParser {
+
+  const COID_INVALID = 0;
+
+  const COID_ROOT = 1;
+  const COID_UNVERSIONED = 2;
+  const COID_VERSIONED = 3;
+  const COID_VERSION_WILDCARD = 4;
+
+  const REGEX_HOSTNAME = "/^([a-z0-9-]+\.)?[a-z0-9-]+\.[a-z]+$/";
+  const REGEX_SEGMENT = "/^[A-Za-z-_0-9\.]+$/";
+  const REGEX_VERSION_WILDCARD = "/^((\^|~)(\d+\.)?\d|(\d+\.){1,2}\*)$/";
+
+  /**
+   * Creates a new IRI object representing a COID from a string.
+   * Adds the "coid://" prefix if necessary and normalizes case.
+   *
+   * @param string $coidString A COID string.
+   * @return IRI
+   */
+  public static function fromString($coidString) {
+    $coidPre = new IRI(
+      (strtolower(substr($coidString, 0, 7))=='coid://') ? $coidString : 'coid://'.$coidString
+    );
+    // Normalize scheme and host segments to lower case
+    return new IRI('coid://'.strtolower($coidPre->getHost()).$coidPre->getPath());
+  }
+
+  /**
+   * Get the type of a COID.
+   *
+   * @param IRI $coid
+   * @return int|null
+   */
+  public static function getType(IRI $coid) {
+    if ($coid->getScheme()!='coid' || $coid->getHost()==''
+        || preg_match(self::REGEX_HOSTNAME, $coid->getHost()) != 1)
+      return self::COID_INVALID;
+
+    if ($coid->getPath()=='' || $coid->getPath()=='/')
+      return self::COID_ROOT;
+
+    $segments = explode('/', $coid->getPath());
+    switch (count($segments)) {
+      case 2:
+        return (preg_match(self::REGEX_SEGMENT, $segments[1]) == 1)
+          ? self::COID_UNVERSIONED
+          : self::COID_INVALID;
+      case 3:
+        if (preg_match(self::REGEX_SEGMENT, $segments[1]) != 1)
+          return self::COID_INVALID;
+
+        if (preg_match(self::REGEX_SEGMENT, $segments[2]) == 1)
+          return self::COID_VERSIONED;
+        else
+        if (preg_match(self::REGEX_VERSION_WILDCARD, $segments[2]) == 1)
+          return self::COID_VERSION_WILDCARD;
+        else
+          return self::COID_INVALID;
+      default:
+        return self::COID_INVALID;
+    }
+  }
+
+  /**
+   * Checks whether the given IRI object is a valid COID.
+   *
+   * @param IRI $coid
+   * @return boolean
+   */
+  public static function isValidCOID(IRI $coid) {
+    return (self::getType($coid)!=self::COID_INVALID);
+  }
+
+  /**
+   * Get the name segment of a valid COID or null if not available.
+   *
+   * @param IRI $coid
+   * @return string|null
+   */
+  public static function getName(IRI $coid) {
+    if (self::getType($coid)!=self::COID_INVALID
+        && self::getType($coid)!=self::COID_ROOT) {
+      $segments = explode('/', $coid->getPath());
+      return $segments[1];
+    } else
+      return null;
+  }
+
+  /**
+   * Get the version segment of a valid, versioned COID or null if not available.
+   *
+   * @param IRI $coid
+   * @return string|null
+   */
+  public static function getVersion(IRI $coid) {
+    if (self::getType($coid)==self::COID_VERSIONED) {
+      $segments = explode('/', $coid->getPath());
+      return $segments[2];
+    } else
+      return null;
+  }
+
+  /**
+   * Get the version segment of a versioned or version wildcard COID or
+   * null if not available.
+   *
+   * @param IRI $coid
+   * @return string|null
+   */
+  public static function getVersionWildcard(IRI $coid) {
+    if (self::getType($coid)==self::COID_VERSION_WILDCARD) {
+      $segments = explode('/', $coid->getPath());
+      return $segments[2];
+    } else
+      return null;
+  }
+
+  /**
+   * Returns the COID itself if it is a root COID or a new IRI object
+   * representing the namespace underlying the given COID.
+   *
+   * @param IRI $coid
+   * @return IRI|null
+   */
+  public static function getNamespaceCOID(IRI $coid) {
+    switch (self::getType($coid)) {
+      case self::COID_ROOT:
+        return $coid;
+      case self::COID_UNVERSIONED:
+      case self::COID_VERSIONED:
+      case self::COID_VERSION_WILDCARD:
+        return new IRI('coid://'.$coid->getHost());
+      default:
+        return null;
+    }
+  }
+
+}