Civi/Api4/Service/Schema/SchemaMap.php

   1 <?php
   2
   3 /*
   4  +--------------------------------------------------------------------+
   5  | Copyright CiviCRM LLC. All rights reserved.                        |
   6  |                                                                    |
   7  | This work is published under the GNU AGPLv3 license with some      |
   8  | permitted exceptions and without any warranty. For full license    |
   9  | and copyright information, see https://civicrm.org/licensing       |
  10  +--------------------------------------------------------------------+
  11  */
  12
  13 /**
  14  *
  15  * @package CRM
  16  * @copyright CiviCRM LLC https://civicrm.org/licensing
  17  */
  18
  19
  20 namespace Civi\Api4\Service\Schema;
  21
  22 use Civi\Api4\Service\Schema\Joinable\BridgeJoinable;
  23
  24 class SchemaMap {
  25
  26   const MAX_JOIN_DEPTH = 3;
  27
  28   /**
  29    * @var Table[]
  30    */
  31   protected $tables = [];
  32
  33   /**
  34    * @param $baseTableName
  35    * @param $targetTableAlias
  36    *
  37    * @return \Civi\Api4\Service\Schema\Joinable\Joinable[]
  38    *   Array of links to the target table, empty if no path found
  39    */
  40   public function getPath($baseTableName, $targetTableAlias) {
  41     $table = $this->getTableByName($baseTableName);
  42     $path = [];
  43
  44     if (!$table) {
  45       return $path;
  46     }
  47
  48     $this->findPaths($table, $targetTableAlias, 1, $path);
  49
  50     foreach ($path as $index => $pathLink) {
  51       if ($pathLink instanceof BridgeJoinable) {
  52         $start = array_slice($path, 0, $index);
  53         $middle = [$pathLink->getMiddleLink()];
  54         $end = array_slice($path, $index, count($path) - $index);
  55         $path = array_merge($start, $middle, $end);
  56       }
  57     }
  58
  59     return $path;
  60   }
  61
  62   /**
  63    * @return Table[]
  64    */
  65   public function getTables() {
  66     return $this->tables;
  67   }
  68
  69   /**
  70    * @param $name
  71    *
  72    * @return Table|null
  73    */
  74   public function getTableByName($name) {
  75     foreach ($this->tables as $table) {
  76       if ($table->getName() === $name) {
  77         return $table;
  78       }
  79     }
  80
  81     return NULL;
  82   }
  83
  84   /**
  85    * Adds a table to the schema map if it has not already been added
  86    *
  87    * @param Table $table
  88    *
  89    * @return $this
  90    */
  91   public function addTable(Table $table) {
  92     if (!$this->getTableByName($table->getName())) {
  93       $this->tables[] = $table;
  94     }
  95
  96     return $this;
  97   }
  98
  99   /**
 100    * @param array $tables
 101    */
 102   public function addTables(array $tables) {
 103     foreach ($tables as $table) {
 104       $this->addTable($table);
 105     }
 106   }
 107
 108   /**
 109    * Recursive function to traverse the schema looking for a path
 110    *
 111    * @param Table $table
 112    *   The current table to base fromm
 113    * @param string $target
 114    *   The target joinable table alias
 115    * @param int $depth
 116    *   The current level of recursion which reflects the number of joins needed
 117    * @param \Civi\Api4\Service\Schema\Joinable\Joinable[] $path
 118    *   (By-reference) The possible paths to the target table
 119    * @param \Civi\Api4\Service\Schema\Joinable\Joinable[] $currentPath
 120    *   For internal use only to track the path to reach the target table
 121    */
 122   private function findPaths(Table $table, $target, $depth, &$path, $currentPath = []
 123   ) {
 124     static $visited = [];
 125
 126     // reset if new call
 127     if ($depth === 1) {
 128       $visited = [];
 129     }
 130
 131     $canBeShorter = empty($path) || count($currentPath) + 1 < count($path);
 132     $tooFar = $depth > self::MAX_JOIN_DEPTH;
 133     $beenHere = in_array($table->getName(), $visited);
 134
 135     if ($tooFar || $beenHere || !$canBeShorter) {
 136       return;
 137     }
 138
 139     // prevent circular reference
 140     $visited[] = $table->getName();
 141
 142     foreach ($table->getExternalLinks() as $link) {
 143       if ($link->getAlias() === $target) {
 144         $path = array_merge($currentPath, [$link]);
 145       }
 146       else {
 147         $linkTable = $this->getTableByName($link->getTargetTable());
 148         if ($linkTable) {
 149           $nextStep = array_merge($currentPath, [$link]);
 150           $this->findPaths($linkTable, $target, $depth + 1, $path, $nextStep);
 151         }
 152       }
 153     }
 154   }
 155
 156 }