Civi/Api4/Query/Api4SelectQuery.php

   1 <?php
   2 /*
   3  +--------------------------------------------------------------------+
   4  | Copyright CiviCRM LLC. All rights reserved.                        |
   5  |                                                                    |
   6  | This work is published under the GNU AGPLv3 license with some      |
   7  | permitted exceptions and without any warranty. For full license    |
   8  | and copyright information, see https://civicrm.org/licensing       |
   9  +--------------------------------------------------------------------+
  10  */
  11
  12 namespace Civi\Api4\Query;
  13
  14 use Civi\Api4\Service\Schema\Joinable\CustomGroupJoinable;
  15 use Civi\Api4\Utils\FormattingUtil;
  16 use Civi\Api4\Utils\CoreUtil;
  17 use Civi\Api4\Utils\SelectUtil;
  18
  19 /**
  20  * A query `node` may be in one of three formats:
  21  *
  22  * * leaf: [$fieldName, $operator, $criteria]
  23  * * negated: ['NOT', $node]
  24  * * branch: ['OR|NOT', [$node, $node, ...]]
  25  *
  26  * Leaf operators are one of:
  27  *
  28  * * '=', '<=', '>=', '>', '<', 'LIKE', "<>", "!=",
  29  * * 'NOT LIKE', 'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN',
  30  * * 'IS NOT NULL', or 'IS NULL', 'CONTAINS'.
  31  */
  32 class Api4SelectQuery {
  33
  34   const
  35     MAIN_TABLE_ALIAS = 'a',
  36     UNLIMITED = '18446744073709551615';
  37
  38   /**
  39    * @var \CRM_Utils_SQL_Select
  40    */
  41   protected $query;
  42
  43   /**
  44    * @var array
  45    */
  46   protected $joins = [];
  47
  48   /**
  49    * @var array[]
  50    */
  51   protected $apiFieldSpec;
  52
  53   /**
  54    * @var array
  55    */
  56   protected $entityFieldNames = [];
  57
  58   /**
  59    * @var array
  60    */
  61   protected $aclFields = [];
  62
  63   /**
  64    * @var \Civi\Api4\Generic\DAOGetAction
  65    */
  66   private $api;
  67
  68   /**
  69    * @var array
  70    * [alias => expr][]
  71    */
  72   protected $selectAliases = [];
  73
  74   /**
  75    * @var bool
  76    */
  77   public $forceSelectId = TRUE;
  78
  79   /**
  80    * @var array
  81    */
  82   private $explicitJoins = [];
  83
  84   /**
  85    * @param \Civi\Api4\Generic\DAOGetAction $apiGet
  86    */
  87   public function __construct($apiGet) {
  88     $this->api = $apiGet;
  89
  90     // Always select ID of main table unless grouping by something else
  91     $this->forceSelectId = !$this->getGroupBy() || $this->getGroupBy() === ['id'];
  92
  93     // Build field lists
  94     foreach ($this->api->entityFields() as $field) {
  95       $this->entityFieldNames[] = $field['name'];
  96       $field['sql_name'] = '`' . self::MAIN_TABLE_ALIAS . '`.`' . $field['column_name'] . '`';
  97       $this->addSpecField($field['name'], $field);
  98     }
  99
 100     $tableName = CoreUtil::getTableName($this->getEntity());
 101     $this->query = \CRM_Utils_SQL_Select::from($tableName . ' ' . self::MAIN_TABLE_ALIAS);
 102
 103     // Add ACLs first to avoid redundant subclauses
 104     $baoName = CoreUtil::getBAOFromApiName($this->getEntity());
 105     $this->query->where($this->getAclClause(self::MAIN_TABLE_ALIAS, $baoName));
 106   }
 107
 108   /**
 109    * Builds main final sql statement after initialization.
 110    *
 111    * @return string
 112    * @throws \API_Exception
 113    * @throws \CRM_Core_Exception
 114    */
 115   public function getSql() {
 116     // Add explicit joins. Other joins implied by dot notation may be added later
 117     $this->addExplicitJoins();
 118     $this->buildSelectClause();
 119     $this->buildWhereClause();
 120     $this->buildOrderBy();
 121     $this->buildLimit();
 122     $this->buildGroupBy();
 123     $this->buildHavingClause();
 124     return $this->query->toSQL();
 125   }
 126
 127   /**
 128    * Why walk when you can
 129    *
 130    * @return array
 131    */
 132   public function run() {
 133     $results = [];
 134     $sql = $this->getSql();
 135     $this->debug('sql', $sql);
 136     $query = \CRM_Core_DAO::executeQuery($sql);
 137     while ($query->fetch()) {
 138       $result = [];
 139       foreach ($this->selectAliases as $alias => $expr) {
 140         $returnName = $alias;
 141         $alias = str_replace('.', '_', $alias);
 142         $result[$returnName] = property_exists($query, $alias) ? $query->$alias : NULL;
 143       }
 144       $results[] = $result;
 145     }
 146     FormattingUtil::formatOutputValues($results, $this->apiFieldSpec, $this->getEntity(), 'get', $this->selectAliases);
 147     return $results;
 148   }
 149
 150   /**
 151    * @return int
 152    * @throws \API_Exception
 153    */
 154   public function getCount() {
 155     $this->addExplicitJoins();
 156     $this->buildWhereClause();
 157     // If no having or groupBy, we only need to select count
 158     if (!$this->getHaving() && !$this->getGroupBy()) {
 159       $this->query->select('COUNT(*) AS `c`');
 160       $sql = $this->query->toSQL();
 161     }
 162     // Use a subquery to count groups from GROUP BY or results filtered by HAVING
 163     else {
 164       // With no HAVING, just select the last field grouped by
 165       if (!$this->getHaving()) {
 166         $select = array_slice($this->getGroupBy(), -1);
 167       }
 168       $this->buildSelectClause($select ?? NULL);
 169       $this->buildHavingClause();
 170       $this->buildGroupBy();
 171       $subquery = $this->query->toSQL();
 172       $sql = "SELECT count(*) AS `c` FROM ( $subquery ) AS `rows`";
 173     }
 174     $this->debug('sql', $sql);
 175     return (int) \CRM_Core_DAO::singleValueQuery($sql);
 176   }
 177
 178   /**
 179    * @param array $select
 180    *   Array of select expressions; defaults to $this->getSelect
 181    * @throws \API_Exception
 182    */
 183   protected function buildSelectClause($select = NULL) {
 184     // Use default if select not provided, exclude row_count which is handled elsewhere
 185     $select = array_diff($select ?? $this->getSelect(), ['row_count']);
 186     // An empty select is the same as *
 187     if (empty($select)) {
 188       $select = $this->entityFieldNames;
 189     }
 190     else {
 191       if ($this->forceSelectId) {
 192         $select = array_merge(['id'], $select);
 193       }
 194
 195       // Expand the superstar 'custom.*' to select all fields in all custom groups
 196       $customStar = array_search('custom.*', array_values($select), TRUE);
 197       if ($customStar !== FALSE) {
 198         $customGroups = civicrm_api4($this->getEntity(), 'getFields', [
 199           'checkPermissions' => FALSE,
 200           'where' => [['custom_group', 'IS NOT NULL']],
 201         ], ['custom_group' => 'custom_group']);
 202         $customSelect = [];
 203         foreach ($customGroups as $groupName) {
 204           $customSelect[] = "$groupName.*";
 205         }
 206         array_splice($select, $customStar, 1, $customSelect);
 207       }
 208
 209       // Expand wildcards in joins (the api wrapper already expanded non-joined wildcards)
 210       $wildFields = array_filter($select, function($item) {
 211         return strpos($item, '*') !== FALSE && strpos($item, '.') !== FALSE && strpos($item, '(') === FALSE && strpos($item, ' ') === FALSE;
 212       });
 213
 214       foreach ($wildFields as $wildField) {
 215         $pos = array_search($wildField, array_values($select));
 216         // If the joined_entity.id isn't in the fieldspec already, autoJoinFK will attempt to add the entity.
 217         $idField = substr($wildField, 0, strrpos($wildField, '.')) . '.id';
 218         $this->autoJoinFK($idField);
 219         $matches = SelectUtil::getMatchingFields($wildField, array_keys($this->apiFieldSpec));
 220         array_splice($select, $pos, 1, $matches);
 221       }
 222       $select = array_unique($select);
 223     }
 224     foreach ($select as $item) {
 225       $expr = SqlExpression::convert($item, TRUE);
 226       $valid = TRUE;
 227       foreach ($expr->getFields() as $fieldName) {
 228         $field = $this->getField($fieldName);
 229         // Remove expressions with unknown fields without raising an error
 230         if (!$field) {
 231           $select = array_diff($select, [$item]);
 232           $this->debug('undefined_fields', $fieldName);
 233           $valid = FALSE;
 234         }
 235       }
 236       if ($valid) {
 237         $alias = $expr->getAlias();
 238         if ($alias != $expr->getExpr() && isset($this->apiFieldSpec[$alias])) {
 239           throw new \API_Exception('Cannot use existing field name as alias');
 240         }
 241         $this->selectAliases[$alias] = $expr->getExpr();
 242         $this->query->select($expr->render($this->apiFieldSpec) . " AS `$alias`");
 243       }
 244     }
 245   }
 246
 247   /**
 248    * Add WHERE clause to query
 249    */
 250   protected function buildWhereClause() {
 251     foreach ($this->getWhere() as $clause) {
 252       $sql = $this->treeWalkClauses($clause, 'WHERE');
 253       if ($sql) {
 254         $this->query->where($sql);
 255       }
 256     }
 257   }
 258
 259   /**
 260    * Add HAVING clause to query
 261    *
 262    * Every expression referenced must also be in the SELECT clause.
 263    */
 264   protected function buildHavingClause() {
 265     foreach ($this->getHaving() as $clause) {
 266       $this->query->having($this->treeWalkClauses($clause, 'HAVING'));
 267     }
 268   }
 269
 270   /**
 271    * Add ORDER BY to query
 272    */
 273   protected function buildOrderBy() {
 274     foreach ($this->getOrderBy() as $item => $dir) {
 275       if ($dir !== 'ASC' && $dir !== 'DESC') {
 276         throw new \API_Exception("Invalid sort direction. Cannot order by $item $dir");
 277       }
 278       $expr = $this->getExpression($item);
 279       $column = $expr->render($this->apiFieldSpec);
 280
 281       // Use FIELD() function to sort on pseudoconstant values
 282       $suffix = strstr($item, ':');
 283       if ($suffix && $expr->getType() === 'SqlField') {
 284         $field = $this->getField($item);
 285         $options = FormattingUtil::getPseudoconstantList($field, substr($suffix, 1));
 286         if ($options) {
 287           asort($options);
 288           $column = "FIELD($column,'" . implode("','", array_keys($options)) . "')";
 289         }
 290       }
 291       $this->query->orderBy("$column $dir");
 292     }
 293   }
 294
 295   /**
 296    * Add LIMIT to query
 297    *
 298    * @throws \CRM_Core_Exception
 299    */
 300   protected function buildLimit() {
 301     if ($this->getLimit() || $this->getOffset()) {
 302       // If limit is 0, mysql will actually return 0 results. Instead set to maximum possible.
 303       $this->query->limit($this->getLimit() ?: self::UNLIMITED, $this->getOffset());
 304     }
 305   }
 306
 307   /**
 308    * Add GROUP BY clause to query
 309    */
 310   protected function buildGroupBy() {
 311     foreach ($this->getGroupBy() as $item) {
 312       $this->query->groupBy($this->getExpression($item)->render($this->apiFieldSpec));
 313     }
 314   }
 315
 316   /**
 317    * Recursively validate and transform a branch or leaf clause array to SQL.
 318    *
 319    * @param array $clause
 320    * @param string $type
 321    *   WHERE|HAVING|ON
 322    * @return string SQL where clause
 323    *
 324    * @throws \API_Exception
 325    * @uses composeClause() to generate the SQL etc.
 326    */
 327   protected function treeWalkClauses($clause, $type) {
 328     // Skip empty leaf.
 329     if (in_array($clause[0], ['AND', 'OR', 'NOT']) && empty($clause[1])) {
 330       return '';
 331     }
 332     switch ($clause[0]) {
 333       case 'OR':
 334       case 'AND':
 335         // handle branches
 336         if (count($clause[1]) === 1) {
 337           // a single set so AND|OR is immaterial
 338           return $this->treeWalkClauses($clause[1][0], $type);
 339         }
 340         else {
 341           $sql_subclauses = [];
 342           foreach ($clause[1] as $subclause) {
 343             $sql_subclauses[] = $this->treeWalkClauses($subclause, $type);
 344           }
 345           return '(' . implode("\n" . $clause[0], $sql_subclauses) . ')';
 346         }
 347
 348       case 'NOT':
 349         // If we get a group of clauses with no operator, assume AND
 350         if (!is_string($clause[1][0])) {
 351           $clause[1] = ['AND', $clause[1]];
 352         }
 353         return 'NOT (' . $this->treeWalkClauses($clause[1], $type) . ')';
 354
 355       default:
 356         return $this->composeClause($clause, $type);
 357     }
 358   }
 359
 360   /**
 361    * Validate and transform a leaf clause array to SQL.
 362    * @param array $clause [$fieldName, $operator, $criteria]
 363    * @param string $type
 364    *   WHERE|HAVING|ON
 365    * @return string SQL
 366    * @throws \API_Exception
 367    * @throws \Exception
 368    */
 369   protected function composeClause(array $clause, string $type) {
 370     // Pad array for unary operators
 371     list($expr, $operator, $value) = array_pad($clause, 3, NULL);
 372     if (!in_array($operator, CoreUtil::getOperators(), TRUE)) {
 373       throw new \API_Exception('Illegal operator');
 374     }
 375
 376     // For WHERE clause, expr must be the name of a field.
 377     if ($type === 'WHERE') {
 378       $field = $this->getField($expr, TRUE);
 379       FormattingUtil::formatInputValue($value, $expr, $field, $operator);
 380       $fieldAlias = $field['sql_name'];
 381     }
 382     // For HAVING, expr must be an item in the SELECT clause
 383     elseif ($type === 'HAVING') {
 384       // Expr references a fieldName or alias
 385       if (isset($this->selectAliases[$expr])) {
 386         $fieldAlias = $expr;
 387         // Attempt to format if this is a real field
 388         if (isset($this->apiFieldSpec[$expr])) {
 389           $field = $this->getField($expr);
 390           FormattingUtil::formatInputValue($value, $expr, $field, $operator);
 391         }
 392       }
 393       // Expr references a non-field expression like a function; convert to alias
 394       elseif (in_array($expr, $this->selectAliases)) {
 395         $fieldAlias = array_search($expr, $this->selectAliases);
 396       }
 397       // If either the having or select field contains a pseudoconstant suffix, match and perform substitution
 398       else {
 399         list($fieldName) = explode(':', $expr);
 400         foreach ($this->selectAliases as $selectAlias => $selectExpr) {
 401           list($selectField) = explode(':', $selectAlias);
 402           if ($selectAlias === $selectExpr && $fieldName === $selectField && isset($this->apiFieldSpec[$fieldName])) {
 403             $field = $this->getField($fieldName);
 404             FormattingUtil::formatInputValue($value, $expr, $field, $operator);
 405             $fieldAlias = $selectAlias;
 406             break;
 407           }
 408         }
 409       }
 410       if (!isset($fieldAlias)) {
 411         throw new \API_Exception("Invalid expression in HAVING clause: '$expr'. Must use a value from SELECT clause.");
 412       }
 413       $fieldAlias = '`' . $fieldAlias . '`';
 414     }
 415     elseif ($type === 'ON') {
 416       $expr = $this->getExpression($expr);
 417       $fieldName = count($expr->getFields()) === 1 ? $expr->getFields()[0] : NULL;
 418       $fieldAlias = $expr->render($this->apiFieldSpec);
 419       if (is_string($value)) {
 420         $valExpr = $this->getExpression($value);
 421         if ($fieldName && $valExpr->getType() === 'SqlString') {
 422           $value = $valExpr->getExpr();
 423           FormattingUtil::formatInputValue($value, $fieldName, $this->apiFieldSpec[$fieldName], $operator);
 424           return \CRM_Core_DAO::createSQLFilter($fieldAlias, [$operator => $value]);
 425         }
 426         else {
 427           $value = $valExpr->render($this->apiFieldSpec);
 428           return sprintf('%s %s %s', $fieldAlias, $operator, $value);
 429         }
 430       }
 431       elseif ($fieldName) {
 432         $field = $this->getField($fieldName);
 433         FormattingUtil::formatInputValue($value, $fieldName, $field, $operator);
 434       }
 435     }
 436
 437     if ($operator === 'CONTAINS') {
 438       switch ($field['serialize'] ?? NULL) {
 439         case \CRM_Core_DAO::SERIALIZE_JSON:
 440           $operator = 'LIKE';
 441           $value = '%"' . $value . '"%';
 442           // FIXME: Use this instead of the above hack once MIN_INSTALL_MYSQL_VER is bumped to 5.7.
 443           // return sprintf('JSON_SEARCH(%s, "one", "%s") IS NOT NULL', $fieldAlias, \CRM_Core_DAO::escapeString($value));
 444           break;
 445
 446         case \CRM_Core_DAO::SERIALIZE_SEPARATOR_BOOKEND:
 447           $operator = 'LIKE';
 448           $value = '%' . \CRM_Core_DAO::VALUE_SEPARATOR . $value . \CRM_Core_DAO::VALUE_SEPARATOR . '%';
 449           break;
 450
 451         default:
 452           $operator = 'LIKE';
 453           $value = '%' . $value . '%';
 454           break;
 455       }
 456     }
 457
 458     $sql_clause = \CRM_Core_DAO::createSQLFilter($fieldAlias, [$operator => $value]);
 459     if ($sql_clause === NULL) {
 460       throw new \API_Exception("Invalid value in $type clause for '$expr'");
 461     }
 462     return $sql_clause;
 463   }
 464
 465   /**
 466    * @param string $expr
 467    * @return SqlExpression
 468    * @throws \API_Exception
 469    */
 470   protected function getExpression(string $expr) {
 471     $sqlExpr = SqlExpression::convert($expr);
 472     foreach ($sqlExpr->getFields() as $fieldName) {
 473       $this->getField($fieldName, TRUE);
 474     }
 475     return $sqlExpr;
 476   }
 477
 478   /**
 479    * Get acl clause for an entity
 480    *
 481    * @param string $tableAlias
 482    * @param \CRM_Core_DAO|string $baoName
 483    * @param array $stack
 484    * @return array
 485    */
 486   public function getAclClause($tableAlias, $baoName, $stack = []) {
 487     if (!$this->getCheckPermissions()) {
 488       return [];
 489     }
 490     // Prevent (most) redundant acl sub clauses if they have already been applied to the main entity.
 491     // FIXME: Currently this only works 1 level deep, but tracking through multiple joins would increase complexity
 492     // and just doing it for the first join takes care of most acl clause deduping.
 493     if (count($stack) === 1 && in_array($stack[0], $this->aclFields, TRUE)) {
 494       return [];
 495     }
 496     $clauses = $baoName::getSelectWhereClause($tableAlias);
 497     if (!$stack) {
 498       // Track field clauses added to the main entity
 499       $this->aclFields = array_keys($clauses);
 500     }
 501     return array_filter($clauses);
 502   }
 503
 504   /**
 505    * Fetch a field from the getFields list
 506    *
 507    * @param string $expr
 508    * @param bool $strict
 509    *   In strict mode, this will throw an exception if the field doesn't exist
 510    *
 511    * @return array|null
 512    * @throws \API_Exception
 513    */
 514   public function getField($expr, $strict = FALSE) {
 515     // If the expression contains a pseudoconstant filter like activity_type_id:label,
 516     // strip it to look up the base field name, then add the field:filter key to apiFieldSpec
 517     $col = strpos($expr, ':');
 518     $fieldName = $col ? substr($expr, 0, $col) : $expr;
 519     // Perform join if field not yet available - this will add it to apiFieldSpec
 520     if (!isset($this->apiFieldSpec[$fieldName]) && strpos($fieldName, '.')) {
 521       $this->autoJoinFK($fieldName);
 522     }
 523     $field = $this->apiFieldSpec[$fieldName] ?? NULL;
 524     if ($strict && !$field) {
 525       throw new \API_Exception("Invalid field '$fieldName'");
 526     }
 527     $this->apiFieldSpec[$expr] = $field;
 528     return $field;
 529   }
 530
 531   /**
 532    * Join onto other entities as specified by the api call.
 533    *
 534    * @throws \API_Exception
 535    * @throws \Civi\API\Exception\NotImplementedException
 536    */
 537   private function addExplicitJoins() {
 538     foreach ($this->getJoin() as $join) {
 539       // First item in the array is the entity name
 540       $entity = array_shift($join);
 541       // Which might contain an alias. Split on the keyword "AS"
 542       list($entity, $alias) = array_pad(explode(' AS ', $entity), 2, NULL);
 543       // Ensure alias is a safe string, and supply default if not given
 544       $alias = $alias ? \CRM_Utils_String::munge($alias, '_', 256) : strtolower($entity);
 545       // First item in the array is a boolean indicating if the join is required (aka INNER or LEFT).
 546       // The rest are join conditions.
 547       $side = array_shift($join) ? 'INNER' : 'LEFT';
 548       // Add all fields from joined entity to spec
 549       $joinEntityGet = \Civi\API\Request::create($entity, 'get', ['version' => 4, 'checkPermissions' => $this->getCheckPermissions()]);
 550       $joinEntityFields = $joinEntityGet->entityFields();
 551       foreach ($joinEntityFields as $field) {
 552         $field['sql_name'] = '`' . $alias . '`.`' . $field['column_name'] . '`';
 553         $this->addSpecField($alias . '.' . $field['name'], $field);
 554       }
 555       $tableName = CoreUtil::getTableName($entity);
 556       // Save join info to be retrieved by $this->getExplicitJoin()
 557       $this->explicitJoins[$alias] = [
 558         'entity' => $entity,
 559         'table' => $tableName,
 560         'bridge' => NULL,
 561       ];
 562       // If the first condition is a string, it's the name of a bridge entity
 563       if (!empty($join[0]) && is_string($join[0]) && \CRM_Utils_Rule::alphanumeric($join[0])) {
 564         $this->explicitJoins[$alias]['bridge'] = $join[0];
 565         $conditions = $this->getBridgeJoin($join, $entity, $alias);
 566       }
 567       else {
 568         $conditions = $this->getJoinConditions($join, $entity, $alias, $joinEntityFields);
 569       }
 570       foreach (array_filter($join) as $clause) {
 571         $conditions[] = $this->treeWalkClauses($clause, 'ON');
 572       }
 573       $this->join($side, $tableName, $alias, $conditions);
 574     }
 575   }
 576
 577   /**
 578    * Supply conditions for an explicit join.
 579    *
 580    * @param array $joinTree
 581    * @param string $joinEntity
 582    * @param string $alias
 583    * @param array $joinEntityFields
 584    * @return array
 585    */
 586   private function getJoinConditions($joinTree, $joinEntity, $alias, $joinEntityFields) {
 587     $conditions = [];
 588     // getAclClause() expects a stack of 1-to-1 join fields to help it dedupe, but this is more flexible,
 589     // so unless this is a direct 1-to-1 join with the main entity, we'll just hack it
 590     // with a padded empty stack to bypass its deduping.
 591     $stack = [NULL, NULL];
 592     // See if the ON clause already contains an FK reference to joinEntity
 593     $explicitFK = array_filter($joinTree, function($clause) use ($alias, $joinEntityFields) {
 594       list($sideA, $op, $sideB) = array_pad((array) $clause, 3, NULL);
 595       if ($op !== '=' || !$sideB) {
 596         return FALSE;
 597       }
 598       foreach ([$sideA, $sideB] as $expr) {
 599         if ($expr === "$alias.id" || !empty($joinEntityFields["$alias.$expr"]['fk_entity'])) {
 600           return TRUE;
 601         }
 602       }
 603       return FALSE;
 604     });
 605     // If we're not explicitly referencing the ID (or some other FK field) of the joinEntity, search for a default
 606     if (!$explicitFK) {
 607       foreach ($this->apiFieldSpec as $name => $field) {
 608         if ($field['entity'] !== $joinEntity && $field['fk_entity'] === $joinEntity) {
 609           $conditions[] = $this->treeWalkClauses([$name, '=', "$alias.id"], 'ON');
 610         }
 611         elseif (strpos($name, "$alias.") === 0 && substr_count($name, '.') === 1 && $field['fk_entity'] === $this->getEntity()) {
 612           $conditions[] = $this->treeWalkClauses([$name, '=', 'id'], 'ON');
 613           $stack = ['id'];
 614         }
 615       }
 616       // Hmm, if we came up with > 1 condition, then it's ambiguous how it should be joined so we won't return anything but the generic ACLs
 617       if (count($conditions) > 1) {
 618         $stack = [NULL, NULL];
 619         $conditions = [];
 620       }
 621     }
 622     $baoName = CoreUtil::getBAOFromApiName($joinEntity);
 623     $acls = array_values($this->getAclClause($alias, $baoName, $stack));
 624     return array_merge($acls, $conditions);
 625   }
 626
 627   /**
 628    * Join via a Bridge table
 629    *
 630    * This creates a double-join in sql that appears to the API user like a single join.
 631    *
 632    * @param array $joinTree
 633    * @param string $joinEntity
 634    * @param string $alias
 635    * @return array
 636    * @throws \API_Exception
 637    */
 638   protected function getBridgeJoin(&$joinTree, $joinEntity, $alias) {
 639     $bridgeEntity = array_shift($joinTree);
 640     /* @var \Civi\Api4\Generic\DAOEntity $bridgeEntityClass */
 641     $bridgeEntityClass = '\Civi\Api4\\' . $bridgeEntity;
 642     $bridgeAlias = $alias . '_via_' . strtolower($bridgeEntity);
 643     $bridgeInfo = $bridgeEntityClass::getInfo();
 644     $bridgeFields = $bridgeInfo['bridge'] ?? [];
 645     // Sanity check - bridge entity should declare exactly 2 FK fields
 646     if (count($bridgeFields) !== 2) {
 647       throw new \API_Exception("Illegal bridge entity specified: $bridgeEntity. Expected 2 bridge fields, found " . count($bridgeFields));
 648     }
 649     /* @var \CRM_Core_DAO $bridgeDAO */
 650     $bridgeDAO = $bridgeInfo['dao'];
 651     $bridgeTable = $bridgeDAO::getTableName();
 652
 653     $joinTable = CoreUtil::getTableName($joinEntity);
 654     $bridgeEntityGet = $bridgeEntityClass::get($this->getCheckPermissions());
 655     // Get the 2 bridge reference columns as CRM_Core_Reference_* objects
 656     $joinRef = $baseRef = NULL;
 657     foreach ($bridgeDAO::getReferenceColumns() as $ref) {
 658       if (in_array($ref->getReferenceKey(), $bridgeFields)) {
 659         if (!$joinRef && in_array($joinEntity, $ref->getTargetEntities())) {
 660           $joinRef = $ref;
 661         }
 662         else {
 663           $baseRef = $ref;
 664         }
 665       }
 666     }
 667     if (!$joinRef || !$baseRef) {
 668       throw new \API_Exception("Unable to join $bridgeEntity to $joinEntity");
 669     }
 670     // Create link between bridge entity and join entity
 671     $joinConditions = [
 672       "`$bridgeAlias`.`{$joinRef->getReferenceKey()}` = `$alias`.`{$joinRef->getTargetKey()}`",
 673     ];
 674     // For dynamic references, also add the type column (e.g. `entity_table`)
 675     if ($joinRef->getTypeColumn()) {
 676       $joinConditions[] = "`$bridgeAlias`.`{$joinRef->getTypeColumn()}` = '$joinTable'";
 677     }
 678     // Register fields (other than bridge FK fields) from the bridge entity as if they belong to the join entity
 679     $fakeFields = [];
 680     foreach ($bridgeEntityGet->entityFields() as $name => $field) {
 681       if ($name === 'id' || $name === $joinRef->getReferenceKey() || $name === $joinRef->getTypeColumn() || $name === $baseRef->getReferenceKey() || $name === $baseRef->getTypeColumn()) {
 682         continue;
 683       }
 684       // Note these fields get a sql alias pointing to the bridge entity, but an api alias pretending they belong to the join entity
 685       $field['sql_name'] = '`' . $bridgeAlias . '`.`' . $field['column_name'] . '`';
 686       $this->addSpecField($alias . '.' . $field['name'], $field);
 687       $fakeFields[] = $alias . '.' . $field['name'];
 688     }
 689     // Move conditions for the bridge join out of the joinTree
 690     $bridgeConditions = [];
 691     $isExplicit = FALSE;
 692     $joinTree = array_filter($joinTree, function($clause) use ($baseRef, $alias, $bridgeAlias, $fakeFields, &$bridgeConditions, &$isExplicit) {
 693       list($sideA, $op, $sideB) = array_pad((array) $clause, 3, NULL);
 694       // Skip AND/OR/NOT branches
 695       if (!$sideB) {
 696         return TRUE;
 697       }
 698       // If this condition makes an explicit link between the bridge and another entity
 699       if ($op === '=' && $sideB && ($sideA === "$alias.{$baseRef->getReferenceKey()}" || $sideB === "$alias.{$baseRef->getReferenceKey()}")) {
 700         $expr = $sideA === "$alias.{$baseRef->getReferenceKey()}" ? $sideB : $sideA;
 701         $bridgeConditions[] = "`$bridgeAlias`.`{$baseRef->getReferenceKey()}` = " . $this->getExpression($expr)->render($this->apiFieldSpec);
 702         $isExplicit = TRUE;
 703         return FALSE;
 704       }
 705       // Explicit link with dynamic "entity_table" column
 706       elseif ($op === '=' && $baseRef->getTypeColumn() && ($sideA === "$alias.{$baseRef->getTypeColumn()}" || $sideB === "$alias.{$baseRef->getTypeColumn()}")) {
 707         $expr = $sideA === "$alias.{$baseRef->getTypeColumn()}" ? $sideB : $sideA;
 708         $bridgeConditions[] = "`$bridgeAlias`.`{$baseRef->getTypeColumn()}` = " . $this->getExpression($expr)->render($this->apiFieldSpec);
 709         $isExplicit = TRUE;
 710         return FALSE;
 711       }
 712       // Other conditions that apply only to the bridge table should be
 713       foreach ([$sideA, $sideB] as $expr) {
 714         if (is_string($expr) && in_array(explode(':', $expr)[0], $fakeFields)) {
 715           $bridgeConditions[] = $this->composeClause($clause, 'ON');
 716           return FALSE;
 717         }
 718       }
 719       return TRUE;
 720     });
 721     // If no bridge conditions were specified, link it to the base entity
 722     if (!$isExplicit) {
 723       if (!in_array($this->getEntity(), $baseRef->getTargetEntities())) {
 724         throw new \API_Exception("Unable to join $bridgeEntity to " . $this->getEntity());
 725       }
 726       $bridgeConditions[] = "`$bridgeAlias`.`{$baseRef->getReferenceKey()}` = a.`{$baseRef->getTargetKey()}`";
 727       if ($baseRef->getTypeColumn()) {
 728         $bridgeConditions[] = "`$bridgeAlias`.`{$baseRef->getTypeColumn()}` = '" . $this->getFrom() . "'";
 729       }
 730     }
 731
 732     $this->join('LEFT', $bridgeTable, $bridgeAlias, $bridgeConditions);
 733
 734     $baoName = CoreUtil::getBAOFromApiName($joinEntity);
 735     $acls = array_values($this->getAclClause($alias, $baoName, [NULL, NULL]));
 736     return array_merge($acls, $joinConditions);
 737   }
 738
 739   /**
 740    * Joins a path and adds all fields in the joined entity to apiFieldSpec
 741    *
 742    * @param $key
 743    * @throws \API_Exception
 744    * @throws \Exception
 745    */
 746   protected function autoJoinFK($key) {
 747     if (isset($this->apiFieldSpec[$key])) {
 748       return;
 749     }
 750
 751     $pathArray = explode('.', $key);
 752
 753     /** @var \Civi\Api4\Service\Schema\Joiner $joiner */
 754     $joiner = \Civi::container()->get('joiner');
 755     // The last item in the path is the field name. We don't care about that; we'll add all fields from the joined entity.
 756     array_pop($pathArray);
 757
 758     try {
 759       $joinPath = $joiner->autoJoin($this, $pathArray);
 760     }
 761     catch (\Exception $e) {
 762       return;
 763     }
 764     $lastLink = array_pop($joinPath);
 765
 766     // Custom field names are already prefixed
 767     $isCustom = $lastLink instanceof CustomGroupJoinable;
 768     if ($isCustom) {
 769       array_pop($pathArray);
 770     }
 771     $prefix = $pathArray ? implode('.', $pathArray) . '.' : '';
 772     // Cache field info for retrieval by $this->getField()
 773     foreach ($lastLink->getEntityFields() as $fieldObject) {
 774       $fieldArray = $fieldObject->toArray();
 775       $fieldArray['sql_name'] = '`' . $lastLink->getAlias() . '`.`' . $fieldArray['column_name'] . '`';
 776       $this->addSpecField($prefix . $fieldArray['name'], $fieldArray);
 777     }
 778   }
 779
 780   /**
 781    * @param string $side
 782    * @param string $tableName
 783    * @param string $tableAlias
 784    * @param array $conditions
 785    */
 786   public function join($side, $tableName, $tableAlias, $conditions) {
 787     // INNER JOINs take precedence over LEFT JOINs
 788     if ($side != 'LEFT' || !isset($this->joins[$tableAlias])) {
 789       $this->joins[$tableAlias] = $side;
 790       $this->query->join($tableAlias, "$side JOIN `$tableName` `$tableAlias` ON " . implode(' AND ', $conditions));
 791     }
 792   }
 793
 794   /**
 795    * @return FALSE|string
 796    */
 797   public function getFrom() {
 798     return CoreUtil::getTableName($this->getEntity());
 799   }
 800
 801   /**
 802    * @return string
 803    */
 804   public function getEntity() {
 805     return $this->api->getEntityName();
 806   }
 807
 808   /**
 809    * @return array
 810    */
 811   public function getSelect() {
 812     return $this->api->getSelect();
 813   }
 814
 815   /**
 816    * @return array
 817    */
 818   public function getWhere() {
 819     return $this->api->getWhere();
 820   }
 821
 822   /**
 823    * @return array
 824    */
 825   public function getHaving() {
 826     return $this->api->getHaving();
 827   }
 828
 829   /**
 830    * @return array
 831    */
 832   public function getJoin() {
 833     return $this->api->getJoin();
 834   }
 835
 836   /**
 837    * @return array
 838    */
 839   public function getGroupBy() {
 840     return $this->api->getGroupBy();
 841   }
 842
 843   /**
 844    * @return array
 845    */
 846   public function getOrderBy() {
 847     return $this->api->getOrderBy();
 848   }
 849
 850   /**
 851    * @return mixed
 852    */
 853   public function getLimit() {
 854     return $this->api->getLimit();
 855   }
 856
 857   /**
 858    * @return mixed
 859    */
 860   public function getOffset() {
 861     return $this->api->getOffset();
 862   }
 863
 864   /**
 865    * @return \CRM_Utils_SQL_Select
 866    */
 867   public function getQuery() {
 868     return $this->query;
 869   }
 870
 871   /**
 872    * @return bool|string
 873    */
 874   public function getCheckPermissions() {
 875     return $this->api->getCheckPermissions();
 876   }
 877
 878   /**
 879    * @param string $alias
 880    * @return array|NULL
 881    */
 882   public function getExplicitJoin($alias) {
 883     return $this->explicitJoins[$alias] ?? NULL;
 884   }
 885
 886   /**
 887    * @param string $path
 888    * @param array $field
 889    */
 890   private function addSpecField($path, $field) {
 891     // Only add field to spec if we have permission
 892     if ($this->getCheckPermissions() && !empty($field['permission']) && !\CRM_Core_Permission::check($field['permission'])) {
 893       $this->apiFieldSpec[$path] = FALSE;
 894       return;
 895     }
 896     $this->apiFieldSpec[$path] = $field;
 897   }
 898
 899   /**
 900    * Add something to the api's debug output if debugging is enabled
 901    *
 902    * @param $key
 903    * @param $item
 904    */
 905   public function debug($key, $item) {
 906     if ($this->api->getDebug()) {
 907       $this->api->_debugOutput[$key][] = $item;
 908     }
 909   }
 910
 911 }