<?php

/**
  @version v5.21.0-flyspray  09-Mar-2021
  @copyright (c) 2000-2013 John Lim (jlim#natsoft.com). All rights reserved.
  @copyright (c) 2014      Damien Regad, Mark Newnham and the ADOdb community
  Released under both BSD license and Lesser GPL library license.
  Whenever there is any discrepancy between the two licenses,
  the BSD license will take precedence.

  Set tabs to 4 for best viewing.
*/

// security - hide paths
if (!defined('ADODB_DIR')) die();

class ADODB2_postgres extends ADODB_DataDict
{
	public $databaseType = 'postgres';
	public $seqField = false;
	public $seqPrefix = 'SEQ_';
	public $addCol = ' ADD COLUMN';
	public $quote = '"';
	public $renameTable = 'ALTER TABLE %s RENAME TO %s'; // at least since 7.1
	public $dropTable = 'DROP TABLE %s CASCADE';

	public $blobAllowsDefaultValue = true;
	public $blobAllowsNotNull = true;

	function metaType($t, $len=-1, $fieldobj=false)
	{
		if (is_object($t)) {
			$fieldobj = $t;
			$t = $fieldobj->type;
			$len = $fieldobj->max_length;
		}
		$is_serial = is_object($fieldobj) && !empty($fieldobj->primary_key) && !empty($fieldobj->unique) &&
			!empty($fieldobj->has_default) && substr($fieldobj->default_value, 0, 8) == 'nextval(';

		switch (strtoupper($t)) {
			case 'INTERVAL':
			case 'CHAR':
			case 'CHARACTER':
			case 'VARCHAR':
			case 'NAME':
	   		case 'BPCHAR':
				if ($len <= $this->blobSize) {
					return 'C';
				}
			case 'TEXT':
				return 'X';

			case 'IMAGE': // user defined type
			case 'BLOB': // user defined type
			case 'BIT':	// This is a bit string, not a single bit, so don't return 'L'
			case 'VARBIT':
			case 'BYTEA':
				return 'B';

			case 'BOOL':
			case 'BOOLEAN':
				return 'L';

			case 'DATE':
				return 'D';

			case 'TIME':
			case 'DATETIME':
			case 'TIMESTAMP':
			case 'TIMESTAMPTZ':
				return 'T';

			case 'INTEGER': return !$is_serial ? 'I' : 'R';
			case 'SMALLINT':
			case 'INT2': return !$is_serial ? 'I2' : 'R';
			case 'INT4': return !$is_serial ? 'I4' : 'R';
			case 'BIGINT':
			case 'INT8': return !$is_serial ? 'I8' : 'R';

			case 'OID':
			case 'SERIAL':
				return 'R';

			case 'FLOAT4':
			case 'FLOAT8':
			case 'DOUBLE PRECISION':
			case 'REAL':
				return 'F';

			 default:
			 	return 'N';
		}
	}

 	function actualType($meta)
	{
		switch ($meta) {
		case 'C': return 'VARCHAR';
		case 'XL':
		case 'X': return 'TEXT';

		case 'C2': return 'VARCHAR';
		case 'X2': return 'TEXT';

		case 'B': return 'BYTEA';

		case 'D': return 'DATE';
		case 'TS':
		case 'T': return 'TIMESTAMP';

		case 'L': return 'BOOLEAN';
		case 'I': return 'INTEGER';
		case 'I1': return 'SMALLINT';
		case 'I2': return 'INT2';
		case 'I4': return 'INT4';
		case 'I8': return 'INT8';

		case 'F': return 'FLOAT8';
		case 'N': return 'NUMERIC';
		default:
			return $meta;
		}
	}

	/**
	 * Adding a new Column
	 *
	 * reimplementation of the default function as postgres does NOT allow to set the default in the same statement
	 *
	 * @param string $tabname table-name
	 * @param string $flds column-names and types for the changed columns
	 * @return array with SQL strings
	 */
	function addColumnSQL($tabname, $flds)
	{
		$tabname = $this->tableName($tabname);
		$sql = array();
		$not_null = false;
		list($lines,$pkey) = $this->_genFields($flds);
		$alter = 'ALTER TABLE ' . $tabname . $this->addCol . ' ';
		foreach($lines as $v) {
			if (($not_null = preg_match('/NOT NULL/i', $v))) {
				$v = preg_replace('/NOT NULL/i', '', $v);
			}
			
			if (preg_match('/^([^ ]+) .*DEFAULT (\'[^\']+\'|\"[^\"]+\"|[^ ]+)/', $v, $matches)) {
				list(, $colname, $default) = $matches;
				$sql[] = $alter . str_replace('DEFAULT '.$default, '', $v);
				$sql[] = 'UPDATE '.$tabname.' SET '.$colname.'='.$default;
				$sql[] = 'ALTER TABLE '.$tabname.' ALTER COLUMN '.$colname.' SET DEFAULT ' . $default;
			}
			// SERIAL is not a true type in PostgreSQL and is only allowed when creating a new table.
			// See https://www.postgresql.org/docs/13/datatype-numeric.html#DATATYPE-SERIAL 8.1.4. Serial Types
			elseif (preg_match('/^([^ ]+) .*SERIAL/i', $v, $matches)) {
				list(, $colname, $default) = $matches;
				$sql[] = 'CREATE SEQUENCE '.$tabname.'_'.$colname.'_seq';
				$sql[] = $alter.$colname.' INTEGER';
				$sql[] = 'ALTER SEQUENCE '.$tabname.'_'.$colname.'_seq OWNED BY '.$tabname.'.'.$colname;
				$sql[] = 'UPDATE '.$tabname.' SET '.$colname.' = nextval(\''.$tabname.'_'.$colname.'_seq\')';
				$sql[] = 'ALTER TABLE '.$tabname.' ALTER COLUMN '.$colname.' SET DEFAULT nextval(\''.$tabname.'_'.$colname.'_seq\')';
				$sql[] = 'ALTER TABLE '.$tabname.' ALTER COLUMN '.$colname.' SET NOT NULL';
				$not_null = false;
			} else {
				$sql[] = $alter . $v;
			}
			if ($not_null) {
				list($colname) = explode(' ',$v);
				$sql[] = 'ALTER TABLE '.$tabname.' ALTER COLUMN '.$colname.' SET NOT NULL';
			}
		}
		return $sql;
	}

	function dropIndexSQL($idxname, $tabname = NULL)
	{
	   return array(sprintf($this->dropIndex, $this->tableName($idxname), $this->tableName($tabname)));
	}

	/**
	 * Change the definition of one column
	 *
	 * Postgres can't do that on it's own, you need to supply the complete defintion of the new table,
	 * to allow, recreating the table and copying the content over to the new table
	 * @param string $tabname table name
	 * @param string $flds column name and type for the changed column
	 * @param string $tableflds complete defintion of the new table, eg. for postgres, default ''
	 * @param array/ $tableoptions options for the new table see createTableSQL, default ''
	 * @return array with SQL strings
	 */
	function alterColumnSQL($tabname, $flds, $tableflds='', $tableoptions='')
	{
		// Check if alter single column datatype available - works with 8.0+
		$has_alter_column = 8.0 <= (float) @$this->serverInfo['version'];

		if ($has_alter_column) {
			$tabname = $this->tableName($tabname);
			$sql = array();
			list($lines, $pkey) = $this->_genFields($flds);
			$set_null = false;
			foreach ($lines as $v) {
				$alter = 'ALTER TABLE ' . $tabname . $this->alterCol . ' ';
				if ($not_null = preg_match('/NOT NULL/i', $v)) {
					$v = preg_replace('/NOT NULL/i', '', $v);
				}

				// SERIAL is not a true type in PostgreSQL and is only allowed when creating a new table.
				// See http://www.postgresql.org/docs/9.4/static/datatype-numeric.html, 8.1.4. Serial Types.
				if (preg_match('/SERIAL/i', $v)) {
					continue;
				}                                
				 // this next block doesn't work - there is no way that I can see to
				 // explicitly ask a column to be null using $flds
				else if ($set_null = preg_match('/NULL/i', $v)) {
					// if they didn't specify not null, see if they explicitely asked for null
					// Lookbehind pattern covers the case 'fieldname NULL datatype DEFAULT NULL'
					// only the first NULL should be removed, not the one specifying
					// the default value
					$v = preg_replace('/(?<!DEFAULT)\sNULL/i', '', $v);
				}

				if (preg_match('/^([^ ]+) .*DEFAULT (\'[^\']+\'|\"[^\"]+\"|[^ ]+)/', $v, $matches)) {
					$existing = $this->metaColumns($tabname);
					list(, $colname, $default) = $matches;
					$alter .= $colname;
					if ($this->connection) {
						$old_coltype = $this->connection->metaType($existing[strtoupper($colname)]);
					} else {
						$old_coltype = $t;
					}
					$v = preg_replace('/^' . preg_quote($colname) . '\s/', '', $v);
					$t = trim(str_replace('DEFAULT '.$default,'',$v));

					// Type change from bool to int
					if ($old_coltype == 'L' && $t == 'INTEGER') {
						$sql[] = $alter . ' DROP DEFAULT';
						$sql[] = $alter . " TYPE $t USING ($colname::BOOL)::INT";
						$sql[] = $alter . " SET DEFAULT $default";
					}
					// Type change from int to bool
					else if ($old_coltype == 'I' && $t == 'BOOLEAN') {
						if (strcasecmp('NULL', trim($default)) != 0) {
							$default = $this->connection->qstr($default);
						}
						$sql[] = $alter . ' DROP DEFAULT';
						$sql[] = $alter . " TYPE $t USING CASE WHEN $colname = 0 THEN false ELSE true END";
						$sql[] = $alter . " SET DEFAULT $default";
					}
					// Any other column types conversion
					else {
						$sql[] = $alter . " TYPE $t";
						$sql[] = $alter . " SET DEFAULT $default";
					}

				} else {
					// drop default?
					preg_match('/^\s*(\S+)\s+(.*)$/', $v, $matches);
					list(, $colname, $rest) = $matches;
					$alter .= $colname;
					$sql[] = $alter . ' TYPE ' . $rest;
				}

				#list($colname) = explode(' ', $v);
				if ($not_null) {
					// this does not error out if the column is already not null
					$sql[] = $alter . ' SET NOT NULL';
				}
				if ($set_null) {
					// this does not error out if the column is already null
					$sql[] = $alter . ' DROP NOT NULL';
				}
			}
			return $sql;
		}

		// does not have alter column
		if (!$tableflds) {
			if ($this->debug) {
				ADOConnection::outp("alterColumnSQL needs a complete table-definiton for PostgreSQL");
			}
			return array();
		}
		return $this->_recreate_copy_table($tabname, false, $tableflds, $tableoptions);
	}

	/**
	 * Drop one column
	 *
	 * Postgres < 7.3 can't do that on it's own, you need to supply the complete definition of the new table,
	 * to allow, recreating the table and copying the content over to the new table
	 * @param string $tabname table name
	 * @param string $flds column name and type for the changed column
	 * @param string $tableflds complete defintion of the new table, eg. for postgres, default ''
	 * @param array/ $tableoptions options for the new table see createTableSQL, default ''
	 * @return array with SQL strings
	 */
	function dropColumnSQL($tabname, $flds, $tableflds='', $tableoptions='')
	{
		$has_drop_column = 7.3 <= (float) @$this->serverInfo['version'];
		if (!$has_drop_column && !$tableflds) {
			if ($this->debug) {
				ADOConnection::outp("dropColumnSQL needs complete table-definiton for PostgreSQL < 7.3");
			}
			return array();
		}
		if ($has_drop_column) {
			return ADODB_DataDict::dropColumnSQL($tabname, $flds);
		}
		return $this->_recreate_copy_table($tabname, $flds, $tableflds, $tableoptions);
	}

	/**
	 * Save the content into a temp. table, drop and recreate the original table and copy the content back in
	 *
	 * We also take care to set the values of the sequence and recreate the indexes.
	 * All this is done in a transaction, to not loose the content of the table, if something went wrong!
	 * @internal
	 * @param string $tabname table name
	 * @param string $dropflds column names to drop
	 * @param string $tableflds complete definition of the new table, eg. for postgres
	 * @param array|string $tableoptions options for the new table see createTableSQL, default ''
	 * @return array with SQL strings
	 */
	function _recreate_copy_table($tabname, $dropflds, $tableflds, $tableoptions='')
	{
		if ($dropflds && !is_array($dropflds)) {
			$dropflds = explode(',', $dropflds);
		}
		$copyflds = array();
		foreach ($this->metaColumns($tabname) as $fld) {
			if (!$dropflds || !in_array($fld->name, $dropflds)) {
				// we need to explicit convert varchar to a number to be able to do an AlterColumn of a char column to a nummeric one
				if (
					preg_match('/'.$fld->name.' (I|I2|I4|I8|N|F)/i', $tableflds, $matches)
					&& in_array($fld->type, array('varchar', 'char', 'text', 'bytea'))
				) {
					$copyflds[] = "to_number($fld->name,'S9999999999999D99')";
				} else {
					$copyflds[] = $fld->name;
				}
				// identify the sequence name and the fld its on
				if (
					$fld->primary_key
					&& $fld->has_default
					&& preg_match("/nextval\('([^']+)'::text\)/", $fld->default_value, $matches)
				) {
					$seq_name = $matches[1];
					$seq_fld = $fld->name;
				}
			}
		}
		$copyflds = implode(', ', $copyflds);

		$tempname = $tabname.'_tmp';
		$aSql[] = 'BEGIN'; // we use a transaction, to make sure not to loose the content of the table
		$aSql[] = "SELECT * INTO TEMPORARY TABLE $tempname FROM $tabname";
		$aSql = array_merge($aSql, $this->dropTableSQL($tabname));
		$aSql = array_merge($aSql, $this->createTableSQL($tabname, $tableflds, $tableoptions));
		$aSql[] = "INSERT INTO $tabname SELECT $copyflds FROM $tempname";
		if ($seq_name && $seq_fld) { // if we have a sequence we need to set it again
			$seq_name = $tabname.'_'.$seq_fld.'_seq'; // has to be the name of the new implicit sequence
			$aSql[] = "SELECT setval('$seq_name', MAX($seq_fld)) FROM $tabname";
		}
		$aSql[] = "DROP TABLE $tempname";
		// recreate the indexes, if they not contain one of the dropped columns
		foreach ($this->metaIndexes($tabname) as $idx_name => $idx_data) {
			if (
				substr($idx_name,-5) != '_pkey'
				&& (!$dropflds || !count(array_intersect($dropflds,$idx_data['columns'])))
			) {
				$aSql = array_merge(
					$aSql,
					$this->createIndexSQL(
						$idx_name,
						$tabname,
						$idx_data['columns'],
						$idx_data['unique'] ? array('UNIQUE') : false
					)
				);
			}
		}
		$aSql[] = 'COMMIT';
		return $aSql;
	}

	function dropTableSQL($tabname)
	{
		$sql = ADODB_DataDict::dropTableSQL($tabname);

		$drop_seq = $this->_dropAutoIncrement($tabname);
		if ($drop_seq) {
			$sql[] = $drop_seq;
		}
		return $sql;
	}

	// return string must begin with space
	function _createSuffix($fname, &$ftype, $fnotnull, $fdefault, $fautoinc, $fconstraint, $funsigned)
	{
		if ($fautoinc) {
			$ftype = 'SERIAL';
			return '';
		}
		$suffix = '';
		if (strlen($fdefault)) $suffix .= " DEFAULT $fdefault";
		if ($fnotnull) $suffix .= ' NOT NULL';
		if ($fconstraint) $suffix .= ' '.$fconstraint;
		return $suffix;
	}

	// search for a sequece for the given table (assumes the sequence-name contains the table-name!)
	// if yes return sql to drop it
	// This is still necessary if postgres < 7.3 or the SERIAL was created on an earlier version!!!
	function _dropAutoIncrement($tabname)
	{
		$tabname = $this->connection->quote('%'.$tabname.'%');

		$seq = $this->connection->getOne("SELECT relname FROM pg_class WHERE NOT relname ~ 'pg_.*' AND relname LIKE $tabname AND relkind='S'");

		// check if a tables depends on the sequenz and it therefor cant and dont need to be droped separatly
		if (!$seq || $this->connection->getOne("SELECT relname FROM pg_class JOIN pg_depend ON pg_class.relfilenode=pg_depend.objid WHERE relname='$seq' AND relkind='S' AND deptype='i'")) {
			return false;
		}
		return "DROP SEQUENCE ".$seq;
	}

	function renameTableSQL($tabname, $newname)
	{
		if (!empty($this->schema)) {
			$rename_from = $this->tableName($tabname);
			$schema_save = $this->schema;
			$this->schema = false;
			$rename_to = $this->tableName($newname);
			$this->schema = $schema_save;
			return array(sprintf($this->renameTable, $rename_from, $rename_to));
		}

		return array(sprintf($this->renameTable, $this->tableName($tabname), $this->tableName($newname)));
	}

	/**
	CREATE [ [ LOCAL ] { TEMPORARY | TEMP } ] TABLE table_name (
	{ column_name data_type [ DEFAULT default_expr ] [ column_constraint [, ... ] ]
	| table_constraint } [, ... ]
	)
	[ INHERITS ( parent_table [, ... ] ) ]
	[ WITH OIDS | WITHOUT OIDS ]
	where column_constraint is:
	[ CONSTRAINT constraint_name ]
	{ NOT NULL | NULL | UNIQUE | PRIMARY KEY |
	CHECK (expression) |
	REFERENCES reftable [ ( refcolumn ) ] [ MATCH FULL | MATCH PARTIAL ]
	[ ON DELETE action ] [ ON UPDATE action ] }
	[ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]
	and table_constraint is:
	[ CONSTRAINT constraint_name ]
	{ UNIQUE ( column_name [, ... ] ) |
	PRIMARY KEY ( column_name [, ... ] ) |
	CHECK ( expression ) |
	FOREIGN KEY ( column_name [, ... ] ) REFERENCES reftable [ ( refcolumn [, ... ] ) ]
	[ MATCH FULL | MATCH PARTIAL ] [ ON DELETE action ] [ ON UPDATE action ] }
	[ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]
	*/


	/**
	CREATE [ UNIQUE ] INDEX index_name ON table
[ USING acc_method ] ( column [ ops_name ] [, ...] )
[ WHERE predicate ]
CREATE [ UNIQUE ] INDEX index_name ON table
[ USING acc_method ] ( func_name( column [, ... ]) [ ops_name ] )
[ WHERE predicate ]
	*/
	function _indexSQL($idxname, $tabname, $flds, $idxoptions)
	{
		$sql = array();

		if (isset($idxoptions['REPLACE']) || isset($idxoptions['DROP'])) {
			$sql[] = sprintf ($this->dropIndex, $idxname, $tabname);
			if (isset($idxoptions['DROP'])) {
				return $sql;
			}
		}

		if (empty($flds)) {
			return $sql;
		}

		$unique = isset($idxoptions['UNIQUE']) ? ' UNIQUE' : '';

		$s = 'CREATE' . $unique . ' INDEX ' . $idxname . ' ON ' . $tabname . ' ';

		if (isset($idxoptions['HASH'])) {
			$s .= 'USING HASH ';
		}
		
		if (isset($idxoptions[$this->upperName])) {
			$s .= $idxoptions[$this->upperName];
		}

		if (is_array($flds)) {
			$flds = implode(', ', $flds);
		}
		$s .= '(' . $flds . ')';
		$sql[] = $s;

		return $sql;
	}

	function _getSize($ftype, $ty, $fsize, $fprec, $options=false)
	{
		if (strlen($fsize) && $ty != 'X' && $ty != 'B' && $ty  != 'I' && strpos($ftype,'(') === false) {
			$ftype .= "(".$fsize;
			if (strlen($fprec)) {
				$ftype .= ",".$fprec;
			}
			$ftype .= ')';
		}

		/**
		* Handle additional options
		*/
		if (is_array($options)) {
			foreach ($options as $type=>$value) {
				switch ($type) {
					case 'ENUM':
					$ftype .= '(' . $value . ')';
					break;

					default:
				}
			}
		}

		return $ftype;
	}

        /**
	 * "Florian Buzin [ easywe ]" <florian.buzin#easywe.de>
	 *
	 * This function changes/adds new fields to your table. You don't
	 * have to know if the col is new or not. It will check on its own.
	*/
	function changeTableSQL($tablename, $flds, $tableoptions = false, $dropOldFlds=false)
	{
		global $ADODB_FETCH_MODE;

		$save = $ADODB_FETCH_MODE;
		$ADODB_FETCH_MODE = ADODB_FETCH_ASSOC;
		if ($this->connection->fetchMode !== false) {
			$savem = $this->connection->setFetchMode(false);
		}

		// check table exists
		$save_handler = $this->connection->raiseErrorFn;
		$this->connection->raiseErrorFn = '';
		$cols = $this->metaColumns($tablename);
		$this->connection->raiseErrorFn = $save_handler;

		if (isset($savem)) {
			$this->connection->setFetchMode($savem);
		}

		$ADODB_FETCH_MODE = $save;

		if (empty($cols)) {
			return $this->createTableSQL($tablename, $flds, $tableoptions);
		}

		$addedcols = array();
		$modifiedcols = array();

		if (is_array($flds)) {
			// Cycle through the update fields, comparing
			// existing fields to fields to update.
			// if the Metatype and size is exactly the
			// same, ignore - by Mark Newham
			foreach ($flds as $k=>$v) {
				if (isset($cols[$k]) && is_object($cols[$k])) {
					// If already not allowing nulls, then don't change
					$obj = $cols[$k];
					if (isset($obj->not_null) && $obj->not_null) {
						$v = str_replace('NOT NULL', '', $v);
					}
					if (isset($obj->auto_increment) && $obj->auto_increment && empty($v['AUTOINCREMENT'])) {
						$v = str_replace('AUTOINCREMENT', '', $v);
					}

					$c = $cols[$k];
					$ml = $c->max_length;
					$mt = $this->metaType($c->type, $ml);

					if (isset($c->scale)) {
						$sc = $c->scale;
					} else {
						$sc = 99; // always force change if scale not known.
					}

					if ($sc == -1) {
						$sc = false;
					}
					list($fsize, $fprec) = $this->_getSizePrec($v['SIZE']);

					if ($ml == -1) {
						$ml = '';
					}
					if ($mt == 'X') {
						$ml = $v['SIZE'];
					}
					if (
						($mt != $v['TYPE'])
						|| ($ml != $fsize || $sc != $fprec)
						|| (isset($v['AUTOINCREMENT']) && $v['AUTOINCREMENT'] != $obj->auto_increment)
					) {
						$modifiedcols[$k] = $v;
                                        }
				} else {
					$addedcols[$k] = $v;
				}
			}
		}

		$sql = array();
		$sql = $this->addColumnSQL($tablename, $addedcols);

		// already exists, alter table instead
		list($lines, $pkey, $idxs) = $this->_genFields($modifiedcols);
		// genfields can return FALSE at times
		if ($lines == null) {
			$lines = array();
		}

		$holdflds = array();
		foreach ($lines as $id => $v) {
			if (isset($cols[$id]) && is_object($cols[$id])) {
				$flds = lens_ParseArgs($v, ',');

				//  We are trying to change the size of the field, if not allowed, simply ignore the request.
				// $flds[1] holds the type, $flds[2] holds the size -postnuke addition
				if (
					$flds
					&& in_array(strtoupper(substr($flds[0][1], 0, 4)), $this->invalidResizeTypes4)
					&& (isset($flds[0][2]) && is_numeric($flds[0][2]))
				) {
					if ($this->debug) {
						ADOConnection::outp(sprintf("<h3>%s cannot be changed to %s currently</h3>", $flds[0][0], $flds[0][1]));
					}
					continue;
	 			}
                                $holdflds[] = $modifiedcols[$id];
			}
		}
                $modifiedcols = $holdflds;
                $sql += $this->alterColumnSQL($tablename, $modifiedcols);

                if ($dropOldFlds) {
                        $alter = 'ALTER TABLE ' . $this->tableName($tablename);
			foreach ($cols as $id => $v) {
				if (!isset($lines[$id])) {
					$sql[] = $alter . $this->dropCol . ' ' . $v->name;
				}
			}
		}
		return $sql;
	}
} // end class