<?php

/**

 * @ingroup database

 * @{

 */

/**

 * @file

 * Query code for PostgreSQL embedded database engine.

 */

class InsertQuery_pgsql extends InsertQuery {

  public function execute() {

    if (!$this->preExecute()) {

      return NULL;

    }

    $stmt = $this->connection->prepareQuery((string) $this);

    // Fetch the list of blobs and sequences used on that table.

    $table_information = $this->connection->schema()->queryTableInformation($this->table);

    $max_placeholder = 0;

    $blobs = array();

    $blob_count = 0;

    foreach ($this->insertValues as $insert_values) {

      foreach ($this->insertFields as $idx => $field) {

        if (isset($table_information->blob_fields[$field])) {

          $blobs[$blob_count] = fopen('php://memory', 'a');

          fwrite($blobs[$blob_count], $insert_values[$idx]);

          rewind($blobs[$blob_count]);

          $stmt->bindParam(':db_insert_placeholder_' . $max_placeholder++, $blobs[$blob_count], PDO::PARAM_LOB);

          // Pre-increment is faster in PHP than increment.

          ++$blob_count;

        }

        else {

          $stmt->bindParam(':db_insert_placeholder_' . $max_placeholder++, $insert_values[$idx]);

        }

      }

      // Check if values for a serial field has been passed.

      if (!empty($table_information->serial_fields)) {

        foreach ($table_information->serial_fields as $index => $serial_field) {

          $serial_key = array_search($serial_field, $this->insertFields);

          if ($serial_key !== FALSE) {

            $serial_value = $insert_values[$serial_key];

            // Force $last_insert_id to the specified value. This is only done

            // if $index is 0.

            if ($index == 0) {

              $last_insert_id = $serial_value;

            }

            // Set the sequence to the bigger value of either the passed

            // value or the max value of the column. It can happen that another

            // thread calls nextval() which could lead to a serial number being

            // used twice. However, trying to insert a value into a serial

            // column should only be done in very rare cases and is not thread

            // safe by definition.

            $this->connection->query("SELECT setval('" . $table_information->sequences[$index] . "', GREATEST(MAX(" . $serial_field . "), :serial_value)) FROM {" . $this->table . "}", array(':serial_value' => (int)$serial_value));

          }

        }

      }

    }

    if (!empty($this->fromQuery)) {

      // bindParam stores only a reference to the variable that is followed when

      // the statement is executed. We pass $arguments[$key] instead of $value

      // because the second argument to bindParam is passed by reference and

      // the foreach statement assigns the element to the existing reference.

      $arguments = $this->fromQuery->getArguments();

      foreach ($arguments as $key => $value) {

        $stmt->bindParam($key, $arguments[$key]);

      }

    }

    // PostgreSQL requires the table name to be specified explicitly

    // when requesting the last insert ID, so we pass that in via

    // the options array.

    $options = $this->queryOptions;

    if (!empty($table_information->sequences)) {

      $options['sequence_name'] = $table_information->sequences[0];

    }

    // If there are no sequences then we can't get a last insert id.

    elseif ($options['return'] == Database::RETURN_INSERT_ID) {

      $options['return'] = Database::RETURN_NULL;

    }

    // Only use the returned last_insert_id if it is not already set.

    if (!empty($last_insert_id)) {

      $this->connection->query($stmt, array(), $options);

    }

    else {

      $last_insert_id = $this->connection->query($stmt, array(), $options);

    }

    // Re-initialize the values array so that we can re-use this query.

    $this->insertValues = array();

    return $last_insert_id;

  }

  public function __toString() {

    // Create a sanitized comment string to prepend to the query.

    $comments = $this->connection->makeComment($this->comments);

    // Default fields are always placed first for consistency.

    $insert_fields = array_merge($this->defaultFields, $this->insertFields);

    // If we're selecting from a SelectQuery, finish building the query and

    // pass it back, as any remaining options are irrelevant.

    if (!empty($this->fromQuery)) {

      $insert_fields_string = $insert_fields ? ' (' . implode(', ', $insert_fields) . ') ' : ' ';

      return $comments . 'INSERT INTO {' . $this->table . '}' . $insert_fields_string . $this->fromQuery;

    }

    $query = $comments . 'INSERT INTO {' . $this->table . '} (' . implode(', ', $insert_fields) . ') VALUES ';

    $max_placeholder = 0;

    $values = array();

      if (count($this->insertValues)) {

      foreach ($this->insertValues as $insert_values) {

        $placeholders = array();

        // Default fields aren't really placeholders, but this is the most convenient

        // way to handle them.

        $placeholders = array_pad($placeholders, count($this->defaultFields), 'default');

        $new_placeholder = $max_placeholder + count($insert_values);

        for ($i = $max_placeholder; $i < $new_placeholder; ++$i) {

          $placeholders[] = ':db_insert_placeholder_' . $i;

        }

        $max_placeholder = $new_placeholder;

        $values[] = '(' . implode(', ', $placeholders) . ')';

      }

    }

    else {

      // If there are no values, then this is a default-only query. We still need to handle that.

      $placeholders = array_fill(0, count($this->defaultFields), 'default');

      $values[] = '(' . implode(', ', $placeholders) . ')';

    }

    $query .= implode(', ', $values);

    return $query;

  }

}

class UpdateQuery_pgsql extends UpdateQuery {

  public function execute() {

    $max_placeholder = 0;

    $blobs = array();

    $blob_count = 0;

    // Because we filter $fields the same way here and in __toString(), the

    // placeholders will all match up properly.

    $stmt = $this->connection->prepareQuery((string) $this);

    // Fetch the list of blobs and sequences used on that table.

    $table_information = $this->connection->schema()->queryTableInformation($this->table);

    // Expressions take priority over literal fields, so we process those first

    // and remove any literal fields that conflict.

    $fields = $this->fields;

    $expression_fields = array();

    foreach ($this->expressionFields as $field => $data) {

      if (!empty($data['arguments'])) {

        foreach ($data['arguments'] as $placeholder => $argument) {

          // We assume that an expression will never happen on a BLOB field,

          // which is a fairly safe assumption to make since in most cases

          // it would be an invalid query anyway.

          $stmt->bindParam($placeholder, $data['arguments'][$placeholder]);

        }

      }

      unset($fields[$field]);

    }

    foreach ($fields as $field => $value) {

      $placeholder = ':db_update_placeholder_' . ($max_placeholder++);

      if (isset($table_information->blob_fields[$field])) {

        $blobs[$blob_count] = fopen('php://memory', 'a');

        fwrite($blobs[$blob_count], $value);

        rewind($blobs[$blob_count]);

        $stmt->bindParam($placeholder, $blobs[$blob_count], PDO::PARAM_LOB);

        ++$blob_count;

      }

      else {

        $stmt->bindParam($placeholder, $fields[$field]);

      }

    }

    if (count($this->condition)) {

      $this->condition->compile($this->connection, $this);

      $arguments = $this->condition->arguments();

      foreach ($arguments as $placeholder => $value) {

        $stmt->bindParam($placeholder, $arguments[$placeholder]);

      }

    }

    $options = $this->queryOptions;

    $options['already_prepared'] = TRUE;

    $this->connection->query($stmt, $options);

    return $stmt->rowCount();

  }

}