class views_join

class views_join {
    public $table = NULL;
    public $left_table = NULL;
    public $left_field = NULL;
    public $field = NULL;
    public $extra = NULL;
    public $type = NULL;
    public $definition = array();
    
    /**
     * Construct the views_join object.
     */
    public function construct($table = NULL, $left_table = NULL, $left_field = NULL, $field = NULL, $extra = array(), $type = 'LEFT') {
        $this->extra_type = 'AND';
        if (!empty($table)) {
            $this->table = $table;
            $this->left_table = $left_table;
            $this->left_field = $left_field;
            $this->field = $field;
            $this->extra = $extra;
            $this->type = strtoupper($type);
        }
        elseif (!empty($this->definition)) {
            // If no arguments, construct from definition. These four must exist or
            // it will throw notices.
            $this->table = $this->definition['table'];
            $this->left_table = $this->definition['left_table'];
            $this->left_field = $this->definition['left_field'];
            $this->field = $this->definition['field'];
            if (!empty($this->definition['extra'])) {
                $this->extra = $this->definition['extra'];
            }
            if (!empty($this->definition['extra type'])) {
                $this->extra_type = strtoupper($this->definition['extra type']);
            }
            $this->type = !empty($this->definition['type']) ? strtoupper($this->definition['type']) : 'LEFT';
        }
    }
    
    /**
     * Build the SQL for the join this object represents.
     *
     * When possible, try to use table alias instead of table names.
     *
     * @param SelectQueryInterface $select_query
     *   An Implements SelectQueryInterface.
     * @param string $table
     *   The base table to join.
     * @param views_plugin_query $view_query
     *   The source query, Implements views_plugin_query.
     */
    public function build_join($select_query, $table, $view_query) {
        if (empty($this->definition['table formula'])) {
            $right_table = $this->table;
        }
        else {
            $right_table = $this->definition['table formula'];
        }
        if ($this->left_table) {
            $left = $view_query->get_table_info($this->left_table);
            $left_field = "{$left['alias']}.{$this->left_field}";
        }
        else {
            // This can be used if left_field is a formula or something. It should be
            // used only *very* rarely.
            $left_field = $this->left_field;
        }
        $condition = "{$left_field} = {$table['alias']}.{$this->field}";
        $arguments = array();
        // Tack on the extra.
        if (isset($this->extra)) {
            // If extra has been provided as string instead of an array, convert it
            // to an array.
            if (!is_array($this->extra)) {
                $this->extra = array(
                    $this->extra,
                );
            }
            $extras = array();
            foreach ($this->extra as $info) {
                if (is_array($info)) {
                    // Figure out the table name. Remember, only use aliases provided if
                    // at all possible.
                    $join_table = '';
                    if (!array_key_exists('table', $info)) {
                        $join_table = $table['alias'] . '.';
                    }
                    elseif (isset($info['table'])) {
                        // If we're aware of a table alias for this table, use the table
                        // alias instead of the table name.
                        if (isset($left) && $left['table'] == $info['table']) {
                            $join_table = $left['alias'] . '.';
                        }
                        else {
                            $join_table = $info['table'] . '.';
                        }
                    }
                    // Convert a single-valued array of values to the single-value case,
                    // and transform from IN() notation to = notation.
                    if (is_array($info['value']) && count($info['value']) == 1) {
                        if (empty($info['operator'])) {
                            $operator = '=';
                        }
                        else {
                            $operator = $info['operator'] == 'NOT IN' ? '!=' : '=';
                        }
                        $info['value'] = array_shift($info['value']);
                    }
                    if (is_array($info['value'])) {
                        $value_placeholders = array();
                        // With an array of values, we need multiple placeholders and the
                        // 'IN' operator is implicit.
                        foreach ($info['value'] as $value) {
                            $placeholder_i = $view_query->placeholder('views_join_condition_');
                            $value_placeholders[] = $placeholder_i;
                            $arguments[$placeholder_i] = $value;
                        }
                        $operator = !empty($info['operator']) ? $info['operator'] : 'IN';
                        $placeholder = '( ' . implode(', ', $value_placeholders) . ' )';
                    }
                    else {
                        // With a single value, the '=' operator is implicit.
                        $operator = !empty($info['operator']) ? $info['operator'] : '=';
                        $placeholder = $view_query->placeholder('views_join_condition_');
                        $arguments[$placeholder] = $info['value'];
                    }
                    $extras[] = "{$join_table}{$info['field']} {$operator} {$placeholder}";
                }
                elseif (is_string($info)) {
                    $extras[] = $info;
                }
            }
            if ($extras) {
                if (count($extras) == 1) {
                    $condition .= ' AND (' . array_shift($extras) . ')';
                }
                else {
                    $condition .= ' AND (' . implode(' ' . $this->extra_type . ' ', $extras) . ')';
                }
            }
        }
        $select_query->addJoin($this->type, $right_table, $table['alias'], $condition, $arguments);
    }

}