class views_join

class views_join {
    var $table = NULL;
    var $left_table = NULL;
    var $left_field = NULL;
    var $field = NULL;
    var $extra = NULL;
    var $type = NULL;
    var $definition = array();
    
    /**
     * Construct the views_join object.
     */
    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);
        }
        else {
            if (!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.
     */
    function join($table, &$query) {
        if (empty($this->definition['table formula'])) {
            $right_table = "{" . $this->table . "}";
        }
        else {
            $right_table = $this->definition['table formula'];
        }
        if ($this->left_table) {
            $left = $query->get_table_info($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;
        }
        $output = " {$this->type} JOIN {$right_table} {$table['alias']} ON {$left_field} = {$table['alias']}.{$this->field}";
        // Load query tokens replacements.
        $view = views_get_current_view();
        $replacements = array();
        if (!empty($view)) {
            $replacements = $view->substitutions();
        }
        else {
            vpr('The current view is not set, maybe some code missed to execute $view->pre_execute()');
        }
        // Tack on the extra.
        if (isset($this->extra)) {
            if (is_array($this->extra)) {
                $extras = array();
                foreach ($this->extra as $info) {
                    $extra = '';
                    // 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'])) {
                        $join_table = $info['table'] . '.';
                    }
                    // Apply query token replacements.
                    $info['value'] = str_replace(array_keys($replacements), $replacements, $info['value']);
                    // And now deal with the value and the operator.  Set $q to
                    // a single-quote for non-numeric values and the
                    // empty-string for numeric values, then wrap all values in $q.
                    if (empty($info['raw'])) {
                        $raw_value = $this->db_safe($info['value'], $info);
                        $q = empty($info['numeric']) ? "'" : '';
                    }
                    else {
                        $raw_value = $info['value'];
                        $q = '';
                    }
                    if (is_array($raw_value)) {
                        $operator = !empty($info['operator']) ? $info['operator'] : 'IN';
                        // Transform from IN() notation to = notation if just one value.
                        if (count($raw_value) == 1) {
                            $value = $q . array_shift($raw_value) . $q;
                            $operator = $operator == 'NOT IN' ? '!=' : '=';
                        }
                        else {
                            $value = "({$q}" . implode("{$q}, {$q}", $raw_value) . "{$q})";
                        }
                    }
                    else {
                        $operator = !empty($info['operator']) ? $info['operator'] : '=';
                        $value = "{$q}{$raw_value}{$q}";
                    }
                    $extras[] = "{$join_table}{$info['field']} {$operator} {$value}";
                }
                if ($extras) {
                    if (count($extras) == 1) {
                        $output .= ' AND ' . array_shift($extras);
                    }
                    else {
                        $output .= ' AND (' . implode(' ' . $this->extra_type . ' ', $extras) . ')';
                    }
                }
            }
            else {
                if ($this->extra && is_string($this->extra)) {
                    $output .= " AND ({$this->extra})";
                }
            }
        }
        return $output;
    }
    
    /**
     * Ensure that input is db safe. We only check strings and ints tho
     * so something that needs floats in their joins needs to do their
     * own type checking.
     */
    function db_safe($input, $info) {
        if (is_array($input)) {
            $output = array();
            foreach ($input as $value) {
                if (empty($info['numeric'])) {
                    $output[] = db_escape_string($value);
                }
                else {
                    $output[] = intval($value);
                }
            }
        }
        else {
            if (empty($info['numeric'])) {
                $output = db_escape_string($input);
            }
            else {
                $output = intval($input);
            }
        }
        return $output;
    }

}