<?php

class Db_Pgsql_Select implements iDb_Select
{
    /** @var array массив параметров запроса */
    public $string = array();

    function __construct()
    {
        $columns = func_get_args();
        if (!empty($columns[0])) {
            $this->addColumns(is_array($columns[0][0]) ? $columns[0][0] : $columns[0]);
        }
    }

    public function __toString()
    {
        $result = 'SELECT '
            . (isset($this->string['distinct']) ? $this->string['distinct'] : '')
            . (isset($this->string['columns']) && is_array($this->string['columns']) && !empty($this->string['columns'])
                ? implode(', ', $this->string['columns']) : '*')
            . (isset($this->string['from'])?' FROM ' . implode(', ', $this->string['from']):'');

        if (isset($this->string['join'])) {
            $result .= implode("\n ", $this->string['join']);
        }

        if (isset($this->string['where'])) {
            $result .= ' WHERE (' . implode(') AND (', $this->string['where']) . ')';
        }

        if (isset($this->string['group'])) {
            $result .= ' ' . $this->string['group'];
        }

        if (isset($this->string['order'])) {
            $result .= ' ORDER BY ' . implode(', ', $this->string['order']);
        }

        if (isset($this->string['having'])) {
            $result .= ' HAVING (' . implode(') AND (', $this->string['having']) . ')';
        }

        if (isset($this->string['limit'])) {
            $result .= ' ' . $this->string['limit'];
        }

        return $result;
    }

    public function distinct()
    {
        $this->string['distinct'] = 'DISTINCT ';
        return $this;
    }

    public function from($tableName)
    {
        if (is_string($tableName)) {
            $this->string['from'][] = $tableName;
        } else if (is_array($tableName) && !empty($tableName)) {
            foreach ($tableName as $name => $alias) {
                $this->string['from'][] = '"' . $name . '" AS ' . $alias;
            }
        }
        return $this;
    }

    private function conditionReplace($condition, $value = null)
    {
        if ($value !== null) {
            if (is_array($value)) {
                foreach ($value as &$val) {
                    if (is_array($val)) {
                        foreach ($val as &$subval) {
                            if (!(is_float($subval) || is_int($subval))){
                                $subval = $this->quote($subval);
                            }
                        }
                        $val = implode(', ', $val);
                    } else {
                        if (!(is_float($val) || is_int($val))) {
                            $val = $this->quote($val);
                        }
                    }
                    $spos = mb_strpos($condition, '?');
                    if ($spos !== false) $condition = mb_substr($condition, 0, $spos).$val.mb_substr($condition, $spos+1);
                }
            } else {
                if (!(is_float($value) || is_int($value))) {
                    $value = $this->quote($value);
                }
                $condition = str_replace('?', $value, $condition);
            }

        }
        return $condition;
    }

    public function where($condition, $value = null)
    {
        $this->string['where'][] = $this->conditionReplace($condition, $value);
        return $this;
    }

    public function having($condition, $value = null)
    {
        $this->string['having'][] = $this->conditionReplace($condition, $value);
        return $this;
    }

    public function order($field, $direction = null)
    {
        $this->string['order'][] = $field . ($direction !== null && is_string($direction) ? ' ' . $direction : '');
        return $this;
    }

    public function group($value)
    {
        if (is_array($value)) {
            $value = implode(', ', $value);
        }
        $this->string['group'] = 'GROUP BY ' . $value;
        return $this;
    }

    public function limit($count, $offset = 0)
    {
        $this->string['limit'] = "LIMIT $count" . ($offset ? ' OFFSET ' . $offset : '');
        return $this;
    }

    /**
     * Присоединение таблицы
     *
     * @param string $type тип соединение таблиц
     * @param string $tableName таблица БД
     * @param string $condition условие присоединения
     * @return Db_Pgsql_Select
     */
    private function _join($type, $tableName, $condition)
    {
        if ($type == 'left') {
            $join = 'LEFT JOIN';
        } else if ($type == 'right') {
            $join = 'RIGHT JOIN';
        } else if ($type == 'inner') {
            $join = 'INNER JOIN';
        } else {
            $join = 'JOIN';
        }
        $this->string['join'][] = " $join $tableName ON $condition ";
        return $this;
    }

    public function quote($str)
    {
        return Db_Driver::getInstance()->quote($str);
    }

    public function join($tableName, $condition)
    {
        return $this->_join('inner', $tableName, $condition);
    }

    public function joinLeft($tableName, $condition)
    {
        return $this->_join('left', $tableName, $condition);
    }

    public function addColumns(array $columns)
    {
        if (empty($columns)) return $this;
        foreach ($columns as $column) {
            if (is_string($column)) {
                $this->string['columns'][] = $column;
            // todo: may be don't need this :)
            } else if (is_array($column)) {
                $this->string['columns'][] = $column[1] . '."' . $column[0] . '"';
            }
        }
        return $this;
    }

    public function fetchCol($server = null)
    {
        return Db_Driver::getInstance()->fetchCol($this, $server);
    }

    public function fetchAll($server = null)
    {
        return Db_Driver::getInstance()->fetchAll($this, $server);
    }

    public function fetchArray($server = null)
    {
        return Db_Driver::getInstance()->fetchArray($this, $server);
    }

    public function fetchAssoc($server = null)
    {
        return Db_Driver::getInstance()->fetchAssoc($this, $server);
    }

    public function fetchOne($server = null)
    {
        return Db_Driver::getInstance()->fetchOne($this, $server);
    }

    public function fetchRow($server = null)
    {
        return Db_Driver::getInstance()->fetchRow($this, $server);
    }

}