<?php
/**
 * Zend Framework (http://framework.zend.com/)
 *
 * @link      http://github.com/zendframework/zf2 for the canonical source repository
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license   http://framework.zend.com/license/new-bsd New BSD License
 * @package   Zend_Service_WindowsAzure
 */

namespace Zend\Service\WindowsAzure\Storage;

/**
 * @category   Zend
 * @package    Zend_Service_WindowsAzure
 * @subpackage Storage
 */
class TableEntityQuery
{
    /**
     * From
     *
     * @var string
     */
    protected $_from = '';

    /**
     * Where
     *
     * @var array
     */
    protected $_where = array();

    /**
     * Order by
     *
     * @var array
     */
    protected $_orderBy = array();

    /**
     * Top
     *
     * @var int
     */
    protected $_top = null;

    /**
     * Partition key
     *
     * @var string
     */
    protected $_partitionKey = null;

    /**
     * Row key
     *
     * @var string
     */
    protected $_rowKey = null;

    /**
     * Select clause
     *
     * @return TableEntityQuery
     */
    public function select()
    {
        return $this;
    }

    /**
     * From clause
     *
     * @param string $name Table name to select entities from
     * @return TableEntityQuery
     */
    public function from($name)
    {
        $this->_from = $name;
        return $this;
    }

    /**
     * Specify partition key
     *
     * @param string $value Partition key to query for
     * @return TableEntityQuery
     */
    public function wherePartitionKey($value = null)
    {
        $this->_partitionKey = $value;
        return $this;
    }

    /**
     * Specify row key
     *
     * @param string $value Row key to query for
     * @return TableEntityQuery
     */
    public function whereRowKey($value = null)
    {
        $this->_rowKey = $value;
        return $this;
    }

    /**
     * Add where clause
     *
     * @param string       $condition   Condition, can contain question mark(s) (?) for parameter insertion.
     * @param string|array $value       Value(s) to insert in question mark (?) parameters.
     * @param string       $cond        Condition for the clause (and/or/not)
     * @return TableEntityQuery
     */
    public function where($condition, $value = null, $cond = '')
    {
        $condition = $this->_replaceOperators($condition);

        if ($value !== null) {
            $condition = $this->_quoteInto($condition, $value);
        }

        if (count($this->_where) == 0) {
            $cond = '';
        } else if ($cond !== '') {
            $cond = ' ' . strtolower(trim($cond)) . ' ';
        }

        $this->_where[] = $cond . $condition;
        return $this;
    }

    /**
     * Add where clause with AND condition
     *
     * @param string       $condition   Condition, can contain question mark(s) (?) for parameter insertion.
     * @param string|array $value       Value(s) to insert in question mark (?) parameters.
     * @return TableEntityQuery
     */
    public function andWhere($condition, $value = null)
    {
        return $this->where($condition, $value, 'and');
    }

    /**
     * Add where clause with OR condition
     *
     * @param string       $condition   Condition, can contain question mark(s) (?) for parameter insertion.
     * @param string|array $value       Value(s) to insert in question mark (?) parameters.
     * @return TableEntityQuery
     */
    public function orWhere($condition, $value = null)
    {
        return $this->where($condition, $value, 'or');
    }

    /**
     * OrderBy clause
     *
     * @param string $column    Column to sort by
     * @param string $direction Direction to sort (asc/desc)
     * @return TableEntityQuery
     */
    public function orderBy($column, $direction = 'asc')
    {
        $this->_orderBy[] = $column . ' ' . $direction;
        return $this;
    }

    /**
     * Top clause
     *
     * @param int $top  Top to fetch
     * @return TableEntityQuery
     */
    public function top($top = null)
    {
        $this->_top = (int)$top;
        return $this;
    }

    /**
     * Assembles the query string
     *
     * @param boolean $urlEncode Apply URL encoding to the query string
     * @return string
     */
    public function assembleQueryString($urlEncode = false)
    {
        $query = array();
        if (count($this->_where) != 0) {
            $filter  = implode('', $this->_where);
            $query[] = '$filter=' . ($urlEncode ? urlencode($filter) : $filter);
        }

        if (count($this->_orderBy) != 0) {
            $orderBy = implode(',', $this->_orderBy);
            $query[] = '$orderby=' . ($urlEncode ? urlencode($orderBy) : $orderBy);
        }

        if ($this->_top !== null) {
            $query[] = '$top=' . $this->_top;
        }

        if (count($query) != 0) {
            return '?' . implode('&', $query);
        }

        return '';
    }

    /**
     * Assemble from
     *
     * @param boolean $includeParentheses Include parentheses? ()
     * @return string
     */
    public function assembleFrom($includeParentheses = true)
    {
        $identifier = '';
        if ($includeParentheses) {
            $identifier .= '(';

            if ($this->_partitionKey !== null) {
                $identifier .= 'PartitionKey=\'' . $this->_partitionKey . '\'';
            }

            if ($this->_partitionKey !== null && $this->_rowKey !== null) {
                $identifier .= ', ';
            }

            if ($this->_rowKey !== null) {
                $identifier .= 'RowKey=\'' . $this->_rowKey . '\'';
            }

            $identifier .= ')';
        }
        return $this->_from . $identifier;
    }

    /**
     * Assemble full query
     *
     * @return string
     */
    public function assembleQuery()
    {
        $assembledQuery = $this->assembleFrom();

        $queryString = $this->assembleQueryString();
        if ($queryString !== '') {
            $assembledQuery .= $queryString;
        }

        return $assembledQuery;
    }

    /**
     * Quotes a variable into a condition
     *
     * @param string       $text   Condition, can contain question mark(s) (?) for parameter insertion.
     * @param string|array $value  Value(s) to insert in question mark (?) parameters.
     * @return string
     */
    protected function _quoteInto($text, $value = null)
    {
        if (!is_array($value)) {
            $text = str_replace('?', '\'' . addslashes($value) . '\'', $text);
        } else {
            $i = 0;
            while (strpos($text, '?') !== false) {
                if (is_numeric($value[$i])) {
                    $text = substr_replace($text, $value[$i++], strpos($text, '?'), 1);
                } else {
                    $text = substr_replace($text, '\'' . addslashes($value[$i++]) . '\'', strpos($text, '?'), 1);
                }
            }
        }
        return $text;
    }

    /**
     * Replace operators
     *
     * @param string $text
     * @return string
     */
    protected function _replaceOperators($text)
    {
        $text = str_replace('==', 'eq', $text);
        $text = str_replace('>', 'gt', $text);
        $text = str_replace('<', 'lt', $text);
        $text = str_replace('>=', 'ge', $text);
        $text = str_replace('<=', 'le', $text);
        $text = str_replace('!=', 'ne', $text);

        $text = str_replace('&&', 'and', $text);
        $text = str_replace('||', 'or', $text);
        $text = str_replace('!', 'not', $text);

        return $text;
    }

    /**
     * __toString overload
     *
     * @return string
     */
    public function __toString()
    {
        return $this->assembleQuery();
    }
}