<?php
namespace Rails\ActiveRecord\Adapter\MySql;

use Rails\ActiveRecord\Adapter\Exception;
use Rails\ActiveRecord\Adapter\AbstractQueryBuilder;

class QueryBuilder extends AbstractQueryBuilder
{
    protected function calculate_found_rows()
    {
        $rows = $this->connection->query("SELECT FOUND_ROWS()");
        $rows = array_shift($rows);
        $rows = array_shift($rows);
        $this->_row_count = (int)$rows;
    }
    
    protected function _build_sql()
    {
        $query = $this->query;
        
        $params = [];
        
        $sql = 'SELECT';
        
        if ($this->will_paginate)
            $sql .= ' SQL_CALC_FOUND_ROWS';
        
        if ($query->distinct)
            $sql .= ' DISTINCT';
        
        $sql .= ' ' . ($query->select ? implode(', ', $query->select) : '`' . $query->from . '`.*');
        $sql .= " FROM `" . $query->from . "`";
        $sql .= ' ' . implode(' ', $query->joins);
        
        if ($where = $this->_build_where_clause($query)) {
            $sql .= " WHERE " . $where[0];
            $params = $where[1];
            unset($where);
        }
        
        if ($query->group)
            $sql .= ' GROUP BY ' . implode(', ', $query->group);
        
        if ($query->order)
            $sql .= ' ORDER BY ' . implode(', ', $query->order);
        
        if ($query->having) {
            $sql .= ' HAVING ' . implode(' ', $query->having);
            $params = array_merge($params, $query->having_params);
        }
        
        if ($query->offset && $query->limit)
            $sql .= ' LIMIT ' . $query->offset . ', ' . $query->limit;
        elseif ($query->limit)
            $sql .= ' LIMIT ' . $query->limit;
        
        array_unshift($params, $sql);
        $this->_params = $params;
    }
    
    private function _build_where_clause($query)
    {
        if (!$query->where)
            return;
        // if (end($query->_where) == 'name in (?)')
            // vpe($query->where_params);
        $where = $where_params = [];
        $param_count = 0;
        
        foreach ($query->where as $condition) {
            # Case: ["foo" => $foo, "bar_baz" => $bar];
            if (is_array($condition)) {
                foreach ($condition as $column => $value) {
                    $where[] = $column . ' = ?';
                    $where_params[] = $value;
                }
            } else {
                if ($count = substr_count($condition, '?')) {
                    foreach (range(0, $count - 1) as $i) {
                        if (!array_key_exists($param_count, $query->where_params))
                            throw new Exception\RuntimeException(sprintf("Value for question mark placeholder for WHERE clause section wasn't found: %s", $condition));
                        
                        if (is_array($query->where_params[$param_count])) {
                            $condition = preg_replace('/\?/', implode(', ', array_fill(0, count($query->where_params[$param_count]), '?')), $condition, 1);
                            $where_params = array_merge($where_params, $query->where_params[$param_count]);
                        } else {
                            $where_params[] = $query->where_params[$param_count];
                        }
                        $param_count++;
                    }
                } elseif ($count = substr_count($condition, ':')) {
                    $where_params = $query->where_params;
                }
                
                $where[] = $condition;
            }
        }
        
        return [implode(' AND ', $where), $where_params];
    }
}