<?php
include_once "conn.php";
include ("functions.php");
$apagenum = 3;//一页几个
if (isset($_GET['kind'])) {

    $kind = (int)$_GET['kind'];
    $page = (int)$_GET['page'];
} else {
    $page = 2;
    $kind = 0;
}
//$kind=$kind-1;
header("Content-type:application/json");
header('Access-Control-Allow-Origin:*');
//0.图片链接 1.日 2.月 3.标题 4.内容 5.跳转链接
$selstr="picnameinfile,teachername,nowpeople,numpeople,coursename,introducetext,c.introduceid,courseid";
if(isset($_COOKIE['majorid']) && isset($_COOKIE['enteryear']) )
{
    //用户已登录 ，进行 专业限制 的分类搜索
    $majorid=$_COOKIE['majorid'];
    $enteryear=$_COOKIE['enteryear'];
    $grade=gettoyear()-$enteryear+1;
    if($kind==0)
    {
        //搜索全部分类
        $result = $link->query("SELECT COUNT(*) 
                                       FROM course as c,introduce as i,teacher as t 
                                       where c.delete='0' and c.introduceid=i.introduceid and t.teacherid=c.teacherid
                                       and c.courseid in (select courseid 
                                                          from electivelimit 
                                                          where (majorid='$majorid' or majorid='0') and (grade='$grade' or grade='0')
                                                          )"
                                );
        list($row_num) = $result->fetch_row();  /// $row_num即为记录数
        $index=($page-1)*$apagenum;
        $sql="select $selstr 
              from course as c,introduce as i,teacher as t
              where c.delete='0' and c.introduceid=i.introduceid and t.teacherid=c.teacherid 
              and c.courseid in (select courseid 
                              from electivelimit 
                              where (majorid='$majorid' or majorid='0') and (grade='$grade' or grade='0')
                              )
              order by courseid desc limit $index,$apagenum";
    }else if($kind=="-1")
    {
        $searchstr=$_GET['searchstr'];
        $result = $link->query("SELECT COUNT(*) 
                                       FROM course as c,introduce as i,teacher as t 
                                       where c.delete='0' and c.introduceid=i.introduceid and t.teacherid=c.teacherid and c.coursename like '%$searchstr%'");
        list($row_num) = $result->fetch_row();  /// $row_num即为记录数
        $index=($page-1)*$apagenum;
        $sql="select $selstr 
              from course as c,introduce as i,teacher as t
              where c.delete='0' and c.introduceid=i.introduceid and t.teacherid=c.teacherid and c.coursename like '%$searchstr%'
              order by courseid desc limit $index,$apagenum";


    }else{
        //搜索指定分类
        $result = $link->query("SELECT COUNT(*) 
                                       FROM course as c,introduce as i,teacher as t 
                                       where c.delete='0' and c.introduceid=i.introduceid and t.teacherid=c.teacherid and kind='$kind'
                                       and c.courseid in (select courseid 
                                                          from electivelimit 
                                                          where (majorid='$majorid' or majorid='0') and (grade='$grade' or grade='0')
                                                          )");
        list($row_num) = $result->fetch_row();  /// $row_num即为记录数
        $index=($page-1)*$apagenum;
        $sql="select $selstr 
              from course as c,introduce as i,teacher as t
              where c.delete='0' and c.introduceid=i.introduceid and t.teacherid=c.teacherid and kind='$kind'
              and c.courseid in (select courseid 
                                  from electivelimit 
                                  where (majorid='$majorid' or majorid='0') and (grade='$grade' or grade='0')
                                  )
              order by courseid desc limit $index,$apagenum";
    }
}else{
    //用户未登录 , 进行 无专业限制 的分类搜索
    if($kind==0)
    {
        //搜索全部分类
        $result = $link->query("SELECT COUNT(*) 
                                       FROM course as c,introduce as i,teacher as t 
                                       where c.delete='0' and c.introduceid=i.introduceid and t.teacherid=c.teacherid");
        list($row_num) = $result->fetch_row();  /// $row_num即为记录数
        $index=($page-1)*$apagenum;
        $sql="select $selstr 
              from course as c,introduce as i,teacher as t
              where c.delete='0' and c.introduceid=i.introduceid and t.teacherid=c.teacherid
              order by courseid desc limit $index,$apagenum";
    }else if($kind=="-1")
    {
        $searchstr=$_GET['searchstr'];
        $result = $link->query("SELECT COUNT(*) 
                                       FROM course as c,introduce as i,teacher as t 
                                       where c.delete='0' and c.introduceid=i.introduceid and t.teacherid=c.teacherid and c.coursename like '%$searchstr%'");
        list($row_num) = $result->fetch_row();  /// $row_num即为记录数
        $index=($page-1)*$apagenum;
        $sql="select $selstr 
              from course as c,introduce as i,teacher as t
              where c.delete='0' and c.introduceid=i.introduceid and t.teacherid=c.teacherid and c.coursename like '%$searchstr%'
              order by courseid desc limit $index,$apagenum";


    }else{
        //搜索指定分类
        $result = $link->query("SELECT COUNT(*) 
                                       FROM course as c,introduce as i,teacher as t 
                                       where c.delete='0' and c.introduceid=i.introduceid and t.teacherid=c.teacherid and kind='$kind'");
        list($row_num) = $result->fetch_row();  /// $row_num即为记录数
        $index=($page-1)*$apagenum;
        $sql="select $selstr 
              from course as c,introduce as i,teacher as t
              where c.delete='0' and c.introduceid=i.introduceid and t.teacherid=c.teacherid and kind='$kind'
              order by courseid desc limit $index,$apagenum";
    }
}



$result = mysqli_query($link,$sql);
if (!$result) {
    printf("Error: %s\n", mysqli_error($link));
    exit();
}else {
    $results=array();
    $i=0;

    while ($row = mysqli_fetch_assoc($result)) {
        //$selstr="picnameinfile,teachername,nowpeople,numpeople,coursename,introducetext,introduceid,courseid"
        $results[$i][0]=$row['picnameinfile'];
        $results[$i][1]=$row['teachername'];
        $results[$i][2]=$row['nowpeople']."/".$row['numpeople'];
        $results[$i][3]=$row['coursename'];
        $results[$i][4]=Trim_tit($row['introducetext'],34);
        $results[$i][5]=$row['introduceid'];
        $results[$i][6]=$row['courseid'];
        $i++;
    }
}
if(count($results)==0)
{
    //没有了
    $results="null";
}
echo json_encode($results);
?>