my Q&a external user file

<?php

/*
    Question2Answer 1.0-beta-2 (c) 2010, Gideon Greenspan

    http://www.question2answer.org/


    File: qa-external-example/qa-external-users.php
    Version: 1.0-beta-2
    Date: 2010-03-08 13:08:01 GMT


    This software is licensed for use in websites which are connected to the
    public world wide web and which offer unrestricted access worldwide. It
    may also be freely modified for use on such websites, so long as a
    link to http://www.question2answer.org/ is displayed on each page.


    THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
    INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
    AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
    THE COPYRIGHT HOLDER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
    TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


Your functions for integrating with your existing user management system.
This file is used if QA_EXTERNAL_USERS is set to true in qa-config.php.
*/

/*
    ==========================================================================
          YOU MUST MODIFY THIS FUNCTION *BEFORE* QA CREATES ITS DATABASE
    ==========================================================================

    qa_get_mysql_user_column_type()

    You should return the appropriate MySQL column type to use for the userid,
    for smooth integration with your existing users. Allowed options are:

    SMALLINT, SMALLINT UNSIGNED, MEDIUMINT, MEDIUMINT UNSIGNED, INT, INT UNSIGNED,
    BIGINT, BIGINT UNSIGNED or VARCHAR(x) where x is the maximum length.
*/

function qa_get_mysql_user_column_type() {

    //  Set this before anything else

    return 'MEDIUMINT UNSIGNED';
}



/*
    ==========================================================================
    YOU MUST MODIFY THIS FUNCTION, BUT CAN DO SO AFTER QA CREATES ITS DATABASE
    ==========================================================================

    qa_get_login_links($relative_url_prefix, $redirect_back_to_url)

    You should return an array containing URLs for the login, register and logout pages on
    your site. These URLs will be used as appropriate within the QA site.

    You may return absolute or relative URLs for each page. If you do not want one of the links
    to show, omit it from the array, or use null or an empty string.

    If you use absolute URLs, then return an array with the URLs in full (see example 1 below).

    If you use relative URLs, the URLs should start with $relative_url_prefix, followed by the
    relative path from the root of the QA site to your login page. Like in example 2 below, if
    the QA site is in a subdirectory, $relative_url_prefix.'../' refers to your site root.

    Now, about $redirect_back_to_url. Let's say a user is viewing a page on the QA site, and
    clicks a link to the login URL that you returned from this function. After they log in using
    the form on your main site, they want to automatically go back to the page on the QA site
    where they came from. This can be done with an HTTP redirect, but how does your login page
    know where to redirect the user to? The solution is $redirect_back_to_url, which is the URL
    of the page on the QA site where you should send the user once they've successfully logged
    in. To implement this, you can add $redirect_back_to_url as a parameter to the login URL
    that you return from this function. Your login page can then read it in from this parameter,
    and redirect the user back to the page after they've logged in. The same applies for your
    register and logout pages. Note that the URL you are given in $redirect_back_to_url is
    relative to the root of the QA site, so you may need to add something.
*/

function qa_get_login_links($relative_url_prefix, $redirect_back_to_url) {

    //  Until you edit this function, don't show login, register or logout links

    return array(
            'login' => 'http://extranet.domain.com/login/',
            //  'register' => 'http://extranet.domain.com/register/',
            'logout' => 'http://extranet.domain.com/logout/'
    );
}



/*
    ==========================================================================
    YOU MUST MODIFY THIS FUNCTION, BUT CAN DO SO AFTER QA CREATES ITS DATABASE
    ==========================================================================

    qa_get_logged_in_user($qa_db_connection)

    You should check (using $_COOKIE, $_SESSION or whatever is appropriate) whether a user is
    currently logged in. If not, return null. If so, return an array with the following elements:

    * userid: a user id appropriate for your response to qa_get_mysql_user_column_type()
    * publicusername: a user description you are willing to show publicly, e.g. the username
    * email: the logged in user's email address
    * level: one of the QA_USER_LEVEL_* values below to denote the user's privileges:

    QA_USER_LEVEL_BASIC, QA_USER_LEVEL_EDITOR, QA_USER_LEVEL_ADMIN, QA_USER_LEVEL_SUPER

    The result of this function will be passed to your other function qa_get_logged_in_user_html()
    so you may add any other elements to the returned array if they will be useful to you.

    $qa_db_connection is an open connection to the QA database. If your database is shared with
    QA, you can use this with PHP's MySQL functions such as mysql_query() to run queries.

    In order to access the admin interface of your QA site, ensure that the array element 'level'
    contains QA_USER_LEVEL_ADMIN or QA_USER_LEVEL_SUPER when you are logged in.
*/

function qa_get_logged_in_user($qa_db_connection) {
    session_start();

    $logged_in = false;
    define('LOGIN_VAR_NAME', 'HEAJTECHINFOSUP_LOGIN');

    if (isset($_SESSION[LOGIN_VAR_NAME]) && $_SESSION[LOGIN_VAR_NAME] === '1') {
        $logged_in = true;
        $userid=$_SESSION['user']['id'];
        $username=$_SESSION['user']['first'].' '.$_SESSION['user']['name'];
        $usermail = $_SESSION['user']['email'];
        $admins = array('mylastnamefirstname','hislastnamefirstname');
        $isadmin = (in_array($_SESSION['user']['alphasort'],$admins));
        return array(
                'userid' => $userid,
                'publicusername' => $username,
                'email' => $usermail,
                'level' => ($isadmin) ? QA_USER_LEVEL_ADMIN : QA_USER_LEVEL_BASIC
        );
    }
    else  if(isset($_COOKIE[LOGIN_VAR_NAME]) && strlen($_COOKIE[LOGIN_VAR_NAME]) > 4) {
        parse_str($_COOKIE[LOGIN_VAR_NAME]);
        // check the user and md5(password) hash stored inside the cookie against the database
        //$user = isRegistered($usr, $hash, false, true);

        $link = mysql_connect('my_ip:3306', 'dbuser', 'dbpassword') or die("Impossible de se connecter : " . mysql_error());

        $sql="SELECT U_id,U_name,U_first,U_password, U_is_student, SaturnCode,sex FROM (
                          SELECT id AS U_id,name AS U_name,first AS U_first,password AS U_password, is_student AS U_is_student, SaturnCode,sex FROM teachers WHERE login='$usr'
                          UNION ALL
                          SELECT id AS U_id,name AS U_name,first AS U_first,password AS U_password, is_student AS U_is_student, SaturnCode,sex FROM students WHERE login='$usr'
                          ) AS sels LIMIT 0 , 1";

        $result=mysql_fetch_assoc(
                mysql_query($sql,
                $link
                )
        );

        if (is_array($result)) {
            $user = $result[0];
            $password=$user['U_password'];
            if($hash == $password) {
                $_SESSION['user'] = $user;
                $_SESSION[LOGIN_VAR_NAME] = '1';

                $userid=$_SESSION['user']['id'];
                $username=$_SESSION['user']['first'].' '.$_SESSION['user']['name'];
                $usermail = $_SESSION['user']['email'];
                $admins = array('mylastnamefirstname','hislastnamefirstname');
                $isadmin = (in_array($_SESSION['user']['alphasort'],$admins));
                return array(
                        'userid' => $userid,
                        'publicusername' => $username,
                        'email' => $usermail,
                        'level' => ($isadmin) ? QA_USER_LEVEL_ADMIN : QA_USER_LEVEL_BASIC
                );

            }
            else {
                if (ini_get("session.use_cookies")) {
                    $params = session_get_cookie_params();
                    setcookie(session_name(), '', mktime(12,0,0,1, 1, 1990),
                            $params["path"], $params["domain"],
                            $params["secure"], $params["httponly"]
                    );
                }
                session_unset();
                session_destroy();
                die("login cookie: invalid hash");
            }
        }
        else {
            die("login cookie: no user found under the name $usr");
        }

    }
}



/*
    ==========================================================================
    YOU MUST MODIFY THIS FUNCTION, BUT CAN DO SO AFTER QA CREATES ITS DATABASE
    ==========================================================================

    qa_get_user_email($qa_db_connection, $userid)

    Return the email address for user $userid, or null if you don't know it.

    $qa_db_connection is an open connection to the QA database. If your database is shared with
    QA, you can use this with PHP's MySQL functions such as mysql_query() to run queries.
*/

function qa_get_user_email($qa_db_connection, $userid) {

    //  Until you edit this function, always return null

    return null;

    /*
        Example 1 - suitable if:

        * Your database is shared with the QA site
        * Your database has a users table that contains emails

        $result=mysql_fetch_assoc(
            mysql_query(
                "SELECT email FROM users WHERE userid='".mysql_real_escape_string($userid, $qa_db_connection)."'",
                $qa_db_connection
            )
        );

        if (is_array($result))
            return $result['email'];

        return null;
    */

}



/*
    ==========================================================================
    YOU MUST MODIFY THIS FUNCTION, BUT CAN DO SO AFTER QA CREATES ITS DATABASE
    ==========================================================================

    qa_get_userids_from_public($qa_db_connection, $publicusernames)

    You should take the array of public usernames in $publicusernames, and return an array which
    maps those usernames to internal user ids. For each element of this array, the username you
    were given should be in the key, with the corresponding user id in the value.

    $qa_db_connection is an open connection to the QA database. If your database is shared with
    QA, you can use this with PHP's MySQL functions such as mysql_query() to run queries. If you
    access this database or any other, try to use a single query instead of one per user.
*/

function qa_get_userids_from_public($qa_db_connection, $publicusernames) {

    //  Until you edit this function, always return null

    $escapedusernames=array();
     $link = mysql_connect('my_ip:3306', 'dbuser', 'dbpassword') or die("Impossible de se connecter : " . mysql_error());


    foreach ($publicusernames as $publicusername)
        $escapedusernames[]="'".mysql_real_escape_string($publicusername, $qa_db_connection)."'";

    $results=mysql_query(
            'SELECT U_id,U_name,U_first,U_password, U_is_student, SaturnCode,sex FROM (
                          SELECT id AS U_id,name AS U_name,first AS U_first,password AS U_password, is_student AS U_is_student, SaturnCode,sex FROM teachers WHERE login IN ('.implode(',', $escapedusernames).')
                          UNION ALL
                          SELECT id AS U_id,name AS U_name,first AS U_first,password AS U_password, is_student AS U_is_student, SaturnCode,sex FROM students WHERE login IN ('.implode(',', $escapedusernames).')
                          ) AS sels ',
            $link
    );

    $publictouserid=array();

    while ($result=mysql_fetch_assoc($results))
        $publictouserid[$result['username']]=$result['userid'];

    return $publictouserid;
}




/*
    ==========================================================================
    YOU MUST MODIFY THIS FUNCTION, BUT CAN DO SO AFTER QA CREATES ITS DATABASE
    ==========================================================================

    qa_get_public_from_userids($qa_db_connection, $userids)

    This is exactly like qa_get_userids_from_public(), but works in the other direction.

    You should take the array of user identifiers in $userids, and return an array which maps
    those to public usernames. For each element of this array, the userid you were given should
    be in the key, with the corresponding username in the value.

    $qa_db_connection is an open connection to the QA database. If your database is shared with
    QA, you can use this with PHP's MySQL functions such as mysql_query() to run queries. If you
    access this database or any other, try to use a single query instead of one per user.
*/

function qa_get_public_from_userids($qa_db_connection, $userids) {

    //  Until you edit this function, always return null
    $escapeduserids=array();
        $link = mysql_connect('my_ip:3306', 'dbuser', 'dbpassword') or die("Impossible de se connecter : " . mysql_error());


    foreach ($userids as $userid)
        $escapeduserids[]="'".mysql_real_escape_string($userid, $qa_db_connection)."'";

    $results=mysql_query(
            'SELECT username, userid FROM users WHERE userid IN ('.implode(',', $escapeduserids).')',
            $qa_db_connection
    );

    $results=mysql_query(
            'SELECT U_id,U_name,U_first,U_password, U_is_student, SaturnCode,sex FROM (
                          SELECT id AS U_id,name AS U_name,first AS U_first,password AS U_password, is_student AS U_is_student, SaturnCode,sex FROM teachers WHERE U_id IN ('.implode(',', $escapeduserids).')
                          UNION ALL
                          SELECT id AS U_id,name AS U_name,first AS U_first,password AS U_password, is_student AS U_is_student, SaturnCode,sex FROM students WHERE U_id IN ('.implode(',', $escapeduserids).')
                          ) AS sels ',
            $link
    );


    $useridtopublic=array();

    while ($result=mysql_fetch_assoc($results))
        $useridtopublic[$result['userid']]=$result['login'];

    return $useridtopublic;
}



/*
    ==========================================================================
         YOU MAY MODIFY THIS FUNCTION, BUT THE DEFAULT BELOW WILL WORK OK
    ==========================================================================

    qa_get_logged_in_user_html($qa_db_connection, $logged_in_user, $relative_url_prefix)

    You should return HTML code which identifies the logged in user, to be displayed next to the
    logout link on the QA pages. This HTML will only be shown to the logged in user themselves.

    $logged_in_user is the array that you returned from qa_get_logged_in_user(). Hopefully this
    contains enough information to generate the HTML without another database query, but if not,
    $qa_db_connection is an open connection to the QA database.

    $relative_url_prefix is a relative URL to the root of the QA site, which may be useful if
    you want to include a link that uses relative URLs. If the QA site is in a subdirectory of
    your site, $relative_url_prefix.'../' refers to your site root (see example 1).

    If you don't know what to display for a user, you can leave the default below. This will
    show the public username, linked to the QA profile page for the user.
*/

function qa_get_logged_in_user_html($qa_db_connection, $logged_in_user, $relative_url_prefix) {

    //  By default, show the public username linked to the QA profile page for the user

    $publicusername=$logged_in_user['publicusername'];

    return '<A HREF="'.htmlspecialchars($relative_url_prefix.'user/'.urlencode($publicusername)).
            '" CLASS="qa-user-link">'.htmlspecialchars($publicusername).'</A>';

    /*
        Example 1 - suitable if:

        * Your QA site:     http://www.mysite.com/qa/
        * Your user pages:   http://www.mysite.com/user/[username]

        $publicusername=$logged_in_user['publicusername'];

        return '<A HREF="'.htmlspecialchars($relative_url_prefix.'../user/'.urlencode($publicusername)).
            '" CLASS="qa-user-link">'.htmlspecialchars($publicusername).'</A>';
    */

    /*
        Example 2 - suitable if:

        * Your QA site:     http://qa.mysite.com/
        * Your user pages:   http://www.mysite.com/[username]/
        * 16x16 user photos:   http://www.mysite.com/[username]/photo-small.jpeg

        $publicusername=$logged_in_user['publicusername'];

        return '<A HREF="http://www.mysite.com/'.htmlspecialchars(urlencode($publicusername)).'/" CLASS="qa-user-link">'.
            '<IMG SRC="http://www.mysite.com/'.htmlspecialchars(urlencode($publicusername)).'/photo-small.jpeg" '.
            'STYLE="width:16px; height:16px; border:none; margin-right:4px;">'.htmlspecialchars($publicusername).'</A>';
    */

}



/*
    ==========================================================================
         YOU MAY MODIFY THIS FUNCTION, BUT THE DEFAULT BELOW WILL WORK OK
    ==========================================================================

    qa_get_users_html($qa_db_connection, $userids, $should_include_link, $relative_url_prefix)

    You should return an array of HTML to display for each user in $userids. For each element of
    this array, the userid should be in the key, with the corresponding HTML in the value.

    $qa_db_connection is an open connection to the QA database. If your database is shared with
    QA, you can use this with PHP's MySQL functions such as mysql_query() to run queries. If you
    access this database or any other, try to use a single query instead of one per user.

    If $should_include_link is true, the HTML may include links to user profile pages.
    If $should_include_link is false, links should not be included in the HTML.

    $relative_url_prefix is a relative URL to the root of the QA site, which may be useful if
    you want to include links that uses relative URLs. If the QA site is in a subdirectory of
    your site, $relative_url_prefix.'../' refers to your site root (see example 1).

    If you don't know what to display for a user, you can leave the default below. This will
    show the public username, linked to the QA profile page for each user.
*/

function qa_get_users_html($qa_db_connection, $userids, $should_include_link, $relative_url_prefix) {

    //  By default, show the public username linked to the QA profile page for each user

    $useridtopublic=qa_get_public_from_userids($qa_db_connection, $userids);

    $usershtml=array();

    foreach ($userids as $userid) {
        $publicusername=$useridtopublic[$userid];

        $usershtml[$userid]=htmlspecialchars($publicusername);

        if ($should_include_link)
            $usershtml[$userid]='<A HREF="'.htmlspecialchars($relative_url_prefix.'user/'.urlencode($publicusername)).
                    '" CLASS="qa-user-link">'.$usershtml[$userid].'</A>';
    }

    return $usershtml;

    /*
        Example 1 - suitable if:

        * Your QA site:     http://www.mysite.com/qa/
        * Your user pages:   http://www.mysite.com/user/[username]

        $useridtopublic=qa_get_public_from_userids($qa_db_connection, $userids);

        foreach ($userids as $userid) {
            $publicusername=$useridtopublic[$userid];

            $usershtml[$userid]=htmlspecialchars($publicusername);

            if ($should_include_link)
                $usershtml[$userid]='<A HREF="'.htmlspecialchars($relative_url_prefix.'../user/'.urlencode($publicusername)).
                    '" CLASS="qa-user-link">'.$usershtml[$userid].'</A>';
        }

        return $usershtml;
    */

    /*
        Example 2 - suitable if:

        * Your QA site:     http://qa.mysite.com/
        * Your user pages:   http://www.mysite.com/[username]/
        * User photos (16x16): http://www.mysite.com/[username]/photo-small.jpeg

        $useridtopublic=qa_get_public_from_userids($qa_db_connection, $userids);

        foreach ($userids as $userid) {
            $publicusername=$useridtopublic[$userid];

            $usershtml[$userid]='<IMG SRC="http://www.mysite.com/'.htmlspecialchars(urlencode($publicusername)).'/photo-small.jpeg" '.
                'STYLE="width:16px; height:16px; border:0; margin-right:4px;">'.htmlspecialchars($publicusername);

            if ($should_include_link)
                $usershtml[$userid]='<A HREF="http://www.mysite.com/'.htmlspecialchars(urlencode($publicusername)).
                    '/" CLASS="qa-user-link">'.$usershtml[$userid].'</A>';
        }

        return $usershtml;
    */

}



/*
    ==========================================================================
         YOU MAY MODIFY THIS FUNCTION, BUT THE DEFAULT BELOW WILL WORK OK
    ==========================================================================

    qa_user_report_action($qa_db_connection, $userid, $action, $questionid, $answerid, $commentid)

    Informs you about an action by user $userid that modified the database, such as posting,
    voting, etc... If you wish, you may use this to log user activity or monitor for abuse.

    $qa_db_connection is an open connection to the QA database. If your database is shared with
    QA, you can use this with PHP's MySQL functions such as mysql_query() to run queries.

    $action is one of:
    q_post, q_edit, q_hide, q_reshow, q_claim, q_vote_up, q_vote_down, q_vote_nil
    a_post, a_edit, a_hide, a_reshow, a_claim, a_vote_up, a_vote_down, a_vote_nil, a_select, a_unselect
    c_post, c_edit, c_hide, c_reshow, c_claim

    $questionid and/or $answerid and/or $commentid contain the ID of the relevant question or answer
    or comment affected, or null if this information is not appropriate for $action.

    FYI, you can get the IP address of the user from $_SERVER['REMOTE_ADDR'].
*/

function qa_user_report_action($qa_db_connection, $userid, $action, $questionid, $answerid, $commentid) {
    // do nothing by default
}

?>