battles/chat.php

<?php
/**
 * Copyright (c) 2018.
 * Author: Igor Barkov <lopar.4ever@gmail.com>
 * Project name: Battles-Game
 */

use Battles\Database\DBPDO;
use Battles\Template;

session_start();
require_once "config.php";

$msg = $_POST['msg'] ?? null;
$uid = $_SESSION['uid'] ?? null;
if ($msg) {
    $db = new DBPDO();
    $db->execute('INSERT INTO chat (user_id,msg) VALUES (?,?)', [$uid, $msg]);
}

function show_messages()
{
    $db = new DBPDO();

    $chat = $db->ofetchALL('SELECT msg,msgdate,type,s.login AS sender, r.login AS receiver, s.id AS sid, r.id AS rid FROM chat 
    LEFT JOIN users s on s.id = chat.user_id 
    LEFT JOIN users r on r.id = chat.receiver_id 
    WHERE r.id = ? OR r.id IS NULL OR s.id = ? ORDER BY chat.id', [$_SESSION['uid'], $_SESSION['uid']]);
    $i = 0;
    while ($i < count($chat)) {
        $d = new DateTime($chat[$i]->msgdate);
        $m = htmlspecialchars($chat[$i]->msg);
        if ($chat[$i]->type == 'sys') { /* Системка */
            echo sprintf('<span style="color:maroon;background:#faa;">%s %s</span><br>', $d->format('H:i'), $m);
        } elseif ($chat[$i]->rid == $_SESSION['uid']) { /* С указанным получателем */
            if ($chat[$i]->type == 'sms') { /* Телеграмма */
                echo sprintf('<span style="color:darkgreen;background:#afa;">%s Телеграмма от [%s]: %s</span><br>', $d->format('d.m.Y H:i'), $chat[$i]->sender, $m);
            } elseif ($chat[$i]->type == 'private') { /* Приват */
                echo sprintf('<span style="background:#efe;">%s [%s] → [%s]: %s</span><br>', $d->format('H:i'), $chat[$i]->sender, $chat[$i]->receiver, $m);
            } else { /* Общак */
                echo sprintf('%s [%s] → [%s]: %s<br>', $d->format('H:i'), $chat[$i]->sender, $chat[$i]->receiver, $m);
            }
        } else { /* Без указанного получателя */
            echo sprintf('%s [%s]: %s<br>', $d->format('H:i'), $chat[$i]->sender, $m);
        }
        $i++;
    }
    unset($i, $chat, $db);
}


Template::header('chat');
show_messages();
?>
<style>
    form {
        padding: 3px;
        position: fixed;
        bottom: 0;
        width: 100%;
    }

    form input {
        border: 0;
        padding: 10px;
        width: 80%;
        margin-right: .5%;
    }

    form input[type="submit"] {
        width: 15%;
        border: none;
        padding: 10px;
    }
</style>
<div>
    <?php ?>
</div>
<form action="chat.php" method="post">
    <input id="msg" name="msg" size="100" placeholder="Введите сообщение...">
    <input type="submit" value="Отправить">
</form>