From b68879798a828e3285d8c5a5a9ffaadc38160c71 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jakub=20=C5=A0krab=C3=A1nek?= <skrabanek@odbornaskola.cz>
Date: Thu, 23 Feb 2023 10:29:08 +0100
Subject: [PATCH] add login system part 1

---
 login/auth.php   | 29 +++++++++++++++++++++++++++++
 login/home.php   | 25 +++++++++++++++++++++++++
 login/index.php  | 39 +++++++++++++++++++++++++++++++++++++++
 login/logout.php |  6 ++++++
 4 files changed, 99 insertions(+)
 create mode 100644 login/auth.php
 create mode 100644 login/home.php
 create mode 100644 login/index.php
 create mode 100644 login/logout.php
diff --git a/login/auth.php b/login/auth.php
new file mode 100644
index 0000000..a0a6f44
--- /dev/null
+++ b/login/auth.php
@@ -0,0 +1,29 @@
+<?php 
+session_start();
+require("init.php");
+$username = $_POST["username"];
+$password = $_POST["password"];
+
+    //příprava k zobrazení dat
+    $sql = "SELECT * FROM users WHERE 
+    username='$username' AND password='$password'"; 
+    $result = mysqli_query($conn,$sql);
+
+    //zjištění jestli uživatel existuje
+    if (mysqli_num_rows($result) == 1) {
+        $row = mysqli_fetch_assoc($result);
+
+        //"zapsání uživatele do paměti" (vytvoření session pro jméno)
+        $_SESSION["username"] = $row["username"];
+        $_SESSION["id"] = $row["id"];
+
+        //přesměrování na hl.stráku
+        header("Location: /?login=1");
+    } else {
+        header("Location: /?error=1");
+        //error 1 = uživatel nenalezen
+    }
+
+
+
+?>
\ No newline at end of file
diff --git a/login/home.php b/login/home.php
new file mode 100644
index 0000000..c1aaad0
--- /dev/null
+++ b/login/home.php
@@ -0,0 +1,25 @@
+<?php
+session_start();
+if(!isset($_SESSION["username"])){
+    header("Location: /?error=2");
+}
+
+?>
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Document</title>
+</head>
+<body>
+    <p>
+        <?php
+            echo "Vítej uživatel:". $_SESSION["username"];
+        ?>
+    </p>
+
+    <a href="logout.php">LOGOUT</a>
+</body>
+</html>
\ No newline at end of file
diff --git a/login/index.php b/login/index.php
new file mode 100644
index 0000000..f2b75f9
--- /dev/null
+++ b/login/index.php
@@ -0,0 +1,39 @@
+<?php
+session_start();
+?>
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Login system</title>
+</head>
+<body>
+    <h1>Login</h1>
+    <form action="auth.php" method="post">
+        <input type="text" name="username" id="username" placeholder="Username">
+        <input type="password" name="password" id="password" placeholder="Password">
+        <input type="submit" value="Login">
+    </form>
+
+    <?php
+    //zjištění stavů a jejich "zpětná vazba"
+    if(isset($_SESSION["username"])){
+        echo "<p>Přihlášený uživatel:". $_SESSION["username"]."</p>";
+        echo "<a href=\"logout.php\">LOGOUT</a>"; // \" escape uvozovek pro odkaz
+    }
+    if(isset($_GET["error"])){
+        echo "<p>Error ". $_GET["error"]. "</p>";
+    }
+    if(isset($_GET["login"])){
+        echo "<p>Uživatel byl přihlášen</p>";
+    }
+    if(isset($_GET["logout"])){
+        echo "<p>Uživatel byl odhlášený</p>";
+    }
+
+    ?>
+    
+</body>
+</html>
\ No newline at end of file
diff --git a/login/logout.php b/login/logout.php
new file mode 100644
index 0000000..acaeaa4
--- /dev/null
+++ b/login/logout.php
@@ -0,0 +1,6 @@
+<?php
+session_start();
+session_unset();
+session_destroy();
+header("Location: /?logout=1");
+?>
\ No newline at end of file
