From a94ab600048f8a4a58f144b03829615baae0db37 Mon Sep 17 00:00:00 2001
From: Carl-Tabuso <carlftabuso@iskolarngbayan.pup.edu.ph>
Date: Fri, 24 May 2024 17:58:12 +0800
Subject: [PATCH 01/11] chore: Ignore text file used for error logging.

---
 .gitignore | 2 ++
 1 file changed, 2 insertions(+)
 create mode 100644 .gitignore

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 00000000..ab01c12a
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+# Ignore
+src/includes/error-logs.txt
\ No newline at end of file

From 880d13c9bf619fe378f200c94f2f7faaa2afc502 Mon Sep 17 00:00:00 2001
From: Carl-Tabuso <carlftabuso@iskolarngbayan.pup.edu.ph>
Date: Fri, 24 May 2024 18:01:20 +0800
Subject: [PATCH 02/11] SPD-82-Add a preloader/spinner for every webpage.

---
 src/includes/preloader.html |  5 +++++
 src/javascript/preloader.js |  9 +++++++++
 src/styles/main.css         | 24 +++++++++++++++++++-----
 src/styles/main.scss        | 17 +++++++++++++++++
 4 files changed, 50 insertions(+), 5 deletions(-)
 create mode 100644 src/includes/preloader.html
 create mode 100644 src/javascript/preloader.js

diff --git a/src/includes/preloader.html b/src/includes/preloader.html
new file mode 100644
index 00000000..fc185a37
--- /dev/null
+++ b/src/includes/preloader.html
@@ -0,0 +1,5 @@
+<div class="spinner-wrapper">
+    <div class="spinner-border text-tiger-orange" role="status">
+      <span class="visually-hidden"></span>
+    </div>     
+  </div>
\ No newline at end of file
diff --git a/src/javascript/preloader.js b/src/javascript/preloader.js
new file mode 100644
index 00000000..4146f362
--- /dev/null
+++ b/src/javascript/preloader.js
@@ -0,0 +1,9 @@
+const spinnerWrapper = document.querySelector(".spinner-wrapper");
+
+window.addEventListener("load", () => {
+  spinnerWrapper.style.opacity = "0";
+
+  setTimeout(() => {
+    spinnerWrapper.style.display = "none";
+  }, 200);
+});
diff --git a/src/styles/main.css b/src/styles/main.css
index 210aec54..11bf7bb1 100644
--- a/src/styles/main.css
+++ b/src/styles/main.css
@@ -13,6 +13,20 @@
   font-weight: 500;
 }
 
+.spinner-wrapper {
+  background-color: rgba(0, 0, 0, 0.8);
+  position: fixed;
+  top: 0;
+  left: 0;
+  width: 100%;
+  height: 100%;
+  z-index: 9999;
+  display: flex;
+  justify-content: center;
+  align-items: center;
+  transition: all 0.3s;
+}
+
 /*!
  * Bootstrap  v5.3.3 (https://getbootstrap.com/)
  * Copyright 2011-2024 The Bootstrap Authors
@@ -6630,10 +6644,10 @@ textarea.form-control-lg {
   }
 }
 .spinner-border {
-  --bs-spinner-width: 2rem;
-  --bs-spinner-height: 2rem;
+  --bs-spinner-width: 4rem;
+  --bs-spinner-height: 4rem;
   --bs-spinner-vertical-align: -0.125em;
-  --bs-spinner-border-width: 0.25em;
+  --bs-spinner-border-width: 0.45em;
   --bs-spinner-animation-speed: 0.75s;
   --bs-spinner-animation-name: spinner-border;
   border: var(--bs-spinner-border-width) solid currentcolor;
@@ -6656,8 +6670,8 @@ textarea.form-control-lg {
   }
 }
 .spinner-grow {
-  --bs-spinner-width: 2rem;
-  --bs-spinner-height: 2rem;
+  --bs-spinner-width: 4rem;
+  --bs-spinner-height: 4rem;
   --bs-spinner-vertical-align: -0.125em;
   --bs-spinner-animation-speed: 0.75s;
   --bs-spinner-animation-name: spinner-grow;
diff --git a/src/styles/main.scss b/src/styles/main.scss
index ad0e13cb..de935d22 100644
--- a/src/styles/main.scss
+++ b/src/styles/main.scss
@@ -47,6 +47,23 @@ $custom-table-variants: (
     box-shadow: 0 0 10px rgba(0, 0, 0, 0.25);
     font-weight: 500;
 }
+.spinner-wrapper {
+    background-color: rgba(0, 0, 0, 0.8);
+    position: fixed;
+    top: 0;
+    left: 0;
+    width: 100%;
+    height: 100%;
+    z-index: 9999;
+    display: flex;
+    justify-content: center;
+    align-items: center;
+    transition: all 0.3s;
+}
+
+$spinner-width: 4rem;
+$spinner-height: $spinner-width;
+$spinner-border-width: .45em;
 $table-variants: map-merge($table-variants , $custom-table-variants);
 
 $theme-colors: map-merge($theme-colors, $custom-colors);

From c80aa8cb0eec8cf6fae184a1a4d3f637f23daf09 Mon Sep 17 00:00:00 2001
From: Carl-Tabuso <carlftabuso@iskolarngbayan.pup.edu.ph>
Date: Fri, 24 May 2024 18:04:39 +0800
Subject: [PATCH 03/11] style: SPD-82-Add style for the preloader and its
 wrapper

---
 src/styles/main.css  | 24 +++++-------------------
 src/styles/main.scss | 17 -----------------
 2 files changed, 5 insertions(+), 36 deletions(-)

diff --git a/src/styles/main.css b/src/styles/main.css
index 11bf7bb1..210aec54 100644
--- a/src/styles/main.css
+++ b/src/styles/main.css
@@ -13,20 +13,6 @@
   font-weight: 500;
 }
 
-.spinner-wrapper {
-  background-color: rgba(0, 0, 0, 0.8);
-  position: fixed;
-  top: 0;
-  left: 0;
-  width: 100%;
-  height: 100%;
-  z-index: 9999;
-  display: flex;
-  justify-content: center;
-  align-items: center;
-  transition: all 0.3s;
-}
-
 /*!
  * Bootstrap  v5.3.3 (https://getbootstrap.com/)
  * Copyright 2011-2024 The Bootstrap Authors
@@ -6644,10 +6630,10 @@ textarea.form-control-lg {
   }
 }
 .spinner-border {
-  --bs-spinner-width: 4rem;
-  --bs-spinner-height: 4rem;
+  --bs-spinner-width: 2rem;
+  --bs-spinner-height: 2rem;
   --bs-spinner-vertical-align: -0.125em;
-  --bs-spinner-border-width: 0.45em;
+  --bs-spinner-border-width: 0.25em;
   --bs-spinner-animation-speed: 0.75s;
   --bs-spinner-animation-name: spinner-border;
   border: var(--bs-spinner-border-width) solid currentcolor;
@@ -6670,8 +6656,8 @@ textarea.form-control-lg {
   }
 }
 .spinner-grow {
-  --bs-spinner-width: 4rem;
-  --bs-spinner-height: 4rem;
+  --bs-spinner-width: 2rem;
+  --bs-spinner-height: 2rem;
   --bs-spinner-vertical-align: -0.125em;
   --bs-spinner-animation-speed: 0.75s;
   --bs-spinner-animation-name: spinner-grow;
diff --git a/src/styles/main.scss b/src/styles/main.scss
index de935d22..ad0e13cb 100644
--- a/src/styles/main.scss
+++ b/src/styles/main.scss
@@ -47,23 +47,6 @@ $custom-table-variants: (
     box-shadow: 0 0 10px rgba(0, 0, 0, 0.25);
     font-weight: 500;
 }
-.spinner-wrapper {
-    background-color: rgba(0, 0, 0, 0.8);
-    position: fixed;
-    top: 0;
-    left: 0;
-    width: 100%;
-    height: 100%;
-    z-index: 9999;
-    display: flex;
-    justify-content: center;
-    align-items: center;
-    transition: all 0.3s;
-}
-
-$spinner-width: 4rem;
-$spinner-height: $spinner-width;
-$spinner-border-width: .45em;
 $table-variants: map-merge($table-variants , $custom-table-variants);
 
 $theme-colors: map-merge($theme-colors, $custom-colors);

From 615ec91b2590bc96ac4ef1d9598c04e0d86e75af Mon Sep 17 00:00:00 2001
From: Carl-Tabuso <carlftabuso@iskolarngbayan.pup.edu.ph>
Date: Fri, 24 May 2024 18:08:17 +0800
Subject: [PATCH 04/11] Revert "style: SPD-82-Add style for the preloader and
 its wrapper"

This reverts commit c80aa8cb0eec8cf6fae184a1a4d3f637f23daf09.
---
 src/styles/main.css  | 24 +++++++++++++++++++-----
 src/styles/main.scss | 17 +++++++++++++++++
 2 files changed, 36 insertions(+), 5 deletions(-)

diff --git a/src/styles/main.css b/src/styles/main.css
index 210aec54..11bf7bb1 100644
--- a/src/styles/main.css
+++ b/src/styles/main.css
@@ -13,6 +13,20 @@
   font-weight: 500;
 }
 
+.spinner-wrapper {
+  background-color: rgba(0, 0, 0, 0.8);
+  position: fixed;
+  top: 0;
+  left: 0;
+  width: 100%;
+  height: 100%;
+  z-index: 9999;
+  display: flex;
+  justify-content: center;
+  align-items: center;
+  transition: all 0.3s;
+}
+
 /*!
  * Bootstrap  v5.3.3 (https://getbootstrap.com/)
  * Copyright 2011-2024 The Bootstrap Authors
@@ -6630,10 +6644,10 @@ textarea.form-control-lg {
   }
 }
 .spinner-border {
-  --bs-spinner-width: 2rem;
-  --bs-spinner-height: 2rem;
+  --bs-spinner-width: 4rem;
+  --bs-spinner-height: 4rem;
   --bs-spinner-vertical-align: -0.125em;
-  --bs-spinner-border-width: 0.25em;
+  --bs-spinner-border-width: 0.45em;
   --bs-spinner-animation-speed: 0.75s;
   --bs-spinner-animation-name: spinner-border;
   border: var(--bs-spinner-border-width) solid currentcolor;
@@ -6656,8 +6670,8 @@ textarea.form-control-lg {
   }
 }
 .spinner-grow {
-  --bs-spinner-width: 2rem;
-  --bs-spinner-height: 2rem;
+  --bs-spinner-width: 4rem;
+  --bs-spinner-height: 4rem;
   --bs-spinner-vertical-align: -0.125em;
   --bs-spinner-animation-speed: 0.75s;
   --bs-spinner-animation-name: spinner-grow;
diff --git a/src/styles/main.scss b/src/styles/main.scss
index ad0e13cb..de935d22 100644
--- a/src/styles/main.scss
+++ b/src/styles/main.scss
@@ -47,6 +47,23 @@ $custom-table-variants: (
     box-shadow: 0 0 10px rgba(0, 0, 0, 0.25);
     font-weight: 500;
 }
+.spinner-wrapper {
+    background-color: rgba(0, 0, 0, 0.8);
+    position: fixed;
+    top: 0;
+    left: 0;
+    width: 100%;
+    height: 100%;
+    z-index: 9999;
+    display: flex;
+    justify-content: center;
+    align-items: center;
+    transition: all 0.3s;
+}
+
+$spinner-width: 4rem;
+$spinner-height: $spinner-width;
+$spinner-border-width: .45em;
 $table-variants: map-merge($table-variants , $custom-table-variants);
 
 $theme-colors: map-merge($theme-colors, $custom-colors);

From c10430a23578b53df8bdabb825d17dc71d286719 Mon Sep 17 00:00:00 2001
From: Carl-Tabuso <carlftabuso@iskolarngbayan.pup.edu.ph>
Date: Fri, 24 May 2024 18:09:32 +0800
Subject: [PATCH 05/11] refactor: Move to includes folder and normalized file
 path.

---
 src/includes/logout.php | 9 +++++++++
 src/logout.php          | 6 ------
 2 files changed, 9 insertions(+), 6 deletions(-)
 create mode 100644 src/includes/logout.php
 delete mode 100644 src/logout.php

diff --git a/src/includes/logout.php b/src/includes/logout.php
new file mode 100644
index 00000000..719907ad
--- /dev/null
+++ b/src/includes/logout.php
@@ -0,0 +1,9 @@
+<?php
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'file-utilities.php');
+require_once FileUtils::normalizeFilePath('session-handler.php');
+include_once FileUtils::normalizeFilePath('error-reporting.php');
+
+session_destroy();
+header("location: ../login.php");
+exit();
+?>
\ No newline at end of file
diff --git a/src/logout.php b/src/logout.php
deleted file mode 100644
index 36966d9c..00000000
--- a/src/logout.php
+++ /dev/null
@@ -1,6 +0,0 @@
-<?php
-require_once 'includes/session-handler.php';
-
-session_destroy();
-header("location: login.php");
-?>
\ No newline at end of file

From a7776a456ab55596d102916873c37b278b834157 Mon Sep 17 00:00:00 2001
From: Carl-Tabuso <carlftabuso@iskolarngbayan.pup.edu.ph>
Date: Fri, 24 May 2024 18:11:04 +0800
Subject: [PATCH 06/11] chore: This file create a new text file called
 error-logs.txt, where all system-generated errors get logged. This file is
 included shall be included in all pages.

---
 src/includes/error-reporting.php | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 src/includes/error-reporting.php

diff --git a/src/includes/error-reporting.php b/src/includes/error-reporting.php
new file mode 100644
index 00000000..40dd730e
--- /dev/null
+++ b/src/includes/error-reporting.php
@@ -0,0 +1,19 @@
+<?php
+
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'file-utilities.php');
+include_once FileUtils::normalizeFilePath('default-timezone.php');
+
+error_reporting(E_ALL);
+ini_set("display_errors", 0);
+
+function logErrors($errno, $errstr, $errfile, $errline) {
+
+    // Relative file path
+    $log_directory = __DIR__ . "/error-logs.txt";
+    $timestamp = date('Y-m-d g:i a');
+    $log_message = "$timestamp Error: [$errno] $errstr - $errfile: $errline";
+    error_log($log_message . PHP_EOL, 3, $log_directory);
+    
+}
+
+set_error_handler("logErrors");
\ No newline at end of file

From b317e3341f6d281cb6d47f88b2378942732547d6 Mon Sep 17 00:00:00 2001
From: Carl-Tabuso <carlftabuso@iskolarngbayan.pup.edu.ph>
Date: Fri, 24 May 2024 18:11:45 +0800
Subject: [PATCH 07/11] refactor: Add the login authenticator to a separate
 file inside the includes folder.

---
 src/includes/login-authenticator.php | 48 ++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 src/includes/login-authenticator.php

diff --git a/src/includes/login-authenticator.php b/src/includes/login-authenticator.php
new file mode 100644
index 00000000..5dba3bf7
--- /dev/null
+++ b/src/includes/login-authenticator.php
@@ -0,0 +1,48 @@
+<?php
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'file-utilities.php');
+require_once FileUtils::normalizeFilePath('session-handler.php');
+require_once FileUtils::normalizeFilePath('db-connector.php');
+include_once FileUtils::normalizeFilePath('error-reporting.php');
+
+if(isset($_POST['sign_in_btn'])) {
+
+    $username = $_POST['username'];
+    $password = $_POST['password'];
+
+    if(empty($username) || empty($password)) {
+        $_SESSION['error_message'] = 'Please do not leave the input fields empty.';
+        header("Location: ../login.php");
+        exit();
+    }
+
+    // Query the user table for the entered username
+    $stmt = $db->prepare("SELECT id, username, password FROM user WHERE BINARY username = ?");
+    $stmt->bind_param('s', $username);
+    $stmt->execute();
+    $result = $stmt->get_result();
+
+    // Check if a user of this username exists
+    if($result->num_rows > 0) {
+        $row = $result->fetch_assoc();
+
+        // Verify if password match the entered username
+        if (password_verify($password, $row['password'])) {
+            $_SESSION['id'] = $row['id'];
+            session_regenerate_id(true);
+            header("location: ../index.php");
+            exit();
+        }
+        // If username and password mismatched, display this      
+        else {
+            $_SESSION['error_message'] = 'Username and password mismatched.';
+            header("Location: ../login.php");
+            exit();
+            }
+    }
+    // If there is no user with the username, display this
+    else {
+        $_SESSION['error_message'] = 'User is not found.';
+        header("Location: ../login.php");
+        exit();
+    }
+}
\ No newline at end of file

From 6f3e395db1c03505fbe6a2d88db43f2564f07601 Mon Sep 17 00:00:00 2001
From: Carl-Tabuso <carlftabuso@iskolarngbayan.pup.edu.ph>
Date: Fri, 24 May 2024 18:16:38 +0800
Subject: [PATCH 08/11] refactor: Normalize file path traversal to make it
 compatible with different OS.

---
 src/add-account.php                        |  4 +++-
 src/create-order.php                       | 14 +++++++++-----
 src/delete-account.php                     |  4 +++-
 src/delete-sale.php                        |  5 ++++-
 src/get-product-details.php                |  4 +++-
 src/get-products.php                       |  4 +++-
 src/includes/db-connector.php              |  4 ++++
 src/includes/execute-prediction-script.php |  4 +++-
 src/includes/mailer.php                    |  4 +++-
 src/includes/process-reset-password.php    |  5 +++--
 src/includes/send-password-reset.php       |  8 +++++---
 src/includes/session-handler.php           |  3 +++
 src/reset-password.php                     |  9 +++++++--
 src/update-account.php                     |  4 +++-
 src/view-sales.php                         |  4 +++-
 15 files changed, 59 insertions(+), 21 deletions(-)

diff --git a/src/add-account.php b/src/add-account.php
index 3671d98a..c57bbfef 100644
--- a/src/add-account.php
+++ b/src/add-account.php
@@ -1,5 +1,7 @@
 <?php
-require_once 'includes/db-connector.php';
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'includes/file-utilities.php');
+require_once FileUtils::normalizeFilePath('includes/db-connector.php');
+include_once FileUtils::normalizeFilePath('includes/error-reporting.php');
 
 $last_name = $_POST['last_name'];
 $first_name = $_POST['first_name'];
diff --git a/src/create-order.php b/src/create-order.php
index 8e265833..bf277695 100644
--- a/src/create-order.php
+++ b/src/create-order.php
@@ -1,6 +1,8 @@
 <?php
-require_once 'includes/db-connector.php';
-require_once 'includes/session-handler.php';
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'includes/file-utilities.php');
+require_once FileUtils::normalizeFilePath('includes/db-connector.php');
+require_once FileUtils::normalizeFilePath('includes/session-handler.php');
+include_once FileUtils::normalizeFilePath('includes/error-reporting.php');
 
 if(isset($_SESSION['id'])) {
 
@@ -26,7 +28,8 @@
 
     <!--Navbar-->
     <?php
-    include 'includes/navbar.php';
+    include FileUtils::normalizeFilePath('includes/navbar.php');
+    include FileUtils::normalizeFilePath('includes/preloader.html');
     ?>
  
     <!--Main Content-->
@@ -82,7 +85,7 @@
                 <?php
                 // Fetch and display the default category's list of items
                 if ($defaultCategoryId !== null) {
-                    include 'get-products.php';
+                    include FileUtils::normalizeFilePath('get-products.php');
                 }
                 ?>
               </div>
@@ -93,7 +96,7 @@
 
 
         <?php
-        include 'billing-section.php';
+        include FileUtils::normalizeFilePath('billing-section.php');
         ?>
 
       </div>
@@ -107,6 +110,7 @@
     <script src="../vendor/node_modules/bootstrap/dist/js/bootstrap.bundle.min.js"></script>
     <!--Custom JavaScript/jQuery-->
     <script src="javascript/get-products.js"></script>
+    <script src="javascript/preloader.js"></script>
 
   </body>
 </html>
diff --git a/src/delete-account.php b/src/delete-account.php
index 12107279..9597073b 100644
--- a/src/delete-account.php
+++ b/src/delete-account.php
@@ -1,6 +1,8 @@
 <?php
 // Include the database connection file
-require_once 'includes/db-connector.php';
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'includes/file-utilities.php');
+require_once FileUtils::normalizeFilePath('includes/db-connector.php');
+include_once FileUtils::normalizeFilePath('includes/error-reporting.php');
 
 // Check if account IDs are provided
 if (isset($_POST['accountIds']) && is_array($_POST['accountIds'])) {
diff --git a/src/delete-sale.php b/src/delete-sale.php
index 484f7508..61d80266 100644
--- a/src/delete-sale.php
+++ b/src/delete-sale.php
@@ -1,6 +1,9 @@
 <?php
 // Include the database connection file
-require_once 'includes/db-connector.php';
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'includes/file-utilities.php');
+require_once FileUtils::normalizeFilePath('includes/db-connector.php');
+include_once FileUtils::normalizeFilePath('includes/error-reporting.php');
+
 // Check if account IDs are provided
 if (isset($_POST['saleIds']) && is_array($_POST['saleIds'])) {
     // Get the account IDs from the POST data
diff --git a/src/get-product-details.php b/src/get-product-details.php
index a775c1b6..4ba3b28a 100644
--- a/src/get-product-details.php
+++ b/src/get-product-details.php
@@ -1,6 +1,8 @@
 <?php
 // Include necessary files and connect to the database
-require_once 'includes/db-connector.php';
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'includes/file-utilities.php');
+require_once FileUtils::normalizeFilePath('includes/db-connector.php');
+include_once FileUtils::normalizeFilePath('includes/error-reporting.php');
 
 // Check if the required parameters are present
 if(isset($_POST['productId']) && isset($_POST['productType'])) {
diff --git a/src/get-products.php b/src/get-products.php
index 18553d60..dadb8b5f 100644
--- a/src/get-products.php
+++ b/src/get-products.php
@@ -1,5 +1,7 @@
 <?php
-require_once 'includes/db-connector.php';
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'includes/file-utilities.php');
+require_once FileUtils::normalizeFilePath('includes/db-connector.php');
+include_once FileUtils::normalizeFilePath('includes/error-reporting.php');
 
 if(isset($_POST['category'])) {
     $categoryId = $_POST['category'];
diff --git a/src/includes/db-connector.php b/src/includes/db-connector.php
index e48ce576..4c5d0e35 100644
--- a/src/includes/db-connector.php
+++ b/src/includes/db-connector.php
@@ -1,4 +1,8 @@
 <?php
+
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'file-utilities.php');
+include_once FileUtils::normalizeFilePath('error-reporting.php');
+
 // Creates connection to the database
 $server = "localhost";
 $username = "root";
diff --git a/src/includes/execute-prediction-script.php b/src/includes/execute-prediction-script.php
index 0618c906..c3b553ce 100644
--- a/src/includes/execute-prediction-script.php
+++ b/src/includes/execute-prediction-script.php
@@ -1,5 +1,7 @@
 <?php
-include_once 'default-timezone.php';
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'file-utilities.php');
+include_once FileUtils::normalizeFilePath('default-timezone.php');
+include_once FileUtils::normalizeFilePath('error-reporting.php');
 
 function should_execute_script() {
     // Get the current day of the week
diff --git a/src/includes/mailer.php b/src/includes/mailer.php
index 53986f83..0bb4387d 100644
--- a/src/includes/mailer.php
+++ b/src/includes/mailer.php
@@ -4,7 +4,9 @@
 use PHPMailer\PHPMailer\SMTP;
 use PHPMailer\PHPMailer\Exception;
 
-require __DIR__ . "/../../vendor/autoload.php";
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'file-utilities.php');
+require FileUtils::normalizeFilePath(__DIR__ . "/../../vendor/autoload.php");
+include_once FileUtils::normalizeFilePath('error-reporting.php');
 
 // CONFIGURATION
 
diff --git a/src/includes/process-reset-password.php b/src/includes/process-reset-password.php
index 781a41ac..7f444fa0 100644
--- a/src/includes/process-reset-password.php
+++ b/src/includes/process-reset-password.php
@@ -1,6 +1,7 @@
 <?php
-
-require_once 'db-connector.php';
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'file-utilities.php');
+require_once FileUtils::normalizeFilePath('db-connector.php');
+include_once FileUtils::normalizeFilePath('error-reporting.php');
 
 $token = $_POST["token"];
 $token_hash = hash("sha256", $token);
diff --git a/src/includes/send-password-reset.php b/src/includes/send-password-reset.php
index c1053b77..d5a1140f 100644
--- a/src/includes/send-password-reset.php
+++ b/src/includes/send-password-reset.php
@@ -1,7 +1,9 @@
 <?php
-
-require_once 'db-connector.php';
-require_once 'session-handler.php';
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'file-utilities.php');
+require_once FileUtils::normalizeFilePath('db-connector.php');
+require_once FileUtils::normalizeFilePath('session-handler.php');
+include_once FileUtils::normalizeFilePath('error-reporting.php');
+include_once FileUtils::normalizeFilePath('default-timezone.php');
 
 if(!isset($_POST['send-email-btn'])) {
     $_SESSION['error_message'] = 'Something went wrong.';
diff --git a/src/includes/session-handler.php b/src/includes/session-handler.php
index 3f4fcde0..81987d21 100644
--- a/src/includes/session-handler.php
+++ b/src/includes/session-handler.php
@@ -1,4 +1,7 @@
 <?php
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'file-utilities.php');
+include_once FileUtils::normalizeFilePath('default-timezone.php');
+include_once FileUtils::normalizeFilePath('error-reporting.php');
 
 ini_set('session.use_only_cookies', 1);
 ini_set('session.use_strict_mode', 1);
diff --git a/src/reset-password.php b/src/reset-password.php
index 5248ddf4..b5ee5116 100644
--- a/src/reset-password.php
+++ b/src/reset-password.php
@@ -1,6 +1,7 @@
 <?php
-
-require_once 'includes/db-connector.php';
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'includes/file-utilities.php');
+require_once FileUtils::normalizeFilePath('includes/db-connector.php');
+include_once FileUtils::normalizeFilePath('includes/error-reporting.php');
 
 $token = $_GET["token"];
 $token_hash = hash("sha256", $token);
@@ -57,6 +58,8 @@
 </head>
 <body>
 
+<?php include 'includes/preloader.html';?>
+
 <div class="container-fluid position-absolute top-50 start-50 translate-middle">
         <div class="row justify-content-center align-items-center">
             <div class="col-md-6 col-lg-4">
@@ -94,5 +97,7 @@
             </div>
         </div>
     </div>
+
+    <script src="javascript/preloader.js"></script>
 </body>
 </html>
\ No newline at end of file
diff --git a/src/update-account.php b/src/update-account.php
index effbcb51..34d9ea6b 100644
--- a/src/update-account.php
+++ b/src/update-account.php
@@ -1,5 +1,7 @@
 <?php
-require_once 'includes/db-connector.php';
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'includes/file-utilities.php');
+require_once FileUtils::normalizeFilePath('includes/db-connector.php');
+include_once FileUtils::normalizeFilePath('includes/error-reporting.php');
 
 $last_name = $_POST['last_name'];
 $first_name = $_POST['first_name'];
diff --git a/src/view-sales.php b/src/view-sales.php
index b019fae2..a1797d21 100644
--- a/src/view-sales.php
+++ b/src/view-sales.php
@@ -1,6 +1,8 @@
 <?php
 // Include necessary files and initialize database connection
-require_once 'includes/db-connector.php';
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'includes/file-utilities.php');
+require_once FileUtils::normalizeFilePath('includes/db-connector.php');
+include_once FileUtils::normalizeFilePath('includes/error-reporting.php');
 
 // Check if sale ID is provided
 if (isset($_GET['saleId'])) {

From 5ce4d90a141fc80ac874d3e5ac69010f3117651f Mon Sep 17 00:00:00 2001
From: Carl-Tabuso <carlftabuso@iskolarngbayan.pup.edu.ph>
Date: Fri, 24 May 2024 18:17:10 +0800
Subject: [PATCH 09/11] feat: SPD-82-Show a spinner preloader with a 2-3
 seconds interval for smooth feel everytime the page is access.

Also, traversal of file path is normalized to make it compatible with different OS.
---
 src/accounts.php | 44 ++++++++++++++++++++---------------
 src/index.php    | 29 +++++++++++------------
 src/login.php    | 60 ++++++------------------------------------------
 src/product.php  | 10 +++++---
 src/report.php   | 10 +++++---
 src/sales.php    | 10 +++++---
 6 files changed, 68 insertions(+), 95 deletions(-)

diff --git a/src/accounts.php b/src/accounts.php
index 2e04a40e..385178dd 100644
--- a/src/accounts.php
+++ b/src/accounts.php
@@ -1,9 +1,15 @@
 <?php
-require_once 'includes/db-connector.php';
-require_once 'includes/session-handler.php';
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'includes/file-utilities.php');
+require_once FileUtils::normalizeFilePath('includes/db-connector.php');
+require_once FileUtils::normalizeFilePath('includes/session-handler.php');
+include_once FileUtils::normalizeFilePath('includes/error-reporting.php');
 
 if(isset($_SESSION['id'])) {
 
+  $sql = "SELECT * FROM user";
+  $result = $db->query($sql);
+  $row = $result->fetch_assoc();
+
 ?>
 
 <!DOCTYPE html>
@@ -28,7 +34,8 @@
 
   <!--Navbar-->
   <?php
-    include 'includes/navbar.php';
+    include FileUtils::normalizeFilePath('includes/navbar.php');
+    include FileUtils::normalizeFilePath('includes/preloader.html');
     ?>
 
     <!--Main Container-->
@@ -73,21 +80,21 @@
                     </thead>
                     <tbody>
                       <?php 
-                              $sql = "SELECT * FROM user";
-                              $result = $db->query($sql);
-
-                              while($row = $result->fetch_assoc()) {
-                                  echo '
-                                  <tr data-id="'.$row['id'].'" class="selectable">
-                                      <td><input type="checkbox" class="account-checkbox" data-account-id="'.$row['id'].'"></td>
-                                      <td>'.$row['last_name'].'</td>
-                                      <td>'.$row["first_name"].'</td>
-                                      <td>'.$row['middle_name'].'</td>
-                                      <td>'.$row['email'].'</td>
-                                  </tr>
-                                  ';
-                              }
-                              ?>
+                      $sql = "SELECT * FROM user";
+                      $result = $db->query($sql);
+                      while($row = $result->fetch_assoc()) {
+                          echo '
+                          <tr data-id="'.$row['id'].'" class="selectable">
+                              <td><input type="checkbox" class="account-checkbox" data-account-id="'.$row['id'].'"></td>
+                              <td>'.$row['last_name'].'</td>
+                              <td>'.$row["first_name"].'</td>
+                              <td>'.$row['middle_name'].'</td>
+                              <td>'.$row['email'].'</td>
+                          </tr>
+                          ';
+                      }
+                      $db->close();
+                      ?>
                     </tbody>
 
                     <tfoot>
@@ -204,6 +211,7 @@ class="btn fw-medium btn-medium-brown text-capitalize py-2 px-4">add account</bu
     <script src="https://code.jquery.com/jquery-3.7.1.js"></script>
     <script src="https://cdn.datatables.net/2.0.3/js/dataTables.js"></script>
     <script src="https://cdn.datatables.net/2.0.3/js/dataTables.bootstrap5.js"></script>
+    <script src="javascript/preloader.js"></script>
 
     <!-- Adding of Accounts -->
     <script>
diff --git a/src/index.php b/src/index.php
index 311ad3e4..a14b7ea0 100644
--- a/src/index.php
+++ b/src/index.php
@@ -1,9 +1,10 @@
 <?php
-
-require_once 'includes/db-connector.php';
-require_once 'includes/session-handler.php';
-require_once 'includes/execute-prediction-script.php';
-include_once 'includes/default-timezone.php';
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'includes/file-utilities.php');
+require_once FileUtils::normalizeFilePath('includes/db-connector.php');
+require_once FileUtils::normalizeFilePath('includes/session-handler.php');
+require_once FileUtils::normalizeFilePath('includes/execute-prediction-script.php');
+include_once FileUtils::normalizeFilePath('includes/default-timezone.php');
+include_once FileUtils::normalizeFilePath('includes/error-reporting.php');
 
 if(!isset($_SESSION['id'])) {
   header("Location: login.php");
@@ -39,11 +40,7 @@
 $stmt->fetch();
 $stmt->close();
 
-$sql = "SELECT SUM(total_amount) AS monthly_sale 
-        FROM transaction 
-        WHERE YEAR(timestamp) = YEAR(CURRENT_DATE()) 
-        AND MONTH(timestamp) = MONTH(CURRENT_DATE()) 
-        AND DAY(timestamp) <= DAY(CURRENT_DATE())";
+$sql = "SELECT SUM(total_amount) AS monthly_sale FROM transaction WHERE YEAR(timestamp) = YEAR(CURRENT_DATE()) AND MONTH(timestamp) = MONTH(CURRENT_DATE()) AND DAY(timestamp) <= DAY(CURRENT_DATE())";
 $stmt = $db->prepare($sql);
 $stmt->execute();
 $stmt->bind_result($monthly_sale);
@@ -69,7 +66,7 @@
 
       <style>
         .card-gradient {
-          background: linear-gradient(to top right, #88531E, #88531E, #88531E, #C57C47);
+          background: linear-gradient(to top right, #88531E, #C57C47, #C57C47, #88531E);
         }
       </style>
   </head>
@@ -78,13 +75,14 @@
 
     <?php
     // Navbar
+    include 'includes/preloader.html';
     include 'includes/navbar.php';
 
     // Charts
-    include 'includes/charts/weekly-sales.php';
-    include 'includes/charts/predicted-weekly-sales.php';
-    include 'includes/charts/weekly-top-sold-products.php';
-    include 'includes/charts/weekly-top-sold-category.php';
+    include FileUtils::normalizeFilePath('includes/charts/weekly-sales.php');
+    include FileUtils::normalizeFilePath('includes/charts/predicted-weekly-sales.php');
+    include FileUtils::normalizeFilePath('includes/charts/weekly-top-sold-products.php');
+    include FileUtils::normalizeFilePath('includes/charts/weekly-top-sold-category.php');
     ?>
 
     <!-- Main Content -->
@@ -252,6 +250,7 @@
     <!--Bootstrap JavaScript-->
     <script src="../vendor/node_modules/bootstrap/dist/js/bootstrap.bundle.min.js"></script>
     <script src="javascript/index.js"></script>
+    <script src="javascript/preloader.js"></script>
 
   </body>
 </html>
\ No newline at end of file
diff --git a/src/login.php b/src/login.php
index f996857e..c5a38bbc 100644
--- a/src/login.php
+++ b/src/login.php
@@ -1,7 +1,7 @@
 <?php
-
-require_once 'includes/session-handler.php';
-require_once 'includes/db-connector.php';
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'includes/file-utilities.php');
+require_once FileUtils::normalizeFilePath('includes/session-handler.php');
+include_once FileUtils::normalizeFilePath('includes/error-reporting.php');
 
 // If session is set, disallow returning to login page
 if(isset($_SESSION['id'])) {
@@ -9,49 +9,6 @@
     exit();
 }
 
-if(isset($_POST['sign_in_btn'])) {
-
-    $username = $_POST['username'];
-    $password = $_POST['password'];
-
-    if(empty($username) || empty($password)) {
-        $_SESSION['error_message'] = 'Please do not leave the input fields empty.';
-        header("Location: login.php");
-        exit();
-    }
-
-    // Query the user table for the entered username
-    $stmt = $db->prepare("SELECT id, username, password FROM user WHERE BINARY username = ?");
-    $stmt->bind_param('s', $username);
-    $stmt->execute();
-    $result = $stmt->get_result();
-
-    // Check if a user of this username exists
-    if($result->num_rows > 0) {
-        $row = $result->fetch_assoc();
-
-        // Verify if password match the entered username
-        if (password_verify($password, $row['password'])) {
-            $_SESSION['id'] = $row['id'];
-            session_regenerate_id(true);
-            header("location: index.php");
-            exit();
-        }
-        // If username and password mismatched, display this      
-        else {
-            $_SESSION['error_message'] = 'Username and password mismatched.';
-            header("Location: login.php");
-            exit();
-            }
-    }
-    // If there is no user with the username, display this
-    else {
-        $_SESSION['error_message'] = 'User is not found.';
-        header("Location: login.php");
-        exit();
-    }
-}
-
 if (isset($_SESSION['error_message'])) {
     $errorMessage = $_SESSION['error_message'];
     unset($_SESSION['error_message']);
@@ -93,6 +50,8 @@
 
 <body>
 
+    <?php include FileUtils::normalizeFilePath('includes/preloader.html'); ?>
+
     <!-- Forgot Password Modal -->
     <div class="modal fade" id="forgotPasswordModal" tabindex="-1" aria-labelledby="forgotPasswordModal" aria-hidden="true">
       <div class="modal-dialog modal-dialog-centered px-3">
@@ -134,7 +93,7 @@
                         <h3 class="sweet-avenue mb-0 fw-semibold"><strong>SWEET AVENUE</strong></h3>
                         <h5 class="coffee-bakeshop mb-4 fw-medium"><strong>COFFEE • BAKESHOP</strong></h5>
                     </div>
-                    <form action="login.php" method="post" id="login-form" class="needs-validation" novalidate>
+                    <form action="includes/login-authenticator.php" method="post" id="login-form" class="needs-validation" novalidate>
                         
                         <?php if (isset($errorMessage)) : ?>
                             <div class="alert alert-danger alert-dismissible fade show" role="alert">
@@ -176,14 +135,9 @@
         </div>
     </div>
     
-    
-
-
-
-
-
     <script src="../vendor/node_modules/bootstrap/dist/js/bootstrap.bundle.min.js"></script>
     <script src="javascript/login.js"></script>
+    <script src="javascript/preloader.js"></script>
 
 </body>
 
diff --git a/src/product.php b/src/product.php
index bd0233a4..bd037f3a 100644
--- a/src/product.php
+++ b/src/product.php
@@ -1,6 +1,8 @@
 <?php
-require_once 'includes/db-connector.php';
-require_once 'includes/session-handler.php';
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'includes/file-utilities.php');
+require_once FileUtils::normalizeFilePath('includes/db-connector.php');
+require_once FileUtils::normalizeFilePath('includes/session-handler.php');
+include_once FileUtils::normalizeFilePath('includes/error-reporting.php');
 
 if(isset($_SESSION['id'])) {
 
@@ -26,7 +28,8 @@
 
     <!--Navbar-->
     <?php
-    include 'includes/navbar.php';
+    include FileUtils::normalizeFilePath('includes/navbar.php');
+    include FileUtils::normalizeFilePath('includes/preloader.html');
     ?>
 
   <body>
@@ -317,6 +320,7 @@
     <script src="https://cdn.datatables.net/2.0.3/js/dataTables.js"></script>
     <script src="https://cdn.datatables.net/2.0.3/js/dataTables.bootstrap5.js"></script>
     <script src="Select_Deselect.js"></script>
+    <script src="javascript/preloader.js"></script>
     <script>
       $(document).ready(function () {
           $('#food').DataTable();
diff --git a/src/report.php b/src/report.php
index 45013d03..2089f8c1 100644
--- a/src/report.php
+++ b/src/report.php
@@ -1,6 +1,8 @@
 <?php
-require_once 'includes/db-connector.php';
-require_once 'includes/session-handler.php';
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'includes/file-utilities.php');
+require_once FileUtils::normalizeFilePath('includes/db-connector.php');
+require_once FileUtils::normalizeFilePath('includes/session-handler.php');
+include_once FileUtils::normalizeFilePath('includes/error-reporting.php');
 
 if(isset($_SESSION['id'])) {
 
@@ -35,7 +37,8 @@
 
     <!--Navbar-->
     <?php
-    include 'includes/navbar.php';
+    include FileUtils::normalizeFilePath('includes/navbar.php');
+    include FileUtils::normalizeFilePath('includes/preloader.html');
     ?>
 
   <body>
@@ -148,6 +151,7 @@
     <script src="https://cdnjs.cloudflare.com/ajax/libs/pdfmake/0.2.7/vfs_fonts.js"></script>
     <script src="https://cdn.datatables.net/buttons/3.0.2/js/buttons.html5.min.js"></script>
     <script src="https://cdn.datatables.net/buttons/3.0.2/js/buttons.print.min.js"></script>
+    <script src="javascript/preloader.js"></script>
 
     <script>
  new DataTable('#example', {
diff --git a/src/sales.php b/src/sales.php
index 313b8682..45bdec6d 100644
--- a/src/sales.php
+++ b/src/sales.php
@@ -1,6 +1,8 @@
 <?php
-require_once 'includes/db-connector.php';
-require_once 'includes/session-handler.php';
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'includes/file-utilities.php');
+require_once FileUtils::normalizeFilePath('includes/db-connector.php');
+require_once FileUtils::normalizeFilePath('includes/session-handler.php');
+include_once FileUtils::normalizeFilePath('includes/error-reporting.php');
 
 if(isset($_SESSION['id'])) {
 
@@ -28,7 +30,8 @@
 
     <!--Navbar-->
     <?php
-    include 'includes/navbar.php';
+    include_once FileUtils::normalizeFilePath('includes/navbar.php');
+    include FileUtils::normalizeFilePath('includes/preloader.html');
     ?>
 
     <!--Main Container-->
@@ -181,6 +184,7 @@
     <script src="https://code.jquery.com/jquery-3.7.1.js"></script>
     <script src="https://cdn.datatables.net/2.0.3/js/dataTables.js"></script>
     <script src="https://cdn.datatables.net/2.0.3/js/dataTables.bootstrap5.js"></script>
+    <script src="javascript/preloader.js"></script>
     
 
     <script>

From 8ddfc2c828a839d7c8912366ff58cfd18c298984 Mon Sep 17 00:00:00 2001
From: Carl-Tabuso <carlftabuso@iskolarngbayan.pup.edu.ph>
Date: Fri, 24 May 2024 18:18:01 +0800
Subject: [PATCH 10/11] chore: Replace forward slashes with appropriate
 directory separator in a file path for current operating system.

---
 src/includes/file-utilities.php | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 src/includes/file-utilities.php

diff --git a/src/includes/file-utilities.php b/src/includes/file-utilities.php
new file mode 100644
index 00000000..f56a1174
--- /dev/null
+++ b/src/includes/file-utilities.php
@@ -0,0 +1,20 @@
+<?php
+
+/**
+ * File function utilities.
+ *
+ */
+class FileUtils
+{
+    /**
+     * Replace forward slashes with appropriate directory separator in a file path for current operating system.
+     *
+     * @param string $path The file path to transform.
+     * @return string The transformed file path.
+     */
+    public static function normalizeFilePath($path)
+    {
+
+        return str_replace('/', DIRECTORY_SEPARATOR, $path);
+    }
+}

From 73a72bc942d0ba382238e5e5b7e1afc2bc0a2cf1 Mon Sep 17 00:00:00 2001
From: Carl-Tabuso <carlftabuso@iskolarngbayan.pup.edu.ph>
Date: Fri, 24 May 2024 18:18:41 +0800
Subject: [PATCH 11/11] chore: Change directory of logout script as it was
 moved to includes folder.

---
 src/includes/navbar.php | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/includes/navbar.php b/src/includes/navbar.php
index fd5c8adc..f803a864 100644
--- a/src/includes/navbar.php
+++ b/src/includes/navbar.php
@@ -1,5 +1,7 @@
 <?php
-require_once 'includes/db-connector.php';
+include_once str_replace('/', DIRECTORY_SEPARATOR, 'file-utilities.php');
+require_once  FileUtils::normalizeFilePath('includes/db-connector.php');
+include_once FileUtils::normalizeFilePath('error-reporting.php');
 
 // Query user table to display the current user
 $sql = $db->prepare("SELECT id, first_name FROM user WHERE id = ?");
@@ -73,7 +75,7 @@
                             </svg>
                             Accounts</a>
                         </li>
-                        <li><a class="dropdown-item" href="logout.php">
+                        <li><a class="dropdown-item" href="includes/logout.php">
                             <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" fill="currentColor" class="bi bi-box-arrow-in-left" viewBox="0 0 16 16">
                             <path fill-rule="evenodd" d="M10 3.5a.5.5 0 0 0-.5-.5h-8a.5.5 0 0 0-.5.5v9a.5.5 0 0 0 .5.5h8a.5.5 0 0 0 .5-.5v-2a.5.5 0 0 1 1 0v2A1.5 1.5 0 0 1 9.5 14h-8A1.5 1.5 0 0 1 0 12.5v-9A1.5 1.5 0 0 1 1.5 2h8A1.5 1.5 0 0 1 11 3.5v2a.5.5 0 0 1-1 0z"/>
                             <path fill-rule="evenodd" d="M4.146 8.354a.5.5 0 0 1 0-.708l3-3a.5.5 0 1 1 .708.708L5.707 7.5H14.5a.5.5 0 0 1 0 1H5.707l2.147 2.146a.5.5 0 0 1-.708.708z"/>