Enhance README and refactor code structure for improved functionality

- Updated README.md with detailed project description, features, and installation instructions.
- Refactored functions.php to include configuration settings and improved database handling.
- Modified index.php for better user experience and added pagination controls.
- Introduced new utility functions for API handling and database interactions.
- Added CSS styles for improved layout and visibility of elements.
- Removed vault.csv as data is now managed through the database.
- Implemented FTP deployment workflow for automated deployment.
- Added exception handling classes for better error management.
- Created JavaScript functions for pagination of transaction records.

includes/exceptions.php

@@ -0,0 +1,24 @@
+<?php
+class ApiKeyMissingException extends Exception {
+  public function __construct($message, $code = 0, Throwable $previous = null) {
+    parent::__construct($message, $code, $previous);
+  }
+}
+
+class CurlErrorException extends Exception {
+  public function __construct($message, $code = 0, Throwable $previous = null) {
+    parent::__construct($message, $code, $previous);
+  }
+}
+
+class JsonDataException extends Exception {
+  public function __construct($message, $code = 0, Throwable $previous = null) {
+    parent::__construct($message, $code, $previous);
+  }
+}
+
+class ApiValidationException extends Exception {
+  public function __construct($message, $code = 0, Throwable $previous = null) {
+    parent::__construct($message, $code, $previous);
+  }
+}

includes/utilities.php

@@ -0,0 +1,201 @@
+<?php
+/** Checks if the database is new and empty.
+ *
+ * This function checks if the 'vault' table in the database has any entries.
+ * If it does not, it returns true, indicating that the database is new and
+ * empty. Otherwise, it returns false.
+ *
+ * @return boolean True if the database is new and empty, false otherwise.
+ */
+function dbNew() {
+  $pdo  = getDatabaseConnection();
+  $stmt = $pdo->query("SELECT COUNT(*) FROM vault");
+
+  return $stmt->fetchColumn() == 0;
+}
+
+/** Ensures that a user has an API key configured.
+ *
+ * @param string $user The user to check the API key for
+ *
+ * @throws Exception If the user does not have an API key configured
+ */
+function ensureUserHasApiKey($user) {
+  if (!array_key_exists($user, USER_KEYS)) {
+    throw new ApiKeyMissingException("User does not have an API key configured.");
+  }
+}
+
+/** Executes a GET request to the given API endpoint and returns the JSON response as an associative array.
+ *
+ * @param string $apiEndpoint The URL of the API endpoint to call
+ *
+ * @throws Exception If the API call fails or if the response is invalid JSON
+ *
+ * @return array The JSON response from the API
+ */
+function executeApiCall($apiEndpoint) {
+  $headers = ["Content-Type: application/json"];
+  $ch = curl_init();
+  curl_setopt($ch, CURLOPT_URL, $apiEndpoint);
+  curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
+  curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
+
+  $response = curl_exec($ch);
+
+  if (curl_errno($ch)) {
+    throw new CurlErrorException("cURL error: " . curl_error($ch));
+  }
+
+  curl_close($ch);
+
+  $responseData = json_decode($response, true);
+
+  if (json_last_error() !== JSON_ERROR_NONE) {
+    throw new JsonDataException("Failed to decode JSON response: " . json_last_error_msg());
+  }
+
+  return $responseData;
+}
+
+/** Validates the API response data for the presence of a log array.
+ *
+ * @param array $responseData The API response data to validate.
+ *
+ * @throws Exception If the log data is missing or not an array.
+ */
+function validateApiResponse($responseData) {
+  if (!isset($responseData['log']) || !is_array($responseData['log'])) {
+    throw new ApiValidationException("Invalid log data received from the API.");
+  }
+}
+
+/** Prepare a PDO statement for checking if a given vault transaction already exists in the database.
+ *
+ * @param PDO $pdo The PDO instance to prepare the statement with
+ *
+ * @return PDOStatement The prepared statement
+ */
+function prepareCheckStatement($pdo) {
+  $checkQuery = "SELECT COUNT(*) FROM vault WHERE user = :user AND timestamp = :timestamp AND amount = :amount";
+  return $pdo->prepare($checkQuery);
+}
+
+/** Prepare a PDO statement for inserting a new vault transaction into the database.
+ *
+ * @param PDO $pdo The PDO instance to prepare the statement with
+ *
+ * @return PDOStatement The prepared statement
+ */
+function prepareInsertStatement($pdo) {
+  $insertQuery = "INSERT INTO vault (ID, user, timestamp, description, amount) VALUES (:id, :user, :timestamp, :description, :amount)";
+  return $pdo->prepare($insertQuery);
+}
+
+/** Process an array of log entries retrieved from the Torn API.
+ *
+ * Goes through each log entry and checks if it's a vault deposit or withdrawal.
+ * If it is, it checks if the entry already exists in the database. If it
+ * doesn't, it inserts the entry into the database.
+ *
+ * @param array $logEntries The array of log entries to process
+ * @param string $user The user whose log entries are being processed
+ * @param PDOStatement $checkStmt A prepared statement to check if an entry
+ *                                already exists in the database
+ * @param PDOStatement $insertStmt A prepared statement to insert a new entry
+ *                                into the database
+ * @param boolean $debug Whether to output debug information (default: false)
+ */
+function processLogEntries($logEntries, $user, $checkStmt, $insertStmt, $debug) {
+  foreach ($logEntries as $key =>$entry) {
+    if ($debug) {
+      $logMessage = "Raw entry:\n" . print_r($entry, true);
+      file_put_contents(__DIR__ . '/debug.log', $logMessage, FILE_APPEND);
+    }
+
+    $timestamp   = $entry['timestamp'];
+    $description = $entry['title'];
+    $amount      = $entry['log'] === 5850 ? $entry['data']['deposited'] : -$entry['data']['withdrawn'];
+
+    if ($debug) {
+      $logMessage = "Vault entry:\n\tUser: $user,\n\tTimestamp: $timestamp,\n\tDescription: $description,\n\tAmount: $amount\n";
+      file_put_contents(__DIR__ . '/debug.log', $logMessage, FILE_APPEND);
+    }
+
+    $checkStmt->execute([
+      ':user'      => $user,
+      ':timestamp' => $timestamp,
+      ':amount'    => $amount
+    ]);
+
+    if ($checkStmt->fetchColumn() == 0) {
+      $insertStmt->execute([
+        ':id'          => $key,
+        ':user'        => $user,
+        ':timestamp'   => $timestamp,
+        ':description' => $description,
+        ':amount'      => $amount
+      ]);
+    }
+  }
+}
+
+/** Fetch vault records from the database
+ * If a user is provided, only that user's records
+ * are returned. Otherwise, all records are returned.
+ *
+ * @param string $user (optional) The user to filter by
+ *
+ * @return array An array of records, or an empty array on error
+ */
+function fetchVaultRecords($user = null) {
+  $pdo = getDatabaseConnection();
+
+  if ($user) {
+    $query  = "SELECT * FROM vault WHERE user = :user ORDER BY timestamp DESC";
+    $params = [':user' => $user];
+  } else {
+    $query  = "SELECT * FROM vault ORDER BY timestamp DESC";
+    $params = [];
+  }
+
+  try {
+    $stmt = $pdo->prepare($query);
+    $stmt->execute($params);
+
+    return $stmt->fetchAll(PDO::FETCH_ASSOC);
+  } catch (PDOException $e) {
+    echo "Error fetching records: " . $e->getMessage();
+
+    return [];
+  }
+}
+
+/** Iterate over all vault records for the given user (or all users if no user is given),
+ *
+ * @param string|null $name (optional) The user to loop over records for.
+ *                          If not provided, all users' records will be looped over.
+ *
+ * @return int The total balance of the given user (or all users if no user is given).
+ */
+function vaultLoop ($name=null) {
+  $vault   = fetchVaultRecords($name);
+  $balance = 0;
+
+  foreach ($vault as $entry) { $balance += $entry['amount']; }
+
+  return $balance;
+}
+
+/** Returns a string indicating the sign of a number, with a dollar symbol.
+ *
+ * @param int|float $number The number to check.
+ *
+ * @return string A string containing a dollar sign and a negative sign if the
+ *                number is negative.
+ */
+function getSign($number) {
+  if (substr($number, 0, 1) == '-') { return '-$'; }
+
+  return '$';
+}