Update -> add new log and analytices users

.gitignore

@@ -1,3 +1,6 @@
 .env.DS_Store
 .env
 .DS_Store
+
+storage/logs/*.log
+storage/

app/controllers/SaveController.php

@@ -1,10 +1,16 @@
 <?php
 require_once __DIR__ . '/../core/security.php';
+require_once __DIR__ . '/../core/logger.php';
 $pdo    = require __DIR__ . '/../core/db.php';
 require_once __DIR__ . '/../models/Paste.php';
+require_once __DIR__ . '/../models/Analytics.php';
 $config = require __DIR__ . '/../config/config.php';
 
+$logger    = new Logger('save');
+$analytics = new Analytics($pdo);
+
 if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
+    $logger->warning('Non-POST request to save endpoint', ['method' => $_SERVER['REQUEST_METHOD']]);
     header('Location: /');
     exit;
 }
@@ -14,6 +20,8 @@ $password = $_POST['password'] ?? '';
 $expire   = isset($_POST['expire']) ? (int)$_POST['expire'] : 0;
 
 if ($text === '') {
+    $logger->warning('Empty paste submission attempt');
+    $analytics->record('paste_validation_failed', null, ['reason' => 'empty_text']);
     jsonResponse(['success' => false, 'message' => 'Text cannot be empty.'], 422);
 }
 
@@ -23,7 +31,28 @@ $password_hash = $password !== '' ? password_hash($password, PASSWORD_DEFAULT) :
 $expire_time   = $expire > 0 ? time() + $expire : null;
 
 $paste = new Paste($pdo);
-$paste->save($id, $enc['cipher'], $enc['iv'], $expire_time, $password_hash);
+$saved = $paste->save($id, $enc['cipher'], $enc['iv'], $expire_time, $password_hash);
+
+if (!$saved) {
+    $logger->error('Failed to save paste to storage', ['id' => $id]);
+    $analytics->record('paste_save_failed', $id);
+    jsonResponse(['success' => false, 'message' => 'Failed to save paste. Please try again.'], 500);
+}
+
+$charCount = mb_strlen($text, 'UTF-8');
+$logger->info('Paste created', [
+    'id'           => $id,
+    'char_count'   => $charCount,
+    'has_password' => $password_hash !== null,
+    'expires_in'   => $expire > 0 ? "{$expire}s" : 'never',
+]);
+
+$analytics->record('paste_created', $id, [
+    'char_count'   => $charCount,
+    'has_password' => $password_hash !== null,
+    'expire_secs'  => $expire > 0 ? $expire : null,
+    'storage'      => $expire_time !== null ? 'redis' : 'mysql',
+]);
 
 $base = rtrim($config['app']['base_url'] ?: ('http' . (isset($_SERVER['HTTPS']) ? 's' : '') . '://' . $_SERVER['HTTP_HOST']), '/');
 $url  = $base . '/view/' . $id;

app/controllers/ViewController.php

@@ -1,12 +1,19 @@
 <?php
 require_once __DIR__ . '/../core/security.php';
+require_once __DIR__ . '/../core/logger.php';
 $pdo    = require __DIR__ . '/../core/db.php';
 require_once __DIR__ . '/../models/Paste.php';
+require_once __DIR__ . '/../models/Analytics.php';
 $config = require __DIR__ . '/../config/config.php';
 
+$logger    = new Logger('view');
+$analytics = new Analytics($pdo);
+
 $id = preg_replace('/[^a-f0-9]/i', '', $_GET['id'] ?? '');
 
 if ($id === '') {
+    $logger->warning('View request with invalid or missing paste ID', ['raw_id' => $_GET['id'] ?? '']);
+    $analytics->record('paste_not_found', null, ['reason' => 'invalid_id']);
     $errorCode    = 404;
     $errorMessage = 'Invalid paste ID.';
     require __DIR__ . '/../../public/error.php';
@@ -17,6 +24,8 @@ $paste = new Paste($pdo);
 $data  = $paste->get($id);
 
 if (!$data) {
+    $logger->info('Paste not found', ['id' => $id]);
+    $analytics->record('paste_not_found', $id);
     $errorCode    = 404;
     $errorMessage = 'Paste not found.';
     require __DIR__ . '/../../public/error.php';
@@ -24,33 +33,49 @@ if (!$data) {
 }
 
 if ($data['expire_time'] !== null && time() > (int)$data['expire_time']) {
+    $logger->info('Expired paste accessed', ['id' => $id, 'expired_at' => $data['expire_time']]);
+    $analytics->record('paste_expired', $id, ['expired_at' => $data['expire_time']]);
     $errorCode    = 410;
     $errorMessage = 'This paste has expired.';
     require __DIR__ . '/../../public/error.php';
     exit;
 }
 
-$needsPassword  = (bool)$data['password_hash'];
+$needsPassword = (bool)$data['password_hash'];
-$wrongPassword  = false;
+$wrongPassword = false;
-$decrypted      = null;
+$decrypted     = null;
 
 if ($needsPassword) {
     $submitted = $_POST['password'] ?? null;
     if ($submitted !== null) {
         if (password_verify($submitted, $data['password_hash'])) {
             $needsPassword = false;
+            $logger->info('Paste unlocked successfully', ['id' => $id]);
+            $analytics->record('paste_unlocked', $id);
         } else {
             $wrongPassword = true;
+            $logger->warning('Failed password attempt for paste', ['id' => $id]);
+            $analytics->record('paste_failed_password', $id);
         }
+    } else {
+        $analytics->record('paste_password_prompt', $id);
     }
 }
 
 if (!$needsPassword) {
     $decrypted = decryptText($data['encrypted_text'], $data['iv'], $config['app']['master_key']);
     if ($decrypted === false) {
+        $logger->error('Decryption failed for paste', ['id' => $id]);
+        $analytics->record('paste_decrypt_error', $id);
         $errorCode    = 500;
         $errorMessage = 'Decryption failed. The paste may be corrupted.';
         require __DIR__ . '/../../public/error.php';
         exit;
     }
+
+    $logger->info('Paste viewed', ['id' => $id, 'char_count' => mb_strlen($decrypted, 'UTF-8')]);
+    $analytics->record('paste_viewed', $id, [
+        'char_count'  => mb_strlen($decrypted, 'UTF-8'),
+        'has_expiry'  => $data['expire_time'] !== null,
+    ]);
 }

app/core/db.php

@@ -1,4 +1,6 @@
 <?php
+require_once __DIR__ . '/logger.php';
+
 $config = require __DIR__ . '/../config/config.php';
 
 try {
@@ -14,6 +16,7 @@ try {
         PDO::ATTR_EMULATE_PREPARES   => false,
     ]);
 } catch (PDOException $e) {
+    (new Logger('db'))->error('Database connection failed', ['error' => $e->getMessage()]);
     http_response_code(503);
     die(json_encode(['success' => false, 'message' => 'Database connection error.']));
 }

app/core/logger.php

@@ -0,0 +1,76 @@
+<?php
+
+class Logger
+{
+    const INFO    = 'INFO';
+    const WARNING = 'WARNING';
+    const ERROR   = 'ERROR';
+
+    private string $logDir;
+    private string $context;
+
+    public function __construct(string $context = 'app')
+    {
+        $this->logDir  = __DIR__ . '/../../storage/logs';
+        $this->context = $context;
+
+        if (!is_dir($this->logDir)) {
+            mkdir($this->logDir, 0755, true);
+        }
+    }
+
+    public function info(string $message, array $extra = []): void
+    {
+        $this->write(self::INFO, $message, $extra);
+    }
+
+    public function warning(string $message, array $extra = []): void
+    {
+        $this->write(self::WARNING, $message, $extra);
+    }
+
+    public function error(string $message, array $extra = []): void
+    {
+        $this->write(self::ERROR, $message, $extra);
+    }
+
+    private function write(string $level, string $message, array $extra = []): void
+    {
+        $date     = date('Y-m-d');
+        $file     = "{$this->logDir}/{$date}.log";
+        $time     = date('Y-m-d H:i:s');
+        $ip       = $this->getClientIp();
+        $extraStr = empty($extra) ? '' : ' ' . json_encode($extra, JSON_UNESCAPED_UNICODE);
+
+        $line = "[{$time}] [{$level}] [{$this->context}] [{$ip}] {$message}{$extraStr}" . PHP_EOL;
+
+        file_put_contents($file, $line, FILE_APPEND | LOCK_EX);
+    }
+
+    private function getClientIp(): string
+    {
+        foreach (['HTTP_X_FORWARDED_FOR', 'HTTP_X_REAL_IP', 'REMOTE_ADDR'] as $key) {
+            if (!empty($_SERVER[$key])) {
+                $ip = trim(explode(',', $_SERVER[$key])[0]);
+                if (filter_var($ip, FILTER_VALIDATE_IP)) {
+                    return $ip;
+                }
+            }
+        }
+        return 'unknown';
+    }
+
+    public static function cleanOldLogs(int $keepDays = 30): void
+    {
+        $logDir = __DIR__ . '/../../storage/logs';
+        if (!is_dir($logDir)) {
+            return;
+        }
+
+        foreach (glob("{$logDir}/*.log") as $file) {
+            if (filemtime($file) < time() - ($keepDays * 86400)) {
+                unlink($file);
+            }
+        }
+    }
+}

app/models/Analytics.php

@@ -0,0 +1,44 @@
+<?php
+
+class Analytics
+{
+    private PDO $pdo;
+
+    public function __construct(PDO $pdo)
+    {
+        $this->pdo = $pdo;
+    }
+
+    public function record(string $event, ?string $pasteId = null, array $extra = []): void
+    {
+        try {
+            $stmt = $this->pdo->prepare(
+                'INSERT INTO analytics (event, paste_id, ip, user_agent, referer, extra)
+                 VALUES (?, ?, ?, ?, ?, ?)'
+            );
+            $stmt->execute([
+                $event,
+                $pasteId,
+                $this->getClientIp(),
+                substr($_SERVER['HTTP_USER_AGENT'] ?? '', 0, 512),
+                substr($_SERVER['HTTP_REFERER']    ?? '', 0, 512),
+                empty($extra) ? null : json_encode($extra, JSON_UNESCAPED_UNICODE),
+            ]);
+        } catch (PDOException $e) {
+            // analytics failure must never break the app
+        }
+    }
+
+    private function getClientIp(): string
+    {
+        foreach (['HTTP_X_FORWARDED_FOR', 'HTTP_X_REAL_IP', 'REMOTE_ADDR'] as $key) {
+            if (!empty($_SERVER[$key])) {
+                $ip = trim(explode(',', $_SERVER[$key])[0]);
+                if (filter_var($ip, FILTER_VALIDATE_IP)) {
+                    return $ip;
+                }
+            }
+        }
+        return '';
+    }
+}

database/analytics_migration.sql

@@ -0,0 +1,17 @@
+-- analytics table: tracks all user actions
+CREATE TABLE IF NOT EXISTS analytics (
+    id           BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
+    event        VARCHAR(50)     NOT NULL COMMENT 'paste_created, paste_viewed, paste_unlocked, paste_failed_password, paste_expired, paste_not_found, decrypt_error',
+    paste_id     CHAR(32)        DEFAULT NULL COMMENT 'related paste ID if applicable',
+    ip           VARCHAR(45)     NOT NULL DEFAULT '',
+    user_agent   VARCHAR(512)    DEFAULT NULL,
+    referer      VARCHAR(512)    DEFAULT NULL,
+    extra        JSON            DEFAULT NULL COMMENT 'expire_time, char_count, has_password, source, etc.',
+    created_at   DATETIME        NOT NULL DEFAULT CURRENT_TIMESTAMP,
+
+    PRIMARY KEY (id),
+    INDEX idx_event      (event),
+    INDEX idx_paste_id   (paste_id),
+    INDEX idx_ip         (ip),
+    INDEX idx_created_at (created_at)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;