<?php

namespace App\Controllers;
use CodeIgniter\Controller;
use App\Controllers\BaseController;

class LogController extends BaseController
{
    private $logPath;
    public $dModel;
    public $session;

    public function __construct()
    {
        // Path to log files
        $this->logPath = WRITEPATH . 'logs/';
        $this->session = session();
    }

    /**
     * Display list of all log files
     */
    public function index()
    {

        $logFiles = $this->getLogFiles();
        
        $data = [
            'title' => 'Log Files',
            'logFiles' => $logFiles
        ];

        return $this->loadLayout('logs/index', $data);

        // return view('logs/index', $data);
    }

    /**
     * Get all log files sorted by date (latest first)
     */
    private function getLogFiles()
    {
        $files = [];

        if (!is_dir($this->logPath)) {
            return $files;
        }

        $iterator = new \DirectoryIterator($this->logPath);

        foreach ($iterator as $fileInfo) {
            if ($fileInfo->isFile() && $fileInfo->getExtension() === 'log') {
                $files[] = [
                    'name' => $fileInfo->getFilename(),
                    'path' => $fileInfo->getPathname(),
                    'size' => $this->formatBytes($fileInfo->getSize()),
                    'modified' => $fileInfo->getMTime(),
                    'modified_date' => date('Y-m-d H:i:s', $fileInfo->getMTime())
                ];
            }
        }

        // Sort by modified time (latest first)
        usort($files, function($a, $b) {
            return $b['modified'] - $a['modified'];
        });

        return $files;
    }

    /**
     * View specific log file content
     */
    public function view($filename = null)
    {

       

        if (!$filename) {
            return redirect()->to('/logs')->with('error', 'No log file specified');
        }

        // Security: prevent directory traversal
        $filename = basename($filename);
        $filePath = $this->logPath . $filename;

        if (!file_exists($filePath)) {
            return redirect()->to('/logs')->with('error', 'Log file not found');
        }

        // ✅ extract date from filename: log-YYYY-MM-DD.log
        if (preg_match('/log-(\d{4}-\d{2}-\d{2})\.log/', $filename, $match)) {
            $currentDate = $match[1];

            $prevDate = date('Y-m-d', strtotime('-1 day', strtotime($currentDate)));
            $nextDate = date('Y-m-d', strtotime('+1 day', strtotime($currentDate)));

            $prevFile = "log-$prevDate.log";
            $nextFile = "log-$nextDate.log";

            $prevExists = file_exists($this->logPath . $prevFile);
            $nextExists = file_exists($this->logPath . $nextFile);
        }

        // Read log file content
        $content = file_get_contents($filePath);
        $logEntries = $this->parseLogFile($content);

        $data = [
            'title' => 'View Log: ' . $filename,
            'filename' => $filename,
            'logEntries' => $logEntries,
            'prevFile'    => $prevExists ? $prevFile : null,
            'nextFile'    => $nextExists ? $nextFile : null,
            'fileSize' => $this->formatBytes(filesize($filePath)),
            'lastModified' => date('Y-m-d H:i:s', filemtime($filePath))
        ];

        // print_r( $data); die;

        return $this->loadLayout('logs/view', $data);
        // return view('logs/view', $data);
    }

    /**
     * Parse log file into structured array
     */

    private function parseLogFile($content)
    {
        $entries = [];
        $lines = explode("\n", $content);
        
        $currentEntry = null;

        // Messages to filter out
        $skipPatterns = [
            '/Session: Class initialized using/',
            '/Session class already loaded/',
        ];

        foreach ($lines as $line) {
            // Match CI4 log format: LEVEL - date --> message
            if (preg_match('/^(\w+)\s*-\s*(\d{4}-\d{2}-\d{2}\s+\d{2}:\d{2}:\d{2})\s*-->\s*(.*)$/', $line, $matches)) {
                
                // Save previous entry if exists (before checking skip)
                if ($currentEntry !== null) {
                    $entries[] = $currentEntry;
                    $currentEntry = null;
                }

                // Check if this message should be skipped
                $shouldSkip = false;
                foreach ($skipPatterns as $pattern) {
                    if (preg_match($pattern, $matches[3])) {
                        $shouldSkip = true;
                        break;
                    }
                }

                if ($shouldSkip) {
                    continue;
                }

                // Start new entry
                $currentEntry = [
                    'level' => $matches[1],
                    'date' => $matches[2],
                    'message' => $matches[3]
                ];
            } elseif ($currentEntry !== null && trim($line) !== '') {
                // Continuation of previous message
                $currentEntry['message'] .= "\n" . $line;
            }
        }

        // Add last entry
        if ($currentEntry !== null) {
            $entries[] = $currentEntry;
        }

        return array_reverse($entries); // Latest first
    }

    /**
     * Download log file
     */
    public function download($filename = null)
    {
        if (!$filename) {
            return redirect()->to('/logs')->with('error', 'No log file specified');
        }

        $filename = basename($filename);
        $filePath = $this->logPath . $filename;

        if (!file_exists($filePath)) {
            return redirect()->to('/logs')->with('error', 'Log file not found');
        }

        return $this->response->download($filePath, null);
    }

    /**
     * Delete log file
     */
    public function delete($filename = null)
    {
        if (!$filename) {
            return redirect()->to('/logs')->with('error', 'No log file specified');
        }

        $filename = basename($filename);
        $filePath = $this->logPath . $filename;

        if (!file_exists($filePath)) {
            return redirect()->to('/logs')->with('error', 'Log file not found');
        }

        if (unlink($filePath)) {
            return redirect()->to('/logs')->with('success', 'Log file deleted successfully');
        } else {
            return redirect()->to('/logs')->with('error', 'Failed to delete log file');
        }
    }

    /**
     * Format bytes to human readable format
     */
    private function formatBytes($bytes, $precision = 2)
    {
        $units = ['B', 'KB', 'MB', 'GB', 'TB'];
        
        $bytes = max($bytes, 0);
        $pow = floor(($bytes ? log($bytes) : 0) / log(1024));
        $pow = min($pow, count($units) - 1);
        
        $bytes /= pow(1024, $pow);
        
        return round($bytes, $precision) . ' ' . $units[$pow];
    }

    /**
     * Clear all log files
     */
    public function clearAll()
    {
        $logFiles = $this->getLogFiles();
        $deleted = 0;

        foreach ($logFiles as $file) {
            if (unlink($file['path'])) {
                $deleted++;
            }
        }

        return redirect()->to('/logs')->with('success', $deleted . ' log file(s) deleted successfully');
    }
}