<?php

namespace App\Services;

use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Auth;
use Illuminate\Support\Facades\Log;

class NeblogisticAuditService
{
    /**
     * Log an INSERT operation
     */
    public static function logInsert($neblogisticId, $newData, Request $request = null)
    {
        return self::log('INSERT', $neblogisticId, null, $newData, $request);
    }

    /**
     * Log an UPDATE operation
     */
    public static function logUpdate($neblogisticId, $oldData, $newData, $changedFields = null, Request $request = null)
    {
        return self::log('UPDATE', $neblogisticId, $oldData, $newData, $request, $changedFields);
    }

    /**
     * Log a DELETE operation
     */
    public static function logDelete($neblogisticId, $oldData, Request $request = null)
    {
        return self::log('DELETE', $neblogisticId, $oldData, null, $request);
    }

    /**
     * Main logging method
     */
    protected static function log($action, $neblogisticId, $oldData = null, $newData = null, Request $request = null, $changedFields = null)
    {
        try {
            $user = Auth::user();
            $requestData = self::getRequestData($request);
            
            // Get old record if not provided and it's an update/delete
            if (in_array($action, ['UPDATE', 'DELETE']) && !$oldData && $neblogisticId) {
                $oldData = DB::table('neblogistic')->where('id', $neblogisticId)->first();
                if ($oldData) {
                    $oldData = json_decode(json_encode($oldData), true);
                }
            }

            // Get new record if it's an insert/update
            if (in_array($action, ['INSERT', 'UPDATE']) && !$newData && $neblogisticId) {
                $newRecord = DB::table('neblogistic')->where('id', $neblogisticId)->first();
                if ($newRecord) {
                    $newData = json_decode(json_encode($newRecord), true);
                }
            }

            // Calculate changed fields if not provided
            if ($action === 'UPDATE' && !$changedFields && $oldData && $newData) {
                $changedFields = [];
                foreach ($newData as $key => $value) {
                    $oldValue = $oldData[$key] ?? null;
                    if ($oldValue !== $value) {
                        $changedFields[$key] = [
                            'old' => $oldValue,
                            'new' => $value
                        ];
                    }
                }
            }

            // Parse browser details
            $browserDetails = self::parseUserAgent($requestData['user_agent'] ?? '');

            $auditData = [
                'neblogistic_id' => $neblogisticId,
                'action' => $action,
                'old_data' => $oldData ? json_encode($oldData) : null,
                'new_data' => $newData ? json_encode($newData) : null,
                'changed_fields' => $changedFields ? json_encode($changedFields) : null,
                'user_id' => $user ? $user->id : null,
                'user_email' => $user ? ($user->email ?? null) : null,
                'user_name' => $user ? ($user->name ?? null) : null,
                'ip_address' => $requestData['ip'],
                'user_agent' => $requestData['user_agent'],
                'browser_details' => json_encode($browserDetails),
                'request_url' => $requestData['url'],
                'request_method' => $requestData['method'],
                'created_at' => now(),
            ];

            DB::table('neblogistic_audit_trail')->insert($auditData);

            return true;
        } catch (\Exception $e) {
            // Log error but don't break the main operation
            Log::error('Neblogistic audit trail logging failed: ' . $e->getMessage(), [
                'action' => $action,
                'neblogistic_id' => $neblogisticId,
                'exception' => $e
            ]);
            return false;
        }
    }

    /**
     * Get request data safely
     */
    protected static function getRequestData($request = null)
    {
        if (!$request && request()) {
            $request = request();
        }

        if (!$request) {
            return [
                'ip' => null,
                'user_agent' => null,
                'url' => null,
                'method' => null,
            ];
        }

        return [
            'ip' => $request->ip() ?? 
                   $request->header('X-Forwarded-For') ?? 
                   $request->server('REMOTE_ADDR') ?? 
                   'unknown',
            'user_agent' => $request->header('User-Agent'),
            'url' => $request->fullUrl(),
            'method' => $request->method(),
        ];
    }

    /**
     * Parse user agent to extract browser details
     */
    protected static function parseUserAgent($userAgent)
    {
        if (empty($userAgent)) {
            return [
                'browser' => 'Unknown',
                'browser_version' => null,
                'platform' => 'Unknown',
                'device' => 'Unknown',
            ];
        }

        $details = [
            'browser' => 'Unknown',
            'browser_version' => null,
            'platform' => 'Unknown',
            'device' => 'Unknown',
        ];

        // Detect browser
        if (preg_match('/MSIE|Trident/i', $userAgent)) {
            $details['browser'] = 'Internet Explorer';
            if (preg_match('/MSIE\s([\d.]+)/', $userAgent, $matches)) {
                $details['browser_version'] = $matches[1];
            }
        } elseif (preg_match('/Edge/i', $userAgent)) {
            $details['browser'] = 'Microsoft Edge';
            if (preg_match('/Edge\/([\d.]+)/', $userAgent, $matches)) {
                $details['browser_version'] = $matches[1];
            }
        } elseif (preg_match('/Chrome/i', $userAgent) && !preg_match('/Edge/i', $userAgent)) {
            $details['browser'] = 'Chrome';
            if (preg_match('/Chrome\/([\d.]+)/', $userAgent, $matches)) {
                $details['browser_version'] = $matches[1];
            }
        } elseif (preg_match('/Firefox/i', $userAgent)) {
            $details['browser'] = 'Firefox';
            if (preg_match('/Firefox\/([\d.]+)/', $userAgent, $matches)) {
                $details['browser_version'] = $matches[1];
            }
        } elseif (preg_match('/Safari/i', $userAgent) && !preg_match('/Chrome/i', $userAgent)) {
            $details['browser'] = 'Safari';
            if (preg_match('/Version\/([\d.]+)/', $userAgent, $matches)) {
                $details['browser_version'] = $matches[1];
            }
        } elseif (preg_match('/Opera|OPR/i', $userAgent)) {
            $details['browser'] = 'Opera';
            if (preg_match('/(?:Opera|OPR)\/([\d.]+)/', $userAgent, $matches)) {
                $details['browser_version'] = $matches[1];
            }
        }

        // Detect platform
        if (preg_match('/Windows/i', $userAgent)) {
            $details['platform'] = 'Windows';
        } elseif (preg_match('/Macintosh|Mac OS X/i', $userAgent)) {
            $details['platform'] = 'macOS';
        } elseif (preg_match('/Linux/i', $userAgent)) {
            $details['platform'] = 'Linux';
        } elseif (preg_match('/Android/i', $userAgent)) {
            $details['platform'] = 'Android';
        } elseif (preg_match('/iPhone|iPad|iPod/i', $userAgent)) {
            $details['platform'] = 'iOS';
        }

        // Detect device
        if (preg_match('/Mobile|Android|iPhone|iPad/i', $userAgent)) {
            if (preg_match('/iPad/i', $userAgent)) {
                $details['device'] = 'Tablet';
            } elseif (preg_match('/iPhone|iPod/i', $userAgent)) {
                $details['device'] = 'Mobile';
            } elseif (preg_match('/Android/i', $userAgent)) {
                $details['device'] = preg_match('/Mobile/i', $userAgent) ? 'Mobile' : 'Tablet';
            } else {
                $details['device'] = 'Mobile';
            }
        } else {
            $details['device'] = 'Desktop';
        }

        return $details;
    }

    /**
     * Clean up old audit logs (older than specified months)
     */
    public static function cleanupOldLogs($months = 6)
    {
        try {
            $cutoffDate = now()->subMonths($months);
            $deleted = DB::table('neblogistic_audit_trail')
                ->where('created_at', '<', $cutoffDate)
                ->delete();
            
            Log::info("Cleaned up {$deleted} old neblogistic audit trail records older than {$months} months");
            return $deleted;
        } catch (\Exception $e) {
            Log::error('Failed to cleanup neblogistic audit trail logs: ' . $e->getMessage());
            return 0;
        }
    }
}