<?php

namespace App\Services;

use Illuminate\Http\Request;

class ClientContextService
{
    public function normalizeFromRequest(Request $request): array
    {
        $data = $request->validate([
            'browser' => ['nullable', 'string', 'max:64'],
            'browser_version' => ['nullable', 'string', 'max:32'],
            'os' => ['nullable', 'string', 'max:64'],
            'os_version' => ['nullable', 'string', 'max:32'],
            'screen' => ['nullable', 'string', 'max:32'],
            'cpu_cores' => ['nullable', 'integer', 'min:1', 'max:256'],
            'device_memory_gb' => ['nullable', 'numeric', 'min:0', 'max:1024'],
            'gpu' => ['nullable', 'string', 'max:255'],
            'language' => ['nullable', 'string', 'max:32'],
            'timezone' => ['nullable', 'string', 'max:64'],
            'webrtc_ip' => ['nullable', 'string', 'max:45'],
        ]);

        $ua = $request->userAgent() ?? '';
        $parsed = $this->parseUserAgent($ua);

        return array_filter([
            'browser' => $data['browser'] ?? $parsed['browser'],
            'browser_version' => $data['browser_version'] ?? $parsed['browser_version'],
            'os' => $data['os'] ?? $parsed['os'],
            'os_version' => $data['os_version'] ?? $parsed['os_version'],
            'screen' => $data['screen'] ?? null,
            'cpu_cores' => isset($data['cpu_cores']) ? (int) $data['cpu_cores'] : null,
            'device_memory_gb' => isset($data['device_memory_gb']) ? (float) $data['device_memory_gb'] : null,
            'gpu' => $data['gpu'] ?? null,
            'language' => $data['language'] ?? null,
            'timezone' => $data['timezone'] ?? null,
            'webrtc_ip' => $data['webrtc_ip'] ?? null,
            'user_agent' => mb_substr($ua, 0, 500),
        ], fn ($value) => $value !== null && $value !== '');
    }

    public function storeInSession(Request $request, array $context): void
    {
        $request->session()->put('audit_client_context', $context);
    }

    public function fromSession(Request $request): array
    {
        $context = $request->session()->get('audit_client_context');

        return is_array($context) ? $context : [];
    }

    /**
     * @return array{browser: ?string, browser_version: ?string, os: ?string, os_version: ?string}
     */
    public function parseUserAgent(string $ua): array
    {
        $browser = null;
        $browserVersion = null;
        $os = null;
        $osVersion = null;

        if (preg_match('/Edg\/([\d.]+)/', $ua, $m)) {
            $browser = 'Edge';
            $browserVersion = $m[1];
        } elseif (preg_match('/OPR\/([\d.]+)/', $ua, $m) || preg_match('/Opera\/([\d.]+)/', $ua, $m)) {
            $browser = 'Opera';
            $browserVersion = $m[1];
        } elseif (preg_match('/Chrome\/([\d.]+)/', $ua, $m) && ! str_contains($ua, 'Edg/')) {
            $browser = 'Chrome';
            $browserVersion = $m[1];
        } elseif (preg_match('/Firefox\/([\d.]+)/', $ua, $m)) {
            $browser = 'Firefox';
            $browserVersion = $m[1];
        } elseif (preg_match('/Version\/([\d.]+).*Safari/', $ua, $m)) {
            $browser = 'Safari';
            $browserVersion = $m[1];
        }

        if (preg_match('/Windows NT ([\d.]+)/', $ua, $m)) {
            $os = 'Windows';
            $osVersion = match ($m[1]) {
                '10.0' => '10/11',
                '6.3' => '8.1',
                '6.2' => '8',
                '6.1' => '7',
                default => $m[1],
            };
        } elseif (preg_match('/Android ([\d.]+)/', $ua, $m)) {
            $os = 'Android';
            $osVersion = $m[1];
        } elseif (preg_match('/iPhone OS ([\d_]+)/', $ua, $m) || preg_match('/iPad.*OS ([\d_]+)/', $ua, $m)) {
            $os = 'iOS';
            $osVersion = str_replace('_', '.', $m[1]);
        } elseif (str_contains($ua, 'Mac OS X')) {
            $os = 'macOS';
            if (preg_match('/Mac OS X ([\d_]+)/', $ua, $m)) {
                $osVersion = str_replace('_', '.', $m[1]);
            }
        } elseif (str_contains($ua, 'Linux')) {
            $os = 'Linux';
        }

        return [
            'browser' => $browser,
            'browser_version' => $browserVersion,
            'os' => $os,
            'os_version' => $osVersion,
        ];
    }

    public function summary(array $context): string
    {
        $parts = [];

        if (! empty($context['browser'])) {
            $parts[] = $context['browser'].(! empty($context['browser_version']) ? ' '.$context['browser_version'] : '');
        }

        if (! empty($context['os'])) {
            $parts[] = $context['os'].(! empty($context['os_version']) ? ' '.$context['os_version'] : '');
        }

        if (! empty($context['screen'])) {
            $parts[] = $context['screen'];
        }

        return $parts !== [] ? implode(' · ', $parts) : '—';
    }
}