<?php
/**
 * AI Agent Detection
 */

if (!defined('ABSPATH')) {
    exit;
}

class AiMiles_Detector {

        private $ai_bot_signatures = [
        // OpenAI
        'gptbot' => ['name' => 'GPTBot', 'company' => 'OpenAI', 'type' => 'crawler', 'category' => 'llm'],
        'chatgpt-user' => ['name' => 'ChatGPT-User', 'company' => 'OpenAI', 'type' => 'agent', 'category' => 'llm'],
        'oai-searchbot' => ['name' => 'OAI-SearchBot', 'company' => 'OpenAI', 'type' => 'crawler', 'category' => 'search'],
        'openai' => ['name' => 'OpenAI', 'company' => 'OpenAI', 'type' => 'agent', 'category' => 'llm'],
        
        // Anthropic
        'claudebot' => ['name' => 'ClaudeBot', 'company' => 'Anthropic', 'type' => 'crawler', 'category' => 'llm'],
        'claude-user' => ['name' => 'Claude-User', 'company' => 'Anthropic', 'type' => 'agent', 'category' => 'llm'],  // ← add this
        'claude-web' => ['name' => 'Claude-Web', 'company' => 'Anthropic', 'type' => 'crawler', 'category' => 'llm'],
        'anthropic-ai' => ['name' => 'Anthropic-AI', 'company' => 'Anthropic', 'type' => 'crawler', 'category' => 'llm'],
                
        // Google
        'google-extended' => ['name' => 'Google-Extended', 'company' => 'Google', 'type' => 'crawler', 'category' => 'llm'],
        'googleother' => ['name' => 'GoogleOther', 'company' => 'Google', 'type' => 'crawler', 'category' => 'llm'],
        'google-cloudvertexbot' => ['name' => 'Google-CloudVertexBot', 'company' => 'Google', 'type' => 'crawler', 'category' => 'embedding'],
        
        // Perplexity
        'perplexitybot' => ['name' => 'PerplexityBot', 'company' => 'Perplexity', 'type' => 'crawler', 'category' => 'search'],
        
        // Microsoft
        'bingbot' => ['name' => 'BingBot', 'company' => 'Microsoft', 'type' => 'crawler', 'category' => 'search'],
        'bingpreview' => ['name' => 'BingPreview', 'company' => 'Microsoft', 'type' => 'preview', 'category' => 'search'],
        
        // Meta
        'meta-externalagent' => ['name' => 'Meta-ExternalAgent', 'company' => 'Meta', 'type' => 'crawler', 'category' => 'llm'],
        'meta-externalfetcher' => ['name' => 'Meta-ExternalFetcher', 'company' => 'Meta', 'type' => 'crawler', 'category' => 'llm'],
        'meta-webindexer' => ['name' => 'Meta-WebIndexer', 'company' => 'Meta', 'type' => 'agent', 'category' => 'llm'],
        'facebookbot' => ['name' => 'FacebookBot', 'company' => 'Meta', 'type' => 'crawler', 'category' => 'embedding'],
        
        // Apple
        'applebot-extended' => ['name' => 'AppleBot-Extended', 'company' => 'Apple', 'type' => 'crawler', 'category' => 'llm'],
        'applebot' => ['name' => 'AppleBot', 'company' => 'Apple', 'type' => 'crawler', 'category' => 'search'],
        
        // Amazon
        'amazonbot' => ['name' => 'AmazonBot', 'company' => 'Amazon', 'type' => 'crawler', 'category' => 'search'],
        
        // Cohere
        'cohere-ai' => ['name' => 'Cohere-AI', 'company' => 'Cohere', 'type' => 'crawler', 'category' => 'llm'],
        
        // AI21
        'ai2bot' => ['name' => 'AI2Bot', 'company' => 'AI21', 'type' => 'crawler', 'category' => 'llm'],
        
        // Common Crawl
        'ccbot' => ['name' => 'CCBot', 'company' => 'Common Crawl', 'type' => 'crawler', 'category' => 'embedding'],
        
        // ByteDance
        'bytespider' => ['name' => 'ByteSpider', 'company' => 'ByteDance', 'type' => 'crawler', 'category' => 'llm'],
        
        // Diffbot
        'diffbot' => ['name' => 'Diffbot', 'company' => 'Diffbot', 'type' => 'crawler', 'category' => 'embedding'],
        
        // You.com
        'youbot' => ['name' => 'YouBot', 'company' => 'You.com', 'type' => 'crawler', 'category' => 'search'],
    ];

    public function detect($user_agent) {
        $signals = [];
        $ua_lower = strtolower($user_agent);

        // Only detect known AI agents
        foreach ($this->ai_bot_signatures as $signature => $agent) {
            if (strpos($ua_lower, $signature) !== false) {
                $signals[] = "ua_match:{$signature}";
                return [
                    'is_ai_agent' => true,
                    'agent' => $agent,
                    'confidence' => 'high',
                    'signals' => $signals,
                ];
            }
        }

        // Not a known AI agent
        return [
            'is_ai_agent' => false,
            'agent' => null,
            'confidence' => 'high',
            'signals' => $signals,
        ];
    }
    
    public function is_ai_agent($user_agent) {
        $ua_lower = strtolower($user_agent);

        foreach ($this->ai_bot_signatures as $signature => $agent) {
            if (strpos($ua_lower, $signature) !== false) {
                return true;
            }
        }

        return false;
    }
    
    public function get_known_agents() {
        return $this->ai_bot_signatures;
    }
    
    public function add_signature($signature, $agent) {
        $this->ai_bot_signatures[strtolower($signature)] = $agent;
    }
}