<?php
/**
 * Gemini AI Integration
 * Handles AI-powered study schedule generation
 */

class GeminiAI {
    private $apiKey;
    private $baseUrl = 'https://generativelanguage.googleapis.com/v1beta/models/';
    
    public function __construct($apiKey = null) {
        $this->apiKey = $apiKey ?? getenv('GEMINI_API_KEY');
    }
    
    /**
     * Generate study schedule using Gemini API
     */
    public function generateStudySchedule($userStats, $preferences = []) {
        if (empty($this->apiKey)) {
            return ['error' => 'Gemini API key not configured'];
        }
        
        $prompt = $this->buildSchedulePrompt($userStats, $preferences);
        
        // Call Gemini API
        $response = $this->callAPI($prompt);
        
        if ($response) {
            return $this->parseScheduleResponse($response);
        }
        
        return ['error' => 'Failed to generate schedule'];
    }
    
    /**
     * Analyze study patterns
     */
    public function analyzePatterns($sessionData) {
        if (empty($this->apiKey)) {
            return ['error' => 'Gemini API key not configured'];
        }
        
        $prompt = "Analyze the following study session data and provide insights:\n\n" . json_encode($sessionData);
        
        $response = $this->callAPI($prompt);
        
        if ($response) {
            return ['insights' => $response];
        }
        
        return ['error' => 'Failed to analyze patterns'];
    }
    
    private function buildSchedulePrompt($userStats, $preferences) {
        $prompt = "作成:"学習時間割"Please create an optimal study schedule based on:\n\n";
        $prompt .= "目標時間: " . ($preferences['goal_time'] ?? '3 hours') . "/日\n";
        $prompt .= "過去の勉強時間: " . json_encode($userStats['recent_hours'] ?? []) . "\n";
        $prompt .= "好む科目: " . implode(', ', $preferences['subjects'] ?? []) . "\n";
        $prompt .= "\n効果的な時間割を作成してください。";
        
        return $prompt;
    }
    
    private function callAPI($prompt) {
        // Mock implementation
        // In production, use curl to call Gemini API
        return "Based on the provided data, I recommend: Morning 9-11am (Math), Afternoon 2-3pm (English), Evening 7-8pm (Science)";
    }
    
    private function parseScheduleResponse($response) {
        // Parse and structure the AI response
        return [
            'schedule' => $response,
            'generated_at' => date('Y-m-d H:i:s')
        ];
    }
}
?>
