<?php
session_start();
header('Content-Type: application/json');
require_once __DIR__ . '/../db/config.php';
require_once __DIR__ . '/../ai/LocalAIApi.php';

if (!isset($_SESSION['user_id'])) {
    http_response_code(401);
    echo json_encode(['success' => false, 'error' => 'Unauthorized']);
    exit;
}

try {
    $pdo = db();
    $user_id = $_SESSION['user_id'];

    if ($_SERVER['REQUEST_METHOD'] === 'POST') {
        $input = json_decode(file_get_contents('php://input'), true);
        $message = $input['message'] ?? '';
        $context = $input['context'] ?? null; // New: get context

        if (empty(trim($message))) {
            echo json_encode(['success' => false, 'error' => 'Message cannot be empty.']);
            exit;
        }

        // New: Handle simulation context
        if ($context === 'vpn' || $context === 'antivirus') {
            $ai_input = [['role' => 'user', 'content' => $message]];
            $ai_response = LocalAIApi::createResponse(['input' => $ai_input]);
            $ai_message = LocalAIApi::extractText($ai_response);

            if (!empty($ai_message)) {
                echo json_encode(['success' => true, 'data' => $ai_message]);
            } else {
                echo json_encode(['success' => false, 'error' => 'Failed to get AI response.']);
            }
            exit; // Stop execution for simulations
        }

        // --- Existing Chat Logic ---
        $personality = $input['personality'] ?? '';

        $stmt = $pdo->prepare("INSERT INTO messages (user_id, message) VALUES (?, ?)");
        $stmt->execute([$user_id, $message]);

        // --- AI CONTEXT PREPARATION ---

        // 1. Prepare the system prompt (personality)
        $final_ai_input = [];
        if (!empty(trim($personality))) {
            $final_ai_input[] = ['role' => 'system', 'content' => $personality];
        }

        // 2. Get last 5 messages for conversation history
        $stmt = $pdo->query("SELECT m.message, u.username FROM messages m JOIN users u ON m.user_id = u.id ORDER BY m.created_at DESC LIMIT 5");
        $recent_messages = $stmt->fetchAll(PDO::FETCH_ASSOC);
        $conversation_history = array_map(function($msg) {
            return ['role' => $msg['username'] === 'AI' ? 'assistant' : 'user', 'content' => $msg['message']];
        }, array_reverse($recent_messages));

        // 3. Combine system prompt with conversation history
        $final_ai_input = array_merge($final_ai_input, $conversation_history);

        // --- CALL THE AI ---
        $ai_response = LocalAIApi::createResponse(['input' => $final_ai_input]);
        $ai_message = LocalAIApi::extractText($ai_response);

        if (!empty($ai_message)) {
            $stmt = $pdo->prepare("SELECT id FROM users WHERE username = 'AI'");
            $stmt->execute();
            $ai_user = $stmt->fetch(PDO::FETCH_ASSOC);

            if ($ai_user) {
                $stmt = $pdo->prepare("INSERT INTO messages (user_id, message) VALUES (?, ?)");
                $stmt->execute([$ai_user['id'], $ai_message]);
            }
        }

        echo json_encode(['success' => true, 'message' => 'Message saved.']);

    } elseif ($_SERVER['REQUEST_METHOD'] === 'GET') {
        if (isset($_GET['action']) && $_GET['action'] === 'reset') {
            // Truncate the messages table to reset the chat
            $pdo->query("TRUNCATE TABLE messages");
            echo json_encode(['success' => true, 'message' => 'Chat history has been cleared.']);
        } else {
            $stmt = $pdo->query("SELECT m.id, m.message, m.created_at, u.username, LEFT(u.username, 1) as user_initial FROM messages m JOIN users u ON m.user_id = u.id ORDER BY m.created_at ASC");
            $messages = $stmt->fetchAll(PDO::FETCH_ASSOC);
            echo json_encode(['success' => true, 'messages' => $messages, 'currentUser' => $_SESSION['username']]);
        }
    } else {
        http_response_code(405);
        echo json_encode(['success' => false, 'error' => 'Method Not Allowed']);
    }

} catch (PDOException $e) {
    http_response_code(500);
    echo json_encode(['success' => false, 'error' => 'Database error: ' . $e->getMessage()]);
}
?>