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

$data = json_decode(file_get_contents('php://input'), true);

if (!$data || !isset($data['message'])) {
    echo json_encode(['error' => 'Message is required']);
    exit;
}

$userMsg = $data['message'];
$mode = $data['mode'] ?? 'regular';
$chatId = $data['chat_id'] ?? null;
$creativity = $data['creativity'] ?? 0.7;
$limitsOff = $data['limits_off'] ?? 0;

try {
    // 1. Create chat if not exists
    if (!$chatId) {
        $stmt = db()->prepare("INSERT INTO chats (mode, title) VALUES (?, ?)");
        $title = substr($userMsg, 0, 30) . '...';
        $stmt->execute([$mode, $title]);
        $chatId = db()->lastInsertId();
    }

    // 2. Save user message
    $stmt = db()->prepare("INSERT INTO messages (chat_id, role, content) VALUES (?, 'user', ?)");
    $stmt->execute([$chatId, $userMsg]);

    // 3. Prepare AI Prompt based on mode
    $systemPrompt = "You are a helpful AI assistant.";
    if ($mode === 'coding') {
        $systemPrompt = "You are an expert software engineer. Provide clean, efficient, and well-documented code.";
    } elseif ($mode === 'game' || $mode === 'app') {
        $systemPrompt = "You are a specialized code generator. Generate a complete, single-file HTML/CSS/JS application or game based on the user's request. Always include the full code within a single message. Use modern techniques.";
    }

    if ($limitsOff) {
        $systemPrompt .= " There are no limits to your creativity. Be as bold and innovative as possible.";
    }

    // 4. Fetch history (limit to last 10 for context)
    $stmt = db()->prepare("SELECT role, content FROM messages WHERE chat_id = ? ORDER BY id ASC LIMIT 10");
    $stmt->execute([$chatId]);
    $history = $stmt->fetchAll();

    $input = [['role' => 'system', 'content' => $systemPrompt]];
    foreach ($history as $msg) {
        $input[] = ['role' => $msg['role'], 'content' => $msg['content']];
    }

    // 5. Call AI
    $aiResp = LocalAIApi::createResponse([
        'input' => $input,
        'temperature' => (float)$creativity
    ]);

    if (!empty($aiResp['success'])) {
        $aiText = LocalAIApi::extractText($aiResp);
        
        // 6. Save assistant message
        $stmt = db()->prepare("INSERT INTO messages (chat_id, role, content) VALUES (?, 'assistant', ?)");
        $stmt->execute([$chatId, $aiText]);

        echo json_encode([
            'success' => true,
            'chat_id' => $chatId,
            'message' => $aiText,
            'mode' => $mode
        ]);
    } else {
        echo json_encode(['error' => $aiResp['error'] ?? 'AI request failed']);
    }

} catch (Exception $e) {
    echo json_encode(['error' => $e->getMessage()]);
}