import { error } from '@sveltejs/kit';
import fs from 'fs';
import path from 'path';
import { fileURLToPath } from 'url';

// Get the directory path
const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

// Path to markdown files
const DOCS_PATH = path.resolve(__dirname, '../../../../lib/taDocs');

export async function GET({ params }) {
    const { slug } = params;
    
    // Validate filename to prevent directory traversal attacks
    if (!slug || slug.includes('..') || slug.includes('/') || !slug.endsWith('.md')) {
        throw error(400, 'Invalid documentation file requested');
    }
    
    const filePath = path.join(DOCS_PATH, slug);
    
    try {
        if (!fs.existsSync(filePath)) {
            throw error(404, 'Documentation file not found');
        }
        
        const content = fs.readFileSync(filePath, 'utf-8');
        
        return new Response(content, {
            headers: {
                'Content-Type': 'text/markdown',
                'Cache-Control': 'max-age=600' // Cache for 10 minutes
            }
        });
    } catch (err) {
        console.error(`Error reading documentation file: ${filePath}`, err);
        throw error(500, 'Error loading documentation');
    }
}