import fs from 'fs'
import path from 'path'

export default defineEventHandler(async (event) => {
  try {
    const slug = getRouterParam(event, 'slug')
    
    if (!slug) {
      throw createError({
        statusCode: 400,
        statusMessage: 'File path is required'
      })
    }
    
    // Clean the slug to prevent directory traversal
    const cleanSlug = slug.replace(/\.\./g, '').replace(/\/+/g, '/')
    const filename = cleanSlug.endsWith('.md') || cleanSlug.endsWith('.json') 
      ? cleanSlug 
      : `${cleanSlug}.md`
    
    // Construct file path
    const filePath = path.join(process.cwd(), 'docs', filename)
    
    // Check if file exists
    if (!fs.existsSync(filePath)) {
      throw createError({
        statusCode: 404,
        statusMessage: 'File not found'
      })
    }
    
    // Read file content
    const content = fs.readFileSync(filePath, 'utf-8')
    
    // Set appropriate content type
    if (filename.endsWith('.json')) {
      setHeader(event, 'Content-Type', 'application/json')
    } else if (filename.endsWith('.md')) {
      setHeader(event, 'Content-Type', 'text/markdown; charset=utf-8')
    } else {
      setHeader(event, 'Content-Type', 'text/plain; charset=utf-8')
    }
    
    // Set cache headers
    setHeader(event, 'Cache-Control', 'public, max-age=300')
    
    return content
    
  } catch (error) {
    console.error('Error serving docs file:', error)
    
    // If it's already a createError, re-throw it
    if (error.statusCode) {
      throw error
    }
    
    throw createError({
      statusCode: 500,
      statusMessage: 'Failed to serve file',
      data: {
        error: error.message
      }
    })
  }
})