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

export default defineEventHandler(async (event) => {
  try {
    // Set CORS headers
    setHeader(event, 'Access-Control-Allow-Origin', '*')
    setHeader(event, 'Access-Control-Allow-Methods', 'GET, OPTIONS')
    setHeader(event, 'Access-Control-Allow-Headers', 'Content-Type, Authorization')
    
    // Handle OPTIONS request for CORS preflight
    if (event.node.req.method === 'OPTIONS') {
      return {}
    }
    
    // Get file path from URL safely
    let filePath = '';
    if (event.context.params && event.context.params._) {
      filePath = Array.isArray(event.context.params._) 
        ? event.context.params._.join('/') 
        : event.context.params._.toString();
    }
    
    console.log(`Requested docs file: ${filePath}`)
    
    // Full path to file
    const fullPath = path.join(process.cwd(), 'docs', filePath)
    
    // Check if file exists
    if (!fs.existsSync(fullPath)) {
      console.error(`File not found: ${fullPath}`)
      throw createError({
        statusCode: 404,
        statusMessage: `File not found: ${filePath}`
      })
    }
    
    // Determine content type based on file extension
    const ext = path.extname(fullPath).toLowerCase()
    let contentType = 'text/plain'
    
    switch (ext) {
      case '.json':
        contentType = 'application/json'
        break
      case '.md':
        contentType = 'text/markdown'
        break
      case '.yaml':
      case '.yml':
        contentType = 'application/x-yaml'
        break
      case '.html':
        contentType = 'text/html'
        break
      case '.css':
        contentType = 'text/css'
        break
      case '.js':
        contentType = 'application/javascript'
        break
      case '.png':
        contentType = 'image/png'
        break
      case '.jpg':
      case '.jpeg':
        contentType = 'image/jpeg'
        break
    }
    
    // Set headers
    setHeader(event, 'Content-Type', contentType)
    setHeader(event, 'Cache-Control', 'no-cache') // Disable caching for development
    
    // For JSON files, we need to validate and potentially parse
    if (ext === '.json') {
      try {
        const content = fs.readFileSync(fullPath, 'utf-8')
        return JSON.parse(content)
      } catch (error) {
        console.error(`Error parsing JSON file: ${error.message}`)
        throw createError({
          statusCode: 500,
          statusMessage: `Invalid JSON file: ${error.message}`
        })
      }
    }
    
    // For other files, return the raw content
    return fs.readFileSync(fullPath)
  } catch (error) {
    console.error(`Error serving docs file: ${error.message}`)
    throw createError({
      statusCode: error.statusCode || 500,
      statusMessage: error.message || 'Failed to serve file',
      data: { error: error.message }
    })
  }
})