import type { H3Event } from 'h3'
import { getHeader } from 'h3'

/**
 * Extract subdomain from the request Host header
 * Handles production domains (tenant1.routebox.co) and development (tenant1.localhost)
 */
export function getSubdomainFromRequest(event: H3Event): string | null {
  const host = getHeader(event, 'host') || ''
  const hostname = host.split(':')[0] // Remove port if present

  const parts = hostname.split('.')

  // For production domains with 3+ parts (e.g., tenant1.routebox.co)
  if (parts.length >= 3) {
    const subdomain = parts[0]
    // Ignore www subdomain
    if (subdomain === 'www') {
      return null
    }
    return subdomain
  }

  // For development (e.g., tenant1.localhost)
  if (parts.length === 2 && parts[1] === 'localhost') {
    return parts[0]
  }

  return null
}

/**
 * Check if the subdomain is a central/admin subdomain
 */
export function isCentralSubdomain(subdomain: string | null): boolean {
  if (!subdomain) return false
  const centralSubdomains = (process.env.CENTRAL_SUBDOMAINS || 'central,admin').split(',')
  return centralSubdomains.includes(subdomain)
}