import type { H3Event } from 'h3'

const INVALID_SUBDOMAINS = new Set([
    '0.0.0.0',
    'www',
    'api',
    'admin',
    'test',
    'dev',
    'development',
    'staging',
    'production',
    'localhost',
])

const DEFAULT_TENANT = 'sistema'

export function tenantFromHost(host: string | undefined): string {
    if (!host) return DEFAULT_TENANT
    const sub = host.split(':')[0]?.split('.')[0]?.toLowerCase()
    if (!sub || sub.length <= 1) return DEFAULT_TENANT
    if (INVALID_SUBDOMAINS.has(sub)) return DEFAULT_TENANT
    if (!/^[a-z0-9-]+$/.test(sub)) return DEFAULT_TENANT
    return sub
}

export function tenantFromEvent(event: H3Event): string {
    const host = getRequestHost(event, { xForwardedHost: true })
    return tenantFromHost(host)
}