import { describe, expect, it } from 'vitest'
import { readConfig } from '../src/config'
import { ConfigError } from '../src/errors'

/** Build a Location-like object from a URL string. */
function loc(url: string): Pick<Location, 'protocol' | 'host' | 'hostname'> {
  const u = new URL(url)
  return { protocol: u.protocol, host: u.host, hostname: u.hostname }
}

describe('readConfig — subdomain + scheme-following same-origin URL (T1, M6)', () => {
  it('derives subdomain and wss: URL on https', () => {
    const cfg = readConfig(loc('https://alice.term.example.com'))
    expect(cfg.subdomain).toBe('alice')
    expect(cfg.wsUrl('/term')).toBe('wss://alice.term.example.com/term')
    expect(cfg.apiBase).toBe('')
  })

  it('follows the page scheme to ws: on http (no mixed-content on TLS)', () => {
    const cfg = readConfig(loc('http://alice.term.localhost:3000'))
    expect(cfg.subdomain).toBe('alice')
    expect(cfg.wsUrl('/term')).toBe('ws://alice.term.localhost:3000/term')
  })

  it('throws ConfigError on a bare host with no subdomain label (fail-fast, never defaults)', () => {
    expect(() => readConfig(loc('https://example.com'))).toThrow(ConfigError)
    expect(() => readConfig(loc('https://localhost'))).toThrow(ConfigError)
    expect(() => readConfig(loc('https://term.example.com'))).toThrow(ConfigError)
  })

  it('keeps wsUrl same-origin — a path cannot inject a foreign host', () => {
    const cfg = readConfig(loc('https://alice.term.example.com'))
    const injected = cfg.wsUrl('//evil.com')
    expect(injected.startsWith('wss://alice.term.example.com/')).toBe(true)
    expect(injected).not.toContain('evil.com/')
    // even a scheme-looking path stays anchored to our host
    expect(new URL(cfg.wsUrl('/x')).host).toBe('alice.term.example.com')
  })
})