import * as t from 'rtcad'
import * as network from './network' // fetcher
// declare runtype
const Password = t.String()
// declare runtype with description and extended validation
const Email = t`
  simple e-mail validation
  ${t.String(value => value.contains('@'))}
`
// declare structure
const User = t`user data ${t.Record({
  id: t.Number(),
  name: t.String(),
  avatar: t.OR(t.Null, t.String(url => url.startsWith('http'))),
})}`
// declare ~generic by custom runtype
// (TypeScript syntax)
const Instanceof = <T extends t.Runtype>(Gen: T) =>
  t.custom<T>(value => value instanceof Gen)
// use generic
const ErrorApi = Instanceof(network.Error)
// declare contract for function with description (Markdown)
export const authUser = t`
  # Return detailed user data from auth service
  > set auth token to cookies
  - ${[Email, Password]}
  - ${t.Promise(User, ErrorApi)}
`((email, password) => network.get(`/user`, { email, password }))
/* EQUAL */
// declare contract for function without description
export const authUser = t([Email, Password], t.Promise(User, ErrorApi))(
  (email, password) => network.get(`/user`, { email, password }),
)
/**
 * Now we can:
 * 1. Infer static types.
 * 2. Validate arguments and result of `authUser` call.
 * 3. Automatically generate documentation.
 * 4. Leave mocks for tests (generate it automatically).
 * 5. Property-base testing out of the box.
 */