examples/aqua-examples/drand/aqua/drand.aqua

data CResult:
  chains: []string
  stderr: string

data Info:
  public_key: string
  period: u64
  genesis_time: u64
  hash: string

data IResult:
  info: Info
  stderr: string

data Randomness:
  round: u64
  randomness: string
  signature: string
  previous_signature: string

data RResult:
  randomness: Randomness
  stderr: string

data VResult:
  verified: bool
  randomness: string
  stderr: string

data ServiceAddress:
  peer_id: string
  service_id: string

service Drand:
  chains(url: string) -> CResult
  info(url: string, chain_hash: string) -> IResult
  latest(url: string, chain_hash: string) -> RResult
  round(url: string, chain_hash: string, round: u64) -> RResult
  verify_bls(pk: string, round: u64, prev_signature: string, signature: string) -> VResult



-- https://drand.love/developer/http-api/#chains
func chains(addr: ServiceAddress, url:string) -> CResult:
  on addr.peer_id:
    Drand addr.service_id
    res <- Drand.chains(url)
  <- res

-- https://drand.love/developer/http-api/#chain-hash-info
func info(addr: ServiceAddress, url:string, chain_hash: string) -> IResult:
  on addr.peer_id:
    Drand addr.service_id
    res <- Drand.info(url, chain_hash)
  <- res
 
 --
func latest(addr: ServiceAddress, url:string, chain_hash: string) -> RResult:
  on addr.peer_id:
    Drand addr.service_id
    res <- Drand.latest(url, chain_hash)
  <- res

--
func round(addr: ServiceAddress, url:string, chain_hash: string, round:u64) -> RResult:
  on addr.peer_id:
    Drand addr.service_id
    res <- Drand.round(url, chain_hash, round)
  <- res

--
func verify(addr: ServiceAddress, pk: string, round_idx:u64, prev_signature: string, signature: string) -> VResult:
  on addr.peer_id:
    Drand addr.service_id
    res <- Drand.verify_bls(pk, round_idx, prev_signature, signature)
  <- res

--
func roundtrip(addrs: []ServiceAddress, url:string) -> bool, string, string:
  on addrs[0].peer_id:
    Drand addrs[0].service_id
    c_res <- Drand.chains(url)
    i_res <- Drand.info(url, c_res.chains[0])
    r_res <- Drand.latest(url, c_res.chains[0])
    -- <- true, "yes", "no"
  on addrs[1].peer_id:
    Drand addrs[1].service_id
    v_res <- Drand.verify_bls(i_res.info.public_key, r_res.randomness.round, r_res.randomness.previous_signature, r_res.randomness.signature)
  
  <- v_res.verified, v_res.randomness, r_res.randomness.randomness