ICO

archetype[%erc20%] ico
​
constant symbol string = "BCDT"
​
constant decimals int  = 18
​
(* contribution thresholds *)
variable[%mutable owner (state = Init)%] min_contribution tez = 0.001tz
variable[%mutable owner (state = Init)%] max_contribution_silver tez = 10tz
​
(* bcd token data *)
variable[%mutable owner (state = Init)%] max_bcd_to_sell int = 100000000
variable[%mutable owner (state = Init)%] exchange_rate_bcd_tez int = 13000
​
(* round caps *)
variable[%mutable owner (state = Init)%] soft_cap tez = 1800tz
variable[%mutable owner (state = Init)%] presales_cap tez = 1800tz
variable[%mutable owner (state = Init)%] round1_cap tez = 3600tz
(* presales_cap + 1600 *)
​
(* Number tokens sent, eth raised, … *)
variable nb_bcd_sold int = 0
variable nb_tez_raised int = 0
​
(* Roles *)
​
variable[%transferable%] owner role
​
variable whitelister role
​
variable reserve role
​
variable community role
​
(* contributor *)
​
enum whitelist =
 | Silver
 | Gold
​
asset[@add @remove @update owner (state = Init)]
     contributor identified by id = {
   id           : address;
   list         : whitelist;
   contrib      : int = 0
} with {
  c1 : contrib >= 0
}
​
states[%incr_mutable_st owner%] =
| Init initial     (* ICO isn't started yet, initial state *)
| PresaleRunning   (* Presale has started *)
| PresaleFinished  (* Presale has ended   *)
| Round1Running    (* Round 1 has started *)
| Round1Finished   (* Round 1 has ended   *)
| Round2Running    (* Round 2 has started *)
| Round2Finished   (* Round 2 has ended   *)
​
function is_running = {
  match state with
  | PresalesRunning | Round1Running | Round2Running -> true
  | _ -> false
  end
}
​
function get_rate = {
  let coeff = (match state with
  | PresalesRunning -> 1.2
  | Round1Running   -> 1.1
  | _               -> 1
  end) in
  coeff * exchange_rate_tez_bcd
}
​
function get_remaining_tez_to_raise = {
  match state with
  | PresalesRunning | PresalesFinished -> presales_cap - nb_tez_raised
  | Round1Running   | Round1Finished   -> round1_cap - nb_tez_raised
  | _ -> (let remaining_bcd = max_bcd_to_sell - nb_bcd_sold in
          remaining_bcd / exchange_rate_bcd_tez)
  end
}
​
function transition_to_finished = {
  match state with
  | PresalesRunning -> PresalesFinished
  | Round1Running   -> Round1Finished
  | Round1Finished  -> Round2Running
  | _               -> Round2Finished
  end
}
​
action contribute = {
​
   require {
      c1 : contributor.contains caller;
      c2 : is_running ();
      c3 : transferred >= min_contribution;
      c4 : let c = contributor.get caller in
             not (c.list = Silver and transferred >= max_contrib_silver)
   }
​
   specification {
     p1 :
       let c = contributor.get caller in
       transferred = transferred_to(caller) + c.contrib - (old c.contrib)
   }
​
   effect {
     (* cap contribution to max_contrib if necessary *)
     let contrib = transferred in
     if    c.list = Silver
       and c.contrib + contrib >= max_contrib_silver
     then contrib := max_contrib_silver - c.contrib;
     (* cap contribution to round cap if necessary *)
     let remaining_tez = get_remaining_tez_to_raise () in
     if remaining_tez <= contrib
     then (
       contrib := remaining_tez;
       state := transition_to_finished ()
     );
     (* convert contribution to nb of bcd tokens *)
     let rate = get_rate () in
     let nb_tokens  = contrib * rate in
     (* update ico stats *)
     nb_bcd_sold   += nb_tokens;
     nb_tez_raised += contrib;
     (* update caller’s contribution *)
     c.contrib     += contrib;
     (* syntaxic sugar for
        contributor.update caller { contrib += contrib } *)
     if contrib <= transferred
     then transfer (transferred - contrib) to caller
   }
}
​
(* the onlyonce extension specifies that withdraw action can be
  executed only once, that is a contributor can withdraw only once. *)
​
action[%onlyonce%] withdraw = {
  require {
    c5 : state = Round2Finished;
    c6 : nb_tez_raised <= soft_cap;
    c7 : (contributor.get caller).contribution > 0
  }
​
  effect {
    let c = contributor.get caller in
    transfer c.contribution to caller;
    (* do not forget this *)
    c.contribution := 0
  }
}
​