(*****************************************************************************)
(*                                                                           *)
(* Open Source License                                                       *)
(* Copyright (c) 2018 Dynamic Ledger Solutions, Inc. <contact@tezos.com>     *)
(*                                                                           *)
(* Permission is hereby granted, free of charge, to any person obtaining a   *)
(* copy of this software and associated documentation files (the "Software"),*)
(* to deal in the Software without restriction, including without limitation *)
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(* Software is furnished to do so, subject to the following conditions:      *)
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(* DEALINGS IN THE SOFTWARE.                                                 *)
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(*****************************************************************************)

let recorded_proposal_count_for_delegate ctxt proposer =
  Storage.Vote.Proposals_count.get_option ctxt proposer
  >>=? function None -> return 0 | Some count -> return count

let record_proposal ctxt proposal proposer =
  recorded_proposal_count_for_delegate ctxt proposer
  >>=? fun count ->
  Storage.Vote.Proposals_count.init_set ctxt proposer (count + 1)
  >>= fun ctxt ->
  Storage.Vote.Proposals.add ctxt (proposal, proposer)
  >>= fun ctxt -> return ctxt

let get_proposals ctxt =
  Storage.Vote.Proposals.fold
    ctxt
    ~init:(ok Protocol_hash.Map.empty)
    ~f:(fun (proposal, delegate) acc ->
      (* Assuming the same listings is used at votings *)
      Storage.Vote.Listings.get ctxt delegate
      >>=? fun weight ->
      Lwt.return
        ( acc
        >>? fun acc ->
        let previous =
          match Protocol_hash.Map.find_opt proposal acc with
          | None ->
              0l
          | Some x ->
              x
        in
        ok (Protocol_hash.Map.add proposal (Int32.add weight previous) acc) ))

let clear_proposals ctxt =
  Storage.Vote.Proposals_count.clear ctxt
  >>= fun ctxt -> Storage.Vote.Proposals.clear ctxt

type ballots = {yay : int32; nay : int32; pass : int32}

let ballots_encoding =
  let open Data_encoding in
  conv
    (fun {yay; nay; pass} -> (yay, nay, pass))
    (fun (yay, nay, pass) -> {yay; nay; pass})
  @@ obj3 (req "yay" int32) (req "nay" int32) (req "pass" int32)

let has_recorded_ballot = Storage.Vote.Ballots.mem

let record_ballot = Storage.Vote.Ballots.init

let get_ballots ctxt =
  Storage.Vote.Ballots.fold
    ctxt
    ~f:(fun delegate ballot (ballots : ballots tzresult) ->
      (* Assuming the same listings is used at votings *)
      Storage.Vote.Listings.get ctxt delegate
      >>=? fun weight ->
      let count = Int32.add weight in
      Lwt.return
        ( ballots
        >>? fun ballots ->
        match ballot with
        | Yay ->
            ok {ballots with yay = count ballots.yay}
        | Nay ->
            ok {ballots with nay = count ballots.nay}
        | Pass ->
            ok {ballots with pass = count ballots.pass} ))
    ~init:(ok {yay = 0l; nay = 0l; pass = 0l})

let get_ballot_list = Storage.Vote.Ballots.bindings

let clear_ballots = Storage.Vote.Ballots.clear

let listings_encoding =
  Data_encoding.(
    list
      (obj2 (req "pkh" Signature.Public_key_hash.encoding) (req "rolls" int32)))

let freeze_listings ctxt =
  Roll_storage.fold ctxt (ctxt, 0l) ~f:(fun _roll delegate (ctxt, total) ->
      (* TODO use snapshots *)
      let delegate = Signature.Public_key.hash delegate in
      Storage.Vote.Listings.get_option ctxt delegate
      >>=? (function None -> return 0l | Some count -> return count)
      >>=? fun count ->
      Storage.Vote.Listings.init_set ctxt delegate (Int32.succ count)
      >>= fun ctxt -> return (ctxt, Int32.succ total))
  >>=? fun (ctxt, total) ->
  Storage.Vote.Listings_size.init ctxt total >>=? fun ctxt -> return ctxt

let listing_size = Storage.Vote.Listings_size.get

let in_listings = Storage.Vote.Listings.mem

let get_listings = Storage.Vote.Listings.bindings

let clear_listings ctxt =
  Storage.Vote.Listings.clear ctxt
  >>= fun ctxt ->
  Storage.Vote.Listings_size.remove ctxt >>= fun ctxt -> return ctxt

let get_current_period_kind = Storage.Vote.Current_period_kind.get

let set_current_period_kind = Storage.Vote.Current_period_kind.set

let get_current_quorum ctxt =
  Storage.Vote.Participation_ema.get ctxt
  >>=? fun participation_ema ->
  let quorum_min = Constants_storage.quorum_min ctxt in
  let quorum_max = Constants_storage.quorum_max ctxt in
  let quorum_diff = Int32.sub quorum_max quorum_min in
  return
    Int32.(add quorum_min (div (mul participation_ema quorum_diff) 100_00l))

let get_participation_ema = Storage.Vote.Participation_ema.get

let set_participation_ema = Storage.Vote.Participation_ema.set

let get_current_proposal = Storage.Vote.Current_proposal.get

let init_current_proposal = Storage.Vote.Current_proposal.init

let clear_current_proposal = Storage.Vote.Current_proposal.delete

let init ctxt =
  (* participation EMA is in centile of a percentage *)
  let participation_ema = Constants_storage.quorum_max ctxt in
  Storage.Vote.Participation_ema.init ctxt participation_ema
  >>=? fun ctxt ->
  Storage.Vote.Current_period_kind.init ctxt Proposal
  >>=? fun ctxt -> return ctxt