(*****************************************************************************)
(*                                                                           *)
(* Open Source License                                                       *)
(* Copyright (c) 2018 Dynamic Ledger Solutions, Inc. <contact@tezos.com>     *)
(* Copyright (c) 2019-2020 Nomadic Labs <contact@nomadic-labs.com>           *)
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(* copy of this software and associated documentation files (the "Software"),*)
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(* DEALINGS IN THE SOFTWARE.                                                 *)
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open Alpha_context

let custom_root = RPC_path.open_root

module Seed = struct
  module S = struct
    open Data_encoding

    let seed =
      RPC_service.post_service
        ~description:"Seed of the cycle to which the block belongs."
        ~query:RPC_query.empty
        ~input:empty
        ~output:Seed.seed_encoding
        RPC_path.(custom_root / "context" / "seed")
  end

  let () =
    let open Services_registration in
    register0 ~chunked:false S.seed (fun ctxt () () ->
        let l = Level.current ctxt in
        Seed.for_cycle ctxt l.cycle)

  let get ctxt block = RPC_context.make_call0 S.seed ctxt block () ()
end

module Nonce = struct
  type info = Revealed of Nonce.t | Missing of Nonce_hash.t | Forgotten

  let info_encoding =
    let open Data_encoding in
    union
      [
        case
          (Tag 0)
          ~title:"Revealed"
          (obj1 (req "nonce" Nonce.encoding))
          (function Revealed nonce -> Some nonce | _ -> None)
          (fun nonce -> Revealed nonce);
        case
          (Tag 1)
          ~title:"Missing"
          (obj1 (req "hash" Nonce_hash.encoding))
          (function Missing nonce -> Some nonce | _ -> None)
          (fun nonce -> Missing nonce);
        case
          (Tag 2)
          ~title:"Forgotten"
          empty
          (function Forgotten -> Some () | _ -> None)
          (fun () -> Forgotten);
      ]

  module S = struct
    let get =
      RPC_service.get_service
        ~description:"Info about the nonce of a previous block."
        ~query:RPC_query.empty
        ~output:info_encoding
        RPC_path.(custom_root / "context" / "nonces" /: Raw_level.rpc_arg)
  end

  let register () =
    let open Services_registration in
    register1 ~chunked:false S.get (fun ctxt raw_level () () ->
        let level = Level.from_raw ctxt raw_level in
        Nonce.get ctxt level >|= function
        | Ok (Revealed nonce) -> ok (Revealed nonce)
        | Ok (Unrevealed {nonce_hash; _}) -> ok (Missing nonce_hash)
        | Error _ -> ok Forgotten)

  let get ctxt block level = RPC_context.make_call1 S.get ctxt block level () ()
end

type error += No_available_snapshots of {min_cycle : int32}

let () =
  Error_monad.register_error_kind
    `Permanent
    ~id:"no_available_snapshots"
    ~title:"No available snapshots"
    ~description:"No available snapshots"
    ~pp:(fun ppf min_cycle ->
      Format.fprintf ppf "No available snapshots until cycle %ld" min_cycle)
    Data_encoding.(obj1 (req "min_cycle" int32))
    (function
      | No_available_snapshots {min_cycle} -> Some min_cycle | _ -> None)
    (fun min_cycle -> No_available_snapshots {min_cycle})

module Snapshot_index = struct
  module S = struct
    let cycle_query : Cycle.t option RPC_query.t =
      let open RPC_query in
      query (fun x -> x)
      |+ opt_field "cycle" Cycle.rpc_arg (fun cycle -> cycle)
      |> seal

    let selected_snapshot =
      RPC_service.get_service
        ~description:
          "Returns the index of the selected snapshot for the current cycle or \
           for the specific `cycle` passed as argument, if any."
        ~query:cycle_query
        ~output:Data_encoding.int31
        RPC_path.(custom_root / "context" / "selected_snapshot")
  end

  let register () =
    let open Services_registration in
    register0 ~chunked:false S.selected_snapshot (fun ctxt cycle () ->
        (* max_snapshot_index can be determined using constants only *)
        let blocks_per_stake_snapshot =
          Alpha_context.Constants.blocks_per_stake_snapshot ctxt
        in
        let blocks_per_cycle = Alpha_context.Constants.blocks_per_cycle ctxt in
        let preserved_cycles =
          Int32.of_int (Alpha_context.Constants.preserved_cycles ctxt)
        in
        let cycle =
          match cycle with
          | None -> Level.(current ctxt).cycle
          | Some cycle -> cycle
        in
        if Compare.Int32.(Cycle.to_int32 cycle <= Int32.succ preserved_cycles)
        then
          (* Early cycles are corner cases, fail if requested *)
          fail
            (No_available_snapshots {min_cycle = Int32.add preserved_cycles 2l})
        else
          let max_snapshot_index =
            Int32.div blocks_per_cycle blocks_per_stake_snapshot |> Int32.to_int
          in
          Alpha_context.Stake_distribution.compute_snapshot_index
            ctxt
            cycle
            ~max_snapshot_index)

  let get ctxt block ?cycle () =
    RPC_context.make_call0 S.selected_snapshot ctxt block cycle ()
end

module Contract = Contract_services
module Constants = Constants_services
module Delegate = Delegate_services
module Voting = Voting_services
module Sapling = Sapling_services
module Tx_rollup = Tx_rollup_services

module Liquidity_baking = struct
  module S = struct
    let get_cpmm_address =
      RPC_service.get_service
        ~description:"Liquidity baking CPMM address"
        ~query:RPC_query.empty
        ~output:Alpha_context.Contract.encoding
        RPC_path.(custom_root / "context" / "liquidity_baking" / "cpmm_address")
  end

  let register () =
    let open Services_registration in
    register0 ~chunked:false S.get_cpmm_address (fun ctxt () () ->
        Alpha_context.Liquidity_baking.get_cpmm_address ctxt)

  let get_cpmm_address ctxt block =
    RPC_context.make_call0 S.get_cpmm_address ctxt block () ()
end

module Cache = struct
  module S = struct
    let cached_contracts =
      RPC_service.get_service
        ~description:"Return the list of cached contracts"
        ~query:RPC_query.empty
        ~output:
          Data_encoding.(list @@ tup2 Alpha_context.Contract.encoding int31)
        RPC_path.(custom_root / "context" / "cache" / "contracts" / "all")

    let contract_cache_size =
      RPC_service.get_service
        ~description:"Return the size of the contract cache"
        ~query:RPC_query.empty
        ~output:Data_encoding.int31
        RPC_path.(custom_root / "context" / "cache" / "contracts" / "size")

    let contract_cache_size_limit =
      RPC_service.get_service
        ~description:"Return the size limit of the contract cache"
        ~query:RPC_query.empty
        ~output:Data_encoding.int31
        RPC_path.(
          custom_root / "context" / "cache" / "contracts" / "size_limit")

    let contract_rank =
      RPC_service.post_service
        ~description:
          "Return the number of cached contracts older than the provided \
           contract"
        ~query:RPC_query.empty
        ~input:Alpha_context.Contract.encoding
        ~output:Data_encoding.(option int31)
        RPC_path.(custom_root / "context" / "cache" / "contracts" / "rank")
  end

  let register () =
    let open Services_registration in
    register0 ~chunked:true S.cached_contracts (fun ctxt () () ->
        Script_cache.entries ctxt |> Lwt.return) ;
    register0 ~chunked:false S.contract_cache_size (fun ctxt () () ->
        Script_cache.size ctxt |> return) ;
    register0 ~chunked:false S.contract_cache_size_limit (fun ctxt () () ->
        Script_cache.size_limit ctxt |> return) ;
    register0 ~chunked:false S.contract_rank (fun ctxt () contract ->
        Script_cache.contract_rank ctxt contract |> return)

  let cached_contracts ctxt block =
    RPC_context.make_call0 S.cached_contracts ctxt block () ()

  let contract_cache_size ctxt block =
    RPC_context.make_call0 S.contract_cache_size ctxt block () ()

  let contract_cache_size_limit ctxt block =
    RPC_context.make_call0 S.contract_cache_size_limit ctxt block () ()

  let contract_rank ctxt block contract =
    RPC_context.make_call0 S.contract_rank ctxt block () contract
end

let register () =
  Contract.register () ;
  Constants.register () ;
  Delegate.register () ;
  Nonce.register () ;
  Snapshot_index.register () ;
  Voting.register () ;
  Sapling.register () ;
  Liquidity_baking.register () ;
  Cache.register () ;
  Tx_rollup.register ()