-- SPDX-FileCopyrightText: 2020 Tocqueville Group
--
-- SPDX-License-Identifier: LicenseRef-MIT-TQ

-- | This module contains the high-level compilation of Indigo to Lorentz,
-- including plain Indigo code, as well as Indigo contracts.

module Indigo.Compilation
  ( compileIndigo
  , compileIndigoContract
  ) where

import qualified Data.Map as M

import Indigo.Compilation.Field
import Indigo.Compilation.Lambda
import Indigo.Compilation.Params
import Indigo.Compilation.Sequential
import Indigo.Frontend.Program (IndigoContract)
import Indigo.Internal hiding (SetField, (>>))
import Indigo.Lorentz
import Indigo.Prelude
import qualified Lorentz.Instr as L
import qualified Lorentz.Macro as L

-- | Compile Indigo code to Lorentz.
--
-- Note: it is necessary to specify the number of parameters (using the first
-- type variable) of the Indigo function. Also, these should be on the top of
-- the input stack in inverse order (see 'IndigoWithParams').
compileIndigoImpl
  :: forall n inp a. (AreIndigoParams n inp, KnownValue a, Default (StackVars inp))
  => IndigoWithParams n inp a
  -> (StackVars inp -> (Block, RefId) -> (inp :-> inp))
  -> inp :-> inp
compileIndigoImpl paramCode runner =
    runner initMd optimized
  where
    (code, initMd, nextRef) = fromIndigoWithParams @n @a paramCode
    optimized = indigoMtoSequential nextRef code
      & compileLambdas
      & optimizeFields

-- | Specialiasation of 'compileIndigoImpl' without var decompositions.
compileIndigo
  :: forall n inp a. (AreIndigoParams n inp, KnownValue a, Default (StackVars inp))
  => IndigoWithParams n inp a
  -> inp :-> inp
compileIndigo paramCode =
  compileIndigoImpl @n @inp @a paramCode (\stk block -> sequentialToLorentz (MetaData stk mempty) block)

-- | Compile Indigo code to Lorentz contract.
-- Drop elements from the stack to return only @[Operation]@ and @storage@.
compileIndigoContract
  :: forall param st .
  ( KnownValue param
  , IsObject st
  )
  => IndigoContract param st
  -> ContractCode param st
compileIndigoContract code =
  prepare $ compileIndigoImpl @3 @'[param, st, Ops] (contractToIndigoWithParams code) $
    \(parRef :& storageRef :& opsStack) (block, nextRef) ->
      let stRef = case storageRef of
                    NoRef -> error "Storage variable hasn't been assigned"
                    Ref r -> r in
      -- during code Indigo code compilation the stack will look like:
      -- [var_10, var_9, ... , var_3, param_var_2, storage_field_11, storage_field_12, ..., storage_field_20, ops_var_0]
      -- var_1 will represent storage and passed to DecomposedObjects
      let (storageObj, nextRef', someGen) = deepDecomposeCompose nextRef (NoRef :& opsStack) in
      case someGen of
        SomeGenCode (GenCode decompStk decompose composeBack) ->
          let md = MetaData (parRef :& decompStk) $ M.singleton stRef (SomeObject storageObj)
              indigoCode = sequentialToLorentz md (block, nextRef') in
          L.dip decompose # -- decompose storage
          indigoCode # -- run indigo code
          L.dip composeBack
  where
    prepare :: ('[param, st, Ops] :-> '[param, st, Ops]) -> ('[(param, st)] :-> '[(Ops, st)])
    prepare cd =
      L.nil # L.swap # L.unpair #
      cd #
      L.drop # -- drop param
      L.swap # L.pair