module Builtins where

import Code
import Control.Monad.IO.Class
import Control.Monad.Trans.Class
import Control.Monad.Trans.State.Lazy
import qualified Data.Map as M
import Env hiding (PrlgEnv)
import qualified IR
import Interpreter (backtrack)
import qualified Operators as O
import System.Console.Haskeline

bi = Builtin

hello :: BuiltinFn
hello = do
  liftIO $ putStrLn "hllo prlg"
  return Nothing

printLocals :: BuiltinFn
printLocals = do
  scope <- gets (gvar . cur)
  Heap _ heap <- gets (heap . cur)
  IR.StrTable _ _ itos <- gets strtable
  flip traverse (M.elems scope) $ \(ref, name) ->
    lift . outputStrLn $ (itos M.! name) ++ " = " ++ show (heap M.! ref)
  return Nothing

promptRetry :: BuiltinFn
promptRetry = do
  x <- lift $ getInputChar "? "
  case x of
    Just ';' -> backtrack
    _ -> return Nothing

addBuiltins :: PrlgEnv ()
addBuiltins = do
  a1 <- findStruct "a" 1
  a <- findAtom "a"
  b <- findAtom "b"
  c <- findAtom "c"
  varX <- findAtom "X"
  b0 <- findStruct "b" 0
  any1 <- findStruct "any" 1
  eq2 <- findStruct "=" 2
  hello0 <- findStruct "hello" 0
  fail0 <- findStruct "fail" 0
  true0 <- findStruct "true" 0
  printlocals0 <- findStruct "print_locals" 0
  debugprint0 <- findStruct "interpreter_state" 0
  promptretry0 <- findStruct "prompt_retry" 0
  modify $ \s ->
    s
      { defs =
          M.fromList
            [ (eq2, [[U (LocalRef 0 varX), U (LocalRef 0 varX), NoGoal]])
            , (a1, [[U (Atom a), NoGoal], [U (Atom b), NoGoal]])
            , ( b0
              , [ [Goal, U (Struct a1), U (Atom c), LastCall]
                , [Goal, U (Struct a1), U (Atom b), LastCall]
                ])
            , (any1, [[U VoidRef, NoGoal]])
            , (hello0, [[Invoke $ bi hello]])
            , (fail0, [[Invoke $ bi backtrack]])
            , (true0, [[Invoke $ bi (pure Nothing)]])
            , ( debugprint0
              , [[Invoke $ bi (get >>= liftIO . print >> pure Nothing)]])
            , (printlocals0, [[Invoke $ bi printLocals]])
            , (promptretry0, [[Invoke $ bi promptRetry]])
            ]
      , ops = [(O.xfy "," 1000), (O.xfx "=" 700)]
      }