-- | Built-in operations and types
module Basis (
  primBasis, srcBasis, basis2venv, basis2tenv
) where

import Util
import BasisUtils
import Value (Valuable(..), Value(..), VRecord(..))
import AST
import Type

import qualified Data.Loc

import qualified Basis.IO
import qualified Basis.Socket
import qualified Basis.Exn
import qualified Basis.Thread
import qualified Basis.Channel
import qualified Basis.MVar
import qualified Basis.Future
import qualified Basis.Array
import qualified Basis.Row

import qualified IO
import qualified System.Environment as Env
import Data.IORef (IORef, newIORef, readIORef, atomicModifyIORef)
import System.Random (randomIO)
import System.Exit (exitWith, ExitCode(..))
import Data.Typeable

-- Primitive operations implemented in Haskell
primBasis :: [Entry Raw]
primBasis  = [
    ---
    --- Ordinary constants:
    ---

    --- name    -: type -= value

    -- Primitive types:
    "unit"      `primtype` tcUnit,
    "exn"       `primtype` tcExn,
    "int"       `primtype` tcInt,
    "char"      `primtype` tcChar,
    "float"     `primtype` tcFloat,
    "string"    `primtype` tcString,
    "unlimited" `primtype` tcUn,
    "affine"    `primtype` tcAf,
    "*"         `primtype` tcTuple,
    "record"    `primtype` tcRecord,
    "variant"   `primtype` tcVariant,
    "rowend"    `primtype` tcRowEnd,
    "rowdots#"  `primtype` tcRowDots, -- Needed by renamer
    "\\/"       `primtype` tcJoin,
    "->"        `primtype` tcFun,

    -- Bool needs to be known to the parser for if expression
    dec [sgQ| type bool = false | true |],

    -- Lists need to be known by the parser for list syntax
    dec [sgQ| type `a list = [] | (::) of `a * `a list |],

    submod "INTERNALS" [
      submod "PrimTypes" [
        dec [sgQ| type unit      = type unit |],
        dec [sgQ| type variant   = type variant |],
        dec [sgQ| type record    = type record |],
        dec [sgQ| type rowend    = type rowend |],
        dec [sgQ| type unlimited = type unlimited |],
        dec [sgQ| type affine    = type affine |],
        dec [sgQ| type bool      = type bool |],
        dec [sgQ| type list      = type list |],
        val "nilRecord" -: [ty| (unlimited, rowend) record |]
          -= MultiplicativeRecord []
      ]
    ],

    -- Sums
    dec [sgQ| type `a option = None | Some of `a |],
    dec [sgQ| type `a + `b = Left of `a | Right of `b |],

    -- Arithmetic
    binArith "+" (+),
    binArith "-" (-),
    binArith "*" (*),
    binArith "/" div,
    binArith "%" mod,
    fun "~" -: [ty| int -> int |]
      -= (negate :: Integer -> Integer),
    fun "abs" -: [ty| int -> int |]
      -= (abs :: Integer -> Integer) ,
    fun "<=" -: [ty| int -> int -> bool |]
      -= ((<=) :: Integer -> Integer -> Bool),
    fun "string_of_int" -: [ty| int -> string |]
      -= (show :: Integer -> String),
    fun "int_of_string" -: [ty| string -> int |]
      -= (read :: String -> Integer),
    fun "random_int" -: [ty| unit -> int |]
      -= \() -> (randomIO :: IO Int),

    -- Floating point arithmetic
    fun "<=." -: [ty| float -> float -> bool |]
      -= ((<=) :: Double -> Double -> Bool),
    fun "<." -: [ty| float -> float -> bool |]
      -= ((<) :: Double -> Double -> Bool),
    fun "+." -: [ty| float -> float -> float |]
      -= ((+) :: Double -> Double -> Double),
    fun "-." -: [ty| float -> float -> float |]
      -= ((-) :: Double -> Double -> Double),
    fun "*." -: [ty| float -> float -> float |]
      -= ((*) :: Double -> Double -> Double),
    fun "/." -: [ty| float -> float -> float |]
      -= ((/) :: Double -> Double -> Double),
    fun "**" -: [ty| float -> float -> float |]
      -= ((**) :: Double -> Double -> Double),
    fun "~." -: [ty| float -> float |]
      -= (negate :: Double -> Double),
    fun "sqrt" -: [ty| float -> float |]
      -= (sqrt :: Double -> Double),
    fun "log" -: [ty| float -> float |]
      -= (log :: Double -> Double),
    fun "absf" -: [ty| float -> float |]
      -= (abs :: Double -> Double),
    fun "float_of_int" -: [ty| int -> float |]
      -= (fromIntegral :: Integer -> Double),
    fun "int_of_float" -: [ty| float -> int |]
      -= (round :: Double -> Integer),
    fun "string_of_float" -: [ty| float -> string |]
      -= (show :: Double -> String),
    fun "float_of_string" -: [ty| string -> float |]
      -= (read :: String -> Double),

    -- Strings
    fun "explode"  -: [ty| string -> char list |]
      -= (map vinj ∷ String → [Value]),
    fun "implode"  -: [ty| char list -> string |]
      -= (map vprj ∷ [Value] → String),
    fun "^" -: [ty| string -> string -> string |]
      -= ((++) :: String -> String -> String),
    fun "string_of" -: [ty| all 'a. 'a -> string |]
      -= (return . show :: Value -> IO String),
    fun "string_length" -: [ty| string -> int |]
      -= \s -> toInteger (length (s :: String)),

    -- "Magic" equality and print; failure
    fun "==" -: [ty| all 'a. 'a -> 'a -> bool |]
      -= ((==) :: Value -> Value -> Bool),
    fun "print" -: [ty| all 'a. 'a -> unit |]
      -= (print :: Value -> IO ()),

    -- I/O
    fun "putChar"  -: [ty| char -> unit |]
      -= putChar . integer2char,
    fun "getChar"  -: [ty| unit -> char |]
      -= \() -> fmap char2integer getChar,
    fun "flush"    -: [ty| unit -> unit |]
      -= \() -> IO.hFlush IO.stdout,
    fun "putStr"   -: [ty| string -> unit |]
      -= putStr,
    fun "putStrLn" -: [ty| string -> unit |]
      -= putStrLn,
    fun "getLine"  -: [ty| unit -> string |]
      -= \() -> getLine,

    -- System and the environment
    fun "getArgs" -: [ty| unit -> string list |]
      -= \() -> Env.getArgs,
    fun "getProgName" -: [ty| unit -> string |]
      -= \() -> Env.getProgName,
    fun "getEnv" -: [ty| string -> string |]
      -= Env.getEnv,
    fun "getEnvironment" -: [ty| unit -> (string * string) list |]
      -= \() -> Env.getEnvironment,
    fun "exit" -: [ty| ∀ `a. int -> `a |]
      -= \z ->
           exitWith (if z == 0 then ExitSuccess else ExitFailure z) ∷ IO (),

    -- References
    dec [sgQ| type `a ref qualifier U |],
    dec [sgQ| type `a aref qualifier A |],
    fun "ref" -: [ty| all `a. `a -> `a ref |]
      -= (\v -> Ref `fmap` newIORef v),
    fun "aref" -: [ty| all `a. `a -> `a aref |]
      -= (\v -> Ref `fmap` newIORef v),

    fun "!" -: [ty| all 'a. 'a ref -> 'a |]
      -= (\r -> readIORef (unRef r)),
    fun "!!" -: [ty| all 'a. 'a aref -> 'a aref * 'a |]
      -= (\r -> do
           v <- readIORef (unRef r)
           return (r, v)),
    fun "<-" -: [ty| all `a. `a ref -> `a -> `a |]
      -= (\r v -> do
           atomicModifyIORef (unRef r) (\v' -> (v, v'))),
    fun "<-!" -: [ty| all `a `b. `a aref ->
                            `b -o `b aref * `a |]
      -= (\r v -> do
           atomicModifyIORef (unRef r) (\v' -> (v, (r, v')))),

    submod "Unsafe" [
      -- Unsafe coercions
      fun "unsafeCoerce" -: [ty| all `b `a. `a -> `b |]
        -= (id :: Value -> Value),
      fun "unsafeDup" -: [ty| all `a. `a -> `a * `a |]
        -= ((\v -> (v, v)) :: Value -> (Value, Value))
    ],

    submod "IO"      Basis.IO.entries,
    submod "Channel" Basis.Channel.entries,
    submod "Thread"  Basis.Thread.entries,
    submod "MVar"    Basis.MVar.entries,
    submod "Future"  Basis.Future.entries,

    submod "Prim" [
      submod "Socket" Basis.Socket.entries,
      submod "Exn"    Basis.Exn.entries,
      submod "Array"  Basis.Array.entries,
      submod "Row"     Basis.Row.entries
    ]
  ]

newtype Ref = Ref { unRef :: IORef Value }
  deriving (Eq, Typeable)

instance Valuable Ref where
  veq = (==)
  vppr _ = text "#<ref>"

-- | Built-in operations implemented in the object language
srcBasis :: String
srcBasis  = "libbasis.alms"