module Micro.Asm.Sdcc where

import qualified Data.Map as Map
import qualified Micro.Ast as A
import Micro.Env (Sym (..), SymMap)

toIdent :: A.Ident -> Bool -> String
toIdent id False = "_" ++ id
toIdent id True = id

toLabel :: A.Ident -> Bool -> String
toLabel id False = toIdent id False ++ "::"
toLabel id True = id ++ ":"

toData :: A.Type -> String
toData (A.Type t)
  | t == "bool" || t == "u8" || t == "s8" = ".ds 1"
  | t == "u16" || t == "s16" = ".ds 2"
  | otherwise = ".ds 2"
toData (A.FuncType _ _) = ".ds 2"

toInit :: A.Type -> String
toInit (A.Type t)
  | t == "bool" || t == "u8" || t == "s8" = ".db"
  | t == "u16" || t == "s16" = ".dw"
  | otherwise = ".dw"
toInit (A.FuncType _ _) = ".dw"

onlyData :: SymMap -> [Sym]
onlyData symm =
  filter (\sym -> symRef sym) $
    Map.elems symm

header :: String -> [String]
header version = [";", "; File created by Micro v" ++ version ++ " (SDCC)", ";"]

module' :: A.Expr -> [String]
module' (A.Module name _) = ["\t.module " ++ name, "\t.optsdcc -mz80"]
module' _ = ["\t.module main"] -- won't happen

exports :: SymMap -> [String]
exports symm =
  [""]
    ++ ( map (\sym -> "\t.globl " ++ toIdent (symId sym) False) $
           Map.elems $ Map.filter (\sym -> not $ symPriv sym) symm
       )

dataVars :: SymMap -> [String]
dataVars symm =
  ["\n\t.area _DATA", "\t.area _INITIALIZED"]
    ++ ( map (\sym -> toLabel (symId sym) (symPriv sym) ++ "\n\t" ++ toData (symType sym)) $
           onlyData symm
       )

initVars :: SymMap -> [String]
initVars symm =
  ["\n\t.area _INITIALIZER"]
    ++ ( map (\sym -> "__xinit_" ++ toLabel (symId sym) True ++ "\n\t" ++ toInit (symType sym) ++ " FIXME") $ onlyData symm
       )
    ++ ["\n\t.area _GSINIT", "\t.area _GSFINAL"]

code :: [String]
code = ["\n\t.area _CODE"]

generate :: String -> SymMap -> [A.Expr] -> String
generate version symm ast = unlines $ header version ++ module' (head ast) ++ exports symm ++ dataVars symm ++ code ++ initVars symm