module Model.CellContent (NamedReference (..),Reference (..)
                         ,CompileReason (..),RuntimeReason (..)
                         ,CellExpr (..),CellValue (..)
                         ,Symbol,dependencies)
    where

import Data.List (intercalate)
import CellCoordinate (CellCoord)
import I18n (__)

type Symbol = String

data NamedReference = NamedCell (String,String)
                    | NamedRange ((String,String),(String,String))
                    | NamedColumn String
                    | NamedRow String
                      deriving (Eq)

instance Show NamedReference where
    show (NamedCell (r,c)) = concat ["$",r,",",c,"$"]
    show (NamedRange (a,b)) = concat [ show $ NamedCell a
                                     , ":",show $ NamedCell b]
    show (NamedColumn a) = concat ["$_,",a,"$"]
    show (NamedRow a) = concat ["$",a,"_$"]

data Reference = Cell CellCoord
               | Range (CellCoord,CellCoord)
               | Column Int
               | Row Int
                 deriving (Eq,Show)

data CompileReason = ParseError String
                   | RefConversionError NamedReference
                   | ReferenceLoop
                     deriving (Eq)

instance Show CompileReason where
    show (ParseError a) = unwords [(__ "Parse error")++ ":",a]
    show (RefConversionError a) = unwords [(__ "Unknown reference") ++ ":",show a]
    show ReferenceLoop = __ "Reference loop"

data RuntimeReason = CompileError CompileReason
                   | TypeError CellValue
                   | Inherited CellValue RuntimeReason 
                   | UnknownIdentifier Symbol
                     deriving (Eq)

instance Show RuntimeReason where
    show (CompileError a) = unwords [(__ "Compile error") ++ ":",show a]
    show (TypeError a) = unwords [__ "Type error in",showValueInError a]
    show (Inherited a b) = unwords [__ "In",showValueInError a,":",show b]
    show (UnknownIdentifier a) = unwords [__ "Unknown identifier",a]

data CellExpr = EmptyExpr
              | NumberExpr Double
              | StringExpr String
              | ListExpr [CellExpr]
              | NamedReference NamedReference
              | Reference Reference
              | UnaryOp Symbol CellExpr
              | BinaryOp Symbol CellExpr CellExpr
              | Call Symbol CellExpr
              | Sub CellExpr
              | CompileErrorExpr CompileReason
                deriving (Eq,Show)

data CellValue = EmptyValue
               | NumberValue Double
               | StringValue String
               | ListValue [CellValue]
               | Error RuntimeReason
                 deriving (Eq)

instance Show CellValue where
    show EmptyValue = ""
    show (NumberValue a) = show a
    show (StringValue a) = a
    show (ListValue a) = concat ["[",intercalate "," $ map show a,"]"]
    show (Error _) = __ "Error"

dependencies :: CellExpr -> [Reference]
dependencies expr =
    case expr of
      Reference ref -> [ref]
      ListExpr a -> concat $ map dependencies a
      UnaryOp _ a -> dependencies a
      BinaryOp _ a b -> (dependencies a) ++ (dependencies b)
      Call _ a -> dependencies a
      Sub a -> dependencies a
      _ -> []

showValueInError :: CellValue -> String
showValueInError value =
    case value of
      EmptyValue -> __ "Empty"
      ListValue a -> 
          concat ["[",intercalate "," $ map showValueInError a,"]"]
      _ -> show value