module CSVTable ( red2Table ) where

-- (c) 2007 Hans van Thiel
-- Version 0.1 License GPL

-- module: convert reduction result to CSV 
-- format that can be read by Open Office Calc

import Data.Char (isDigit )
import Data.List ( delete )
import Data.Array

---------- some auxiliary functions ----------------

-- check whether a string is a number or text

allDigit :: String -> Bool
allDigit [] = True
allDigit (x:xs) | isDigit x = allDigit xs
                | otherwise = False

-- convert string or number to OO Calc format

toCalc :: String -> String
toCalc x | allDigit x = x
         | otherwise = "\"" ++ x ++ "\""

-- get the value string of an attribute-value tuple

strVal :: Array Int [String] -> (Int,Int) ->  String
strVal attvarr x  =   
     toCalc $ (attvarr ! (fst x)) !! (snd x)

-- get the attribute string from an index 
strAtt :: Array Int [String] -> Int -> String
strAtt attvarr ix = head (attvarr ! ix)

-- insert a separator s between two strings

inSep :: String -> String -> String -> String
inSep s x y = x ++ s ++ y
----------------------------------------------

-- show the value of the attribute index or a blank

indStr :: Array Int [String] -> [(Int,Int)] ->  Int-> String
indStr attvarr []  x = " "
indStr attvarr (y:ys) x | x == fst y = strVal  attvarr y
                        | otherwise = indStr attvarr ys x 


-- turn antecedent into CSV string 

ant2Str :: Array Int [String] -> [Int]-> [(Int,Int)]-> String
ant2Str attvarr indls redlin =  
           foldl1 (inSep ",") y where
                   y = map (indStr attvarr redlin ) indls


-- get consequent value string and newline
cns2Str :: Array Int [String] -> (Int,Int) ->  String
cns2Str attvarr cons = 
           ",\" is \"," ++ (strVal attvarr cons) ++ "\n"

-- get the table antecedent header
ahd2Str :: Array Int [String] -> [Int] ->  String
ahd2Str attvarr indls  = foldl1 (inSep ",") y where
                   y = [ strAtt attvarr z | z <- indls ]

-- get consequent attribute string and newline
chd2Str ::  Array Int [String] -> Int -> String
chd2Str attvarr ati = 
     ", ," ++  (toCalc (head (attvarr ! ati))) ++ "\n"

-- show the table header in csv format
hd2csv :: Array Int [String] -> ([Int], Int) -> String
hd2csv attvarr hdp = 
     (ahd2Str attvarr (fst hdp)) ++ (chd2Str attvarr (snd hdp))
---------------------------------------------------

-- show a reduction for a consequent value in csv

red2csv :: Array Int [String] -> [Int] -> ([[(Int,Int)]], (Int,Int)) -> [String]
red2csv attvarr indls rstp = 
          map ( ++ cns2Str attvarr (snd rstp)) redstr where 
                    redstr =  map (ant2Str attvarr indls) (fst rstp)

-- show the reduction results for an attribute in csv

all2csv :: Array Int [String] -> [Int] -> [([[(Int,Int)]], (Int,Int))] -> String
all2csv attvarr indls redres = concat $ concatMap (red2csv attvarr indls) redres

-- output a csv table from the array of attribute-value names,
-- the antecedent attributes and consequent, and the 
-- zip of the reduction results and the consequent values

red2Table :: Array Int [String] -> ([Int],Int)-> [([[(Int,Int)]], (Int,Int))] -> String
red2Table attvarr indls redres = 
  (hd2csv attvarr indls) ++ (all2csv attvarr (fst indls) redres)