-- | Basic table building for prettier futhark-test output.
module Futhark.Util.Table
  ( buildTable,
    mkEntry,
    Entry,
  )
where

import Data.List (intercalate, transpose)
import Futhark.Util (maxinum)
import Futhark.Util.Console (color)
import System.Console.ANSI

data RowTemplate = RowTemplate [Int] Int deriving (Show)

-- | A table entry. Consists of the content as well a list of
-- SGR commands to color/stylelize the entry.
type Entry = (String, [SGR])

-- | Makes a table entry with the default SGR mode.
mkEntry :: String -> (String, [SGR])
mkEntry s = (s, [])

buildRowTemplate :: [[Entry]] -> Int -> RowTemplate
buildRowTemplate rows = RowTemplate widths
  where
    widths = map (maxinum . map (length . fst)) . transpose $ rows

buildRow :: RowTemplate -> [Entry] -> String
buildRow (RowTemplate widths pad) entries = cells ++ "\n"
  where
    bar = "\x2502"
    cells = concatMap buildCell (zip entries widths) ++ bar
    buildCell ((entry, sgr), width) =
      let padding = width - length entry + pad
       in bar ++ " " ++ color sgr entry ++ replicate padding ' '

buildSep :: Char -> Char -> Char -> RowTemplate -> String
buildSep lCorner rCorner sep (RowTemplate widths pad) =
  corners . concatMap cellFloor $ widths
  where
    cellFloor width = replicate (width + pad + 1) '\x2500' ++ [sep]
    corners [] = ""
    corners s = [lCorner] ++ init s ++ [rCorner]

-- | Builds a table from a list of entries and a padding amount that
-- determines padding from the right side of the widest entry in each column.
buildTable :: [[Entry]] -> Int -> String
buildTable rows pad = buildTop template ++ sepRows ++ buildBottom template
  where
    sepRows = intercalate (buildFloor template) builtRows
    builtRows = map (buildRow template) rows
    template = buildRowTemplate rows pad
    buildTop rt = buildSep '\x250C' '\x2510' '\x252C' rt ++ "\n"
    buildFloor rt = buildSep '\x251C' '\x2524' '\x253C' rt ++ "\n"
    buildBottom = buildSep '\x2514' '\x2518' '\x2534'