module Charts (plotChart) where

import Data.Foldable (traverse_, toList)
import Graphics.Rendering.Chart.Easy (plot, line, (.=), layout_title)
import Graphics.Rendering.Chart.Backend.Diagrams (toFile,
                                                  loadSansSerifFonts,
                                                  FileOptions (..),
                                                  FileFormat (SVG))
import QuoteData

plotChart :: (Functor t, Foldable t) =>
             String -> t QuoteData -> [QField] -> FilePath -> IO ()
plotChart title quotes qfs fname = toFile fileOptions fname $ do
    layout_title .= title
    traverse_ plotLine qfs
  where
    fileOptions = FileOptions (800, 600) SVG loadSansSerifFonts
    plotLine qf = plot $ line (show qf)
                              [toList $ fmap (qf2pd qf) quotes]
    qf2pd qf q = (day q,
                  realToFrac $ field2fun qf q :: Double)