{-# LANGUAGE OverloadedStrings #-}

module Main
  ( main
  ) where

import HTTP

import System.Environment (getArgs, getProgName)
import System.Directory (createDirectory)

import Data.List (intercalate)
import Data.Text (Text)
import qualified Data.Text as T
import qualified Data.Text.IO as T
import Data.Text.Encoding (encodeUtf8)
import Data.Aeson (eitherDecodeStrict)

import Model.URL
import Model.Json.Search
import Model.Perfume

import PerfumeParser (parsePerfumes)

main :: IO ()
main = do
  args <- getArgs
  case args of
    [] -> do
      progName <- T.pack <$> getProgName
      T.putStrLn (T.concat ["Usage: ", progName, " material"])
    materials -> do
      eitherPages <- fmap sequence <$> sequence . map getHtmlPerfumes . map T.pack $ materials
      case eitherPages of
        Left error ->
          T.putStrLn error
        Right perfumesSequences ->
          let commonPerfumes = getCommonPerfumes perfumesSequences
              outputDirectory = "output"
              outputName = outputDirectory ++ "/" ++ (intercalate "-" materials) ++ ".csv"
          in  do
                createDirectory outputDirectory
                T.writeFile outputName (csvPerfumes commonPerfumes)
                putStrLn ("Successfully generated " ++ outputName)

getHtmlPerfumes :: Text -> IO (Either Text [Perfume])
getHtmlPerfumes material = do
  eitherPage <- getPage (getIdURL material)
  case eitherPage of
    Left error ->
      return . Left $ error
    Right page ->
      case eitherDecodeStrict (encodeUtf8 page) :: Either String [Search] of
        Left error ->
          return . Left . T.pack $ error
        Right searches ->
          case getMaterialIdentifier searches of
            Nothing ->
              return . Left $ "No material identifier found"
            Just identifier -> do
              fmap parsePerfumes <$> getPage (getMaterialURL identifier)