{-# LANGUAGE OverloadedStrings #-}
module ICAFocus where

import Data.Aeson
import Data.Aeson.Types
import Data.Aeson.KeyMap
import Data.Text
import Text.Read
import Data.Int (Int32)
import Data.ByteString.Lazy

import Misc

newtype ImageLink = ImageLink { getLink :: String }
  deriving (Show)

newtype ImageData = ImageData { getData :: ByteString }

type ProductID = Int32

instance Show ImageData where
  show _ = "ImageData { ... }"

data ICAFocusItem a = ICAFocusItem
  { name :: Text
  , costPerKg :: Float
  , costPerUnit :: Float
  , image :: a
  }
  deriving (Show, Functor)

type ICAFocusData = ICAFocusItem ImageLink
type ICAFocusProduct = ICAFocusItem ImageData

apiEndpoint :: ProductID -> String
apiEndpoint i = "https://handlaprivatkund.ica.se/stores/1004247/api/v4/products/bop?retailerProductId=" ++ show i

instance FromJSON ICAFocusData where
  parseJSON (Object v) = do
    productMap <- v .: "entities" .:: "product"
    product <- case elems productMap of
      [Object x] -> pure x
      [] -> fail "No products"
      _ -> fail "Too many products"

    ICAFocusItem
      <$> product .: "name"
      <*> (unpackEither . readEither =<< product .: "price"            .:: "current" .:: "amount")
      <*> (unpackEither . readEither =<< product .: "price" .:: "unit" .:: "current" .:: "amount")
      <*> (ImageLink <$> product .: "image" .:: "src")