module Main (main) where

import Interop.Shared (Summary (..))
import RustClient (callRustMessage, callRustSummary)
import System.Environment (getArgs)
import Text.Read (readMaybe)

main :: IO ()
main = do
    args <- getArgs
    let (name, left, right) = parseArgs args
    summary <- callRustSummary left right
    message <- callRustMessage name left right

    putStrLn "Haskell -> Rust demo"
    putStrLn $ "Inputs: name=" ++ name ++ ", left=" ++ show left ++ ", right=" ++ show right
    putStrLn $ "Stats from Rust: " ++ renderSummary summary
    putStrLn $ "Message from Rust: " ++ message

parseArgs :: [String] -> (String, Int, Int)
parseArgs args =
    let name = case args of
            value : _ -> value
            [] -> "Ada"
        left = maybe 7 id (pickNumber 1 args)
        right = maybe 5 id (pickNumber 2 args)
     in (name, left, right)

pickNumber :: Int -> [String] -> Maybe Int
pickNumber index values = do
    value <- safeIndex index values
    readMaybe value

safeIndex :: Int -> [a] -> Maybe a
safeIndex index values
    | index < 0 = Nothing
    | otherwise = case drop index values of
        value : _ -> Just value
        [] -> Nothing

renderSummary :: Summary -> String
renderSummary summary =
    "total="
        ++ show (total summary)
        ++ ", product="
        ++ show (combinedProduct summary)
        ++ ", gap="
        ++ show (gap summary)