module Algo.MaxRate where

import Types
import Heap
import Algo.Common

createHeap :: [Time] -> Heap Unit
createHeap [] = Nil
createHeap (t:ts) = insert (Unit (1 / (fromIntegral t)) t 1 0) $ createHeap ts -- we use speed as metric 

runUntilCycle :: Int -> [Int] -> Heap Unit
runUntilCycle p ts = fst $ run 0 (h, emptyHeap) -- maintain two heaps - one for clients with remaining packets, one for clients without available packets
    where h = createHeap ts
          run :: Time -> (Heap Unit, Heap Unit) -> (Heap Unit, Heap Unit)
          run curr_t (h, exh_h) | (mod curr_t p == 0) && (curr_t /= 0) = (h, exh_h) -- cycle found
                                | otherwise = let (Just m,h') = deleteMax h in
                                              run (curr_t + period m) $ updateHeap curr_t (curr_t + period m) $ insertDecreased m h' exh_h where
                                                insertDecreased el h exh_h = if (rem_p el == 1) then 
                                                    (h, insert el {sent_p = sent_p el + 1, rem_p = 0} exh_h) -- move best client to the "exhausted" heap if his rem_p is equal to zero 
                                                else (insert el {sent_p = sent_p el + 1, rem_p = rem_p el - 1} h, exh_h)