{-# LANGUAGE BangPatterns #-}

module HTTP2.PrioritySpec where

import Data.List (group, sort)
import Test.Hspec

import Network.HTTP2.Priority
import qualified Network.HTTP2.Priority.PSQ as P
import Network.HTTP2.Types

spec :: Spec
spec = do
    describe "priority tree" $ do
        it "enqueue and dequeue frames from Firefox properly" $ firefox
    describe "base priority queue" $ do
        it "queues entries based on weight" $ do
            let q = P.enqueue 5   1 5 $
                    P.enqueue 3 101 3 $
                    P.enqueue 1 201 1 P.empty
                xs = enqdeq q 1000
            map length (group (sort xs)) `shouldBe` [664,333,3]

firefox :: IO ()
firefox = do
    pt <- newPriorityTree :: IO (PriorityTree Int)
    prepare pt  3 (pri 0 201)
    prepare pt  5 (pri 0 101)
    prepare pt  7 (pri 0   1)
    prepare pt  9 (pri 7   1)
    prepare pt 11 (pri 3   1)
    enQ pt 13 (pri 11 32)
    dequeue pt `shouldReturn` (13,13)
    enQ pt 15 (pri  3 32)
    enQ pt 17 (pri  3 32)
    enQ pt 19 (pri  3 32)
    enQ pt 21 (pri  3 32)
    enQ pt 23 (pri  3 32)
    enQ pt 25 (pri  3 32)
    enQ pt 27 (pri 11 22)
    enQ pt 29 (pri 11 22)
    enQ pt 31 (pri 11 22)
    enQ pt 33 (pri  5 32)
    enQ pt 35 (pri  5 32)
    enQ pt 37 (pri  5 32)
    dequeue pt `shouldReturn` (15,15)
    clear pt 15 (pri  3 32)
    clear pt 15 (pri  3 32)
    dequeue pt `shouldReturn` (33,33)
    dequeue pt `shouldReturn` (17,17)
    clear pt 17 (pri  3 32)
    clear pt 17 (pri  3 32)
    delete pt 17 (pri  3 32) `shouldReturn` Nothing
    delete pt 31 (pri 11 22) `shouldReturn` Just 31
    dequeue pt `shouldReturn` (19,19)
    dequeue pt `shouldReturn` (35,35)
    dequeue pt `shouldReturn` (21,21)
    dequeue pt `shouldReturn` (23,23)
    dequeue pt `shouldReturn` (37,37)
    dequeue pt `shouldReturn` (25,25)
    dequeue pt `shouldReturn` (27,27)
    dequeue pt `shouldReturn` (29,29)
    enQ pt 39 (pri  3 32)
    dequeue pt `shouldReturn` (39,39)

enQ :: PriorityTree Int -> StreamId -> Priority -> IO ()
enQ pt sid p = enqueue pt sid p sid

pri :: StreamId -> Weight -> Priority
pri dep w = Priority False dep w

enqdeq :: P.PriorityQueue Int -> Int -> [Int]
enqdeq pq num = loop pq num []
  where
    loop _   0 xs = xs
    loop !q !n xs = case P.dequeue q of
        Nothing         -> error "enqdeq"
        Just (k,w,x,q') -> loop (P.enqueue k w x q') (n - 1) (x:xs)