module Exercise06 where

import Data.List

import Effects
import Types

sinPeriod :: Signal
sinPeriod sec = sin (2.0*pi*sec) 

sqwPeriod :: Signal
sqwPeriod sec
 | sec < 0.5  = - 1
 | otherwise  = 1

sawPeriod :: Signal
sawPeriod sec = 2.0*sec -1

triPeriod :: Signal
triPeriod sec
 | sec < 0.5  = 4.0 * sec - 1
 | otherwise  = -4.0 * sec + 3

silence :: Signal
silence = undefined

-- NOTE: the formula is taken from https://pages.mtu.edu/~suits/NoteFreqCalcs.html
f :: Semitone -> Hz
f n = 440.0 * (2 ** (fromInteger n / 12.0))

osc :: Signal -> ADSR -> Oscillator
osc sig aDSR semTo secs = adsr aDSR secs fitSig
 where fitSig s = let wdh = s * f semTo in sig (wdh - fromIntegral (floor wdh))

adsr :: ADSR -> Seconds -> Signal -> Signal
adsr (attack, decay, sustain, release) dur sig sec
 | sec < attack        = sec / attack * sig sec
 | sec < attack+decay  = ((sustain - 1) * (sec-attack) / decay + 1) * sig sec
 | sec < dur-release   = sustain * sig sec
 | otherwise           = (-sustain * (sec-(dur-release)) / release + sustain) * sig sec

mix :: [SampledSignal] -> SampledSignal
mix samps= map norm (foldl vectorAdd [] samps)
 where norm x = x/fromIntegral(length samps)

vectorAdd :: [Double] -> [Double] -> [Double]
vectorAdd [] [] = []
vectorAdd (x:xs) [] = x:xs
vectorAdd [] (y:ys) = y:ys
vectorAdd (x:xs) (y:ys) = x+y:vectorAdd xs ys

{-WETT-}

-- you can add new oscillators here
piano :: Oscillator
piano = osc sawPeriod (0.01, 0.1, 0.7, 0.2)

lead :: Oscillator
lead = osc sqwPeriod (0.01, 0.2, 0.3, 0.1)

bass :: Oscillator
bass = osc sinPeriod (0.001, 0.2, 0.9, 0.1)

-- you can add more effects here



-- mix the signals with some volume
mixTracks :: [SampledSignal] -> [Double] -> SampledSignal
mixTracks trks vols = mix $ zipWith (\trk vol -> map (* vol) trk) trks vols

-- here we mix it all together and apply the effects
notesToSignal :: (Oscillator -> [Note] -> SampledSignal) -> [[Note]] -> SampledSignal
notesToSignal playNotes tracks = audio
  where
    -- specify the instruments of each track
    -- try the following instruments with the mario.mid file
    instrs = cycle [piano, bass]
    audioTracks = zipWith playNotes instrs tracks
    audioNoEffects = mixTracks audioTracks [0.8, 0.7]
    -- audio = audioNoEffects
    -- To add effects, replace the line above by the line at the end of this comment and change the list off effects to your own effects.
    -- Note that the effects are applied from right to left, ie. the rightmost effect is applied first.
    --audio = addEffects [clip 0.7, addGain 4] audioNoEffects

    --audio = addEffects [slowTremolo (0.6, 1.4) 4000 4000] audioNoEffects

    {-MC Wettbewerb-}
    -- I used: 
    --    stack run synth "...\fpv2021ex06-ge25lim\mid\carol_of_the_bells_01.mid" "...\carol_of_the_bells_02.wav"
    -- and I had to give the whole path
    audio = addEffects [clip 0.5, bitCrunchSpeed] (applyEffectToInterval (0, 23) (applyEffectToInterval (67, 96) audioNoEffects (slowTremolo (0.6, 1.4) 4000 4000 . addGain 1.6)) (wreck 0.0 0.0001 0.8 . addGain 0.5))

    -- If you want to apply an effect only to parts of the signal, you can use the function applyEffectToInterval, as shown below.
    -- Thereby the first argument specifies the interval to which the effect should be applied in seconds.
    -- audio = applyEffectToInterval (2, 10) audioNoEffects distortion

    --audio = applyEffectToInterval (10, 30) audioNoEffects (slowTremolo (0.6, 1.4) 4000 4000)
    --audio = applyEffectToInterval (25, 45) (applyEffectToInterval (55, 80) audioNoEffects (slowTremolo (0.6, 1.4) 4000 4000)) (wreck 0.0 0.0001 0.6)
{-TTEW-}