module Exercise06 where

import Data.List
import Effects
import Types

sinPeriod :: Signal
sinPeriod sec = sin (2 * sec * pi)

triPeriod :: Signal
triPeriod sec = 1 - abs ((- 4 * sec) + 2)

sawPeriod :: Signal
sawPeriod sec = 2 * sec -1

sqwPeriod :: Signal
sqwPeriod sec = if sec < 0.5 then -1 else 1

silence :: Signal
silence _ = 1

-- 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))

adsr :: ADSR -> Seconds -> Signal -> Signal
adsr (attack, decay, sustainValue, release) duration signal sec
  | sec <= decayStart = (sec / attack) * o
  | sec <= sustainStart = o * (1 - decayP * decayDiff)
  | sec <= releaseStart = o * sustainValue
  | sec <= duration = o * (1 - releaseP) * sustainValue
  | otherwise = 0
  where
    sustain = duration - attack - decay - release
    decayStart = attack
    decayP = (sec - decayStart) / decay
    decayDiff = 1 - sustainValue
    sustainStart = decayStart + decay
    releaseStart = sustainStart + sustain
    releaseP = (sec - releaseStart) / release
    o = signal sec

getRest :: Double -> Double
getRest n = n - fromIntegral (floor n)

osc :: Signal -> ADSR -> Oscillator
osc signal adsrValue tone duration sec = o * p
  where
    frequency = f tone
    secRest = getRest sec
    realSec = getRest (frequency * secRest)
    o = signal realSec
    p = adsr adsrValue duration silence sec

mix :: [SampledSignal] -> SampledSignal
mix signals
  | null valid = []
  | otherwise = (here / num) : mix rest
  where
    valid = filter (not . null) signals
    notValid = filter null signals
    num = fromIntegral (length signals)
    here = sum (map head valid)
    rest = map tail valid ++ notValid

{-MCCOMMENT
Hi 🐧

Please use `stack run synth mid/star.mid b.wav`
Output: b.wav
There is no creativity and Simon realized, he is in a long way to be a good DJ
I hope this music doesnt hurt your ears
I chose star because it is short, so lower damage to ears
Happy Christmas Day
Simon
-}

{-WETT-}
oscDown :: Integer -> Signal -> ADSR -> Oscillator
oscDown x signal adsrValue tone duration sec = o * p
  where
    frequency = f (tone + x)
    realSec = getRest (frequency * getRest sec)
    o = signal realSec
    p = adsr adsrValue duration silence sec

groupB :: Int -> [a] -> [[a]]
groupB _ [] = []
groupB n x = take n x : groupB n (drop n x)

-- you can add new oscillators here
piano :: Oscillator
piano = osc sinPeriod (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)

drum :: Oscillator
drum = osc sinPeriod (0.001, 0.1, 0.1, 0.4)

idk :: Oscillator
idk = osc triPeriod (0.001, 0.001, 0.9, 0.001)

-- 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

tempMix :: Double -> Double -> SampledSignal -> SampledSignal -> SampledSignal
tempMix _ _ [] _ = []
tempMix p sec (a : ax) (b : bx) = (a * factorA + b * factorB) / 2 : tempMix (p + 1) sec ax bx
  where
    factorA = (1 + sin (p / sampleRate / sec * pi)) / 2
    factorB = 1 - factorA

delay :: Double -> DSPEffect
delay sec audio = replicate l 0 ++ reverse (drop l (reverse audio))
  where
    l = round (sec * sampleRate)

-- 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 = repeat piano
    audioTracks = zipWith playNotes instrs tracks
    audioNoEffects = mixTracks audioTracks [0.8, 0.7]
    audioNoEffectsDrum = mixTracks (map (playNotes drum) tracks) [0.8, 0.7]
    audioClip = addEffects [addGain 0.66, clip 0.9, addGain 4] audioNoEffects
    audioClipMix = mix [audioClip, audioClip, audioClip, audioNoEffects]
    audioMixClip = tempMix 0 3 audioClipMix audioNoEffects
    audioDumpMix = addEffects [addGain 0.7] audioNoEffectsDrum
    audioBackgroudTrack = mixTracks (map (playNotes (oscDown (-2) sinPeriod (0.001, 0.1, 0.1, 0.4))) tracks) [0.8, 0.7]
    audioBackgroudTrack2 = mixTracks (map (playNotes (oscDown (-4) sinPeriod (0.001, 0.1, 0.1, 0.4))) tracks) [0.8, 0.7]
    audioBackgroudTrack3 = mixTracks (map (playNotes (oscDown (-5) sinPeriod (0.001, 0.1, 0.1, 0.4))) tracks) [0.8, 0.7]
    audioBackgroudMix = mix [audioBackgroudTrack, addEffects [addGain 1.6] audioBackgroudTrack2, addEffects [addGain 2.1] audioBackgroudTrack3]
    idkMix = addEffects [addGain 0.4] (mixTracks (map (playNotes idk) tracks) [0.8, 0.7])
    audio = mix [audioMixClip, audioDumpMix, audioBackgroudMix, idkMix]

-- 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 0.9, addGain 4] audioNoEffects

-- 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, 6) audioNoEffects distortion
{-TTEW-}