module Exercise06 where

import Data.List

import Effects
import Types
import Data.Ord (comparing)

sinPeriod :: Signal
sinPeriod d
  | d < 0 = 0
  | d <= 1 = sin (pi * d * 2)

triPeriod :: Signal
triPeriod d
  | d < 0 = 0
  | d < 0.5 = 4 * d - 1
  | d <= 1 =  -4 * d + 3

sawPeriod :: Signal
sawPeriod d
  | d < 0 = 0
  | d <= 1 = 2 * d - 1

specialSawPeriod :: Signal
specialSawPeriod d
  | d < 0 = 0
  | d <= 0.5 = -2 * d + 1
  | d <= 1 = 2 * d - 1

sqwPeriod :: Signal
sqwPeriod d
  | d < 0 = 0
  | d < 0.5 = -1
  | d == 0.5 = 0
  | d > 0.5 = 1
  | d > 1 = 0


guitarNope :: Signal
guitarNope dx =
  let 
    normal dx = sin (pi * dx * 2)
    ticks dx
      | dx < 0.05 = normal dx * 1.6
      | dx < 0.08 = 0.85
      | dx < 0.13 = normal dx * 1.2
      | dx < 0.19 = 0.8
      | dx < 0.20 = 0.6
      | dx < 0.21 = 0.9
      | dx < 0.22 = 0.95
      | dx < 0.23 = 1
      | dx < 0.3 = normal dx
      | dx < 0.55 = normal (dx+0.1) * 0.8 -- nach links verschieben
      | dx < 0.7 = normal dx * 0.2 - 0.6
      | dx <= 1 = normal dx
  in
    if dx < 0 then 0
    else if dx <= 1 then ticks dx
    else 0

guitarHope :: Signal
guitarHope dx =
  let 
    normal dx = sin (pi * dx * 2)
    ticks dx
      | dx <= 1 = normal dx * specialSawPeriod dx
  in
    if dx < 0 then 0
    else if dx <= 1 then ticks dx
    else 0


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 original env tone duration = 
  let 
    -- some number between 100 and 700
    periodsPS = f tone

    periods = periodsPS * duration

    periodTime = 1 / periodsPS

    -- dx is between 0 and duration
    fast dx = 
      let 
        lastFullPeriodTime =  periodTime * fromInteger (floor(dx / periodTime))

        -- phase in the original
        -- * periodsPS to get to max 1
        phase = (dx - lastFullPeriodTime) * periodsPS
      in
        original phase

  in
    adsr env duration fast



adsr :: ADSR -> Seconds -> Signal -> Signal
adsr (att, dec, sus, rel) sampleTime fast dx =
  let 
      susEnd = sampleTime - rel

      attF = (1 / att) * dx
      -- (y2 - y1) / (x2 - x1) für die Steigung
      -- ((att+dec) - att)
      decM = (sus - 1) / dec
      -- bekannter Punkt (att, 1)
      -- 1 = decM * att + decY <=>
      -- -decY = decM * att - 1
      decY = -decM * att + 1
      decF = decM * dx + decY

      -- releaseFunction
      relM = (-sus) / (sampleTime - susEnd)
      -- 0 = relM * sampleTime + relY
      -- -relY = relM * sampleTime
      relY = -relM * sampleTime
      relF = relM * dx + relY


      multiplier
        | dx < 0 = 0
        | dx < att = attF
        | dx < att + dec = decF
        | dx < susEnd = sus
        | dx < sampleTime = relF
        |otherwise = 0
  in
    fast dx * multiplier


cast :: Seconds -> Double
cast d = d

mix :: [SampledSignal] -> SampledSignal
mix signals = 
  let
      -- maybe unnecessary
      -- sorted = map snd $ sortBy (comparing fst) $ map (\s -> (length s, s)) signals

      divL amp = amp / fromIntegral (length signals)

      quiter = [ [ divL amp | amp <- signal ] | signal <- signals ]

      normalized = [ sum l | l <- transpose quiter]
  in
    normalized


{-WETT-}

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

revSawW :: Oscillator
revSawW = osc sawPeriod (0.01, 0.3, 0.3, 0.2)

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




sinW :: Oscillator
sinW = osc sinPeriod (0.01, 0.2, 0.9, 0.2)

sinSaw :: Oscillator
sinSaw = osc (sinPeriod . sawPeriod) (0.01, 0.2, 0.7, 0.2)

sinSq :: Oscillator
sinSq = osc (sinPeriod . sqwPeriod) (0.01, 0.2, 0.7, 0.2)

sinTri :: Oscillator
sinTri = osc (sinPeriod . triPeriod) (0.01, 0.2, 0.7, 0.2)




sawSin :: Oscillator
sawSin = osc (sawPeriod . sinPeriod) (0.01, 0.2, 0.7, 0.2)



triSq :: Oscillator
triSq = osc (triPeriod . sqwPeriod) (0.01, 0.2, 0.7, 0.2)



triSaw :: Oscillator
triSaw = osc (triPeriod . sqwPeriod) (0.01, 0.2, 0.7, 0.2)

allW :: Oscillator
allW = osc (sinPeriod . sawPeriod . triPeriod . sqwPeriod) (0.01, 0.1, 0.7, 0.2)


-- you can add more effects here

guitar :: Oscillator
guitar = osc guitarHope (0.1, 0.1, 0.3, 0.1)



-- 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 [sawW, sinTri] -- [guitar, sawSin]
    audioTracks = zipWith playNotes instrs tracks
    audioNoEffects = mixTracks audioTracks [0.8, 0.8, 0.2]
    -- 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 [distortion, addGain 4] audioNoEffects


    -- This doesn't work because it repeats the section
    -- 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-}