-- | Time-domain filter unit generators.
module Sound.SC3.UGen.Filter where

import Data.List
import Sound.SC3.UGen.Rate
import Sound.SC3.UGen.Type
import Sound.SC3.UGen.UGen

-- | Audio to control rate converter.
a2K ::  UGen -> UGen
a2K i = mkOscR [KR] KR "A2K" [i] 1

-- | Allpass filter (no interpolation)
allpassN :: UGen -> UGen -> UGen -> UGen -> UGen
allpassN i mt dly dcy = mkFilter "AllpassN" [i,mt,dly,dcy] 1

-- | Allpass filter (linear interpolation)
allpassL :: UGen -> UGen -> UGen -> UGen -> UGen
allpassL i mt dly dcy = mkFilter "AllpassL" [i,mt,dly,dcy] 1

-- | Allpass filter (cubic interpolation)
allpassC :: UGen -> UGen -> UGen -> UGen -> UGen
allpassC i mt dly dcy = mkFilter "AllpassC" [i,mt,dly,dcy] 1

-- | Basic psychoacoustic amplitude compensation.
ampComp :: UGen -> UGen -> UGen -> UGen
ampComp f r e = mkFilter "AmpComp" [f,r,e] 1

-- | ANSI A-weighting curve psychoacoustic amplitude compensation.
ampCompA :: UGen -> UGen -> UGen -> UGen -> UGen
ampCompA f r ma ra = mkFilter "AmpCompA" [f,r,ma,ra] 1

-- | Bandpass filter
bpf :: UGen -> UGen -> UGen -> UGen
bpf i freq rq = mkFilter "BPF" [i,freq,rq] 1

-- | Two zero fixed midpass filter.
bpz2 :: UGen -> UGen
bpz2 i = mkFilter "BPZ2" [i] 1

-- | Band reject filter
brf :: UGen -> UGen -> UGen -> UGen
brf i freq rq = mkFilter "BRF" [i,freq,rq] 1

-- | Two zero fixed midcut filter.
brz2 :: UGen -> UGen
brz2 i = mkFilter "BRZ2" [i] 1

-- | Clip input between lower and upper bounds.
clip :: UGen -> UGen -> UGen -> UGen
clip i l h = mkFilter "Clip" [i,l,h] 1

-- | Comb filter (no interpolation)
combN :: UGen -> UGen -> UGen -> UGen -> UGen
combN i mt dly dcy = mkFilter "CombN" [i,mt,dly,dcy] 1

-- | Comb filter (linear interpolation)
combL :: UGen -> UGen -> UGen -> UGen -> UGen
combL i mt dly dcy = mkFilter "CombL" [i,mt,dly,dcy] 1

-- | Comb filter (cubic interpolation)
combC :: UGen -> UGen -> UGen -> UGen -> UGen
combC i mt dly dcy = mkFilter "CombC" [i,mt,dly,dcy] 1

-- | Compressor,expander,limiter,gate,ducker.
compander :: UGen -> UGen -> UGen -> UGen -> UGen -> UGen -> UGen -> UGen
compander i c t sb sa ct rt = mkFilter "Compander" [i,c,t,sb,sa,ct,rt] 1

-- | Convert signal to modal pitch.
degreeToKey :: UGen -> UGen -> UGen -> UGen
degreeToKey b i o = mkFilter "DegreeToKey" [b,i,o] 1

-- | Exponential decay.
decay :: UGen -> UGen -> UGen
decay i dcy = mkFilter "Decay" [i,dcy] 1

-- | Exponential decay (equvalent to $decay dcy - decay atk$).
decay2 :: UGen -> UGen -> UGen -> UGen
decay2 i atk dcy = mkFilter "Decay2" [i,atk,dcy] 1

-- | Single sample delay.
delay1 :: UGen -> UGen
delay1 i = mkFilter "Delay1" [i] 1

-- | Two sample delay.
delay2 :: UGen -> UGen
delay2 i = mkFilter "Delay2" [i] 1

-- | Simple delay line (cubic interpolation).
delayC :: UGen -> UGen -> UGen -> UGen
delayC i mt dly = mkFilter "DelayC" [i,mt,dly] 1

-- | Simple delay line (linear interpolation).
delayL :: UGen -> UGen -> UGen -> UGen
delayL i mt dly = mkFilter "DelayL" [i,mt,dly] 1

-- | Simple delay line (no interpolation).
delayN :: UGen -> UGen -> UGen -> UGen
delayN i mt dly = mkFilter "DelayN" [i,mt,dly] 1

-- | Tap a delay line from a DelTapWr UGen
delTapRd :: UGen -> UGen -> UGen -> UGen -> UGen
delTapRd buffer phase delTime interp = mkFilter "DelTapRd" [buffer,phase,delTime,interp] 1

-- | Write to a buffer for a DelTapRd UGen
delTapWr :: Rate -> UGen -> UGen -> UGen
delTapWr rate buffer in_ = mkOscR [AR,KR] rate "DelTapWr" [buffer,in_] 1

-- | Fold to range.
fold :: UGen -> UGen -> UGen -> UGen
fold i j k = mkFilter "Fold" [i,j,k] 1

-- | FOF like filter.
formlet :: UGen -> UGen -> UGen -> UGen -> UGen
formlet i f a d = mkFilter "Formlet" [i,f,a,d] 1

-- | First order filter section.
fos :: UGen -> UGen -> UGen -> UGen -> UGen
fos i a0 a1 b1 = mkFilter "FOS" [i,a0,a1,b1] 1

-- | A simple reverb.
freeVerb :: UGen -> UGen -> UGen -> UGen -> UGen
freeVerb i mx room damp = mkFilter "FreeVerb" [i,mx,room,damp] 1

-- | A simple reverb (two channel).
freeVerb2 :: UGen -> UGen -> UGen -> UGen -> UGen -> UGen
freeVerb2 i1 i2 mx room damp = mkFilter "FreeVerb2" [i1,i2,mx,room,damp] 2

-- | Gate.
gate :: UGen -> UGen -> UGen
gate i t = mkFilter "Gate" [i,t] 1

-- | A less-simple reverb.
gVerb :: UGen -> UGen -> UGen -> UGen -> UGen -> UGen -> UGen -> UGen -> UGen -> UGen -> UGen
gVerb i rs rt d bw sp dl rl tl mrs = mkFilter "GVerb" [i,rs,rt,d,bw,sp,dl,rl,tl,mrs] 2

-- | Hash input values.
hasher :: UGen -> UGen
hasher i = mkFilter "Hasher" [i] 1

-- | Hilbert transform.
hilbert :: UGen -> UGen
hilbert i = mkFilter "Hilbert" [i] 2

-- | Highpass filter.
hpf :: UGen -> UGen -> UGen
hpf i f = mkFilter "HPF" [i,f] 1

-- | Two point difference filter.
hpz1 :: UGen -> UGen
hpz1 i = mkFilter "HPZ1" [i] 1

-- | Two zero fixed highpass filter.
hpz2 :: UGen -> UGen
hpz2 i = mkFilter "HPZ2" [i] 1

-- | Is signal within specified range.
inRange :: UGen -> UGen -> UGen -> UGen
inRange i lo hi = mkFilter "InRange" [i,lo,hi] 1

-- | Control to audio rate converter.
k2A :: UGen -> UGen
k2A i = mkOscR [AR] AR "K2A" [i] 1

-- | Fixed resonator filter bank.
klank :: UGen -> UGen -> UGen -> UGen -> UGen -> UGen
klank i fs fp d s = mkFilterMCER [AR] "Klank" [i,fs,fp,d] s 1

-- | Format frequency, amplitude and decay time data as required for klank.
klankSpec :: [UGen] -> [UGen] -> [UGen] -> UGen
klankSpec f a dt = mce ((concat . transpose) [f,a,dt])

-- | Variant for non-UGen inputs.
klankSpec' :: [Double] -> [Double] -> [Double] -> UGen
klankSpec' f a dt =
    let u = map constant
    in klankSpec (u f) (u a) (u dt)

-- | Variant of 'klankSpec' for 'MCE' inputs.
klankSpec_mce :: UGen -> UGen -> UGen -> UGen
klankSpec_mce f a dt =
    let m = mceChannels
    in klankSpec (m f) (m a) (m dt)

-- | Simple averaging filter.
lag :: UGen -> UGen -> UGen
lag i t = mkFilter "Lag" [i,t] 1

-- | Nested lag filter.
lag2 :: UGen -> UGen -> UGen
lag2 i t = mkFilter "Lag2" [i,t] 1

-- | Twice nested lag filter.
lag3 :: UGen -> UGen -> UGen
lag3 i t = mkFilter "Lag3" [i,t] 1

-- | Lag variant with separate upward and downward times.
lagUD :: UGen -> UGen -> UGen -> UGen
lagUD i t1 t2 = mkFilter "LagUD" [i,t1,t2] 1

-- | Nested lag filter.
lag2UD :: UGen -> UGen -> UGen -> UGen
lag2UD i t1 t2 = mkFilter "Lag2UD" [i,t1,t2] 1

-- | Twice nested lag filter.
lag3UD :: UGen -> UGen -> UGen -> UGen
lag3UD i t1 t2 = mkFilter "Lag3UD" [i,t1,t2] 1

-- | Last value before chang above threshhold.
lastValue :: UGen -> UGen -> UGen
lastValue i t = mkFilter "LastValue" [i,t] 1

-- | Sample and hold.
latch :: UGen -> UGen -> UGen
latch i t = mkFilter "Latch" [i,t] 1

-- | Remove DC offset.
leakDC :: UGen -> UGen -> UGen
leakDC i coef = mkFilter "LeakDC" [i,coef] 1

-- | Limiter.
limiter :: UGen -> UGen -> UGen -> UGen
limiter i l d = mkFilter "Limiter" [i,l,d] 1

-- | Map from a linear range to an exponential range.
linExp :: UGen -> UGen -> UGen -> UGen -> UGen -> UGen
linExp i sl sh dl dh = mkFilter "LinExp" [i,sl,sh,dl,dh] 1

-- | Lowpass filter.
lpf :: UGen -> UGen -> UGen
lpf i f = mkFilter "LPF" [i,f] 1

-- | Two point average filter.
lpz1 :: UGen -> UGen
lpz1 i = mkFilter "LPZ1" [i] 1

-- | Two zero fixed lowpass filter.
lpz2 :: UGen -> UGen
lpz2 i = mkFilter "LPZ2" [i] 1

-- | Masks off bits in the mantissa of signal.
mantissaMask :: UGen -> UGen -> UGen
mantissaMask i bits = mkFilter "MantissaMask" [i,bits] 1

-- | Median filter.
median :: UGen -> UGen -> UGen
median size i = mkFilter "Median" [size,i] 1

-- | Parametric filter.
midEQ :: UGen -> UGen -> UGen -> UGen -> UGen
midEQ i f rq db = mkFilter "MidEQ" [i,f,rq,db] 1

-- | Moog VCF implementation.
moogFF :: UGen -> UGen -> UGen -> UGen -> UGen
moogFF i f g r = mkFilter "MoogFF" [i,f,g,r] 1

-- | Most changed input.
mostChange :: UGen -> UGen -> UGen
mostChange a b = mkFilter "MostChange" [a,b] 1

-- | Multiply add ternary operator.
mulAdd :: UGen -> UGen -> UGen -> UGen
mulAdd s m a = mkFilter "MulAdd" [s,m,a] 1

-- | Normalizer (flattens dynamics).
normalizer :: UGen -> UGen -> UGen -> UGen
normalizer i l d = mkFilter "Normalizer" [i,l,d] 1

-- | One pole filter.
onePole :: UGen -> UGen -> UGen
onePole i coef = mkFilter "OnePole" [i,coef] 1

-- | One zero filter.
oneZero :: UGen -> UGen -> UGen
oneZero i coef = mkFilter "OneZero" [i,coef] 1

-- | Maximum value.
peak :: UGen -> UGen -> UGen
peak t r = mkFilter "Peak" [t,r] 1

-- | Simple time domain pitch shifter.
pitchShift :: UGen -> UGen -> UGen -> UGen -> UGen -> UGen
pitchShift i w p d t = mkFilter "PitchShift" [i,w,p,d,t] 1

-- | Karplus-Strong synthesis.
pluck :: UGen -> UGen -> UGen -> UGen -> UGen -> UGen -> UGen
pluck i tr mdl dl dc coef = mkFilter "Pluck" [i,tr,mdl,dl,dc,coef] 1

-- | Trigger counter.
pulseCount :: UGen -> UGen -> UGen
pulseCount t r = mkFilter "PulseCount" [t,r] 1

-- | Pass every nth trigger.
pulseDivider :: UGen -> UGen -> UGen -> UGen
pulseDivider t factor start = mkFilter "PulseDivider" [t,factor,start] 1

-- | Linear lag.
ramp :: UGen -> UGen -> UGen
ramp i t = mkFilter "Ramp" [i,t] 1

-- | Resonant highpass filter.
rhpf :: UGen -> UGen -> UGen -> UGen
rhpf i freq rq = mkFilter "RHPF" [i,freq,rq] 1

-- | Resonant lowpass filter.
rlpf :: UGen -> UGen -> UGen -> UGen
rlpf i freq rq = mkFilter "RLPF" [i,freq,rq] 1

-- | Resonant filter.
resonz :: UGen -> UGen -> UGen -> UGen
resonz i freq bwr = mkFilter "Resonz" [i,freq,bwr] 1

-- | Ringing filter (equivalent to Resonz).
ringz :: UGen -> UGen -> UGen -> UGen
ringz i freq dcy = mkFilter "Ringz" [i,freq,dcy] 1

-- | Track maximum level.
runningMax :: UGen -> UGen -> UGen
runningMax i t = mkFilter "RunningMax" [i,t] 1

-- | Track minimum level.
runningMin :: UGen -> UGen -> UGen
runningMin i t = mkFilter "RunningMin" [i,t] 1

-- | Running sum.
runningSum :: UGen -> UGen -> UGen
runningSum i n = mkFilter "RunningSum" [i,n] 1

-- | Select output from array of inputs.
select :: UGen -> UGen -> UGen
select i a = mkFilterMCE "Select" [i] a 1

-- | Send a trigger message from the server back to the all registered clients.
sendTrig :: UGen -> UGen -> UGen -> UGen
sendTrig i k v = mkFilter "SendTrig" [i,k,v] 0

-- | Send a reply message from the server back to the all registered clients.
sendReply :: UGen -> UGen -> String -> [UGen] -> UGen
sendReply i k n v =
    let n' = map (fromIntegral . fromEnum) n
        s = fromIntegral (length n')
    in mkFilter "SendReply" ([i,k,s] ++ n' ++ v) 0

-- | Set-reset flip flop.
setResetFF :: UGen -> UGen -> UGen
setResetFF t r = mkFilter "SetResetFF" [t,r] 1

-- | Wave shaper.
shaper :: UGen -> UGen -> UGen
shaper b s = mkFilter "Shaper" [b,s] 1

-- | Remove transients and higher frequencies.
slew :: UGen -> UGen -> UGen -> UGen
slew i up dn = mkFilter "Slew" [i,up,dn] 1

-- | Second order filter section (biquad).
sos :: UGen -> UGen -> UGen -> UGen -> UGen -> UGen -> UGen
sos i a0 a1 a2 b1 b2 = mkFilter "SOS" [i,a0,a1,a2,b1,b2] 1

-- | Stepper pulse counter.
stepper :: UGen -> UGen -> UGen -> UGen -> UGen -> UGen -> UGen
stepper t r mn mx s v = mkFilter "Stepper" [t,r,mn,mx,s,v] 1

-- | Triggered linear ramp.
sweep :: UGen -> UGen -> UGen
sweep t r = mkFilter "Sweep" [t,r] 1

-- | Control rate trigger to audio rate trigger converter
t2A :: UGen -> UGen -> UGen
t2A i offset = mkOscR [AR] AR "T2A" [i,offset] 1

-- | Audio rate trigger to control rate trigger converter
t2K :: UGen -> UGen
t2K i = mkOscR [KR] KR "T2K" [i] 1

-- | Delay trigger by specified interval.
tDelay :: UGen -> UGen -> UGen
tDelay i d = mkFilter "TDelay" [i,d] 1

-- | Time since last triggered.
timer :: UGen -> UGen
timer t = mkFilter "Timer" [t] 1

-- | Toggle flip flop.
toggleFF :: UGen -> UGen
toggleFF t = mkFilter "ToggleFF" [t] 1

-- | When triggered output trigger for specified duration.
trig :: UGen -> UGen -> UGen
trig i d = mkFilter "Trig" [i,d] 1

-- | When triggered output unit signal for specified duration.
trig1 :: UGen -> UGen -> UGen
trig1 i d = mkFilter "Trig1" [i,d] 1

-- | Two pole filter.
twoPole :: UGen -> UGen -> UGen -> UGen
twoPole i freq radius = mkFilter "TwoPole" [i,freq,radius] 1

-- | Two zero filter.
twoZero :: UGen -> UGen -> UGen -> UGen
twoZero i freq radius = mkFilter "TwoZero" [i,freq,radius] 1

-- | Variable shaped lag.
varLag :: UGen -> UGen -> UGen -> UGen
varLag i t s = mkFilter "VarLag" [i,t,s] 1

-- | Wrap to range.
wrap :: UGen -> UGen -> UGen -> UGen
wrap i j k = mkFilter "Wrap" [i,j,k] 1

-- | Index into a table with a signal.
wrapIndex :: UGen -> UGen -> UGen
wrapIndex b i = mkFilter "WrapIndex" [b,i] 1

-- * BEQ filters

-- | Bi-quad low-pass filter.
bLowPass :: UGen -> UGen -> UGen -> UGen
bLowPass i f rq = mkFilter "BLowPass" [i,f,rq] 1

-- | Bi-quad high-pass filter.
bHiPass :: UGen -> UGen -> UGen -> UGen
bHiPass i f rq = mkFilter "BHiPass" [i,f,rq] 1

-- | Bi-quad all-pass filter.
bAllPass :: UGen -> UGen -> UGen -> UGen
bAllPass i f rq = mkFilter "BAllPass" [i,f,rq] 1

-- | Bi-quad band-pass filter.
bBandPass :: UGen -> UGen -> UGen -> UGen
bBandPass i f bw = mkFilter "BBandPass" [i,f,bw] 1

-- | Bi-quad band-stop filter.
bBandStop :: UGen -> UGen -> UGen -> UGen
bBandStop i f bw = mkFilter "BBandStop" [i,f,bw] 1

-- | Bi-quad peak equaliser.
bPeakEQ :: UGen -> UGen -> UGen -> UGen -> UGen
bPeakEQ i f rq db = mkFilter "BPeakEQ" [i,f,rq,db] 1

-- | Bi-quad low shelf filter.
bLowShelf :: UGen -> UGen -> UGen -> UGen -> UGen
bLowShelf i f rs db = mkFilter "BLowShelf" [i,f,rs,db] 1

-- | Bi-quad high shelf filter.
bHiShelf :: UGen -> UGen -> UGen -> UGen -> UGen
bHiShelf i f rs db = mkFilter "BHiShelf" [i,f,rs,db] 1

-- | Calculate coefficients for bi-quad low pass filter.
bLowPassCoef :: Floating a => a -> a -> a -> (a,a,a,a,a)
bLowPassCoef sr freq rq =
    let w0 = pi * 2 * freq * (1 / sr)
        cos_w0 = cos w0
        i = 1 - cos_w0
        alpha = sin w0 * 0.5 * rq
        b0rz = recip (1 + alpha)
        a0 = i * 0.5 * b0rz
        a1 = i * b0rz
        b1 = cos_w0 * 2 * b0rz
        b2 = (1 - alpha) * negate b0rz
    in (a0,a1,a0,b1,b2)