showcase.flow

use "@std"
use "@audio"
use "@composition"

(print "Flow Showcase -- v1.3 Polyrhythmic Minimal")
(print "Generating examples/output/flow_showcase.{wav,mid} ...")

tempo 120 {
    timesig 4/4 {
        key Cmajor {

            // Dict-driven drum kit -- Symbol keys with INSERTION-ORDER iteration (DICT-03).
            // Construct in the order you want iteration to happen: kick -> snare -> hihat.
            Dict<Symbol, Note> kit = (dict #kick C2 #snare D2 #hihat F#3)

            // Tuplet groove leading the genre -- {3:2 ...}q triplets on beats 1 and 3
            // against straight kicks on the off-beats. Polyrhythmic feel without losing the downbeat.
            // No ties INSIDE tuplet brackets (RESEARCH Pitfall 3 -- the 100ms tied-overlap can
            // over-extend short tuplet members; safest form is plain notes inside the bracket).
            Sequence drumTriplets = | {3:2 _ C2 _}q C2 {3:2 _ C2 D2}q C2 |

            // Sparse euclidean drum on the kick -- humanized, fixed seed for byte-identical reruns.
            Sequence drums = (euclidean 5 16 (get kit #kick) 0.18 0.12 7)

            // Soft mezzo-piano melody humanized via Gaussian -- fixed seed for byte-identical reruns.
            Sequence melody = (humanizeGaussian | mp _ _ E5q G5q | A5h E5h | _ _ G5q B5q | A5w | 0.08 314)

            // Ambient pad bed -- long whole notes outline the I / IV / V / I shape
            Sequence pad = | C4w | F4w | G4w | C4w |

            // Progression DSL demo (D-12) -- voice-led I / IV / V / I in the active key.
            // NON-RENDERED on purpose: progDemo is NOT fed into `section showcase` or the
            // Song below, so the pinned flow_showcase.wav stays byte-identical. This line
            // just shows the `progression | ... |` surface alongside the hand-written pad
            // (voice-led chords differ from the pad's root whole-notes).
            Sequence progDemo = progression | I IV V I |
            (print "Progression DSL demo: progression | I IV V I | (voice-led, non-rendered)")

            section showcase {
                Sequence groove = drums
                Sequence triplets = drumTriplets
                Sequence lead = melody
                Sequence bed = pad
            }

            Song piece = [showcase]
            Buffer rawMix = (renderSong piece "strings")

            // Phase 26.2 audible features chained on the rendered Buffer (per D-103):
            //   1. (lowpass _ 1.2kHz)  Hertz literal -- filter sweep tightens the top
            //   2. (delay _ 250ms _ _) Ms-typed delay -- adds a quarter-note slap
            //   3. (reverb _ 0.5 1.8s) Second-decay reverb -- 1.8s tail
            //   4. (volume _ 0.7)      linear post-render trim (NOT gain -- gain is dB)
            Buffer filtered = rawMix -> (lowpass 1.2kHz)
            Buffer delayed = filtered -> (delay 250ms 0.5 0.4)
            Buffer reverbed = delayed -> (reverb 0.5 1.8s)
            Buffer finalMix = (volume reverbed 0.7)

            (writeWav "examples/output/flow_showcase.wav" finalMix)
            (writeMidi "examples/output/flow_showcase.mid" piece)
        }
    }
}

(print "WAV:  examples/output/flow_showcase.wav")
(print "MIDI: examples/output/flow_showcase.mid")