-- DreamStack Step Sequencer
-- Collaborative beat grid: two tabs, same pads, real-time sync

let bpm = 120
let step = 0

-- 4 instruments × 8 steps = 32 pads (flat array, index with row*8+col)
let pads = [0, 0, 0, 0, 0, 0, 0, 0,
            0, 0, 0, 0, 0, 0, 0, 0,
            0, 0, 0, 0, 0, 0, 0, 0,
            0, 0, 0, 0, 0, 0, 0, 0]

-- Playhead advances every beat
every (60000 / bpm / 2) -> step = (step + 1) % 8

-- Stream for multiplayer
stream sequencer on "ws://localhost:9100/source/beats" { mode: signal }

view sequencer =
  column [
    text "DreamStack Beats"
    text "BPM: {bpm}"

    -- Kick (pads 0-7)
    text "Kick"
    row [
      for i in [0, 1, 2, 3, 4, 5, 6, 7] ->
        button (if pads[i] then "●" else "○") {
          click: pads[i] = if pads[i] then 0 else 1
        }
    ]

    -- Snare (pads 8-15)
    text "Snare"
    row [
      for i in [8, 9, 10, 11, 12, 13, 14, 15] ->
        button (if pads[i] then "●" else "○") {
          click: pads[i] = if pads[i] then 0 else 1
        }
    ]

    -- Hi-hat (pads 16-23)
    text "HiHat"
    row [
      for i in [16, 17, 18, 19, 20, 21, 22, 23] ->
        button (if pads[i] then "●" else "○") {
          click: pads[i] = if pads[i] then 0 else 1
        }
    ]

    -- Bass (pads 24-31)
    text "Bass"
    row [
      for i in [24, 25, 26, 27, 28, 29, 30, 31] ->
        button (if pads[i] then "●" else "○") {
          click: pads[i] = if pads[i] then 0 else 1
        }
    ]

    -- Playhead indicator
    row [
      for i in [0, 1, 2, 3, 4, 5, 6, 7] ->
        text (if i == step then "▼" else "·")
    ]

    -- BPM controls
    row [
      button "−10" { click: bpm -= 10 }
      text "{bpm}"
      button "+10" { click: bpm += 10 }
    ]
  ]