prototype.lua

wezterm.on('show-or-hide-overlay', function(window, pane)
  wezterm.log_info 'Event: show-or-hide-terminal'
  local overlay_pane_ids = wezterm.GLOBAL.overlay_pane_ids
  local tab_old_pane_ids = {}
  local found = false

  if overlay_pane_ids then
    local active_tab = window:active_tab()

    for _, pane_with_info in pairs(active_tab:panes_with_info()) do
      local pane_id = pane_with_info.pane:pane_id()
      table.insert(tab_old_pane_ids, pane_id)

      if overlay_pane_ids[tostring(pane_id)] then
        found = true
  
        local pixel_width = pane_with_info.pixel_width;
        local pixel_height = pane_with_info.pixel_height;

        wezterm.log_info('Found overlay pane ' .. tostring(pane_id) .. ', height = ' .. pixel_height)
  
        local action = act.AdjustPaneSize { 'Down', 1 }
        window:perform_action(action, pane_with_info.pane)
      end
    end
  end

  if not found then
    wezterm.log_info('NOT Found overlay pane, create a new one')
    local active_pane = window:active_tab():active_pane()
    local new_pane = active_pane:split {
      direction = 'Bottom',
      args = { 'bash' },
      size = 0.5,
      top_level = true
    }

    local new_pane_id = new_pane:pane_id()
    wezterm.log_info('Created new pane with id ' .. tostring(new_pane_id))
    if not overlay_pane_ids then
      overlay_pane_ids = {}
    end
    overlay_pane_ids[tostring(new_pane_id)] = true
    wezterm.GLOBAL.overlay_pane_ids = overlay_pane_ids

    -- pane:split { direction = 'Bottom', top_level = true }
    -- window:perform_action(wezterm.action.SplitPane {
    --   direction = 'Bottom',
    --   command = { args = { 'bash' } },
    --   size = { Percent = 40 },
    --   top_level = true
    -- })
  end
end)