-- Version 0.2
-- Hist: 0.2 Corrected initial comment
--       0.3 Corrected bug with boundaries with unchecked lower/upper
--       0.4 Corrected bug when other user objects are around

--[[--------------------------------------------------------------------------

This plugin will connect barlines with the staff below. You must specify if the current staff is Upper, Middle or Lower staff in order to draw connections correctly.

--]]--------------------------------------------------------------------------

---- Necessary testcases: 
---- Legend: 
----    B    boundary u/l=with upper/lower value; r=reset 
----    C    connect f=staffsig<>None,n=staffsig=None,s=standard
----    S    collapsible section s=start, f=forbid
----    #    staff breaks
----    $    ending bar
----    |    bar line
----    ...  other things in staff
----    +    expect correctly drawn connect lines
----    -    expect no connect lines
----
---- staffsig/standard working
---- TestC1: Cf ... +# ... +# ... +$
---- TestC2: ... -# ... Cf ... +# ... +# ... +$
---- TestC3: ... -# ... Cf ... +# ... +# ... Cn ... -# ... -$
---- TestC4: ... -# ... -# ... Cs +| ... -| ... -# ... -$
---- TestC5: ... -# ... Cf ... +# ... Cs +| ... -| ... +# ... Cn ... -# ... -$
----
---- boundary working
---- TestB1: Cf ... +# ... Bul(larger) ... +# ... +# ... +# ... +$
---- TestB2: Cf ... +# ... Bul(larger) ... +# ... +# ... Br ... +# ... +$
---- TestB3: Cf ... +# ... Bul(larger) ... +# ... Bul(larger) ... +# ... +$
---- TestB4: Cf ... +# ... Bul(larger) ... +# ... Bul(smaller) ... +# ... +$
---- TestB5: Cf ... +# ... Bul(larger) ... Bul(larger) ... +# ... +$
---- TestB6: Cf ... +# ... Bul(larger) ... Bul(smaller) ... +# ... +$
---- TestB7: Cf ... +# ... Bul(larger) ... +# ... +# ... Br ... Bul(larger) ... +# ... +$
---- TestB8: Cf ... +# ... Bul(larger) ... +# ... +# ... Br ... Bul(smaller) ... +# ... +$
---- TestB9: Cf ... +# ... Bu(larger) ... +# ... +# ... Br ... +# ... +$
----
---- collapsing
---- TestD1: Cf ... +# ... Sc ... +# ... Bul(larger) ... # ... Sf ... +# ... +# ... +$
----
---- TestD2: Cf ... +# ... Sc ... +# ...                               ... +# ... +# ... Sf                      ... +# ... +$
----         Cf ... +# ...    ... +# ... Cf(without conn to collapsed) ... +# ... +# ... Cf(conn to uncollapsed) ... +# ... +$
----
---- TestD3: Cf ... +# ... Sc                             ... +# ... +# ... Sf                      ... +# ... +$
----         Cf ... +# ... Cf(without conn to collapsed)  ... +# ... +# ... Cf(conn to uncollapsed) ... +# ... +$
----
---- top, bottom and middle working 
---- TestE8: Like B8, with top & bottom
---- TestF8: Like B8, with top & middle & bottom

local userObjTypeName = ...
local drawpos = nwcdraw.user

local printedStaffIterator = nwc.drawpos
local fullScoreIterator = nwc.ntnidx.new()
local barToEnlarge = nwc.drawpos.new()

local object_spec = {
{ id='System', label='Staff Location', type='enum', default='Top Staff', list={'Top Staff', 'Middle Staff', 'Bottom Staff', 'None'}},
{ id='Delayed', label='Active after next break (useful if other staff collapses)', type='bool', default=false},
}

local function do_create(t)
  t.Class = 'StaffSig'
end

local function do_draw(t)
  ---- nwc.debug("c0")

	local isStaffSig = (t.Class == 'StaffSig')
  local w = nwc.toolbox.drawStaffSigLabel('ConnectBarLines')
  if not nwcdraw.isDrawing() then return w end

  ---- nwc.debug("c1")
  -- if nwcdraw.getTarget() ~= 'print' then return end
  ------ nwc.debug("c2")

  if drawpos:isHidden() then return end
  ---- nwc.debug("c3")

  local yPosTop
  local yPosBottom 

  local setTopIfNil = function(value, offset)
    ---- nwc.debug("setTopIfNil", value)
    if not yPosTop and value then
      yPosTop = value + offset
    end
  end

  local setBottomIfNil = function(value, offset)
    ---- nwc.debug("setBottomIfNil", value)
    if not yPosBottom and value then
      yPosBottom = value + offset
    end
  end

  local setTopToMax = function(value, offset)
    ---- nwc.debug("setTopToMax", type(yPosTop), type(value), yPosTop, value)
    if value and yPosTop < value + offset then
      yPosTop = value + offset
    end
  end

  local setBottomToMax = function(value, offset)
    ---- nwc.debug("setBottomToMax", type(yPosBottom), type(value), yPosBottom, value)
    if value and yPosBottom < value + offset then
      yPosBottom = value + offset
    end
  end

  local setTopBottom = function(idx,setTop,setBottom)
    if idx:objType() == 'Boundary' and idx:objProp('Style') == 'NewSize' then
      ---- nwc.debug("setTopBottom1", idx:objProp('Upper'), idx:objProp('Lower'))
      setTop(idx:objProp('Upper'), 4)
      setBottom(idx:objProp('Lower'), 4)
      ---- nwc.debug("setTopBottom1r", yPosTop, yPosBottom)
    elseif idx:objType() == 'Boundary' and idx:objProp('Style') == 'Reset' then
      ---- nwc.debug("setTopBottom2", nwcdraw.getStaffProp('BoundaryTop'), nwcdraw.getStaffProp('BoundaryBottom'))
      setTop(nwcdraw.getStaffProp('BoundaryTop'), 0)
      setBottom(nwcdraw.getStaffProp('BoundaryBottom'), 0)
      ---- nwc.debug("setTopBottom2r", yPosTop, yPosBottom)
    elseif idx:objType() == 'Text' then
      ---- nwc.debug("t", idx:objProp('Text'))
    end
  end

  local me = nwcdraw.user

  -- don't do anything when hidden
  if me:isHidden() then return end

  ---- nwc.debug("c4")

  -- also don't do anything when explicitly delayed, and 
  -- we are the "real" (not auto-inserted) one
	if t.Delayed and not me:isAutoInsert() then return end

  ---- nwc.debug("c5")

  -- the actual drawing of staffsig-controlled bar lines is defined by the 
  -- *rightmost* staffsig ConnectBarLines in the printed staff;
  -- so if there is another staffsig item to the right of the current, we dont
  -- do anything (this makes e.g. "None" shut off bar line drawing, even though
  -- there is that autoInserted one at the beginning of the same printed staff)
  -- However, a "delayed" instance is ignored at its actual position (i.e., 
  -- when it is not auto-inserted)
  printedStaffIterator:reset()
  while printedStaffIterator:find('next', user, userObjTypeName) do
    ---- nwc.debug("c5a", printedStaffIterator:objType())
    if printedStaffIterator:userType() == userObjTypeName and printedStaffIterator:objProp('Class') == 'StaffSig' then
      if printedStaffIterator:objProp('Delayed') and not printedStaffIterator:isAutoInsert() then
        -- ignore it
      else
        -- there is an active one to the right - the current instance is not active 
        return
      end
    end
  end

  ---- nwc.debug("c6")

  -- Algorithm for finding the right size to draw:
  -- a. Find boundary values at beginning of printed staff (by running back over score)
  -- b. Find largest values inside printed staff

  -- Step a.
  -- start from the start of the current printed staff 
  printedStaffIterator:reset() -- now at current object (might be in middle of printed staff)
  printedStaffIterator:find('first', 'bar') -- now at beginning of printed staff 

  -- run backwards to find nearest definitions of boundaries
  fullScoreIterator:find(printedStaffIterator)
  while fullScoreIterator:find('prior') do
    setTopBottom(fullScoreIterator,setTopIfNil,setBottomIfNil)
  end

  -- if none found, use staff sizes
  setTopIfNil(nwcdraw.getStaffProp('BoundaryTop'), 0)
  setBottomIfNil(nwcdraw.getStaffProp('BoundaryBottom'), 0)
  ---- nwc.debug("c7", yPosTop, yPosBottom)

  -- Step b.
  printedStaffIterator:reset() -- now at current object
  printedStaffIterator:find('last', 'bar') -- now at last bar but one
  printedStaffIterator:find('next', 'bar') -- now at last bar

  -- run over printed staff to find maximum
  while printedStaffIterator:find('prior') do
    setTopBottom(printedStaffIterator,setTopToMax,setBottomToMax)
  end
  -- yPosTop and yPosBottom are now correctly set
  
  -- Find the bar that is to be enlarged
  local found
  barToEnlarge:reset() -- now at current object
  if isStaffSig then
    barToEnlarge:find('last', 'bar') -- now at last bar but one
    found = barToEnlarge:find('next', 'bar') -- now at last bar
  else
    found = barToEnlarge:find('next', 'bar') -- now at next bar
  end
    
  if found then 
    -- we found a bar - finally draw the enlargement lines
    local x,y = barToEnlarge:xyAnchor()
    local barType = barToEnlarge:objProp('Style')

    if t.System == 'Top Staff' then
      nwcdraw.moveTo(x,y)
      nwcdraw.barSegment(barType,y-4,y-yPosBottom)
    elseif t.System == 'Middle Staff' then
      nwcdraw.moveTo(x,y)
      nwcdraw.barSegment(barType,y+yPosTop,y+4)
      nwcdraw.moveTo(x,y)
      nwcdraw.barSegment(barType,y-4,y-yPosBottom)
    elseif t.System == 'Bottom Staff' then
      nwcdraw.moveTo(x,y)
      nwcdraw.barSegment(barType,y+yPosTop,y+4)
    end
  end
end

return {
  spec  = object_spec,
  create  = do_create,
  width  = do_draw,
  draw  = do_draw,
}