--- ${PACKAGE_NAME}
-- @file-author@
-- @project-revision@ @project-hash@
-- @file-revision@ @file-hash@
-- Created: 3/30/2016 12:49 AM
local B = select(2,...).frame
local ipairs, max, min, unpack, floor, pairs, tostring, type = ipairs, max, min, unpack, floor, pairs, tostring, type
local IsResting, UnitXP, UnitXPMax, GetXPExhaustion = IsResting, UnitXP, UnitXPMax, GetXPExhaustion
local UnitLevel, IsQuestWatched, UIParent = UnitLevel, IsQuestWatched, UIParent
local CreateFrame = CreateFrame
local mod = B:RegisterModule("ObjectiveTracker", _G.VeneerObjectiveWrapper, 'BuffFrame')
local print = B.print('Objectives')
--------------------------------------------------------------------
--- Global frame layout
--------------------------------------------------------------------

--- Upvalues
local Wrapper = VeneerObjectiveWrapper
local Scroller = Wrapper.scrollArea
local Scroll = VeneerObjectiveScroll
local orderedHandlers = mod.orderedHandlers
local orderedNames = mod.orderedNames

--- Temp values set during updates
local wrapperWidth, wrapperHeight
local scrollWidth, scrollHeight
local previousBlock
local currentBlock
--- todo: map these into config table when its sorted out
local titleFont, textFont = [[Interface\Addons\SharedMedia_MyMedia\font\ArchivoNarrow-Bold.ttf]], [[Interface\Addons\SharedMedia_MyMedia\font\ArchivoNarrow-Regular.ttf]]
local titleSize, textSize = 15, 15
local titleOutline, textOutline = "OUTLINE", "OUTLINE"
local titleSpacing, textSpacing = 4, 3
local textIndent = 5
local wrapperMaxWidth, wrapperMaxHeight = 280, 490 -- these are the hard bounds, actual *Height variables are changed
local wrapperHeadFont, wrapperHeadSize, wrapperHeadOutline = [[Interface\Addons\SharedMedia_MyMedia\font\ArchivoNarrow-Bold.ttf]], 16, 'NONE'
local headerFont, headerSize, headerHeight = [[Interface\Addons\SharedMedia_MyMedia\font\ArchivoNarrow-Bold.ttf]], 18, 24
local headerOutline, headerColor, headerSpacing = 'OUTLINE', {1,1,1,1}, 2
local wrapperPosition = {'RIGHT', UIParent, 'RIGHT', -84, 0}

--- These are mostly aesthetic choices so it lives here
mod.defaults = {
  ObjectiveTrackerAnchor = {'BOTTOM', 'RIGHT'},
  ObjectiveTrackerParent = 'DebuffButton',
  ObjectiveTrackerSize = {250, 600},
  ObjectiveWrapperParent = '',
  WrapperStyle = {
    Header = {
      Background = {Left = [[Objective-Header]], Right = [[Objective-Header]], Tile = [[Objective-Header]]},
      BackgroundCrop = {Left = {0, 0.4, 0,1}, Right={0.6,1,0,1}, Tile = {0.4,.6,0,1,}},
      BackgroundScale = {Left = 100, Right = 100},
      Font = {wrapperHeadFont, wrapperHeadSize, wrapperHeadOutline}
    }
  },
  ObjectiveHeaderStyle = {
    Normal = {
      Gradient = {MinColor = {0,0,0,0.5}, MaxColor = {0,0,0,.25}},
      Font = {headerFont, headerSize, headerOutline}, Spacing = headerSpacing,
    }
  },
  ObjectiveTrackerStyle = {
    Normal = {
      Title = {
        Gradient = { MinColor = {0.2, .4, 1, 0.45}, MaxColor = {.7, 0, 0.9, 0}},
        Font = {titleFont, titleSize, titleOutline}, Spacing = titleSpacing,
      },
      Text = {
        Gradient = { MinColor = {0.2, .4, 1, 0.25}, MaxColor = {.7, 0, 0.9, 0}},
        Font = {textFont, textSize, textOutline}, Spacing = textSpacing,
      },
    },
    Super = {
      Title = {
        Gradient = { MinColor = {0, .7, .6, .8}, MaxColor = {0, .7, .6, 0.2}},
        Font = {titleFont, titleSize, titleOutline},
        Spacing = titleSpacing, BackgroundFullWidth = true
      },
      Text = {
        Gradient = { MinColor = {0, .7, .6, 0.5}, MaxColor = {0, .7, .6, 0.1} },
        Font = {textFont, textSize, textOutline}, Spacing = textSpacing,
      },
    },
    Active = {
      Title = {
        Gradient = {          MinColor = {0.2, .4, 1, 1}, MaxColor = {0.2, .4, 1, 1},        },
        Font = {titleFont, titleSize, titleOutline},
        Spacing = titleSpacing,
        BackgroundFullWidth = true
      },
      Text = {
        Gradient = {          MinColor = {0.2, .4, 1, 1}, MaxColor = {0.2, .4, 1, 1},        },
        Font = {textFont, textSize, textOutline},
        Spacing = textSpacing,
        BackgroundFullWidth = true
      }
    },
    Complete = {
      Title = {
        Gradient = {          MinColor = {0, 1, 0, 0.34},          MaxColor = {0, 1, 0, .17},        },
        Font = {titleFont, titleSize, titleOutline},        Spacing = titleSpacing,
        BackgroundFullWidth = true
      },
      Text = {
        Gradient = {          MinColor = {0, 1, 0, .25},          MaxColor = {0, 1, 0, 0.12},        },
        Font = {textFont, textSize, textOutline},        Spacing = textSpacing,
        BackgroundFullWidth = true
      }
    },
  }
}

local FontBank = {
  ['Normal'] = VeneerCriteriaFontNormal,
  ['Progress'] = VeneerCriteriaFontProgress,
  ['Complete'] = VeneerCriteriaFontComplete,
  ['Failed'] = VeneerCriteriaFontFailed,
}

local Scroller_OnShow = function()
  Wrapper.watchMoneyReasons = 0;
  mod.UpdateWrapper()
  mod.SetEvents()
  for i, region in ipairs(Wrapper.header) do
    region:Show()
  end
end

local Scroller_OnHide = function()
  local self = Wrapper
  Wrapper:UnregisterAllEvents()
  Wrapper:SetScript('OnEvent', nil)
  for i, region in ipairs(Wrapper.header) do
    region:Hide()
  end
end

local Scroller_OnMouseWheel = function(self, delta)
  local r = Scroll:GetHeight() - Scroller:GetHeight()
  local s = self:GetVerticalScroll() - delta * floor(r/5+.5)
  if r == 0 then return end
  if s >= r then
    s = r
  elseif s < 1 then
    s = 0
  end
  self:SetVerticalScroll(s)
  print(s, r, self:GetVerticalScroll())

  mod.UpdateActionButtons()
end

local WrapperCloseButton_OnClick = function(self)
  if Scroller:IsVisible() then
    Scroller:Hide()
  else
    Scroller:Show()
  end
end

mod.InitializeTrackers = function()

  local c = mod.defaults.ObjectiveHeaderStyle.Normal
  local g1, g2, g3, g4 = unpack(c.Gradient.MinColor)
  local h1, h2, h3, h4 = unpack(c.Gradient.MaxColor)

  for i, name in ipairs(orderedNames) do
    if not mod.orderedHandlers[i] then
      if mod.Tracker(name, i) then
        local handler = mod[name]

        local tracker = CreateFrame('Frame', 'Veneer'..name..'Tracker', Scroll, 'VeneerTrackerTemplate')
        tracker.header:SetText(handler.name)
        tracker.header:SetHeight(headerHeight)
        tracker.header:SetFont(unpack(c.Font))
        tracker.header:SetTextColor(unpack(headerColor))

        tracker.headerbg:SetGradientAlpha('HORIZONTAL', g1, g2 ,g3, g4, h1, h2, h3, h4)
        tracker.headerbg:SetHeight(headerHeight)

        handler.Tracker = tracker
        mod.orderedTrackers[i] = tracker
        mod.namedTrackers[name] = tracker
        mod.indexedTrackers[handler] = tracker
        print('created new tracker frames for new handler')
      end
    end
  end

  Scroller:SetScrollChild(Scroll)
  Scroller:SetScript('OnMouseWheel', Scroller_OnMouseWheel)
  Scroller:SetScript('OnShow', Scroller_OnShow)
  Scroller:SetScript('OnHide', Scroller_OnHide)
  Wrapper.close:SetScript('OnClick', WrapperCloseButton_OnClick)
  Wrapper:SetPoint(unpack(wrapperPosition))
  Scroller_OnShow(Scroller)

  mod.UpdateWrapperStyle()
end

mod.InitializeXPTracker = function()
  local XPBar = Wrapper.XPBar
  if UnitLevel('player') == 100 then
    XPBar:Hide()
    return
  end

  --- xp bar
  XPBar:Show()
  XPBar.rested:SetTexture(2,.6,1,1)
  XPBar.fg:SetTexture(.3,.1,.95,1)
  XPBar.bg:SetTexture(0,0,0,.25)
  XPBar:RegisterEvent('PLAYER_XP_UPDATE')
  XPBar:RegisterEvent('PLAYER_LEVEL_UP')
  XPBar:RegisterEvent('PLAYER_UPDATE_RESTING')
  XPBar:SetScript('OnEvent', mod.UpdateXP)
  mod.UpdateXP(Wrapper.xpBar)
end

mod.UpdateXP = function()
  local XPBar = Wrapper.XPBar
  local xp = UnitXP('player')
  local xpmax = UnitXPMax('player')
  local rest = GetXPExhaustion()

  XPBar.bg:SetAllPoints(XPBar)
  XPBar.fg:SetWidth((xp/xpmax) * XPBar:GetWidth())

  if IsResting() then
    XPBar.bg:SetTexture(.2,.8,.2,.5)
  else
    XPBar.bg:SetTexture(0,0,0,.25)
  end

  if rest then
    XPBar.rested:ClearAllPoints()
    if xp == 0 then
      XPBar.rested:SetPoint('TOPLEFT', XPBar, 'TOPLEFT', 0, 0)
    else
      XPBar.rested:SetPoint('TOPLEFT', XPBar.fg, 'TOPRIGHT', 0, 0)
    end

    if (xp + rest) > xpmax then
      XPBar.rested:SetPoint('BOTTOMRIGHT', XPBar, 'BOTTOMRIGHT', 0, 0)
    else
      XPBar.rested:SetWidth((rest/xpmax) * XPBar:GetWidth())
    end
    XPBar.rested:SetPoint('BOTTOM', XPBar, 'BOTTOM')
    XPBar.rested:Show()
  else
    XPBar.rested:Hide()
  end

  XPBar.xpText:SetText(xp .. '/'.. xpmax .. (rest and (' ('..tostring(rest)..')') or ''))
end

mod.UpdateReputation = function(self)
end

--- Argument containers
local a1, a2, a3, a4, b1, b2, b3, b4, f1, f2, f3, w1, w2
mod.SetBlockStyle = function(block, name)
  -- var names intended to reflect argument order
  --@debug@
  local c = mod.defaults.ObjectiveTrackerStyle[name]
  --@end-debug@
  --[===[@non-debug
  local c = mod.Conf
  --@end-non-debug]===]
  a1, a2, a3, a4 = unpack(c.Title.Gradient.MinColor)
  b1, b2, b3, b4 = unpack(c.Title.Gradient.MaxColor)
  block.titlebg:SetGradientAlpha('HORIZONTAL', a1, a2, a3, a4, b1, b2, b3, b4)

  a1, a2, a3, a4 = unpack(c.Text.Gradient.MinColor)
  b1, b2, b3, b4 = unpack(c.Text.Gradient.MaxColor)
  block.bg:SetGradientAlpha('HORIZONTAL', a1, a2, a3, a4, b1, b2, b3, b4)

  f1, f2, f3 = unpack(c.Title.Font)
  block.title:SetFont(f1, f2, f3)

  f1, f2 ,f3 = unpack(c.Text.Font)
  block.objectives:SetFont(f1,f2,f3)

  w1 = Wrapper:GetWidth()
  w2 = (c.Title.BackgroundFullWidth and w1 or  block.title:GetStringWidth())

  local titleSpacing, titleSpacing2 = c.Title.Spacing, (c.Title.Spacing * 2)
  local textSpacing, textSpacing2 = c.Text.Spacing, (c.Text.Spacing * 2)

  if block.info.isTrivial then
    block.title:SetTextColor(0.7, 0.7, 0.7, 1)
  elseif block.info.isComplete then
    block.title:SetTextColor(1,1,1,1)
  else
    block.title:SetTextColor(0,.7,1,1)
  end
  block.title:SetSpacing(titleSpacing)
  block.objectives:SetSpacing(textSpacing)
  block.objectives:SetWordWrap(true)

  local titleHeight, textHeight = block.title:GetStringHeight(), block.objectives:GetStringHeight()
  local blockHeight = titleHeight + titleSpacing2 + textHeight + textSpacing2
  local blockWidth = wrapperMaxWidth

  block.titlebg:SetSize(min(w1, w2), titleHeight + titleSpacing2)
  block.bg:SetSize(w1, textHeight + textSpacing2)
  block:SetSize(blockWidth, blockHeight)

  block.title:SetPoint('TOPLEFT', block.titlebg, 'TOPLEFT', 0, -titleSpacing)
  block.objectives:SetPoint('TOPLEFT', block.titlebg, 'BOTTOMLEFT', textIndent, -textSpacing)

  -- store
  block.titleHeight = titleHeight
  block.textHeight = textHeight
  block.width = blockWidth
  block.height = blockHeight

  print('    |cFF00FFFF'..block:GetName()..'|r:|cFF0088FFSetStyle|r(', blockWidth, 'x', blockHeight, '(textH', textHeight,', titleH', titleHeight, ')')
end

local segments = {'Left', 'Right', 'Tile'}
mod.UpdateWrapperStyle = function()
  local c = mod.defaults.WrapperStyle
  for _, segment in ipairs(segments) do
    Wrapper['Background'..segment]:SetAtlas(c.Header.Background[segment])
    Wrapper['Background'..segment]:SetTexCoord(unpack(c.Header.BackgroundCrop[segment]))
    if c.Header.BackgroundScale[segment] then
    Wrapper['Background'..segment]:SetWidth(c.Header.BackgroundScale[segment])
    end
  end
end

--- Updates the selected block frame to display the given info batch
-- If `previousBlock` is set, it will attempt to anchor to that
-- @param blockNum the ordered block to be updated, not a watchIndex value
-- @param info the reference returned by the GetXInfo functions
-- REMEMBER: t.info and questData[questID] are the same table
mod.UpdateTrackerBlock = function (handler, blockIndex, info)
  print('  |cFF00FFFFUpdateTrackerBlock('..blockIndex..'|r')
  if not blockIndex or not info then
    return
  end

  local tracker = handler.Tracker

  local t = handler:GetBlock(blockIndex)
  if previousBlock then
    if blockIndex == 1 then
      t:SetPoint('TOPLEFT', previousBlock, 'TOPLEFT', 0, -headerHeight)
    else
      t:SetPoint('TOPLEFT', previousBlock, 'BOTTOMLEFT', 0, 0)
    end
    t:SetPoint('RIGHT', tracker,'RIGHT', 0, 0)
  end
  --print(t:GetName(), t:GetSize())
  --print(t:GetPoint(1))

  t.info = info

  if info.questID then handler.QuestBlock[info.questID] = t end
  if info.questLogIndex then handler.LogBlock[info.questLogIndex] = t end
  if info.watchIndex then handler.WatchBlock[info.watchIndex] = t end

  info.blockIndex = blockIndex
  handler.BlockInfo[blockIndex] = info
  t.Select = handler.Select
  t.Open = handler.Open
  t.Remove = handler.Remove
  t.Link = handler.Link
  t:SetScript('OnMouseUp', handler.OnMouseUp)
  t:SetScript('OnMouseDown', handler.OnMouseDown)
  t.title:SetText(info.title)

  if info.isComplete then
    t.objectives:Show()
    t.objectives:SetText(info.completionText)
  elseif info.numObjectives >= 1 then
    t.objectives:Show()
    print('  - objective lines:', info.numObjectives, 'can wrap:', t.objectives:CanWordWrap())

    local text = ''
    if info.description then
      print('  -- has description text:', select('#', info.description), info.description)
      text = info.description
    end

    --- todo: implement objective displays
     -- in an accumulator loop, call upon handler for the appropriate display frame, each defining:
      -- * height of whatever display widget is involved in conveying the task
      -- * number of non-wrapped text lines to account for line space; may be discarded depending on things
      -- * boolean that determines listening for money events or not
    t.attachmentHeight, text = mod.UpdateObjectives(t, info, text)

    t.objectives:SetText(text)
    t.objectives:SetWordWrap(true)



  elseif info.description then
    t.objectives:SetText(info.description)
    t.objectives:SetWordWrap(true)
  else
    t.objectives:SetText(nil)
  end
  local style = 'Normal'
  if info.isComplete then
    style = 'Complete'
  elseif info.superTracked then
    style = 'Super'
  end

  if info.specialItem and not info.itemButton then
    print('  - |cFF00FFFFgenerating item button for info set')
    info.itemButton = mod.SetItemButton(t, info)
  else
    --info.itemButton = nil
  end

  --- metrics are calculated in SetStyle
  t:SetStyle(style)
  t:Show()

  print('  |cFF00FFFF)|r -> ', t, t:GetHeight())
  return t
end

mod.UpdateObjectives = function(block, info, text)
  local attachmentHeight = 0
  for o, obj in ipairs(info.objectives) do
    --- achievement criteria
    if obj.flags then


      if bit.band(obj.flags, 0x00000001) > 0 then
        obj.type = 'ProgressBar'
        obj.widget = mod.SetWidget(obj, info)
      elseif bit.band(obj.flags, 0x00000002) then
        obj.type = 'Hidden'
        obj.widget = nil
      else
        obj.type = 'Text'
        obj.widget = nil
        text = text .. ((text == '') and "" or "\n") .. obj.text
      end

      print(obj.type, obj.text, obj.quantityString)
      --- none of the above (most quests)
    else
      local line = obj.text
      local color = '00FFFF'
      if obj.finished then
        color = 'FFFFFF'
      elseif obj.type == 'monster' then
        color = 'FFFF00'
      elseif obj.type == 'item' then
        color = '44DDFF'
      elseif obj.type == 'object' then
        color = 'FF44DD'
      end
      text = text .. ((text == '') and "" or "\n") .. '|cFF'..color.. line .. '|r'
    end

    if obj.widget then
      attachmentHeight = attachmentHeight + obj.widget.height
    end

  end
  return attachmentHeight, text
end

mod.UpdateTracker = function(handler)
  print('|cFF00FF88UpdateTracker(|r|cFFFF4400' .. type(handler) .. '|r :: |cFF88FFFF' .. tostring(handler) .. '|r')
  local tracker = handler.Tracker
  local blockIndex = 0
  local trackerHeight = headerHeight
  local w = 300

  previousBlock = handler.Tracker
  local numWatched = handler.GetNumWatched()
  local numBlocks = handler.numBlocks
  local actualBlocks = handler.actualBlocks
  for watchIndex = 1, 25 do
    blockIndex = blockIndex + 1
    if watchIndex <= numWatched then
      local info = handler:GetInfo(watchIndex)
      if info then
        local currentBlock = mod.UpdateTrackerBlock(handler, blockIndex, info)
        previousBlock = currentBlock
        trackerHeight = trackerHeight + currentBlock.height
        numBlocks = max(numBlocks, watchIndex)
        actualBlocks = actualBlocks + 1
      else
        print('|cFFFF0000Failed to draw info for index #'..watchIndex)
      end

    elseif watchIndex <= numBlocks then
      local used = handler.usedBlocks
      local free = handler.freeBlocks
      print('clean up dead quest block')
      if used[blockIndex] then
        used[blockIndex]:Hide()
        used[blockIndex]:ClearAllPoints()
        free[#free+1]= used[blockIndex]
        used[blockIndex] = nil
      end
    else
      print('Stopping scan at', blockIndex)
      break -- done with quest stuff
    end
  end
  handler.numWatched = numWatched
  handler.numBlocks = numBlocks
  handler.actualBlocks = actualBlocks
  handler:Report()
  previousBlock = nil
  if numBlocks > 0 then
    tracker.height = trackerHeight
  else
    tracker.height = 0
  end

  print('|cFF00FF88)|r ->', numBlocks, 'blocks; height', tracker.height, 'last block: ')
end

mod.Quest.numButtons = 0
local usedButtons = mod.Quest.itemButtons
local freeButtons = mod.Quest.freeButtons
mod.UpdateWrapper = function()
  wrapperWidth = wrapperMaxWidth
  scrollWidth = wrapperWidth
  local wrapperBlocks = 0
  -- Update scroll child vertical size
  scrollHeight = 0
  for i, handler in ipairs(orderedHandlers) do
    mod.UpdateTracker(handler)
    if handler.actualBlocks >= 1 then
      local tracker = handler.Tracker
      print('setting', handler.Tracker, 'to anchor to offset', -scrollHeight)
      tracker:SetParent(Scroll) -- this doesn't do anything that relativeTo doesn't
      tracker:SetPoint('TOPLEFT', Scroll, 'TOPLEFT', 0, - scrollHeight)
      tracker:SetSize(wrapperWidth, tracker.height)
      print('adding ', tracker.height)
      scrollHeight = scrollHeight + tracker.height
    end
    wrapperBlocks = wrapperBlocks + handler.actualBlocks
  end
  print('final scrollHeight:', scrollHeight)



  -- Update frame dimensions
  if scrollHeight > wrapperMaxHeight then
    print('  is larger than', wrapperMaxHeight)
    --ScrollBar:Show()
    --scrollWidth = wrapperMaxWidth - scrollBarWidth
    wrapperHeight = wrapperMaxHeight
    -- Make ThumbTexture reflect the viewing scale (smaller for longer scroll, bigger for shorter)
    --ScrollBar:GetThumbTexture():SetHeight((wrapperMaxHeight/scrollHeight) * (wrapperMaxHeight))
    --ScrollBar:SetWidth(scrollBarWidth)
    --ScrollBar:SetPoint('TOPRIGHT', Scroller, 'TOPRIGHT', 0, 0)
    --ScrollBar:SetPoint('BOTTOMLEFT', Scroller, 'BOTTOMRIGHT', -scrollBarWidth, 0)
    --ScrollBar:SetMinMaxValues(1, scrollHeight - wrapperMaxHeight)
  else
    --ScrollBar:Hide()
    wrapperHeight = scrollHeight
  end
  scrollWidth = floor(scrollWidth+.5)
  scrollHeight = floor(scrollHeight+.5)
  wrapperWidth = floor(wrapperWidth+.5)
  wrapperHeight = floor(wrapperHeight+.5)
  headerHeight = floor(headerHeight+.5)

  if wrapperBlocks >= 1 then
    for i, region in ipairs(Wrapper.header) do
      region:Show()
    end
  else
    for i, region in ipairs(Wrapper.header) do
      region:Hide()
    end
    return
  end
  --wrapperHeight = scrollHeight

  print('|cFFFFFF00params:|r scroller:', scrollWidth, 'x', scrollHeight)
  print('|cFFFFFF00params:|r scroll:', scrollWidth, 'x', scrollHeight)
  print('|cFFFFFF00params:|r wrapper:', wrapperWidth, 'x', wrapperHeight)
  print('|cFFFFFF00params:|r header:', headerHeight)

  Scroller:SetSize(wrapperWidth, wrapperHeight)
  Scroller:SetPoint('TOPLEFT', Wrapper, 'TOPLEFT', 0, -headerHeight)
  Scroller:SetPoint('BOTTOMRIGHT', Wrapper, 'BOTTOMRIGHT')

  Scroll:SetSize(scrollWidth, scrollHeight)
  Scroll:SetPoint('TOPLEFT', Scroller, 'TOPLEFT', 0, 0)
  Scroll:SetPoint('RIGHT', Scroller, 'RIGHT')

  --Scroller:UpdateScrollChildRect()
  Wrapper:SetSize(wrapperWidth, wrapperHeight + headerHeight)

  -- update action buttons


  print('scroll size:', Scroll:GetSize())
  print('scroller size:',Scroller:GetSize())
  print('wrapper size:', Wrapper:GetSize())
  print('scroll range :', floor(Scroller:GetVerticalScrollRange()+.5))


  mod.UpdateActionButtons()
end

--- Queue any active item buttons for update for that frame
mod.UpdateActionButtons = function()
  local previousItem
  for questID, itemButton in pairs(usedButtons) do
    local questIndex = mod.Quest.Info[questID].questLogIndex
    print('|cFF00FFFF'.. questID .. '|r', itemButton:GetName())
    local block = mod.Quest.QuestBlock[questID]
    if block then
        -- Dispatch the probe
      if IsQuestWatched(questIndex) then

        print('  |cFFFFFF00probing', block:GetName())
        block:SetScript('OnUpdate', function()
          if block:GetBottom() and not InCombatLockdown() then
            print('  '..block:GetName()..' |cFF00FF00probe hit!')
            mod.UpdateBlockAction(block, itemButton, previousItem)
            block:SetScript('OnUpdate', nil)
          end
        end)
      else
        print('hidden block or unwatched quest')
        itemButton:Hide()
      end
    else
      print('  |cFFFF0088missing block data', itemButton:GetName())
    end
  end
end

mod.UpdateBlockAction = function (block, itemButton, previousItem)
  print('**|cFF0088FF'..itemButton:GetName(), '|r:Update()')
  if itemButton.questID ~= block.info.questID then
    print('** |cFFFF0088mismatched block assignment', itemButton.questID,'<~>', block.info.questID)

    return mod.UpdateActionButtons()
  end

  if block:GetBottom() < Scroller:GetBottom() then
    print('** ',block:GetName() ,'|cFFFFFF00bottom not fully visible')
    if previousItem then
      previousItem:ClearAllPoints()
      previousItem:SetPoint('BOTTOM', itemButton, 'TOP', 0, 4)
    end
    itemButton:ClearAllPoints()
    itemButton:SetPoint('BOTTOMRIGHT', UIParent, 'BOTTOMLEFT', Wrapper:GetLeft(), Wrapper:GetBottom())
    itemButton:Show()
  else
    print('** ',block:GetName() ,'|cFF00FF00visible positions')
    itemButton:ClearAllPoints()
    itemButton:SetPoint('TOPRIGHT', UIParent, 'BOTTOMLEFT', block:GetLeft(), block:GetTop())
    itemButton:Show()
  end
end

mod.UpdateItemButtonCooldown = function(button)

end