battleWindow = nil
battleButton = nil
battlePanel = nil
filterPanel = nil
toggleFilterButton = nil
lastBattleButtonSwitched = nil
battleButtonsByCreaturesList = {}
creatureAgeList = {}

mouseWidget = nil

sortTypeBox = nil
sortOrderBox = nil
hidePlayersButton = nil
hideNPCsButton = nil
hideMonstersButton = nil
hideSkullsButton = nil
hidePartyButton = nil

function init()
  g_ui.importStyle('battlebutton')
  battleButton = modules.client_topmenu.addRightGameToggleButton('battleButton', tr('Battle') .. ' (Ctrl+B)', '/images/topbuttons/battle', toggle)
  battleButton:setOn(true)
  battleWindow = g_ui.loadUI('battle', modules.game_interface.getRightPanel())
  g_keyboard.bindKeyDown('Ctrl+B', toggle)

  -- this disables scrollbar auto hiding
  local scrollbar = battleWindow:getChildById('miniwindowScrollBar')
  scrollbar:mergeStyle({ ['$!on'] = { }})

  battlePanel = battleWindow:recursiveGetChildById('battlePanel')

  filterPanel = battleWindow:recursiveGetChildById('filterPanel')
  toggleFilterButton = battleWindow:recursiveGetChildById('toggleFilterButton')

  if isHidingFilters() then
    hideFilterPanel()
  end

  sortTypeBox = battleWindow:recursiveGetChildById('sortTypeBox')
  sortOrderBox = battleWindow:recursiveGetChildById('sortOrderBox')
  hidePlayersButton = battleWindow:recursiveGetChildById('hidePlayers')
  hideNPCsButton = battleWindow:recursiveGetChildById('hideNPCs')
  hideMonstersButton = battleWindow:recursiveGetChildById('hideMonsters')
  hideSkullsButton = battleWindow:recursiveGetChildById('hideSkulls')
  hidePartyButton = battleWindow:recursiveGetChildById('hideParty')

  mouseWidget = g_ui.createWidget('UIButton')
  mouseWidget:setVisible(false)
  mouseWidget:setFocusable(false)
  mouseWidget.cancelNextRelease = false

  battleWindow:setContentMinimumHeight(80)

  sortTypeBox:addOption('Name', 'name')
  sortTypeBox:addOption('Distance', 'distance')
  sortTypeBox:addOption('Age', 'age')
  sortTypeBox:addOption('Health', 'health')
  sortTypeBox:setCurrentOptionByData(getSortType())
  sortTypeBox.onOptionChange = onChangeSortType

  sortOrderBox:addOption('Asc.', 'asc')
  sortOrderBox:addOption('Desc.', 'desc')
  sortOrderBox:setCurrentOptionByData(getSortOrder())
  sortOrderBox.onOptionChange = onChangeSortOrder

  connect(Creature, {
    onSkullChange = updateCreatureSkull,
    onEmblemChange = updateCreatureEmblem,
    onOutfitChange = onCreatureOutfitChange,
    onHealthPercentChange = onCreatureHealthPercentChange,
    onPositionChange = onCreaturePositionChange,
    onAppear = onCreatureAppear,
    onDisappear = onCreatureDisappear
  })

  connect(LocalPlayer, {
    onPositionChange = onCreaturePositionChange
  })

  connect(g_game, {
    onAttackingCreatureChange = onAttack,
    onFollowingCreatureChange = onFollow,
    onGameEnd = removeAllCreatures
  })

  checkCreatures()
  battleWindow:setup()
end

function terminate()
  g_keyboard.unbindKeyDown('Ctrl+B')
  battleButtonsByCreaturesList = {}
  battleButton:destroy()
  battleWindow:destroy()
  mouseWidget:destroy()

  disconnect(Creature, {
    onSkullChange = updateCreatureSkull,
    onEmblemChange = updateCreatureEmblem,
    onOutfitChange = onCreatureOutfitChange,
    onHealthPercentChange = onCreatureHealthPercentChange,
    onPositionChange = onCreaturePositionChange,
    onAppear = onCreatureAppear,
    onDisappear = onCreatureDisappear
  })

  disconnect(LocalPlayer, {
    onPositionChange = onCreaturePositionChange
  })

  disconnect(g_game, {
    onAttackingCreatureChange = onAttack,
    onFollowingCreatureChange = onFollow,
    onGameEnd = removeAllCreatures
  })
end

function toggle()
  if battleButton:isOn() then
    battleWindow:close()
    battleButton:setOn(false)
  else
    battleWindow:open()
    battleButton:setOn(true)
  end
end

function onMiniWindowClose()
  battleButton:setOn(false)
end

function getSortType()
  local settings = g_settings:getNode('BattleList')
  if not settings then
    return 'name'
  end
  return settings['sortType']
end

function setSortType(state)
  settings = {}
  settings['sortType'] = state
  g_settings:mergeNode('BattleList', settings)

  checkCreatures()
end

function getSortOrder()
  local settings = g_settings:getNode('BattleList')
  if not settings then
    return 'asc'
  end
  return settings['sortOrder']
end

function setSortOrder(state)
  settings = {}
  settings['sortOrder'] = state
  g_settings:mergeNode('BattleList', settings)

  checkCreatures()
end

function isSortAsc()
    return getSortOrder() == 'asc'
end

function isSortDesc()
    return getSortOrder() == 'desc'
end

function isHidingFilters()
  local settings = g_settings:getNode('BattleList')
  if not settings then
    return false
  end
  return settings['hidingFilters']
end

function setHidingFilters(state)
  settings = {}
  settings['hidingFilters'] = state
  g_settings:mergeNode('BattleList', settings)
end

function hideFilterPanel()
  filterPanel.originalHeight = filterPanel:getHeight()
  filterPanel:setHeight(0)
  toggleFilterButton:getParent():setMarginTop(0)
  toggleFilterButton:setImageClip(torect("0 0 21 12"))
  setHidingFilters(true)
  filterPanel:setVisible(false)
end

function showFilterPanel()
  toggleFilterButton:getParent():setMarginTop(5)
  filterPanel:setHeight(filterPanel.originalHeight)
  toggleFilterButton:setImageClip(torect("21 0 21 12"))
  setHidingFilters(false)
  filterPanel:setVisible(true)
end

function toggleFilterPanel()
  if filterPanel:isVisible() then
    hideFilterPanel()
  else
    showFilterPanel()
  end
end

function onChangeSortType(comboBox, option)
  setSortType(option:lower())
end

function onChangeSortOrder(comboBox, option)
  setSortOrder(option:lower():gsub('[.]', ''))  -- Replace dot in option name
end

function checkCreatures()
  removeAllCreatures()

  local spectators = {}
  local player = g_game.getLocalPlayer()
  if g_game.isOnline() then
    creatures = g_map.getSpectators(player:getPosition(), false)
    for i, creature in ipairs(creatures) do
      if creature ~= player and doCreatureFitFilters(creature) then
        table.insert(spectators, creature)
      end
    end
  end

  for i, v in pairs(spectators) do
    addCreature(v)
  end
end


function doCreatureFitFilters(creature)
  local localPlayer = g_game.getLocalPlayer()
  if creature == localPlayer then
    return false
  end

  local pos = creature:getPosition()
  if not pos then return false end

  if pos.z ~= localPlayer:getPosition().z or not creature:canBeSeen() then return false end

  local hidePlayers = hidePlayersButton:isChecked()
  local hideNPCs = hideNPCsButton:isChecked()
  local hideMonsters = hideMonstersButton:isChecked()
  local hideSkulls = hideSkullsButton:isChecked()
  local hideParty = hidePartyButton:isChecked()

  if hidePlayers and creature:isPlayer() then
    return false
  elseif hideNPCs and creature:isNpc() then
    return false
  elseif hideMonsters and creature:isMonster() then
    return false
  elseif hideSkulls and creature:isPlayer() and creature:getSkull() == SkullNone then
    return false
  elseif hideParty and creature:getShield() > ShieldWhiteBlue then
    return false
  end

  return true
end

function onCreatureHealthPercentChange(creature, health)
  local battleButton = battleButtonsByCreaturesList[creature:getId()]
  if battleButton then
    if getSortType() == 'health' then
      removeCreature(creature)
      addCreature(creature)
      return
    end
    battleButton:setLifeBarPercent(creature:getHealthPercent())
  end
end

local function getDistanceBetween(p1, p2)
    return math.max(math.abs(p1.x - p2.x), math.abs(p1.y - p2.y))
end

function onCreaturePositionChange(creature, newPos, oldPos)
  if creature:isLocalPlayer() then
    if oldPos and newPos and newPos.z ~= oldPos.z then
      checkCreatures()
    else
      -- Distance will change when moving, recalculate and move to correct index
      if getSortType() == 'distance' then
        local distanceList = {}
        for id, creatureButton in pairs(battleButtonsByCreaturesList) do
          table.insert(distanceList, {distance = getDistanceBetween(newPos, creatureButton.creature:getPosition()), widget = creatureButton})
        end

        if isSortAsc() then
          table.sort(distanceList, function(a, b) return a.distance < b.distance end)
        else
          table.sort(distanceList, function(a, b) return a.distance > b.distance end)
        end

        for i = 1, #distanceList do
          battlePanel:moveChildToIndex(distanceList[i].widget, i)
        end
      end

      for id, creatureButton in pairs(battleButtonsByCreaturesList) do
        addCreature(creatureButton.creature)
      end
    end
  else
    local has = hasCreature(creature)
    local fit = doCreatureFitFilters(creature)
    if has and not fit then
      removeCreature(creature)
    elseif fit then
      if has and getSortType() == 'distance' then
        removeCreature(creature)
      end
      addCreature(creature)
    end
  end
end

function onCreatureOutfitChange(creature, outfit, oldOutfit)
  if doCreatureFitFilters(creature) then
    addCreature(creature)
  else
    removeCreature(creature)
  end
end

function onCreatureAppear(creature)
  if doCreatureFitFilters(creature) then
    addCreature(creature)
  end
end

function onCreatureDisappear(creature)
  removeCreature(creature)
end

function hasCreature(creature)
  return battleButtonsByCreaturesList[creature:getId()] ~= nil
end

function addCreature(creature)
  local creatureId = creature:getId()
  local battleButton = battleButtonsByCreaturesList[creatureId]

  -- Register when creature is added to battlelist for the first time
  if not creatureAgeList[creatureId] then
    creatureAgeList[creatureId] = os.time()
  end

  if not battleButton then
    battleButton = g_ui.createWidget('BattleButton')
    battleButton:setup(creature)

    battleButton.onHoverChange = onBattleButtonHoverChange
    battleButton.onMouseRelease = onBattleButtonMouseRelease

    battleButtonsByCreaturesList[creatureId] = battleButton

    if creature == g_game.getAttackingCreature() then
      onAttack(creature)
    end

    if creature == g_game.getFollowingCreature() then
      onFollow(creature)
    end

    local inserted = false
    local nameLower = creature:getName():lower()
    local healthPercent = creature:getHealthPercent()
    local playerPosition = g_game.getLocalPlayer():getPosition()
    local distance = getDistanceBetween(playerPosition, creature:getPosition())
    local age = creatureAgeList[creatureId]

    local childCount = battlePanel:getChildCount()
    for i = 1, childCount do
      local child = battlePanel:getChildByIndex(i)
      local childName = child:getCreature():getName():lower()
      local equal = false
      if getSortType() == 'age' then
        local childAge = creatureAgeList[child:getCreature():getId()]
        if (age < childAge and isSortAsc()) or (age > childAge and isSortDesc()) then
          battlePanel:insertChild(i, battleButton)
          inserted = true
          break
        elseif age == childAge then
          equal = true
        end
      elseif getSortType() == 'distance' then
        local childDistance = getDistanceBetween(child:getCreature():getPosition(), playerPosition)
        if (distance < childDistance and isSortAsc()) or (distance > childDistance and isSortDesc()) then
          battlePanel:insertChild(i, battleButton)
          inserted = true
          break
        elseif childDistance == distance then
          equal = true
        end
      elseif getSortType() == 'health' then
          local childHealth = child:getCreature():getHealthPercent()
          if (healthPercent < childHealth and isSortAsc()) or (healthPercent > childHealth and isSortDesc()) then
            battlePanel:insertChild(i, battleButton)
            inserted = true
            break
          elseif healthPercent == childHealth then
            equal = true
          end
      end

      -- If any other sort type is selected and values are equal, sort it by name also
      if getSortType() == 'name' or equal then
          local length = math.min(childName:len(), nameLower:len())
          for j=1,length do
            if (nameLower:byte(j) < childName:byte(j) and isSortAsc()) or (nameLower:byte(j) > childName:byte(j) and isSortDesc()) then
              battlePanel:insertChild(i, battleButton)
              inserted = true
              break
            elseif (nameLower:byte(j) > childName:byte(j) and isSortAsc()) or (nameLower:byte(j) < childName:byte(j) and isSortDesc()) then
              break
            elseif j == nameLower:len() and isSortAsc() then
              battlePanel:insertChild(i, battleButton)
              inserted = true
            elseif j == childName:len() and isSortDesc() then
              battlePanel:insertChild(i, battleButton)
              inserted = true
            end
          end
      end

      if inserted then
        break
      end
    end

    -- Insert at the end if no other place is found
    if not inserted then
      battlePanel:insertChild(childCount + 1, battleButton)
    end
  else
    battleButton:setLifeBarPercent(creature:getHealthPercent())
  end

  local localPlayer = g_game.getLocalPlayer()
  battleButton:setVisible(localPlayer:hasSight(creature:getPosition()) and creature:canBeSeen())
end

function removeAllCreatures()
  creatureAgeList = {}
  for i, v in pairs(battleButtonsByCreaturesList) do
    removeCreature(v.creature)
  end
end

function removeCreature(creature)
  if hasCreature(creature) then
    local creatureId = creature:getId()

    if lastBattleButtonSwitched == battleButtonsByCreaturesList[creatureId] then
      lastBattleButtonSwitched = nil
    end

    battleButtonsByCreaturesList[creatureId].creature:hideStaticSquare()
    battleButtonsByCreaturesList[creatureId]:destroy()
    battleButtonsByCreaturesList[creatureId] = nil
  end
end

function onBattleButtonMouseRelease(self, mousePosition, mouseButton)
  if mouseWidget.cancelNextRelease then
    mouseWidget.cancelNextRelease = false
    return false
  end
  if ((g_mouse.isPressed(MouseLeftButton) and mouseButton == MouseRightButton)
    or (g_mouse.isPressed(MouseRightButton) and mouseButton == MouseLeftButton)) then
    mouseWidget.cancelNextRelease = true
    g_game.look(self.creature)
    return true
  elseif mouseButton == MouseLeftButton and g_keyboard.isShiftPressed() then
    g_game.look(self.creature)
    return true
  elseif mouseButton == MouseRightButton and not g_mouse.isPressed(MouseLeftButton) then
    modules.game_interface.createThingMenu(mousePosition, nil, nil, self.creature)
    return true
  elseif mouseButton == MouseLeftButton and not g_mouse.isPressed(MouseRightButton) then
    if self.isTarget then
      g_game.cancelAttack()
    else
      g_game.attack(self.creature)
    end
    return true
  end
  return false
end

function onBattleButtonHoverChange(widget, hovered)
  if widget.isBattleButton then
    widget.isHovered = hovered
    updateBattleButton(widget)
  end
end

function onAttack(creature)
  local battleButton = creature and battleButtonsByCreaturesList[creature:getId()] or lastBattleButtonSwitched
  if battleButton then
    battleButton.isTarget = creature and true or false
    updateBattleButton(battleButton)
  end
end

function onFollow(creature)
  local battleButton = creature and battleButtonsByCreaturesList[creature:getId()] or lastBattleButtonSwitched
  if battleButton then
    battleButton.isFollowed = creature and true or false
    updateBattleButton(battleButton)
  end
end

function updateCreatureSkull(creature, skullId)
  local battleButton = battleButtonsByCreaturesList[creature:getId()]
  if battleButton then
    battleButton:updateSkull(skullId)
  end
end

function updateCreatureEmblem(creature, emblemId)
  local battleButton = battleButtonsByCreaturesList[creature:getId()]
  if battleButton then
    battleButton:updateSkull(emblemId)
  end
end

function updateBattleButton(battleButton)
  battleButton:update()
  if battleButton.isTarget or battleButton.isFollowed then
    -- set new last battle button switched
    if lastBattleButtonSwitched and lastBattleButtonSwitched ~= battleButton then
      lastBattleButtonSwitched.isTarget = false
      lastBattleButtonSwitched.isFollowed = false
      updateBattleButton(lastBattleButtonSwitched)
    end
    lastBattleButtonSwitched = battleButton
  end
end