local function getAdjustedTickTimer()
  local adjustedEnergyTick = 2

  -- Check rogue talents and compute energy tick timing reduction for Combat spec (1.18.0 Blade Rush Talent)
  if UnitClass("player") == "Rogue" then
    local _, _, _, _, currRank = GetTalentInfo(2, 16)
    local bladeRushRank = currRank or 0

    if bladeRushRank > 0 then
      local agility = UnitStat("player", 2)       -- 2 is agility stat index
      local reductionPerAgi = 0.0006 * bladeRushRank -- 0.0006 for rank 1, 0.0012 for rank 2
      local totalReduction = agility * reductionPerAgi
      adjustedEnergyTick = adjustedEnergyTick - totalReduction
    end
  end

  return adjustedEnergyTick
end

pfUI:RegisterModule("energytick", "vanilla:tbc", function()
  if not pfUI.uf or not pfUI.uf.player then
    return
  end

  local energytick = CreateFrame("Frame", nil, pfUI.uf.player.power.bar)
  energytick:SetAllPoints(pfUI.uf.player.power.bar)
  energytick:RegisterEvent("PLAYER_ENTERING_WORLD")
  energytick:RegisterEvent("UNIT_DISPLAYPOWER")
  energytick:RegisterEvent("UNIT_ENERGY")
  energytick:RegisterEvent("UNIT_MANA")
  energytick:RegisterEvent("CHAT_MSG_SPELL_SELF_BUFF")
  energytick:RegisterEvent("CHAT_MSG_SPELL_PERIODIC_SELF_BUFFS")

  energytick:SetScript("OnEvent", function()
    if UnitPowerType("player") == 0 and C.unitframes.player.manatick == "1" then
      this.mode = "MANA"
      this:Show()
    elseif UnitPowerType("player") == 3 and C.unitframes.player.energy == "1" then
      this.mode = "ENERGY"
      this:Show()
    else
      this:Hide()
    end

    -- Filter nur eigene Energy-Gewinne von Talents/Buffs
    if event == "CHAT_MSG_SPELL_SELF_BUFF" or event == "CHAT_MSG_SPELL_PERIODIC_SELF_BUFFS" then
      if string.find(arg1, "You gain") and string.find(arg1, "Energy from") then
        this.ignoreNextGain = true
      end
      return
    end

    if event == "PLAYER_ENTERING_WORLD" then
      this.lastMana = UnitMana("player")
    end

    if (event == "UNIT_MANA" or event == "UNIT_ENERGY") and arg1 == "player" then
      this.currentMana = UnitMana("player")
      local diff = 0
      if this.lastMana then
        diff = this.currentMana - this.lastMana
      end

      if this.mode == "MANA" and diff < 0 then
        this.target = 5
      elseif this.mode == "MANA" and diff > 0 then
        if UnitMana("player") >= UnitManaMax("player") then
          this.start = nil
          this.spark:SetAlpha(0)
          this:Hide()
        elseif this.max ~= 5 and diff > (this.badtick and this.badtick * 1.2 or 5) then
          this.target = 2
        else
          this.badtick = diff
        end
      elseif this.mode == "ENERGY" and diff >= 0 then
        if not this.ignoreNextGain then
          this.target = getAdjustedTickTimer()
        end
        this.ignoreNextGain = false
      end
      this.lastMana = this.currentMana
    end
  end)

  energytick:SetScript("OnUpdate", function()
    -- Throttle for performance
    if (this.tick or 0) > GetTime() then
      return
    end
    this.tick = GetTime() + 0.020  -- ~50 FPS

    if this.target then
      this.start, this.max = GetTime(), this.target
      this.target = nil
      this.spark:SetAlpha(1)
      this:Show()
    end

    if not this.start then
      return
    end

    this.current = GetTime() - this.start

    if this.current > this.max then
      -- Don't restart tick timer if mana is full
      if this.mode == "MANA" and UnitMana("player") >= UnitManaMax("player") then
        this.start = nil
        this.spark:SetAlpha(0)
        return
      end
      this.start, this.max, this.current = GetTime(), getAdjustedTickTimer(), 0
    end

    local pos = (C.unitframes.player.pwidth ~= "-1" and C.unitframes.player.pwidth or C.unitframes.player.width)
        * (this.current / this.max)
    if not C.unitframes.player.pheight then
      return
    end
    this.spark:SetPoint("LEFT", pos - ((C.unitframes.player.pheight + 5) / 2), 0)
  end)

  energytick.spark = energytick:CreateTexture(nil, "OVERLAY")
  energytick.spark:SetTexture("Interface\\CastingBar\\UI-CastingBar-Spark")
  energytick.spark:SetHeight(C.unitframes.player.pheight + 15)
  energytick.spark:SetWidth(C.unitframes.player.pheight + 5)
  energytick.spark:SetBlendMode("ADD")

  local hookUpdateConfig = pfUI.uf.player.UpdateConfig
  function pfUI.uf.player.UpdateConfig()
    energytick.spark:SetHeight(C.unitframes.player.pheight + 15)
    energytick.spark:SetWidth(C.unitframes.player.pheight + 5)
    hookUpdateConfig(pfUI.uf.player)
  end
end)