pfUI:RegisterModule("focus", function ()
  -- do not go further on disabled UFs
  if C.unitframes.disable == "1" then return end

  pfUI.uf.focus = pfUI.uf:CreateUnitFrame("Focus", nil, C.unitframes.focus)
  pfUI.uf.focus:UpdateFrameSize()
  pfUI.uf.focus:SetPoint("BOTTOMLEFT", UIParent, "BOTTOM", 220, 220)
  UpdateMovable(pfUI.uf.focus)
  pfUI.uf.focus:Hide()

  pfUI.uf.focustarget = pfUI.uf:CreateUnitFrame("FocusTarget", nil, C.unitframes.focustarget)
  pfUI.uf.focustarget:UpdateFrameSize()
  pfUI.uf.focustarget:SetPoint("BOTTOMLEFT", pfUI.uf.focus, "TOP", 0, 10)
  UpdateMovable(pfUI.uf.focustarget)
  pfUI.uf.focustarget:Hide()

  -- PLAYER_FOCUS_CHANGED drives immediate refresh on focus assign / clear.
  -- Between events, ClassicAPI fires UNIT_* (health/mana/aura/...) with
  -- arg1 == "focus" and arg1 == "focustarget", so both frames update
  -- event-driven like target and need no polling tick.
  local refresher = CreateFrame("Frame")
  refresher:RegisterEvent("PLAYER_FOCUS_CHANGED")
  refresher:SetScript("OnEvent", function()
    pfUI.uf.focus.instantRefresh = true
    pfUI.uf:RefreshUnit(pfUI.uf.focus, "all")
    pfUI.uf.focustarget.instantRefresh = true
    pfUI.uf:RefreshUnit(pfUI.uf.focustarget, "all")
  end)
end)

-- /focus and /clearfocus live in ClassicAPI's SlashCommandsRegistry now.
-- /focusname is pfUI-specific because the engine has no name→GUID
-- lookup for off-screen units — we resolve via a short target-swap.

pfUI.api.RegisterSlashCommand("PFFOCUSNAME", { '/focusname', '/pffocusname' }, function(msg)
  if msg == "" then return end

  local prevGUID = UnitGUID("target")
  local prevPlayer = UnitIsUnit("target", "player")

  -- Suppress async "Unknown unit" errors fired by TargetByName misses.
  UIErrorsFrame:UnregisterEvent("UI_ERROR_MESSAGE")

  -- Try exact match first, then prefix match via /target.
  TargetByName(msg, true)
  if not UnitExists("target") then
    SlashCmdList.TARGET(msg)
  end

  if UnitExists("target") then
    FocusUnit("target")
  end

  RunNextFrame(function()
    UIErrorsFrame:RegisterEvent("UI_ERROR_MESSAGE")
  end)

  if prevGUID and prevGUID ~= "0x0000000000000000" then
    TargetUnit(prevGUID)
  elseif prevPlayer then
    TargetUnit("player")
  else
    ClearTarget()
  end
end, true)

pfUI.api.RegisterSlashCommand("PFCASTFOCUS", { '/castfocus', '/pfcastfocus' }, function(msg)
  local focusGUID = UnitGUID("focus")
  if not focusGUID or focusGUID == "0x0000000000000000" then
    UIErrorsFrame:AddMessage(SPELL_FAILED_BAD_TARGETS, 1, 0, 0)
    return
  end

  local func = pfUI.api.TryMemoizedFuncLoadstringForSpellCasts(msg)

  -- GUID-based cast (Nampower) - no target toggle needed
  if not func then
    CastSpellByName(msg, focusGUID)
    return
  end

  -- Lua-function cast: short target swap via GUID
  local prevGUID = UnitGUID("target")
  local prevPlayer = UnitIsUnit("target", "player")

  TargetUnit(focusGUID)
  if UnitGUID("target") ~= focusGUID then
    if prevGUID and prevGUID ~= "0x0000000000000000" then
      TargetUnit(prevGUID)
    elseif prevPlayer then
      TargetUnit("player")
    else
      TargetLastTarget()
    end
    UIErrorsFrame:AddMessage(SPELL_FAILED_BAD_TARGETS, 1, 0, 0)
    return
  end

  func()

  if prevGUID and prevGUID ~= "0x0000000000000000" then
    TargetUnit(prevGUID)
  elseif prevPlayer then
    TargetUnit("player")
  else
    TargetLastTarget()
  end
end, true)

pfUI.api.RegisterSlashCommand("PFSWAPFOCUS", { '/swapfocus', '/pfswapfocus' }, function(msg)
  local targetGUID = UnitGUID("target")
  local oldFocusGUID = UnitGUID("focus")

  if targetGUID and targetGUID ~= "0x0000000000000000" then
    FocusUnit("target")
    if oldFocusGUID and oldFocusGUID ~= "0x0000000000000000" then
      TargetUnit(oldFocusGUID)
    end
  end
end, true)