local _G = ShaguTweaks.GetGlobalEnv()
local T = ShaguTweaks.T
local GetUnitData = ShaguTweaks.GetUnitData
local API = ShaguTweaks.API

local module = ShaguTweaks:register({
  title = T["Nameplate Class Colors"],
  description = T["Changes the nameplate health bar color to the class color."],
  expansions = { ["vanilla"] = true },
  category = T["Nameplates"],
  enabled = true,
})

module.enable = function(self)
  if ShaguPlates then return end

  local colorsByName = {}
  local useClassicTokens = API and API.eventutils and _G.C_EventUtils
    and _G.C_EventUtils.IsEventValid("NAME_PLATE_UNIT_ADDED")
    and _G.C_EventUtils.IsEventValid("NAME_PLATE_UNIT_REMOVED")

  if useClassicTokens then
    local listener = CreateFrame("Frame")
    listener:RegisterEvent("NAME_PLATE_UNIT_ADDED")
    listener:RegisterEvent("NAME_PLATE_UNIT_REMOVED")
    listener:SetScript("OnEvent", function()
      local unit = arg1
      if not unit then return end

      -- Use only the exact nameplateN unit token here. Do not request or
      -- decorate ClassicAPI's Lua frame wrapper: the legacy libnameplate
      -- discovery path is deliberately kept isolated after native crashes.
      local name = UnitName(unit)
      if not name then return end

      if event == "NAME_PLATE_UNIT_ADDED" then
        local color
        if UnitIsPlayer(unit) then
          local _, class = UnitClass(unit)
          color = class and RAID_CLASS_COLORS[class] or nil
        end
        colorsByName[name] = color or false
      elseif event == "NAME_PLATE_UNIT_REMOVED" then
        colorsByName[name] = nil
      end
    end)
  end

  table.insert(ShaguTweaks.libnameplate.OnUpdate, function()
    if useClassicTokens then
      -- libnameplate owns the real native frame. The token listener above only
      -- caches exact class information, so this hot path is just one name read
      -- and one table lookup with no TargetByName scan and no C frame wrapper.
      local name = this.name and this.name:GetText()
      local color = name and colorsByName[name]
      if color then
        this.healthbar:SetStatusBarColor(color.r, color.g, color.b, 1)
      end
      return
    end

    -- Plain Vanilla / old ClassicAPI compatibility path.
    local name = this.name:GetText()
    local class, _, _, player = GetUnitData(name, true)
    if class and player then
      local color = RAID_CLASS_COLORS[class] or { r = .5, g = .5, b = .5, a = 1 }
      this.healthbar:SetStatusBarColor(color.r, color.g, color.b, 1)
    end
  end)
end