local UIParent = UIParent

local Chorus = Chorus

local function disableNativeFrames()
	local t = {
		FocusFrame,
		PlayerFrame,
		TargetFrame,
		PartyMemberFrame1,
		PartyMemberFrame2,
		PartyMemberFrame3,
		PartyMemberFrame4,
		PartyMemberBackground,
	}
	local i = 0
	while (i < #t) do
		i = i + 1
		local e = t[i]
		if e then
			e:Hide()
			e:HookScript('OnShow', function(self)
				self:Hide()
			end)
			--[[ Post-hook hack ]]--
			local v = e:GetScript('OnEvent')
			e:SetScript('OnEvent', function(self, ...)
				v(self, ...)
				self:Hide()
			end)
		end
	end
end

local function applyLayout(self)
	assert(self ~= nil)
	assert(UIParent ~= nil)

	self:UnregisterAllEvents();
	self:SetScript('OnEvent', nil)

	--[[ FIXME Range indicator shows false information. ]]--

	ChorusPlayerButtonHealthFrame.strategy = 'UnitClass'
	ChorusPlayerButton.menu = function()
		local offsetX = ChorusPlayerButton:GetWidth() / 2
		local offsetY = ChorusPlayerButton:GetHeight()
		ToggleDropDownMenu(1, nil, PlayerFrameDropDown, 'ChorusPlayerButton', offsetX, offsetY)
	end

	local focuscastModifier = GetModifiedClick('FOCUSCAST')
	if focuscastModifier and 'NONE' ~= focuscastModifier then
		local key = string.lower(focuscastModifier) .. '-type1'
		ChorusPlayerButton:SetAttribute(key, 'focus')
		ChorusTargetButton:SetAttribute(key, 'focus')
	end

	ChorusFocusButtonHealthFrame.strategy = 'UnitIsFriend'
	ChorusFocusButtonUnitNameFrame.strategy = 'UnitClass'

	ChorusTargetButtonHealthFrame.strategy = 'UnitIsFriend'
	ChorusTargetButtonUnitNameFrame.strategy = 'UnitClass'

	--[[ FIXME Selecting "Set focus" option in the context menu for Chorus
	unit button results in permission violation exception (restricted
	execution environment issue). ]]--

	ChorusTargetButton.menu = function()
		local offsetX = ChorusTargetButton:GetWidth() / 2
		local offsetY = ChorusTargetButton:GetHeight()
		ToggleDropDownMenu(1, nil, TargetFrameDropDown, 'ChorusTargetButton', offsetX, offsetY)
	end

	ChorusFocusButton.menu = function()
		local offsetX = ChorusFocusButton:GetWidth() / 2
		local offsetY = ChorusFocusButton:GetHeight()
		ToggleDropDownMenu(1, nil, FocusFrameDropDown, 'ChorusFocusButton', offsetX, offsetY)
	end

	--[[ NOTE The menu functions are equivalent of PlayerFrame.menu and
	TargetFrame.menu. It is possible to use them direcctly. THe only
	quirk is that the context menu will be displayed at the display point
	of the native unit frames. Hence, the need to define separate menu
	functions. ]]--
end

local function chorusFrameMain(self)
	--[[ Wait for the game to finish loading completely, only then apply
	changes. ]]--

	--[[ TODO Add pet buttons. ]]--

	self:RegisterEvent('PLAYER_LOGIN'); self:SetScript('OnEvent', applyLayout)

	disableNativeFrames()
end

Chorus.chorusFrameMain = function(...)
	return chorusFrameMain(...)
end