local VUHDO_1_DIV_2_PI_MUL_108 = 108 / math.pi / 2;
local UnitIsUnit = UnitIsUnit;
local floor = floor;
local sOldButton;
local sOldDistance;
local sIsDeadOnly;
local sIsAlways;
local sIsDistanceText;
local sScale;
local VuhDoDirectionFrame;
local VuhDoDirectionFrameArrow;
local VuhDoDirectionFrameText;
local VUHDO_setMapToCurrentZone;
local VUHDO_getDistanceBetween;
local VUHDO_getUnitDirection;

local VUHDO_RAID = { };
function VUHDO_directionsInitLocalOverrides()
	VUHDO_RAID = _G["VUHDO_RAID"];

	sIsDeadOnly = VUHDO_CONFIG["DIRECTION"]["isDeadOnly"];
	sIsAlways = VUHDO_CONFIG["DIRECTION"]["isAlways"];
	sIsDistanceText = VUHDO_CONFIG["DIRECTION"]["isDistanceText"];
	sScale = VUHDO_CONFIG["DIRECTION"]["scale"] * 0.01;
	sOldButton = nil;
	sOldDistance = nil;

	VuhDoDirectionFrame = _G["VuhDoDirectionFrame"];
	VuhDoDirectionFrameArrow = _G["VuhDoDirectionFrameArrow"];
	VuhDoDirectionFrameText = _G["VuhDoDirectionFrameText"];
	VUHDO_setMapToCurrentZone = _G["VUHDO_setMapToCurrentZone"];
	VUHDO_getDistanceBetween = _G["VUHDO_getDistanceBetween"];
	VUHDO_getUnitDirection = _G["VUHDO_getUnitDirection"];
end



--
function VUHDO_getCellForDirection(aDirection)
	return floor(aDirection * VUHDO_1_DIV_2_PI_MUL_108 + 0.5) % 108
end
local VUHDO_getCellForDirection = VUHDO_getCellForDirection;



--
local tStartX, tStartY;
function VUHDO_getTexCoordsForCell(aCell)
	tStartX, tStartY = (aCell % 9) * 0.109375, floor(aCell / 9) * 0.08203125;
	return tStartX, tStartX + 0.109375, tStartY, tStartY + 0.08203125;
end
local VUHDO_getTexCoordsForCell = VUHDO_getTexCoordsForCell;



--
local tQuota;
local tR, tG;
local tInvModi;
function VUHDO_getRedGreenForDistance(aDistance)
	tQuota = 4 - 0.05 * aDistance;

	if tQuota > 2 then tQuota = 2;
	elseif tQuota < 0 then tQuota = 0; end

	if tQuota > 1 then
		tR, tG = 0, 1;
		tQuota = tQuota - 1;
	else
		tR, tG = 1, 0;
	end

	tInvModi = 1 - tQuota;
	return tInvModi + tR * tQuota, tG * tInvModi + tQuota;
end
local VUHDO_getRedGreenForDistance = VUHDO_getRedGreenForDistance;



--
local tInfo;
function VUHDO_shouldDisplayArrow(aUnit)
	tInfo = VUHDO_RAID[aUnit];
	return
	  not UnitIsUnit("player", aUnit)
		and tInfo
		and (not tInfo["range"] or sIsAlways)
		and (not sIsDeadOnly or tInfo["dead"])
		and tInfo["connected"]
		and not tInfo["isPet"];
end
local VUHDO_shouldDisplayArrow = VUHDO_shouldDisplayArrow;



--
local tUnit;
local tCell;
local sLastCell = nil;
local tButton = nil;
local tHeight;
local tDistance;
local tHeight;
local tDestR, tDestG;
function VUHDO_updateDirectionFrame(aButton)
	if aButton then tButton = aButton;
	elseif not tButton then return; end

	tUnit = tButton:GetAttribute("unit");

	if not VUHDO_shouldDisplayArrow(tUnit) then
		VuhDoDirectionFrame["shown"] = false;
		VuhDoDirectionFrame:Hide();
		return;
	end

	tDirection = VUHDO_getUnitDirection(tUnit);
	if not tDirection then
		VuhDoDirectionFrame["shown"] = false;
		VuhDoDirectionFrame:Hide();
		return;
	end

	tCell = VUHDO_getCellForDirection(tDirection);
	if tCell ~= sLastCell then
		sLastCell = tCell;
		VuhDoDirectionFrameArrow:SetTexCoord(VUHDO_getTexCoordsForCell(tCell));
	end

	if sIsDistanceText then
		tDistance = VUHDO_getDistanceBetween("player", tUnit);
		if (tDistance or 0) > 0 then
			tDistance = floor(tDistance + 0.5);

			if tDistance ~= sOldDistance then
				sOldDistance = tDistance;

				VuhDoDirectionFrameText:SetText(tDistance);

				tDestR, tDestG = VUHDO_getRedGreenForDistance(tDistance);
				VuhDoDirectionFrameText:SetTextColor(tDestR, tDestG, 0.2, 0.8);
				VuhDoDirectionFrameArrow:SetVertexColor(tDestR, tDestG, 0);
			end
		else
			VuhDoDirectionFrameText:SetText("");
		end
	end

	if sOldButton ~= tButton then
		sOldButton = tButton;
		tHeight = tButton:GetHeight() * sScale * tButton:GetEffectiveScale();
		VuhDoDirectionFrame:SetPoint("CENTER", tButton:GetName(), "CENTER", 0, 0);
		VuhDoDirectionFrame:SetWidth(tHeight);
		VuhDoDirectionFrame:SetHeight(tHeight);
	end
	VuhDoDirectionFrame:Show();
	VuhDoDirectionFrame["shown"] = true;
end
