local Plx2Dist = {}

local function trim(s)
	s = mw.ustring.gsub(s,"\n","");
	while mw.ustring.sub(s,1,1) == " " do
		s=  mw.ustring.sub(s,2,-1);
	end
	while mw.ustring.sub(s,-1,-1) == " " do
		s=  mw.ustring.sub(s,1,-2);
	end
	return s;
end

local function round(value)
	if value < 1 then
		value = math.floor (1000*value+0.5) / 1000;
	elseif  value < 10 then
		value = math.floor (100*value+0.5) / 100;
	elseif  value < 100 then
		value = math.floor (10* value+0.5) /10;
	elseif  value < 1000 then
		value =  math.floor (value+0.5)
	elseif   value < 10000 then
		value = 10 *  math.floor (value/10+0.5)
	else
		value = 100 *  math.floor (value/100+0.5)
	end
	return value
end

local function GetMinMaxParsec(value,sigma)
	local Plx= tonumber(value) or 0;
	local Diff=tonumber(sigma) or 0;
	local quality;
	if Plx <= 0 or Diff >= Plx then
		quality = 0;
	elseif Diff >= 0.5 * Plx then
		quality = 1;
	elseif Diff >= 0.2 * Plx then
		quality = 2;
	elseif Diff >= 0.1 * Plx then
		quality = 3;
	elseif Diff >= 0.05 * Plx then
		quality = 4;
	elseif Diff >= 0.02 * Plx then
		quality = 5;
	elseif Diff >= 0.01 * Plx then
		quality = 6;
	else
		quality = 7;
	end

	if quality == 0 then
		return 0, 0, 0, 0, false
	end
	local Dist = 1000 / Plx;
	if Diff > 0 then
		local DistMin = 1000 / (Plx + Diff);
		local DistMax = 1000 / (Plx - Diff);
		return DistMin, Dist, DistMax, quality, true;
	else
		return Dist, Dist, Dist, 0, true;
	end
end

local function CreateOutputValues(Pc1, Pc2, Pc3)
	local Lj1,Lj2,Lj3
	Lj1 = round(3.26156 * Pc1) 
	Lj2 = round(3.26156 * Pc2)
	Lj3 = round(3.26156 * Pc3)
	Pc1 = round(Pc1) 
	Pc2 = round(Pc2) 
	Pc3 = round(Pc3)
	return Pc1,Pc2,Pc3,Lj1,Lj2,Lj3
end

function Plx2Dist.Run(frame)
	local MinPc = 0;
	local ValPc = 0;
	local MaxPc = 0;
	local MinLj = 0;
	local ValLj = 0;
	local MaxLj = 0;
	local IsOk = false;
	local value = tonumber(trim(frame.args[1])) or 0;
	local sigma = tonumber(trim(frame.args[2])) or 0;
	MinPc, ValPc, MaxPc, IsOk = GetMinMaxParsec(value,sigma);
	local Result='<span class="error">???</span>';
	if not IsOk then
		return Result;
	end
	MinPc,ValPc,MaxPc,MinLj,ValLj,MaxLj = CreateOutputValues(MinPc,ValPc,MaxPc)
	if MinPc == MaxPc then
		Result = tostring(ValPc) .. ' Pc ('.. tostring(ValLj) .. ' Lj)'
	else
		Result = tostring(MinPc) .. ' Pc ('.. tostring(MinLj) .. ' Lj) bis ' .. tostring(MaxPc) .. ' Pc ('.. tostring(MaxLj) .. ' Lj)'
	end
	return Result
end

function Plx2Dist.GetPlxDist(frame)
	local MinPc = 0;
	local ValPc = 0;
	local MaxPc = 0;
	local MinLj = 0;
	local ValLj = 0;
	local MaxLj = 0;
	local Quality = 0;
	local IsOk = false;
	local value = tonumber(trim(frame.args[1])) or 0;
	local sigma = tonumber(trim(frame.args[2])) or 0;
	local format = frame.args[fmt] or "";
	MinPc, ValPc, MaxPc, Quality, IsOk = GetMinMaxParsec(value,sigma);
	if IsOk then
		return round(ValPc);
	else
		return "???";
	end 	
end

function Plx2Dist.GetPc(frame)
	local IsOk = false;
	local Parsec = 0;
	local Plx =  tonumber(trim(string.gsub(frame.args[1],',','.'))) or 0;
	if Plx > 0 then
		Parsec = round(1000 / Plx);
		IsOk = true;
	end
	if IsOk then
		return Parsec;
	else
		return '???';
	end
end

function Plx2Dist.GetLj(frame)
	local IsOk = false;
	local Lj = 0;
	local Plx =  tonumber(trim(string.gsub(frame.args[1],',','.'))) or 0;
	if Plx > 0 then
		Lj = round(3261.56 / Plx);
		IsOk = true;
	end
	if IsOk then
		return Lj;
	else
		return '???';
	end
end


return Plx2Dist;