Editing Module:Parliament diagram

require('strict')
local p = {}
local getArgs = require('Module:Arguments').getArgs
local errorCategory = '[[Category:Compilation error of the Parliamentary diagram template]]'
local getColor = require('Module:Political party').fetch
local dimx = 175
local dimr = 50
local dimc = 40
local limite = 2000
local bgcolor = "#fff"

-- Error handler using xpcall, format the error
local function errhandler(msg)
	local cat = mw.title.getCurrentTitle().namespace == 0 and errorCategory or ''
	return string.format('<span class="error">%s</span>%s', msg, cat)
end

-- create a single array from string
local function agg(a,...)
    local args = {...}
    for _, s in ipairs(args) do
        table.insert(a, s)
    end
end

-- get the party color from Module:Party color
-- a = party; b = optional color
local function color(a,b)
	local c = '#CCC'
	if (b) then
		c = b
	else
		c = getColor({a, "color"})
	end
	if string.sub(c,1,5) == '&#35;' then c = "#" .. string.sub(c, 6, 11) end
	return c
end

-- create circles
local function values(n)
	local totals= {4, 17, 36, 65, 100, 144, 196, 255, 322, 398, 480, 571, 670, 776, 891, 1013, 1143, 1281, 1427, 1580, 1743, 1911, 2089}

   	local dots = 0
	local benches = 1
	local jj,rr,aa

	-- searches for the amount of benches needed to show all the dots
   	while (n > totals[benches]) do
      benches = benches + 1
	end
	local dd = dimr/benches -- distance between the arches
	dimc = 0.7*dimr/benches -- size of the circles
	local list = {} -- list of dots
	-- calculate angle and radius of each dot
	for rg=0,benches-2 do
		rr = dimx - dd*(2*rg+1) -- radius
    	jj = math.floor((n/totals[benches])*math.pi/(2*math.asin(dd/rr)))+1 --n° dots
    	if (jj==1) then
      		dots = dots + 1
        	list[dots] = {0.5, rr}
    	else
        	for ps=0,jj-1 do
        		aa = ps/(jj-1)
        		dots = dots + 1
        		list[dots] = {aa,rr}
        	end
        end
	end
	-- dots left to place on an internal arch
    jj=n-dots
    rr= dimx - dd*(2*benches-1) -- radius
    if (jj==1) then
		dots = dots + 1
		list[dots] = {1/2, rr}
    else
    	for ps=0,jj-1 do
			aa=ps/(jj-1)
			dots = dots + 1
			list[dots] = {aa,rr}
		end
	end
	-- order dots per increasing angle from the center
	table.sort(list, function(a,b) return ((a[1]<b[1]) or (a[1]==b[1] and a[2]<b[2])) end)
	return list
end

-- create the parliamentary arch
function p._parliament(args)
	local ss = {}
	local ss2 = {}
	local data = {}
	local num = 1
	local totalDots = 0
	local cap = args.caption or ''
	local show = tonumber(args.show) or 0

	while (args['n'..num]) do
		if (tonumber(args['n'..num])) then
			data[num] = {
				n = args['n'..num] and tonumber(args['n'..num]),
				c = color(args['p'..num] or '', args['c'..num]),
				b = args['b'..num] or '-',
				p = args['p'..num] or 'Serie '..num
			}
			totalDots = totalDots + data[num].n
			num = num+1
		else
			error(string.format('Invalid value for n%d', num),2)
		end
	end
	num = num - 1
	if (totalDots>limite) then
		error('Number of dots superior to the limit')
	elseif (totalDots<1) then
		error('No dots are indicated')
	end
	local dots = values(totalDots)
	local width = 2*dimx
	local height = dimx+dimc
	local scale = 1.0
	if (args['background']) then
		bgcolor = args['background']
	end
	if (args['width'] and tonumber(args['width'])) then
		width = tonumber(args['width'])
		scale = width/(2*dimx)
		height = (dimx+dimc)*scale
	elseif (args['height'] and tonumber(args['height'])) then
		height = tonumber(args['height'])
		scale = height/(dimx+dimc)
		width = 2*dimx*scale
	elseif (totalDots<29) then
		width = 200
		scale = width/(2*dimx)
		height = (dimx+dimc)*scale
	elseif (totalDots<101) then
		width = 250
		scale = width/(2*dimx)
		height = (dimx+dimc)*scale
	elseif (totalDots<281) then
		width = 300
		scale = width/(2*dimx)
		height = (dimx+dimc)*scale
	end
	local graph = {
		version = 2, width = width, height = height, padding = "no",
		background = bgcolor,
		data = { },
		scales = {
			{ name = "x", type = "linear", range = "width", zero = true, domainMin = 0, domainMax = 2*dimx },
			{ name = "y", type = "linear", range = "height", zero = true, domainMin = 0, domainMax = dimx + dimc }
		},
		marks = { }
	}
	local ee = 0
	local values
	for i=1,num do
		values = {}
		for j=1,data[i].n do
			ee = ee + 1
			values[j] = {
				px = dimx-dots[ee][2]*math.cos(math.pi*dots[ee][1]),
				py = dimc+dots[ee][2]*math.sin(math.pi*dots[ee][1]),
			}
		end
		graph['data'][i] = { name = "tab"..i, values = values }
		graph['marks'][i] = { type = "symbol", from = {data = "tab"..i },
			properties = {
				enter = {
					x = {scale = "x",field = "px"},
					y = {scale = "y",field = "py"},
					fill = {value = data[i].c},
					size = {value = (2*dimc*scale)^2}
				}
			}
		}
		if (data[i].b ~= "-") then
			local bl = data[i].b
			if string.sub(bl,1,5) == '&#35;' then bl = "#" .. string.sub(bl, 6, 11) end
			graph['marks'][i]['properties']['enter']['stroke'] = {value = bl}
			graph['marks'][i]['properties']['enter']['strokeWidth'] = {value = 1}
		end
	end
	graph['marks'][num+1] = {
		type = "text",
		properties = {
			enter = {
				x = {scale = "x",value=dimx},
				y = {scale = "y",value=dimc+8},
				align = {value = "center"},
				fill = {value = "#000"},
				font = {value = "Helvetica"},
				fontSize = { value = 36*scale },
				fontWeight = { value = "bold" },
				text = {value = totalDots }
			}
		}
	}
	agg(ss, mw.getCurrentFrame():extensionTag('graph', mw.text.jsonEncode(graph)))
	if (cap ~= '') then
		agg(ss,string.format('<p style="font-size:90%%; margin-left:10px">%s</p>',cap))
	end
	if show == 1 then
		for i=1,num do
			agg(ss2,string.format('<span style="display:inline-block;border:solid grey 1px;background:%s;width:1em;height:1em">&nbsp;</span>&nbsp;%s', data[i].c, data[i].n))
		end
		agg(ss,'<p style="font-size:90%; margin-left:10px">')
		agg(ss,table.concat(ss2," · "))
		agg(ss,'</p>')
	elseif show ==2 then
		for i=1,num do
			agg(ss2,string.format('<span style="display:inline-block;border:solid grey 1px;background:%s;width:1em;height:1em">&nbsp;</span>&nbsp;%s %s', data[i].c, data[i].p, data[i].n))
		end
		agg(ss,'<p style="font-size:90%; margin-left:10px">')
		agg(ss,table.concat(ss2,"<br/>"))
		agg(ss,'</p>')
	end
	if args['debug'] then
		return mw.text.jsonEncode(graph)
	else
		return table.concat(ss)
	end
end

function p.parliament(frame)
	return select(2, xpcall(function()
		return p._parliament(getArgs(frame, { parentOnly = true }))
	end, errhandler))
end

return p