Chart

Documentation for this module may be created at Module:Chart/doc

local keywords = {
	pieChart     = "pie chart",
	slices       = "slices",
	slice        = "slice",
	radius       = "radius",
	innerRadius  = "inner radius",
	innerPercent = "inner percent",
}

local defColors = mw.loadData("Module:Chart/Default colors")

local function nulOrWhitespace(s)
	return not s or mw.text.trim(s) == ""
end

local function pieChart(frame)
	local args, lang = frame.args, mw.getContentLanguage()
	local function getArg(k, def) return args[keywords[k]] or def or "" end

	-- parse slices: (value:name:color:link)
	local delimiter = args.delimiter or ":"
	local values, colors, names, links = {}, {}, {}, {}

	local fallbackPalette = { "red","blue","green","yellow","fuchsia","aqua","brown","orange","purple","sienna" }

	local function addSlice(i, slice)
		local v, name, col, link = unpack(mw.text.split(slice, "%s*"..delimiter.."%s*"))
		values[i] = tonumber(lang:parseFormattedNumber(v)) or error(("Slice %d not a number: %s"):format(i, v or ""))

		-- name normalization for lookup
		local normName = name and mw.text.trim(name) or nil

		-- resolve color priority: explicit > lookup by name > fallback palette rotation
		if not nulOrWhitespace(col) then
			colors[i] = col
		elseif normName and defColors[normName] then
			colors[i] = defColors[normName]
		else
			colors[i] = fallbackPalette[((i - 1) % #fallbackPalette) + 1]
		end

		if not nulOrWhitespace(name) then
			names[i] = name
		elseif not nulOrWhitespace(link) then
			names[i] = link
		else
			names[i] = "?"
		end
		links[i]  = link or ""
	end

	local i = 0
	local slicesStr = getArg("slices")
	for s in (slicesStr or ""):gmatch("%b()") do
		i = i + 1
		addSlice(i, s:match("^%(%s*(.-)%s*%)$"))
	end
	for k,v in pairs(args) do
		local ind = k:match("^"..keywords.slice.."%s+(%d+)$")
		if ind then addSlice(tonumber(ind), v) end
	end
	if #values == 0 then error("no slices found") end

	-- radii
	local radius = tonumber(getArg("radius", 100)) or 100
	local innerPx = tonumber(getArg("innerRadius",""))
	local innerPct = tonumber(getArg("innerPercent",""))
	local innerR = innerPx and math.max(0, math.min(radius-1, innerPx))
		or (innerPct and radius * math.max(0, math.min(99, innerPct))/100)
		or math.floor(radius * 0.6)

	local size = radius*2
	local stroke = 1
	local pad = stroke/2
	local viewSize = size + stroke
	local cx, cy = radius + pad, radius + pad

	-- arc helpers
	local function arc(x, y, r, a1, a2)
		local x1, y1 = x + r*math.cos(a1), y + r*math.sin(a1)
		local x2, y2 = x + r*math.cos(a2), y + r*math.sin(a2)
		local large = (a2-a1) % (2*math.pi) > math.pi and 1 or 0
		return string.format("A %.3f %.3f 0 %d 1 %.3f %.3f", r, r, large, x2, y2), x1, y1, x2, y2
	end

	local function arcInner(x, y, r, a1, a2)
		local x1, y1 = x + r*math.cos(a1), y + r*math.sin(a1)
		local x2, y2 = x + r*math.cos(a2), y + r*math.sin(a2)
		local large = (a1-a2) % (2*math.pi) > math.pi and 1 or 0
		return string.format("A %.3f %.3f 0 %d 0 %.3f %.3f", r, r, large, x2, y2), x1, y1, x2, y2
	end

	-- build SVG
	local total = 0 for _,v in ipairs(values) do total = total + v end
	local angle = -math.pi/2
	local paths = {}

	for idx,v in ipairs(values) do
		if #values == 1 then
			local tooltip = (names[idx] ~= "" and names[idx] or "?") .. ": " .. v
			local outer = string.format('<circle cx="%.3f" cy="%.3f" r="%.3f" fill="%s" stroke="#fff" stroke-width="1"/>',
				cx, cy, radius, colors[idx])
			local inner = string.format('<circle cx="%.3f" cy="%.3f" r="%.3f" fill="black"/>',
				cx, cy, innerR)
			local group = string.format('<g><title>%s</title>%s%s</g>', mw.text.encode(tooltip), outer, inner)
			if not nulOrWhitespace(links[idx]) then
				local titleObj = mw.title.new(links[idx])
				if titleObj then
					local url = titleObj:localUrl()
					group = string.format('<a xlink:href="%s">%s</a>', mw.text.encode(url), group)
				end
			end
			table.insert(paths, group)
		else
			local a1 = angle
			local a2 = angle + (v/total)*2*math.pi
			local outerArc, xOuterStart, yOuterStart = arc(cx, cy, radius, a1, a2)
			local innerArc, xInnerStart, yInnerStart = arcInner(cx, cy, innerR, a2, a1)
			local d = string.format("M %.3f %.3f %s L %.3f %.3f %s Z",
				xOuterStart, yOuterStart, outerArc, xInnerStart, yInnerStart, innerArc)
			local tooltip = (names[idx] ~= "" and names[idx] or "?") .. ": " .. v
			local path = string.format('<path d="%s" fill="%s" stroke="#fff" stroke-width="1"><title>%s</title></path>',
				d, colors[idx], mw.text.encode(tooltip))
			if not nulOrWhitespace(links[idx]) then
				local titleObj = mw.title.new(links[idx])
				if titleObj then
					local url = titleObj:localUrl()
					path = string.format('<a xlink:href="%s">%s</a>', mw.text.encode(url), path)
				end
			end
			table.insert(paths, path)
			angle = a2
		end
	end

	local svg = string.format(
		'<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" ' ..
		'width="%d" height="%d" viewBox="0 0 %d %d" style="background:none">%s</svg>',
		size, size, viewSize, viewSize, table.concat(paths, "\n")
	)

	return frame:callParserFunction{ name = "#tag", args = { "html", svg } }
end

return { [keywords.pieChart] = pieChart }