local getArgs = require('Module:Arguments').getArgs  
local p = {}
---------- Config data ----------
local namedColours = mw.loadData( 'Module:Box-header/colours' )
local modes = {
lightest = { sat=0.10, val=1.00 },
light = { sat=0.15, val=0.95 },
normal = { sat=0.40, val=0.85 },
dark = { sat=0.90, val=0.70 },
darkest = { sat=1.00, val=0.45 },
content = { sat=0.04, val=1.00 },
grey = { sat=0.00 }
}
local min_contrast_ratio_normal_text = 7 -- i.e 7:1
local min_contrast_ratio_large_text = 4.5 -- i.e. 4.5:1  
-- Template parameter aliases
-- Specify each as either a single value, or a table of values
-- Aliases are checked -to-, i.e. `['one'] = { 'two', 'three' }` is equivalent to using `}` in a template
local parameterAliases = {
['1'] = 1,
['2'] = 2,
['colour'] = 'color'
}  
---------- Dependecies ----------
local colourContrastModule = require('Module:Color contrast')
local hex = require( 'luabit.hex' )  
---------- Utility functions ----------
local function getParam(args, parameter)
if args[parameter] then
return args[parameter]
end
local aliases = parameterAliases[parameter]
if not aliases then
return nil
end
if type(aliases) ~= 'table' then
return args[aliases]
end
for _, alias in ipairs(aliases) do
if args[alias] then
return args[alias]
end
end
return nil
end  
local function setCleanArgs(argsTable)
local cleanArgs = {}
for key, val in pairs(argsTable) do
if type(val) == 'string' then
val = val:match('^%s*(.-)%s*$')
if val ~= '' then
cleanArgs[key] = val
end
else
cleanArgs[key] = val
end
end
return cleanArgs
end  
-- Merge two tables into a new table. If the are any duplicate keys, the values from the second overwrite the values from the first.
local function mergeTables(first, second)
local merged = {}
for key, val in pairs(first) do
merged[key] = val
end
for key, val in pairs(second) do
merged[key] = val
end
return merged
end  
local function toOpenTagString(selfClosedHtmlObject)
local closedTagString = tostring(selfClosedHtmlObject)
local openTagString = mw.ustring.gsub(closedTagString, ' />$', '>')
return openTagString
end  
local function normaliseHexTriplet(hexString)
if not hexString then return nil end
local hexComponent = mw.ustring.match(hexString, '^#(%x%x%x)$') or mw.ustring.match(hexString, '^#(%x%x%x%x%x%x)$')
if hexComponent and #hexComponent == 6 then
return mw.ustring.upper(hexString)
end
if hexComponent and #hexComponent == 3 then
local r = mw.ustring.rep(mw.ustring.sub(hexComponent, 1, 1), 2)
local g = mw.ustring.rep(mw.ustring.sub(hexComponent, 2, 2), 2)
local b = mw.ustring.rep(mw.ustring.sub(hexComponent, 3, 3), 2)
return '#' .. mw.ustring.upper(r .. g .. b)
end
return nil
end  
---------- Conversions ----------
local function decimalToPaddedHex(number)
local prefixedHex = hex.to_hex(tonumber(number)) -- prefixed with '0x'
local padding = #prefixedHex == 3 and '0' or ''
return mw.ustring.gsub(prefixedHex, '0x', padding)
end
local function hexToDecimal(hexNumber)
return tonumber(hexNumber, 16)
end
local function RGBtoHexTriplet(R, G, B)
return '#' .. decimalToPaddedHex(R) .. decimalToPaddedHex(G) .. decimalToPaddedHex(B)
end
local function hexTripletToRGB(hexTriplet)
local R_hex, G_hex, B_hex = string.match(hexTriplet, '(%x%x)(%x%x)(%x%x)')
return hexToDecimal(R_hex), hexToDecimal(G_hex), hexToDecimal(B_hex)
end
local function HSVtoRGB(H, S, V) -- per HSL and HSV#Converting_to_RGB
local C = V * S
local H_prime = H / 60
local X = C * ( 1 - math.abs(math.fmod(H_prime, 2) - 1) )
local R1, G1, B1
if H_prime <= 1 then
R1 = C
G1 = X
B1 = 0
elseif H_prime <= 2 then
R1 = X
G1 = C
B1 = 0
elseif H_prime <= 3 then
R1 = 0
G1 = C
B1 = X
elseif H_prime <= 4 then
R1 = 0
G1 = X
B1 = C
elseif H_prime <= 5 then
R1 = X
G1 = 0
B1 = C
elseif H_prime <= 6 then
R1 = C
G1 = 0
B1 = X
end
local m = V - C
local R = R1 + m
local G = G1 + m
local B = B1 + m  
local R_255 = math.floor(R*255)
local G_255 = math.floor(G*255)
local B_255 = math.floor(B*255)
return R_255, G_255, B_255
end
local function RGBtoHue(R_255, G_255, B_255) -- per HSL and HSV#Hue and chroma
local R = R_255/255
local G = G_255/255
local B = B_255/255  
local M = math.max(R, G, B)
local m = math.min(R, G, B)
local C = M - m
local H_prime
if C == 0 then
return null
elseif M == R then
H_prime = math.fmod(((G - B)/C + 6), 6) -- adding six before taking mod ensures positive value
elseif M == G then
H_prime = (B - R)/C + 2
elseif M == B then
H_prime = (R - G)/C + 4
end
local H = 60 * H_prime
return H
end
local function nameToHexTriplet(name)
if not name then return nil end
local codename = mw.ustring.gsub(mw.ustring.lower(name), ' ', '')
return namedColours[codename]
end  
---------- Choose colours ----------
local function calculateColours(H, S, V, minContrast)
local bgColour = RGBtoHexTriplet(HSVtoRGB(H, S, V))
local textColour = colourContrastModule._greatercontrast({bgColour})
local contrast = colourContrastModule._ratio({ bgColour, textColour })
if contrast >= minContrast then
return bgColour, textColour
elseif textColour == '#FFFFFF' then
-- make the background darker and slightly increase the saturation
return calculateColours(H, math.min(1, S+0.005), math.max(0, V-0.03), minContrast)
else
-- make the background lighter and slightly decrease the saturation
return calculateColours(H, math.max(0, S-0.005), math.min(1, V+0.03), minContrast)
end
end  
local function makeColours(hue, modeName)
local mode = modes[modeName]
local isGrey = not(hue)
if isGrey then hue = 0 end  
local borderSat = isGrey and modes.grey.sat or 0.15
local = RGBtoHexTriplet(HSVtoRGB(hue, borderSat, 0.75))  
local titleSat = isGrey and modes.grey.sat or mode.sat
local titleBackground, titleForeground = calculateColours(hue, titleSat, mode.val, min_contrast_ratio_large_text)  
local contentSat = isGrey and modes.grey.sat or modes.content.sat
local contentBackground, contentForeground = calculateColours(hue, contentSat, modes.content.val, min_contrast_ratio_normal_text)  
return , titleForeground, titleBackground, contentForeground, contentBackground
end  
local function findHue(colour)
local colourAsNumber = tonumber(colour)
if colourAsNumber and ( -1 < colourAsNumber ) and ( colourAsNumber < 360) then
return colourAsNumber
end  
local colourAsHexTriplet = normaliseHexTriplet(colour) or nameToHexTriplet(colour)
if colourAsHexTriplet then
return RGBtoHue(hexTripletToRGB(colourAsHexTriplet))
end  
return null
end  
local function normaliseMode(mode)
if not mode or not modes[mw.ustring.lower(mode)] or mw.ustring.lower(mode) == 'grey' then
return 'normal'
end
return mw.ustring.lower(mode)
end
---------- Build output ----------
local function boxHeaderOuter(args)
local baseStyle = {
clear = 'both',
['box-sizing'] = '-box',
= ( getParam(args, '-type') or 'solid' ) .. ' ' .. ( getParam(args, 'titleborder') or getParam(args, '') or '#ababab' ),
background = getParam(args, 'titlebackground') or '#bcbcbc',
color = getParam(args, 'titleforeground') or '#000',
padding = getParam(args, 'padding') or '.1em',
['text-align'] = getParam(args, 'title-align') or '',
['font-family'] = getParam(args, 'font-family') or 'sans-serif',
['font-size'] = getParam(args, 'titlefont-size') or '100%',
['margin-bottom'] = '',
}  
local tag = mw.html.create('div', {selfClosing = true})
:addClass('box-header-title-container')
:addClass('flex-columns-noflex')
:css(baseStyle)
:css('-width', ( getParam(args, '-top') or getParam(args, '-width') or '1' ) .. 'px ' .. ( getParam(args, '-width') or '1' ) .. 'px 0')
:css('padding-top', getParam(args, 'padding-top') or '.1em')
:css('padding-', getParam(args, 'padding-') or '.1em')
:css('padding-', getParam(args, 'padding-') or '.1em')
:css('padding-bottom', getParam(args, 'padding-bottom') or '.1em')
:css('moz--radius', getParam(args, 'title--radius') or '0')
:css('webkit--radius', getParam(args, 'title--radius') or '0')
:css('-radius', getParam(args, 'title--radius') or '0')
return toOpenTagString(tag)
end  
local function boxHeaderTopLinks(args)
local style = {
float = '',
['margin-bottom'] = '.1em',