Модуль:Box-header

local getArgs = require('Модуль:Arguments').getArgs

local p = {}
---------- Config data ----------
local namedColours = mw.loadData( 'Модуль: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 left-to-right, i.e. `['one'] = { 'two', 'three' }` is equivalent to using `{{{one| {{{two| {{{three|}}} }}} }}}` in a template
local parameterAliases = {
	['1'] = 1,
	['2'] = 2,
	['colour'] = 'color',
	['hidden'] = 'hide'
}

---------- Dependecies ----------
local colourContrastModule = require('Модуль: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 border = 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 border, 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 boxCollapsibleDiv(args)
	local tag = mw.html.create('div', {selfClosing = true})
		:addClass('mw-collapsible' .. (getParam(args, 'hidden') and 'mw-collapsed' or ''))
	return toOpenTagString(tag)
end	

local function boxHeaderOuter(args)
	local baseStyle = {
		clear = 'both',
		['box-sizing'] = 'border-box',
		border = ( getParam(args, 'border-type') or 'solid' ) .. ' ' .. ( getParam(args, 'titleborder') or getParam(args, 'border') 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 'center',
		['font-family'] = getParam(args, 'font-family') or 'sans-serif',
		['font-size'] = getParam(args, 'titlefont-size') or '100%',
		['margin-bottom'] = '0px',
	}


	local tag = mw.html.create('div', {selfClosing = true})
		:addClass('box-header-title-container')
		:addClass('flex-columns-noflex')
		:css(baseStyle)
		:css('border-width', ( getParam(args, 'border-top') or getParam(args, 'border-width') or '1' ) .. 'px ' .. ( getParam(args, 'border-width') or '1' ) .. 'px 0')
		:css('padding-top', getParam(args, 'padding-top') or '.1em')
		:css('padding-left', getParam(args, 'padding-left') or '.1em')
		:css('padding-right', getParam(args, 'padding-right') or '.1em')
		:css('padding-bottom', getParam(args, 'padding-bottom') or '.1em')
		:css('moz-border-radius', getParam(args, 'title-border-radius') or '0')
		:css('webkit-border-radius', getParam(args, 'title-border-radius') or '0')
		:css('border-radius', getParam(args, 'title-border-radius') or '0')
	return toOpenTagString(tag)
end

local function boxHeaderTopLinks(args)
	local style = {
		float = 'right',
		['margin-bottom'] = '.1em',
		['font-size'] = getParam(args, 'font-size') or '80%',
		color = getParam(args, 'titleforeground') or '#000'
	}
	local tag = mw.html.create('div', {selfClosing = true})
		:addClass('plainlinks noprint' )
		:css(style)
	return toOpenTagString(tag)
end

local function boxHeaderCollapsibleButton()
	local tag = mw.html.create('span')
		:addClass('mw-collapsible-toggle-placeholder')

	return tostring(tag)
end

local function boxHeaderEditLink(args)
	local page = getParam(args, 'editpage')
	if not page or page == '{{{2}}}'
	then
		return ''
	end
	local style = {
		color = getParam(args, 'titleforeground') or '#000'
	}
	local tag = mw.html.create('span')
		:css(style)
		:wikitext('редагувати')
	local linktext = tostring(tag)
	local linktarget = tostring(mw.uri.fullUrl(page, {action='edit', section=getParam(args, 'section')}))
	return '[' .. linktarget  .. ' ' .. linktext .. ']&nbsp;'
end

local function boxHeaderViewLink(args)
	local style = {
		color = getParam(args, 'titleforeground') or '#000'
	}
	local tag = mw.html.create('span')
		:css(style)
		:wikitext('переглянути')
	local linktext = tostring(tag)
	local linktarget = ':' .. getParam(args, 'viewpage')
	return "<b>·</b>&nbsp;[[" .. linktarget  .. '|' .. linktext .. ']]&nbsp;'
end

local function boxHeaderTitle(args)
	local baseStyle = {
		['font-family'] = getParam(args, 'title-font-family') or 'sans-serif',
		['font-size'] = getParam(args, 'title-font-size') or '100%',
		['font-weight'] = getParam(args, 'title-font-weight') or 'bold',
		border = 'none',
		margin = '0',
		padding = '0',
		color = getParam(args, 'titleforeground') or '#000';
	}
	local tagName = getParam(args, 'SPAN') and 'span' or 'h2'
	local tag = mw.html.create(tagName)
		:css(baseStyle)
		:css('padding-bottom', '.1em')
		:wikitext(getParam(args, 'title'))
	if getParam(args, 'extra') then
		local rules = mw.text.split(getParam(args, 'extra'), ';', true)
		for _, rule in pairs(rules) do
			local parts = mw.text.split(rule, ':', true)
			local prop = parts[1]
			local val = parts[2]
			if prop and val then
				tag:css(prop, val)
			end
		end
	end
	return tostring(tag)
end

local function boxBody(args)
	local baseStyle = {
		['box-sizing'] = 'border-box',
		border = ( getParam(args, 'border-width') or '1' ) .. 'px solid ' .. ( getParam(args, 'border') or '#ababab'),
		['vertical-align'] = 'top';
		background = getParam(args, 'background') or '#fefeef',
		opacity = getParam(args, 'background-opacity') or '1',
		color = getParam(args, 'foreground') or '#000',
		['text-align'] = getParam(args, 'text-align') or 'left',
		margin = '0 0 10px',
		padding = getParam(args, 'padding') or '1em',
	}
	local tag = mw.html.create('div', {selfClosing = true})
		:addClass(args.collapsible and 'mw-collapsible-content' or '')
		:css(baseStyle)
		:css('border-top-width', ( getParam(args, 'border-top') or '1' ) .. 'px')
		:css('padding-top', getParam(args, 'padding-top') or '.3em')
		:css('border-radius', getParam(args, 'border-radius') or '0')
	return toOpenTagString(tag)
end

local function contrastCategories(args)
	local cats = ''

	local titleText = nameToHexTriplet(getParam(args, 'titleforeground')) or normaliseHexTriplet(getParam(args, 'titleforeground')) or '#000000'
	local titleBackground = nameToHexTriplet(getParam(args, 'titlebackground')) or normaliseHexTriplet(getParam(args, 'titlebackground')) or '#bcbcbc'
	local titleContrast = colourContrastModule._ratio({titleBackground, titleText})
	local insufficientTitleContrast = type(titleContrast) == 'number' and ( titleContrast < min_contrast_ratio_large_text )

	local bodyText = nameToHexTriplet(getParam(args, 'foreground')) or normaliseHexTriplet(getParam(args, 'foreground')) or '#000000'
	local bodyBackground = nameToHexTriplet(getParam(args, 'background')) or normaliseHexTriplet(getParam(args, 'background')) or '#fefeef'
	local bodyContrast =  colourContrastModule._ratio({bodyBackground, bodyText})
	local insufficientBodyContrast = type(bodyContrast) == 'number' and ( bodyContrast < min_contrast_ratio_normal_text )

	if insufficientTitleContrast and insufficientBodyContrast then
		return '[[Категорія:Box-header із недостатнім контрастом title]][[Категорія:Box-header із недостатнім контрастом body]]'
	elseif insufficientTitleContrast then
		return '[[Категорія:Box-header із недостатнім контрастом title]]'
	elseif insufficientBodyContrast then
		return '[[Категорія:Box-header із недостатнім контрастом body]]'
	else
		return ''
	end
end

---------- Main functions / entry points ----------

-- Entry point for templates (manually-specified colours)
function p.boxHeader(frame)
	local args = getArgs(frame)
	local page = args.editpage
	if not args.editpage or args.editpage == '' then
		page = mw.title.getCurrentTitle().prefixedText
	end
	local output = p._boxHeader(args, page)
	if mw.ustring.find(output, '{') then
		return frame:preprocess(output)
	end
	return output
end

-- Entry point for modules (manually-specified colours)
function p._boxHeader(_args, page)
	local args = setCleanArgs(_args)
	if page and not args.editpage then
		args.editpage = page
	end
	if not args.title then
		args.title = '{{{title}}}'
	end
	args.collapsible = getParam(args, 'collapsible')
	local output = {}
	if args.collapsible then
		table.insert(output, boxCollapsibleDiv(args))
	end
	table.insert(output, boxHeaderOuter(args))
	if args.collapsible then
		table.insert(output, boxHeaderCollapsibleButton())
	end
	if not getParam(args, 'EDITLINK') then
		table.insert(output, boxHeaderTopLinks(args))
		if not getParam(args, 'noedit') then
			table.insert(output, boxHeaderEditLink(args))
		end
		if getParam(args, 'viewpage') then
			table.insert(output, boxHeaderViewLink(args))
		end
		if getParam(args, 'top') then
			table.insert(output, getParam(args, 'top') .. '&nbsp;')
		end
		table.insert(output, '</div>')
	end
	table.insert(output, boxHeaderTitle(args))
	table.insert(output, '</div>')
	table.insert(output, boxBody(args))
	if not getParam(args, 'TOC') then
		table.insert(output, '__NOTOC__')
	end
	if not getParam(args, 'EDIT') then
		table.insert(output, '__NOEDITSECTION__')
	end
	table.insert(output, contrastCategories(args))

	return table.concat(output)
end

-- Entry point for templates (automatically calculated colours)
function p.autoColour(frame)
	local args = getArgs(frame)
	local colourParam = getParam(args, 'colour')
	local generatedColour = nil
	if not colourParam or colourParam == '' then
		-- convert the root page name into a number and use that
		local root = mw.title.getCurrentTitle().rootPageTitle.prefixedText
		local rootStart = mw.ustring.sub(root, 1, 12)
		local digitsFromRootStart = mw.ustring.gsub(rootStart, ".", function(s) return math.fmod(string.byte(s, 2) or string.byte(s, 1), 10) end)
		local numberFromRoot = tonumber(digitsFromRootStart, 10)
		generatedColour = math.fmod(numberFromRoot, 360)
	end
	local output = p._autoColour(args, generatedColour)
	if mw.ustring.find(output, '{') then
		return frame:preprocess(output)
	end
	return output
end

-- Entry point for modules (automatically calculated colours)
function p._autoColour(_args, generatedColour)
	local args = setCleanArgs(_args)
	local hue = generatedColour or findHue(getParam(args, 'colour'))
	local mode = normaliseMode(getParam(args, 'mode'))
	local border, titleForeground, titleBackground, contentForeground, contentBackground = makeColours(hue, mode)
	local boxTemplateArgs = mergeTables(args, {
		title = getParam(args, '1') or '{{{1}}}',
		editpage = getParam(args, '2') or '',
		noedit = getParam(args, '2') and '' or 'yes',
		border = border,
		titleforeground = titleForeground,
		titlebackground = titleBackground,
		foreground = contentForeground,
		background = contentBackground
	})
	return p._boxHeader(boxTemplateArgs)
end
	
return p