--
-- This module implements {{Navbox}}
--

local p = {}

local getArgs -- lazily initialized

local args
local border
local listnums
local ODD_EVEN_MARKER = '\127_ODDEVEN_\127'
local RESTART_MARKER = '\127_ODDEVEN0_\127'
local REGEX_MARKER = '\127_ODDEVEN(%d?)_\127'

local lists = {
	plainlist_t = {
		patterns = {
			'^plainlist$',
			'%splainlist$',
			'^plainlist%s',
			'%splainlist%s'
		},
		found = false,
		styles = 'Plainlist/styles.css'
	},
	hlist_t = {
		patterns = {
			'^hlist$',
			'%shlist$',
			'^hlist%s',
			'%shlist%s'
		},
		found = false,
		styles = 'Hlist/styles.css'
	}
}

local function has_list_class(args_to_check)
	for _, list in pairs(lists) do
		if not list.found then
			for _, arg in pairs(args_to_check) do
				for _, pattern in ipairs(list.patterns) do
					if mw.ustring.find(arg or '', pattern) then
						list.found = true
						break
					end
				end
				if list.found then break end
			end
		end
	end
end

local function striped(wikitext)
	-- Return wikitext with markers replaced for odd/even striping.
	-- Child (subgroup) navboxes are flagged with a category that is removed
	-- by parent navboxes. The result is that the category shows all pages
	-- where a child navbox is not contained in a parent navbox.
	local orphanCat = '[[Category:孤立的子导航框]]'
	if border == 'subgroup' and args.orphan ~= 'yes' then
		-- No change; striping occurs in outermost navbox.
		return wikitext .. orphanCat
	end
	local first, second = 'odd', 'even'
	if args.evenodd then
		if args.evenodd == 'swap' then
			first, second = second, first
		else
			first = args.evenodd
			second = first
		end
	end
	local changer
	if first == second then
		changer = first
	else
		local index = 0
		changer = function (code)
			if code == '0' then
				-- Current occurrence is for a group before a nested table.
				-- Set it to first as a valid although pointless class.
				-- The next occurrence will be the first row after a title
				-- in a subgroup and will also be first.
				index = 0
				return first
			end
			index = index + 1
			return index % 2 == 1 and first or second
		end
	end
	local regex = orphanCat:gsub('([%[%]])', '%%%1')
	return (wikitext:gsub(regex, ''):gsub(REGEX_MARKER, changer))  -- () omits gsub count
end

local function processItem(item, nowrapitems)
	if item:sub(1, 2) == '{|' then
		-- Applying nowrap to lines in a table does not make sense.
		-- Add newlines to compensate for trim of x in |parm=x in a template.
		return '\n' .. item ..'\n'
	end
	if nowrapitems == 'yes' then
		local lines = {}
		for line in (item .. '\n'):gmatch('([^\n]*)\n') do
			local prefix, content = line:match('^([*:;#]+)%s*(.*)')
			if prefix and not content:match('^<span class="nowrap">') then
				line = prefix .. '<span class="nowrap">' .. content .. '</span>'
			end
			table.insert(lines, line)
		end
		item = table.concat(lines, '\n')
	end
	if item:match('^[*:;#]') then
		return '\n' .. item ..'\n'
	end
	return item
end

local function has_collapsible_toggle()
	return args.state ~= 'off'
		and args.state ~= 'plain'
end

local function has_navbar()
	return args.navbar ~= 'off'
		and args.navbar ~= 'plain'
		and (
			args.name
			or (
				mw.getCurrentFrame():getParent():getTitle():gsub('/sandbox$', '')
					~= 'Template:Navbox' and
				mw.getCurrentFrame():getParent():getTitle():gsub('/sandbox$', '')
					~= 'Template:Navbox subgroup'
			)
		)
end

-- extract text color from css, which is the only permitted inline CSS for the navbar
local function extract_color(css_str)
	-- return nil because navbar takes its argument into mw.html which handles
	-- nil gracefully, removing the associated style attribute
	return mw.ustring.match(';' .. css_str .. ';', '.*;%s*([Cc][Oo][Ll][Oo][Rr]%s*:%s*.-)%s*;') or nil
end

local function renderNavBar(titleCell)

	if has_navbar() then
		local navbar = require('Module:Navbar/sandbox')._navbar
		titleCell:wikitext(navbar{
			args.name,
			mini = 1,
			fontstyle = extract_color(
				(args.basestyle or '') .. ';' .. (args.titlestyle or '')
			)
		})
	end

end

--
--   Title row
--
local function renderTitleRow(tbl)
	if not args.title then return end

	has_list_class({args.titleclass})

	local titleRow = tbl:tag('tr')

	local titleCell = titleRow:tag('th'):attr('scope', 'col')

	if has_collapsible_toggle() then
		titleCell
			:addClass('collapsible-title')
	end

	local titleColspan = 2
	if args.imageleft then titleColspan = titleColspan + 1 end
	if args.image then titleColspan = titleColspan + 1 end

	titleCell
		:cssText(args.basestyle)
		:cssText(args.titlestyle)
		:addClass('navbox-div-title')
		:attr('colspan', titleColspan)

	renderNavBar(titleCell)

	titleCell
		:tag('div')
			-- id for aria-labelledby attribute
			:attr('id', mw.uri.anchorEncode(args.title))
			:addClass(args.titleclass)
			:css('font-size', '110%')
			:css('margin', '0 5em')
			:wikitext(processItem(args.title))
end

--
--   Above/Below rows
--

local function getAboveBelowColspan()
	local ret = 2
	if args.imageleft then ret = ret + 1 end
	if args.image then ret = ret + 1 end
	return ret
end

local function renderAboveRow(tbl)
	if not args.above then return end

	has_list_class({ args.aboveclass })

	tbl:tag('tr')
		:tag('td')
			:addClass('navbox-div-abovebelow')
			:addClass(args.aboveclass)
			:cssText(args.basestyle)
			:cssText(args.abovestyle)
			:attr('colspan', getAboveBelowColspan())
			:tag('div')
				-- id for aria-labelledby attribute, if no title
				:attr('id', (not args.title) and mw.uri.anchorEncode(args.above) or nil)
				:wikitext(processItem(args.above, args.nowrapitems))
end

local function renderBelowRow(tbl)
	if not args.below then return end

	has_list_class({ args.belowclass })

	tbl:tag('tr')
		:tag('td')
			:addClass('navbox-div-abovebelow')
			:addClass(args.belowclass)
			:cssText(args.basestyle)
			:cssText(args.belowstyle)
			:attr('colspan', getAboveBelowColspan())
			:tag('div')
				:wikitext(processItem(args.below, args.nowrapitems))
end

--
--   List rows
--
local function renderListRow(tbl, index, listnum)
	local row = tbl:tag('tr')

	if index == 1 and args.imageleft then
		has_list_class({ args.imageclass })

		row
			:tag('td')
				:addClass('noviewer')
				:addClass('navbox-div-image')
				:addClass(args.imageclass)
				:css('width', '1px')               -- Minimize width
				:css('padding', '0px 2px 0px 0px')
				:cssText(args.imageleftstyle)
				:attr('rowspan', #listnums)
				:tag('div')
					:wikitext(processItem(args.imageleft))
	end

	if args['group' .. listnum] then
		has_list_class({ args.groupclass })

		local groupCell = row:tag('th')

		-- id for aria-labelledby attribute, if lone group with no title or above
		if listnum == 1 and not (args.title or args.above or args.group2) then
			groupCell
				:attr('id', mw.uri.anchorEncode(args.group1))
		end

		groupCell
			:attr('scope', 'row')
			:addClass('navbox-div-group')
			:addClass(args.groupclass)
			:cssText(args.basestyle)
			:css('width', args.groupwidth or '1%') -- If groupwidth not specified, minimize width

		groupCell
			:cssText(args.groupstyle)
			:cssText(args['group' .. listnum .. 'style'])
			:wikitext(args['group' .. listnum])
	end

	has_list_class({ args.listclass, args['list' .. listnum .. 'class'] })

	local listCell = row:tag('td')

	if args['group' .. listnum] then
		listCell
			:addClass('navbox-div-list-with-group')
	else
		listCell:attr('colspan', 2)
	end

	if not args.groupwidth then
		listCell:css('width', '100%')
	end

	local rowstyle  -- usually nil so cssText(rowstyle) usually adds nothing
	if index % 2 == 1 then
		rowstyle = args.oddstyle
	else
		rowstyle = args.evenstyle
	end

	local listText = args['list' .. listnum]
	local oddEven = ODD_EVEN_MARKER
	if listText:sub(1, 12) == '</div><table' then
		-- Assume list text is for a subgroup navbox so no automatic striping for this row.
		oddEven = listText:find('<th[^>]*["? ?]navbox%-title"') and RESTART_MARKER or 'odd'
	end
	listCell
		:css('padding', '0px')
		:cssText(args.liststyle)
		:cssText(rowstyle)
		:cssText(args['list' .. listnum .. 'style'])
		:addClass('navbox-div-list')
		:addClass('navbox-div-' .. oddEven)
		:addClass(args.listclass)
		:addClass(args['list' .. listnum .. 'class'])
		:tag('div')
			:css('padding', (index == 1 and args.list1padding) or args.listpadding or '0em 0.25em')
			:wikitext(processItem(listText, args.nowrapitems))

	if index == 1 and args.image then
		has_list_class({ args.imageclass })

		row
			:tag('td')
				:addClass('noviewer')
				:addClass('navbox-div-image')
				:addClass(args.imageclass)
				:css('width', '1px')               -- Minimize width
				:css('padding', '0px 0px 0px 2px')
				:cssText(args.imagestyle)
				:attr('rowspan', #listnums)
				:tag('div')
					:wikitext(processItem(args.image))
	end
end

--
--   Tracking categories
--

local function needsHorizontalLists()
	if border == 'subgroup' or args.tracking == 'no' then
		return false
	end

	return not lists.hlist_t.found and not lists.plainlist_t.found
end

local function hasBackgroundColors()
	for _, key in ipairs({'titlestyle', 'groupstyle', 'basestyle', 'abovestyle', 'belowstyle'}) do
		if tostring(args[key]):find('background', 1, true) then
			return true
		end
	end
end

local function hasBorders()
	for _, key in ipairs({'groupstyle', 'basestyle', 'abovestyle', 'belowstyle'}) do
		if tostring(args[key]):find('border', 1, true) then
			return true
		end
	end
end

local function isIllegible()
	local styleratio = require('Module:Color contrast')._styleratio

	for key, style in pairs(args) do
		if tostring(key):match("style$") then
			if styleratio{mw.text.unstripNoWiki(style)} < 4.5 then
				return true
			end
		end
	end
	return false
end

local function argNameAndRealTitleAreDifferent()
	if border == 'subgroup' or args.tracking == 'no' then
		return false
	end

	if has_navbar() and args.name ~= mw.title.getCurrentTitle().text then
		return true
	end

	return false
end

local function getTrackingCategories()
	local cats = {}
	if needsHorizontalLists() then table.insert(cats, '没有使用水平列表的导航框') end
	if hasBackgroundColors() then table.insert(cats, '使用背景颜色的导航框') end
	if isIllegible() then table.insert(cats, '可能难以辨认的导航框') end
	if hasBorders() then table.insert(cats, '使用边框的导航框') end
	if argNameAndRealTitleAreDifferent() then table.insert(cats, 'name參數和實際不同的導航框') end
	return cats
end

local function renderTrackingCategories(builder)
	local title = mw.title.getCurrentTitle()
	if title.namespace ~= 10 then return end -- not in template space
	local subpage = title.subpageText
	if subpage == 'doc' or subpage == 'sandbox' or subpage == 'testcases' then return end

	for _, cat in ipairs(getTrackingCategories()) do
		builder:wikitext('[[Category:' .. cat .. ']]')
	end
end

--
-- Load the templatestyles for the navbox
--
local function loadTemplateStyles(hiding_templatestyles)
	local frame = mw.getCurrentFrame()

	local hlist_templatestyles = ''
	if lists.hlist_t.found then
		hlist_templatestyles = frame:extensionTag{
			name = 'templatestyles', args = { src = lists.hlist_t.styles }
		}
	end

	-- a second workaround for [[phab:T303378]]
	-- when that issue is fixed, we can actually use has_navbar not to emit the
	-- tag here if we want
	if has_navbar() and hlist_templatestyles == '' then
		hlist_templatestyles = frame:extensionTag{
			name = 'templatestyles', args = { src = lists.hlist_t.styles }
		}
	end

	local plainlist_templatestyles = ''
	if lists.plainlist_t.found then
		plainlist_templatestyles = frame:extensionTag{
			name = 'templatestyles', args = { src = lists.plainlist_t.styles }
		}
	end

	local base_templatestyles = frame:extensionTag{
		name = 'templatestyles', args = { src = 'Module:Navbox/div/styles.css' }
	}

	local templatestyles = ''
	if args['templatestyles'] then
		templatestyles = frame:extensionTag{
			name = 'templatestyles', args = { src = args['templatestyles'] }
		}
	end

	local child_templatestyles = ''
	if args['child templatestyles'] then
		child_templatestyles = frame:extensionTag{
			name = 'templatestyles', args = { src = args['child templatestyles'] }
		}
	end

	return mw.html.create('div')
		:addClass('navbox-div-styles')
		:wikitext(
			-- hlist -> plainlist -> base is best-effort to preserve old Common.css ordering.
			-- this ordering is not a guarantee because the rows of interest invoking
			-- each class may not be on a specific page
			hlist_templatestyles ..
			plainlist_templatestyles ..
			base_templatestyles ..
			templatestyles ..
			child_templatestyles ..
			table.concat(hiding_templatestyles)
		)
		:done()
end

-- work around [[phab:T303378]]
-- for each arg: find all the templatestyles strip markers, insert them into a
-- table. then remove all templatestyles markers from the arg
local function move_hiding_templatestyles(args)
	local gfind = string.gfind
	local gsub = string.gsub
	local templatestyles_markers = {}
	local strip_marker_pattern = '(\127[^\127]*UNIQ%-%-templatestyles%-%x+%-QINU[^\127]*\127)'
	for k, arg in pairs(args) do
		for marker in gfind(arg, strip_marker_pattern) do
			table.insert(templatestyles_markers, marker)
		end
		args[k] = gsub(arg, strip_marker_pattern, '')
	end
	return templatestyles_markers
end

--
--   Main navbox tables
--
local function renderMainTable()
	local tbl = mw.html.create('table')
		:addClass('nowraplinks')
		:addClass(args.bodyclass)

		has_list_class({ args.bodyclass })

	if args.title and has_collapsible_toggle() then
		if args.state == 'collapsed' then args.state = 'mw-collapsed' end
		tbl
			:addClass('mw-collapsible')
			:addClass(args.state or 'autocollapse')
	end

	tbl:css('border-spacing', 0)
	if border == 'subgroup' or border == 'none' then
		tbl
			:addClass('navbox-div-subgroup')
			:cssText(args.bodystyle)
			:cssText(args.style)
	else  -- regular navbox - bodystyle and style will be applied to the wrapper table
		tbl
			:addClass('navbox-div-inner')
			:css('background', 'transparent')
			:css('color', 'inherit')
	end
	tbl:cssText(args.innerstyle)

	renderTitleRow(tbl)
	renderAboveRow(tbl)
	for i, listnum in ipairs(listnums) do
		renderListRow(tbl, i, listnum)
	end
	renderBelowRow(tbl)

	return tbl
end

function p._navbox(navboxArgs)
	args = navboxArgs
	local hiding_templatestyles = move_hiding_templatestyles(args)
	listnums = {}

	for k, _ in pairs(args) do
		if type(k) == 'string' then
			local listnum = k:match('^list(%d+)$')
			if listnum then table.insert(listnums, tonumber(listnum)) end
		end
	end
	table.sort(listnums)

	border = mw.text.trim(args.border or args[1] or '')
	if border == 'child' then
		border = 'subgroup'
	end

	-- render the main body of the navbox
	local tbl = renderMainTable()

	-- render the appropriate wrapper around the navbox, depending on the border param
	local res = mw.html.create()
	if border == 'none' then
		res:node(loadTemplateStyles(hiding_templatestyles))
		local nav = res:tag('div')
			:attr('role', 'navigation')
			:node(tbl)
		-- aria-labelledby title, otherwise above, otherwise lone group
		if args.title or args.above or (args.group1 and not args.group2) then
			nav:attr('aria-labelledby', mw.uri.anchorEncode(args.title or args.above or args.group1))
		else
			nav:attr('aria-label', 'Navbox')
		end
	elseif border == 'subgroup' then
		-- We assume that this navbox is being rendered in a list cell of a parent navbox, and is
		-- therefore inside a div with padding:0em 0.25em. We start with a </div> to avoid the
		-- padding being applied, and at the end add a <div> to balance out the parent's </div>
		res
			:wikitext('</div>')
			:node(tbl)
			:wikitext('<div>')
	else
		res:node(loadTemplateStyles(hiding_templatestyles))

		has_list_class({ args.navboxclass })

		local nav = res:tag('div')
			:attr('role', 'navigation')
			:addClass('navbox')
			:addClass(args.navboxclass)
			:cssText(args.bodystyle)
			:cssText(args.style)
			:css('padding', '3px')
			:node(tbl)
		-- aria-labelledby title, otherwise above, otherwise lone group
		if args.title or args.above or (args.group1 and not args.group2) then
			nav:attr('aria-labelledby', mw.uri.anchorEncode(args.title or args.above or args.group1))
		else
			nav:attr('aria-label', 'Navbox')
		end
	end

	if (args.nocat or 'false'):lower() == 'false' then
		renderTrackingCategories(res)
	end
	return striped(tostring(res))
end

function p.navbox(frame)
	if not getArgs then
		getArgs = require('Module:Arguments').getArgs
	end
	args = getArgs(frame, {wrappers = {'Template:Navbox', 'Template:Navbox subgroup'}})
	if frame.args.border then
		-- This allows Template:Navbox_subgroup to use {{#invoke:Navbox|navbox|border=...}}.
		args.border = frame.args.border
	end

	-- Read the arguments in the order they'll be output in, to make references number in the right order.
	local _
	_ = args.title
	_ = args.above
	for i = 1, 35 do
		_ = args["group" .. tostring(i)]
		_ = args["list" .. tostring(i)]
	end
	_ = args.below

	return p._navbox(args)
end

return p