Modul:Navseasoncats

Daripada Wikipedia, ensiklopedia bebas.

Pendokumenan untuk modul ini boleh diciptakan di Modul:Navseasoncats/doc

local p = {}

local errors = ''
local nexistingcats = 0
local currtitle = mw.title.getCurrentTitle()
local testcasecolon = ''
local testcases = (currtitle.subpageText == 'testcases')
if    testcases then testcasecolon = ':' end
local navborder = true
local misctrackingcats = {
	[1] = '', --placeholder for [[Kategori:Navseasoncats using cat parameter]]'
	[2] = '', --placeholder for [[Kategori:Navseasoncats using testcase parameter]]'
	[3] = '', --placeholder for [[Kategori:Navseasoncats range not using en dash]]
	[4] = '', --placeholder for [[Kategori:Navseasoncats range abbreviated]]
	[5] = '', --placeholder for [[Kategori:Navseasoncats range redirected (base change)]]
	[6] = '', --placeholder for [[Kategori:Navseasoncats range redirected (MOS)]]
	[7] = '', --placeholder for [[Kategori:Navseasoncats isolated]]
	[8] = '', --placeholder for [[Kategori:Navseasoncats default season gap size]]
}
local avoidself =  (currtitle.text ~= 'Navseasoncats' and          --avoid self
					currtitle.text ~= 'Navseasoncats/doc' and      --avoid self
					currtitle.text ~= 'Navseasoncats/sandbox' and  --avoid self
					(currtitle.nsText ~= 'Template' or testcases)) --avoid nested transclusion errors (i.e. {{Infilmdecade}})


--[[==========================================================================]]
--[[                      Utility & category functions                        ]]
--[[==========================================================================]]

--Error message handling
--Also used by {{Navseasoncats with centuries below decade}}.
function p.errorclass( msg )
	return mw.text.tag( 'span', {class='error mw-ext-cite-error'}, '<b>Error!</b> '..string.gsub(msg, '&#', '&amp;#') )
end

--Failure handling
--Also used by {{Navseasoncats with centuries below decade}}.
function p.failedcat( errors, sortkey )
	if avoidself then
		return (errors or '')..'&#42;&#42;&#42;Navseasoncats failed to generate navbox***'..
			   '[['..testcasecolon..'Kategori:Navseasoncats failed to generate navbox|'..(sortkey or 'O')..']]'
	end
	return ''
end

--Check for nav*() navigational isolation (not necessarily an error).
--Used by all nav*().
function isolatedcat()
	if nexistingcats == 0 and avoidself then
		misctrackingcats[7] = '[['..testcasecolon..'Kategori:Navseasoncats isolated]]'
	end
end

--Similar to {{LinkCatIfExists2}}: make a piped link to a category, if it exists;
--if it doesn't exist, just display the greyed link title without linking.
--Used by all nav*().
function catlink( catname, displaytext )
	catname = mw.text.trim(catname or '')
	displaytext = mw.text.trim(displaytext or '')
	local grey = '#888'
	local disp = catname
	if displaytext ~= '' then --use 'displaytext' parameter if present
		disp = mw.ustring.gsub(displaytext, '%s+%(.+$', ''); --strip any trailing disambiguator
	end
	
	local catpage = mw.title.new( catname, 'Kategori' )
	if catpage.exists then
		--TODO?: ignore cat #Rs: see 2019 link on nav @ Kategori:2018 Asian Games
		--isRedirect did not change expensive function count (b/c catname passed instead of id?),
		--but isRedirect also did not recognize {{Kategori redirect}},
		--and it's not worth calling & parsing getContent, so TODONT
		nexistingcats = nexistingcats + 1
		return '[[:Kategori:'..catname..'|'..disp..']]'
	else
		return '<span style="color:'..grey..'">'..disp..'</span>'
	end
end

--Returns an unsigned string of the 1-4 digit decade ending in "0", else error.
--Used by navdecade() only.
function sterilizedec( decade )
	if decade == nil then return nil end
	
	local dec = string.match(decade, '^[-%+]?(%d?%d?%d?0)$') or 
				string.match(decade, '^[-%+]?(%d?%d?%d?0)%D')
	if dec then
		return dec
	else
		--fix 2-4 digit decade
		local decade_fixed234 = string.match(decade, '^[-%+]?(%d%d?%d?)%d%D') or
								string.match(decade, '^[-%+]?(%d%d?%d?)%d$')
		if decade_fixed234 then
			return decade_fixed234..'0'
		end
		
		--fix 1-digit decade
		local decade_fixed1   = string.match(decade, '^[-%+]?(%d)%D') or
								string.match(decade, '^[-%+]?(%d)$')
		if decade_fixed1 then
			return '0'
		end
		
		--unfixable
		errors = 'sterilizedec() error'
		return nil
	end
end

--Check for navhyphen default gap size + isolatedcat() (not necessarily an error).
--Used by navhyphen() only.
function defaultgapcat( bool )
	if bool and nexistingcats == 0 and avoidself then
		--using "nexistingcats > 0" isn't as useful, since the default gap size obviously worked
		misctrackingcats[8] = '[['..testcasecolon..'Kategori:Navseasoncats default season gap size]]'
	end
end

--Returns the target of {{Kategori redirect}}, if it exists, else returns the original cat.
--Used by navhyphen() only.
function rtarget( cat )
	local catcontent = mw.title.new( cat or '', 'Kategori' ):getContent()
	if string.match( catcontent or '', '{{ *[Cc]at' ) then
		local regex = {
			--from https://dispenser.info.tm/~dispenser/cgi-bin/rdcheck.py?page=Template:Kategori_redirect:
			--the following 11 pages redirect to Template:Kategori redirect (as of 6/2019):
			{ '1', '{{ *[Cc]ategory *[Rr]edirect' }, --most likely 1st
			{ '2', '{{ *[Cc]at *redirect' },         --444+240
			{ '3', '{{ *[Cc]at *redir' },            --8+3
			{ '4', '{{ *[Cc]ategory *move' },        --6
			{ '5', '{{ *[Cc]at *red' },              --6
			{ '6', '{{ *[Cc]atr' },                  --4
			{ '7', '{{ *[Cc]at *move' },             --0
		}
		for k, v in pairs (regex) do
			local rtarget = string.match( catcontent or '', v[2]..' *| *([^}]+)' )
			if rtarget then
				rtarget = string.gsub(rtarget, '^1 *= *', '')
				rtarget = string.gsub(rtarget, '^[Cc]ategory:', '')
				return rtarget
			end
		end
	end
	return cat
end

--12 -> 12th, etc.
--Used by navordinal() only & {{Navseasoncats with centuries below decade}}.
function p.addord( i )
	if tonumber(i) then
		local s = tostring(i)
		
		local tens = string.match(s, '1%d$')
		if    tens then return s..'th' end
		
		local  ones = string.match(s, '%d$')
		if     ones == '1' then return 'pertama' end
		return 'ke-'..s
	end
	return i
end


--[[==========================================================================]]
--[[                   Formerly separated templates/modules                   ]]
--[[==========================================================================]]


--[[============================={{  navyear  }}==============================]]

function navyear( firstpart, year, lastpart, minimumyear, maximumyear )
	--Expects a PAGENAME of the form "Some sequential 1760 example cat", where 
	--	{{{1}}}=Some sequential
	--	{{{2}}}=1760
	--	{{{3}}}=example cat
	--	{{{4}}}=1758 ('min' year parameter; optional)
	--	{{{5}}}=1800 ('max' year parameter; optional)
	year = tonumber(year) or tonumber(mw.ustring.match(year or '', '^%s*(%d*)'))
	local minyear = tonumber(string.match(minimumyear or '', '-?%d+')) or -9999    --allow +/- qualifier
	local maxyear = tonumber(string.match(maximumyear or '', '-?%d+')) or  9999    --allow +/- qualifier
	if string.match(minimumyear or '', 'BC') then minyear = -math.abs(minyear) end --allow BC qualifier (AD otherwise assumed)
	if string.match(maximumyear or '', 'BC') then maxyear = -math.abs(maxyear) end --allow BC qualifier (AD otherwise assumed)
	
	if year == nil then
		errors = p.errorclass('Function navyear can\'t recognize the year sent to its 2nd parameter.')
		return p.failedcat(errors, 'Y')
	end
	
	--AD/BC switches & vars
	
	local yearBCElastparts = { --needed for parent = AD 1-5, when the BC/E format is unknown
		--"BCE" removed to match both AD & BCE cats; easier & faster than multiple string.match()s
		['example_Hebrew people_example'] = 'BCE', --example entry format; add to & adjust as needed
	}
	local parentAD = string.match(firstpart, 'AD$')  --following the "AD 1" convention from AD 1 to AD 10
	local parentBC = string.match(lastpart, '^BCE?') --following the "1 BC" convention for all years BC
	firstpart = mw.ustring.gsub(firstpart, '%s*AD$', '') --handle AD/BC separately for easier & faster accounting
	lastpart  = mw.ustring.gsub(lastpart,  '^BCE?%s*', '')
	local BCe = parentBC or yearBCElastparts[lastpart] or 'BC' --"BC" default
	
	local year1to15AD = (year >= 1 and year <= 15 and not parentBC) --special behavior in this range
	local switchADBC = 1                 --  1=AD parent
	if parentBC then switchADBC = -1 end -- -1=BC parent; possibly adjusted later
	local Y = 0 --secondary iterator for AD-on-a-BC-parent
	
	if minyear > year*switchADBC then minyear = year*switchADBC end --input error; minyear should be <= parent
	if maxyear < year*switchADBC then maxyear = year*switchADBC end --input error; maxyear should be >= parent
	
	--determine interyear gap size to condense special category types, if possible
	local ygapdefault = 1 --assume/start at the most common case: 2001, 2002, etc.
	local ygap = ygapdefault
	if string.match(lastpart, 'presidential') then
		local ygap1, ygap2 = ygapdefault, ygapdefault --need to determine previous & next year gaps indepedently
		local ygap1_success, ygap2_success = false, false
		
		local prevseason = nil
		while ygap1 <= 5 do --Czech Republic, Poland, Sri Lanka, etc. have 5-year terms
			prevseason = firstpart..' '..(year-ygap1)..' '..lastpart
			if mw.title.new(prevseason, 'Kategori').exists then
				ygap1_success = true
				break
			end
			ygap1 = ygap1 + 1
		end
		
		local nextseason = nil
		while ygap2 <= 5 do --Czech Republic, Poland, Sri Lanka, etc. have 5-year terms
			nextseason = firstpart..' '..(year+ygap2)..' '..lastpart
			if mw.title.new(nextseason, 'Kategori').exists then
				ygap2_success = true
				break
			end
			ygap2 = ygap2 + 1
		end
		
		if ygap1_success and ygap2_success then
			if ygap1 == ygap2 then ygap = ygap1 end
		elseif ygap1_success then  ygap = ygap1
		elseif ygap2_success then  ygap = ygap2
		end
	end
	
	--begin navyears
	local navy = '{| class="toccolours hlist" style="text-align: center; margin: auto;"\n'..'|\n'
	
	local i = -5
	while i <= 5 do
		local y = year + i*ygap*switchADBC
		local BCdisp = ''
		if i ~= 0 then --left/right navy
			
			local AD = ''
			local BC = ''
			if year1to15AD then
				if year >= 11 then --parent = 11-15 AD
					if y <= 10 then --prepend AD on y = 1-10 cats only, per existing cats
						AD = 'AD '
					end
					
				elseif year >= 1 then --parent = 1-10 AD
					if y <= 0 then
						BC = BCe..' '
						y = math.abs(y - 1) --skip y = 0 (DNE)
					elseif y >= 1 and y <= 10 then --prepend AD on y = 1-10 cats only, per existing cats
						AD = 'AD '
					end
				end
				
			elseif parentBC then
				if switchADBC == -1 then --displayed y is in the BC regime
					if y >= 1 then     --the common case
						BC = BCe..' '   
					elseif y == 0 then --switch from BC to AD regime
						switchADBC = 1
					end
				end
				if switchADBC == 1 then --displayed y is now in the AD regime
					Y = Y + 1 --skip y = 0 (DNE)
					y = Y     --easiest solution: start another iterator for these AD ys displayed on a BC year parent
					AD = 'AD '
				end
			end
			if BC ~= '' and year <= 5 then --only show 'BC' for parent years <= 5: saves room, easier to read,
				BCdisp = ' '..BCe          --and 6 is the first/last nav year that doesn't need a disambiguator;
			end                            --the center/parent year will always show BC, so no need to show it another 10x
			
			--populate left/right navy
			local ysign = y --use y for display & ysign for logic
			if BC ~= '' then ysign = -ysign end
			if (minyear <= ysign) and (ysign <= maxyear) then -- ex: 1758, 1759, 1761, 1762, 1763, 1764, 1765
				navy = navy..'*'..catlink( firstpart..' '..AD..y..' '..BC..lastpart, y..BCdisp )..'\n'
			else -- ex: 1755, 1756, 1757
				navy = navy..'*<span style="visibility:hidden">'..y..BCdisp..'</span>\n'
			end
		else --center navy; ex: 1760
			if parentBC then BCdisp = ' '..BCe end
			navy = navy..'*<b>'..year..BCdisp..'</b>\n'
		end
		
		i = i + 1
	end
	
	isolatedcat()
	return navy..'|}'
end


--[[============================{{  navdecade  }}=============================]]

function navdecade( firstpart, decade, lastpart, mindecade, maxdecade )
	--Expects a PAGENAME of the form "Some sequential 2000 example cat", where 
	--	{{{1}}}=Some sequential
	--	{{{2}}}=2000
	--	{{{3}}}=example cat
	--and
	--	{{{4}}}=1800 ('min' decade parameter; optional)
	--	{{{5}}}=2020 ('max' decade parameter; optional; defaults to next decade)
	
	--sterilize dec
	local dec = sterilizedec(decade)
	if errors ~= '' then
		errors = p.errorclass('Function navdecade was sent "'..(decade or '')..'" as its 2nd parameter, '..
							'but expects a 1 to 4-digit year ending in "0".')
		return p.failedcat(errors, 'D')
	end
	local ndec = tonumber(dec)
	
	--sterilize mindecade & determine AD/BC
	local mindefault = '-9999'
	local mindec = sterilizedec(mindecade) --returns a tostring(unsigned int), or nil + error
	if mindec then
		if string.match(mindecade, '-%d') or 
		   string.match(mindecade, 'BC')
		then
			mindec = '-'..mindec --better +/-0 behavior with strings (0-initialized int == "-0" string...)
		end
	elseif errors ~= '' then
		errors = p.errorclass('Function navdecade was sent "'..(mindecade or '')..'" as its 4th parameter, '..
							'but expects a 1 to 4-digit year ending in "0", the earliest decade to be shown.')
		return p.failedcat(errors, 'E')
	else
		mindec = mindefault --tonumber() later, after error checks
	end
	
	--sterilize maxdecade & determine AD/BC
	local maxdefault = '9999'
	local maxdec = sterilizedec(maxdecade) --returns a tostring(unsigned int), or nil + error
	if maxdec then
		if string.match(maxdecade, '-%d') or 
		   string.match(maxdecade, 'BC')
		then                     --better +/-0 behavior with strings (0-initialized int == "-0" string...),
			maxdec = '-'..maxdec --but a "-0" string -> tonumber() -> tostring() = "-0",
		end                      --and a  "0" string -> tonumber() -> tostring() =  "0"
	elseif errors ~= '' then
		errors = p.errorclass('Function navdecade was sent "'..(maxdecade or '')..'" as its 5th parameter, '..
							'but expects a 1 to 4-digit year ending in "0", the highest decade to be shown.')
		return p.failedcat(errors, 'F')
	else
		maxdec = maxdefault
	end
	
	local tspace = ' ' --assume trailing space for "1950s in X"-type cats
	if string.match(lastpart, '^-') then tspace = '' end --DNE for "1970s-related"-type cats
	
	--AD/BC switches & vars
	
	local parentBC = string.match(lastpart, '^BC') --following the "0s BC" convention for all years BC
	lastpart = mw.ustring.gsub(lastpart, '^BC%s*', '') --handle BC separately; AD never used
	--TODO?: handle BCE, but only if it exists in the wild
	
	local dec0to40AD = (ndec >= 0 and ndec <= 40 and not parentBC) --special behavior in this range
	local switchADBC = 1                 --  1=AD parent
	if parentBC then switchADBC = -1 end -- -1=BC parent; possibly adjusted later
	local BCdisp = ''
	local D = -math.huge --secondary switch & iterator for AD/BC transition
	
	--check non-default min/max more carefully; determine right-offset
	local roffset = 0
	if mindec ~= mindefault then
		if tonumber(mindec) > ndec*switchADBC then
			mindec = tostring(ndec*switchADBC) --input error; mindec should be <= parent
		end
	end
	if maxdec ~= maxdefault then --a non-default max will override offsetting behavior
		if tonumber(maxdec) < ndec*switchADBC then
			maxdec = tostring(ndec*switchADBC) --input error; maxdec should be >= parent
		end
	else                            --offset only if 1) max == maxdefault,
		local thisyear = mw.getContentLanguage():formatDate( 'Y' )
		local nthisdecade = tonumber(string.match(thisyear, '^%d%d%d')..'0')
		if ndec <= nthisdecade then --and 2) we're not on a future-decade cat (e.g. Works set in the 2100s)
			local diff = nthisdecade - ndec*switchADBC --in 2019: diff=30 for 1980, 0 for 2010, -20 for 2030
			if diff < 0 then diff = 0 end  --always show at least 1 decade ahead for present-decade+ cats
			if diff >= 0 and diff <= 30 then
				roffset = 40 - diff --in 2019: roffset=10 for 1980, 40 for 2010, 40 for 2030
			end
		end
	end
	local nmindec = tonumber(mindec) --similar behavior to navyear & navordinal
	local nmaxdec = tonumber(maxdec) --similar behavior to navordinal
	
	--begin navdecade
	local bnb = '' --border/no border
	if navborder == false then --for embedding in {{Navseasoncats with decades below year}}
		bnb = ' border-style: none; background-color: transparent;'
	end
	local navd = '{| class="toccolours hlist" style="text-align: center; margin: auto;'..bnb..'"\n'..'|\n'
	
	local i = (-50 - roffset)
	while i <= (50 - roffset) do
		local d = ndec + i*switchADBC
		
		if i ~= 0 then --left/right navd
			local BC = ''
			BCdisp = ''
			if dec0to40AD then
				if D < -10 then
					d = math.abs(d + 10) --b/c 2 "0s" decades exist: "0s BC" & "0s" (AD)
					BC = 'BC '
					if d == 0 then
						D = -10 --track 1st d = 0 use (BC)
					end
				elseif D >= -10 then
					D = D + 10 --now iterate from 0s AD
					d = D      --2nd d = 0 use
				end
			elseif parentBC then
				if switchADBC == -1 then --parentBC looking at the BC side (the common case)
					BC = 'BC '
					if d == 0 then     --prepare to switch to the AD side on the next iteration
						switchADBC = 1 --1st d = 0 use (BC)
						D = -10        --prep
					end
				elseif switchADBC == 1 then --switched to the AD side
					D = D + 10 --now iterate from 0s AD
					d = D      --2nd d = 0 use (on first use)
				end
			end
			if BC ~= '' and ndec <= 50 then
				BCdisp = ' BC' --show BC for all BC decades whenever a "0s" is displayed on the nav
			end
			
			--populate left/right navd
			local hidden = '*<span style="visibility:hidden">'..d..'s'..BCdisp..'</span>\n'
			local shown = '*'..catlink( firstpart..' '..d..'s'..tspace..BC..lastpart, d..'s'..BCdisp )..'\n'
			local dsign = d --use d for display & dsign for logic
			if BC ~= '' then dsign = -dsign end
			if (nmindec <= dsign) and (dsign <= nmaxdec) then
				if dsign == 0 and (nmindec == 0 or nmaxdec == 0) then --distinguish b/w -0 (BC) & 0 (AD)
					--"zoom in" on +/- 0 and turn dsign/min/max temporarily into +/- 1 for easier processing
					local zsign, zmin, zmax = 1, nmindec, nmaxdec
					if BC ~= '' then zsign = -1 end
					if     mindec == '-0' then zmin = -1
					elseif mindec ==  '0' then zmin =  1 end
					if     maxdec == '-0' then zmax = -1
					elseif maxdec ==  '0' then zmax =  1 end
					
					if (zmin <= zsign) and (zsign <= zmax) then
						navd = navd..shown
					else
						navd = navd..hidden
					end
				else
					navd = navd..shown --the common case
				end
			else
				navd = navd..hidden
			end
			
		else --center navd
			if D >= -10 then
				D = D + 10 --housekeeping b/w left/right sides
			end
			if parentBC then
				BCdisp = ' BC'
				if ndec == 0 then
					switchADBC = 1 --next element will be 0s AD
					D = -10 --for this special case, D is still -inf
				end
			else
				BCdisp = ''
			end
			navd = navd..'*<b>'..dec..'s'..BCdisp..'</b>\n'
		end
		
		i = i + 10
	end
	
	isolatedcat()
	return navd..'|}'
end


--[[============================{{  navhyphen  }}=============================]]

function navhyphen( start, hyph, finish, firstpart, lastpart, minseas, maxseas, testgap )
	--Expects a PAGENAME of the form "Some sequential 2015–16 example cat", where 
	--	{{{1}}}=2015
	--	{{{2}}}=–
	--	{{{3}}}=16 (sequential years can be abbreviated, but others must be full year, i.e. "2001–2005")
	--	{{{4}}}=Some sequential
	--	{{{5}}}=example cat
	--	{{{6}}}=1800 ('min' starting season shown; optional)
	--	{{{7}}}=1999 ('max' starting season shown; optional; 1999 will show 1999-00)
	--	{{{8}}}=0 (testcasegap parameter for easier testing; optional)
	
	--sterilize start
	if string.match(start or '', '^%d%d?%d?%d?$') == nil then --1-4 digits, AD only
		local start_fixed = mw.ustring.match(start or '', '^%s*(%d%d?%d?%d?)%D')
		if start_fixed then
			start = start_fixed
		else
			errors = p.errorclass('Function navhyphen can\'t recognize the number "'..(start or '')..'" '..
								'in the first part of the "season" that was passed to it. '..
								'For e.g. "2015–16", "2015" is expected via "|2015|–|16|".')
			return p.failedcat(errors, 'H')
		end
	end
	local nstart = tonumber(start)
	
	--en dash check
	if hyph ~= '–' then
		misctrackingcats[3] = '[['..testcasecolon..'Kategori:Navseasoncats range not using en dash]]' --nav still processable, but track
	end
	
	--sterilize finish
	if string.match(finish or '', '^%d+$') == nil then
		local finish_fixed = mw.ustring.match(finish or '', '^%s*(%d%d?%d?%d?)%D')
		if finish_fixed then
			finish = finish_fixed
		else
			errors = p.errorclass('Function navhyphen can\'t recognize "'..(finish or '')..'" '..
								'in the second part of the "season" that was passed to it. '..
								'For e.g. "2015–16", "16" is expected via "|2015|–|16|".')
			return p.failedcat(errors, 'I')
		end
	else
		if string.len(finish) >= 5 then
			errors = p.errorclass('The second part of the season passed to function navhyphen should only be four or fewer digits, not "'..(finish or '')..'". '..
								'See MOS:DATERANGE for details.')
			return p.failedcat(errors, 'J')
		end
	end
	local nfinish = tonumber(finish)
	
	--sterilize min/max
	local nminseas = tonumber(minseas) or -9999 --not yet implemented; pending discussion
	local nmaxseas = tonumber(maxseas) or  9999 --not yet implemented; pending discussion
	
	local lspace = ' ' --assume a leading space (most common)
	local tspace = ' ' --assume a trailing space (most common)
	if string.match(firstpart, '%($') then lspace = '' end --DNE for "Madrid city councillors (2007–2011)"-type cats
	if string.match(lastpart,  '^%)') then tspace = '' end --DNE for "Madrid city councillors (2007–2011)"-type cats
	
	--calculate term length/intRAseason size & finishing year
	local t = 1
	while t <= 10 do
		local nish = nstart + t --use switchADBC to flip this sign to work for years BC
		if nish == nfinish or string.match(nish, '%d?%d$') == finish then
			break
		end
		if t == 10 then
			errors = p.errorclass('Function navhyphen can\'t determine a reasonable term length for "'..start..hyph..finish..'".')
			return p.failedcat(errors, 'K')
		end
		t = t + 1
	end
	
	--apply MOS:DATERANGE to parent
	local lenstart = string.len(start)
	local lenfinish = string.len(finish)
	if lenstart == 4 then --"2001–"
		if t == 1 then --"2001–02" & "2001–2002" both allowed
			if lenfinish ~= 2 and lenfinish ~= 4 then
				errors = p.errorclass('The second part of the season passed to function navhyphen should be two or four digits, not "'..finish..'".')
				return p.failedcat(errors, 'L')
			end
		else --"2001–2005" is required for t > 1; track "2001–05"; anything else = error
			if lenfinish == 2 then
				if avoidself then
					misctrackingcats[4] = '[['..testcasecolon..'Kategori:Navseasoncats range abbreviated]]'
				end
			elseif lenfinish ~= 4 then
				errors = p.errorclass('The second part of the season passed to function navhyphen should be four digits, not "'..finish..'".')
				return p.failedcat(errors, 'M')
			end
		end
		if finish == '00' and avoidself then --full year required regardless of term length
			misctrackingcats[4] = '[['..testcasecolon..'Kategori:Navseasoncats range abbreviated]]'
		end
	end
	
	--calculate intERseason gap size
	local hgapdefault = 0 --assume & start at the most common case: 2001–02, 2002–03, etc.
	local hgap = hgapdefault
	local hgap_success = false
	while hgap <= 5 do --verify
		local prevseason = firstpart..lspace..(nstart-t-hgap)..hyph..string.match(nstart-hgap, '%d?%d$')..tspace..lastpart
		local nextseason = firstpart..lspace..(nstart+t+hgap)..hyph..string.match(nstart+2*t+hgap, '%d?%d$')..tspace..lastpart
		if mw.title.new(prevseason, 'Kategori').exists or   --use 'or', in case we're at the edge of the cat structure,
		   mw.title.new(nextseason, 'Kategori').exists then --or we hit a "–00"/"–2000" situation on one side
			hgap_success = true
			break
		end
		hgap = hgap + 1
	end
	if hgap_success == false then
		hgap = tonumber(testgap) or hgapdefault --tracked via defaultgapcat()
	end
	
	--begin navhyphen
	local navh = '{| class="toccolours hlist" style="text-align: center; margin: auto;"\n'..'|\n'
	
	local i = -3
	while i <= 3 do
		local from  = nstart + i*(t+hgap)
		local from2 = string.match(from, '%d?%d$')
		local to  = tostring(from+t)
		local to2 = string.match(to, '%d?%d$')
		local tofinal = to2 --assume t=1 and abbreviated 'to' (the most common case)
		if t > 1 or         --per MOS:DATERANGE (e.g. 1999-2004)
		  (from2 - to2) > 0 --century transition exception (e.g. 1999–2000)
		then
			tofinal = to --default to the MOS-correct format, in case no fallbacks found
		end
		
		--check existance of 4-digit, MOS-correct range, with abbreviation fallback
		if t > 1 and string.len(from) == 4 then --e.g. 1999-2004
			--determine which link exists (full or abbr)
			local full = firstpart..lspace..from..hyph..tofinal..tspace..lastpart
			if not mw.title.new( full, 'Kategori' ).exists then
				local abbr = firstpart..lspace..from..hyph..to2..tspace..lastpart
				if mw.title.new( abbr, 'Kategori' ).exists then
					tofinal = to2 --rv to MOS-incorrect format; if full AND abbr DNE, then tofinal is still in its MOS-correct format
				end
			end
		elseif t == 1 then --full-year consecutive ranges are also allowed
			local abbr = firstpart..lspace..from..hyph..tofinal..tspace..lastpart --assume tofinal is in abbr format
			if not mw.title.new( abbr, 'Kategori' ).exists and tofinal ~= to then
				local full = firstpart..lspace..from..hyph..to..tspace..lastpart
				if mw.title.new( full, 'Kategori' ).exists then
					tofinal = to --if abbr AND full DNE, then tofinal is still in its abbr format (unless it's a century transition)
				end
			end
		end
		
		--populate navh
		if i ~= 0 then --left/right navh
			local orig = firstpart..lspace..from..hyph..tofinal..tspace..lastpart
			local rtar = rtarget(orig) --look for & follow {{Kategori redirect}}s
			if orig ~= rtar and avoidself then --figure out why
				local origbase = string.gsub(orig, '%d+[–-]%d+', '')
				local rtarbase = string.gsub(rtar, '%d+[–-]%d+', '')
				if origbase ~= rtarbase then
					misctrackingcats[5] = '[['..testcasecolon..'Kategori:Navseasoncats range redirected (base change)]]'
				else
					misctrackingcats[6] = '[['..testcasecolon..'Kategori:Navseasoncats range redirected (MOS)]]'
				end
			end
			local disp = string.match(rtar, '%d+%'..hyph..'%d+') or from..hyph..tofinal
			if from >= 0 then --shown
				navh = navh..'*'..catlink(rtar, disp)..'\n'
			else              --hidden
				navh = navh..'*<span style="visibility:hidden">'..disp..'</span>\n'
			end
		else --center navh
			navh = navh..'*<b>'..start..hyph..finish..'</b>\n'
		end
		
		i = i + 1
	end
	
	isolatedcat()
	defaultgapcat(not hgap_success)
	return navh..'|}'
end


--[[============================{{  navordinal  }}============================]]

function navordinal( firstpart, ord, lastpart, minimumord, maximumord )
	local nord = tonumber(ord)
	local minord = tonumber(string.match(minimumord or '', '(-?%d+)[snrt]?[tdh]?')) or -9999 --allow full ord & +/- qualifier
	local maxord = tonumber(string.match(maximumord or '', '(-?%d+)[snrt]?[tdh]?')) or  9999 --allow full ord & +/- qualifier
	if string.match(minimumord or '', 'BC') then minord = -math.abs(minord) end --allow BC qualifier (AD otherwise assumed)
	if string.match(maximumord or '', 'BC') then maxord = -math.abs(maxord) end --allow BC qualifier (AD otherwise assumed)
	
	local temporal = string.match(lastpart, 'century') or
					 string.match(lastpart, 'millennium')
	
	local tspace = ' ' --assume a trailing space after ordinal
	if string.match(lastpart, '^-') then tspace = '' end --DNE for "19th-century"-type cats
	
	--AD/BC switches & vars
	
	local ordBCElastparts = { --needed for parent = AD 1-5, when the BC/E format is unknown
		--lists the lastpart of valid BCE cats
		--"BCE" removed to match both AD & BCE cats; easier & faster than multiple string.match()s
		['-century Hebrew people'] = 'BCE', --WP:CFD/Log/2016 June 21#Kategori:11th-century BC Hebrew people
		['-century Jews']          = 'BCE', --co-nominated
		['-century Judaism']       = 'BCE', --co-nominated
		['-century rabbis']        = 'BCE', --co-nominated
	}
	local parentBC = mw.ustring.match(lastpart, '%s(BCE?)')       --"1st-century BC" format
	local lastpartNoBC = mw.ustring.gsub(lastpart, '%sBCE?', '')  --easier than splitting lastpart up in 2; AD never used
	local BCe = parentBC or ordBCElastparts[lastpartNoBC] or 'BC' --"BC" default
	
	local switchADBC = 1                 --  1=AD parent
	if parentBC then switchADBC = -1 end -- -1=BC parent; possibly adjusted later
	local O = 0 --secondary iterator for AD-on-a-BC-parent
	
	if not temporal and minord < 1 then minord = 1 end --nothing before "1st parliament", etc.
	if minord > nord*switchADBC then minord = nord*switchADBC end --input error; minord should be <= parent
	if maxord < nord*switchADBC then maxord = nord*switchADBC end --input error; maxord should be >= parent
	
	--determine right-offset, to not show unnecessary future millenia
	local roffset = 0
	if temporal and nord <= 3 then
		if string.match(lastpartNoBC, 'millennium ') and --only offset "1st millennium BC in Egypt" to "3rd-millennium people"-type cats
		   string.match(lastpartNoBC, 'millennium in fiction') == nil and --except these, which extend > 4th millennium
		   maxord == 9999 --only apply if max unspecified
		then
			if not parentBC and nord <= 3 then --1st, 2nd, & 3rd millennium parents
				roffset = nord + 1
			elseif parentBC and nord == 1 then --1st millennium BC only
				roffset = 1
			end
		end
	end
	
	--begin navordinal
	local bnb = '' --border/no border
	if navborder == false then --for embedding in {{Navseasoncats with centuries below decade}}
		bnb = ' border-style: none; background-color: transparent;'
	end
	local navo = '{| class="toccolours hlist" style="text-align: center; margin: auto;'..bnb..'"\n'..'|\n'
	
	local i = (-5 - roffset)
	while i <= (5 - roffset) do
		local o = nord + i*switchADBC
		local BC = ''
		local BCdisp = ''
		if i ~= 0 then --left/right navo
			
			if parentBC then
				if switchADBC == -1 then --parentBC looking at the BC side
					if o >= 1 then     --the common case
						BC = ' '..BCe
					elseif o == 0 then --switch to the AD side
						BC = ''
						switchADBC = 1
					end
				end
				if switchADBC == 1 then --displayed o is now in the AD regime
					O = O + 1 --skip o = 0 (DNE)
					o = O     --easiest solution: start another iterator for these AD o's displayed on a BC year parent
				end
			elseif o <= 0 then --parentAD looking at BC side
				BC = ' '..BCe
				o = math.abs(o - 1) --skip o = 0 (DNE)
			end
			if BC ~= '' and nord <= 5 then --only show 'BC' for parent ords <= 5: saves room, easier to read,
				BCdisp = ' '..BCe          --and 6 is the first/last nav ord that doesn't need a disambiguator;
			end                            --the center/parent ord will always show BC, so no need to show it another 10x
			
			--populate left/right navo
			local oth = p.addord(o)
			local osign = o --use o for display & osign for logic
			if BC ~= '' then osign = -osign end
			local hidden = '*<span style="visibility:hidden">'..oth..'</span>\n'
			if temporal then --e.g. "3rd-century BC"
				if (minord <= osign) and (osign <= maxord) then
					local lastpart = lastpartNoBC --lest we recursively add multiple "BC"s
					if BC ~= '' then
						lastpart = string.gsub(lastpart, temporal, temporal..BC) --replace BC if needed
					end
					navo = navo..'*'..catlink( firstpart..' '..oth..tspace..lastpart, oth..BCdisp )..'\n'
				else
					navo = navo..hidden
				end
			elseif BC == '' and minord <= osign and osign <= maxord then --e.g. >= "1st parliament"
				navo = navo..'*'..catlink( firstpart..' '..oth..tspace..lastpart, oth )..'\n'
			else --either out-of-range (hide), or non-temporal + BC = something might be wrong (2nd X parliament BC?); handle exceptions if/as they arise
				navo = navo..hidden
			end
		else --center navo
			if parentBC then BC = ' '..BCe end
			navo = navo..'*<b>'..p.addord(o)..BC..'</b>\n'
		end
		
		i = i + 1
	end
	
	isolatedcat()
	return navo..'|}'
end


--[[============================{{  var_season  }}============================]]

--Also used by {{Navseasoncats with centuries below decade}}.
function p.var_season( pn )
	--Extracts e.g. 2015–16, 3rd, 2000s, or 1999 out of a string
	local pagename = currtitle.baseText
	if pn and pn ~= '' then
		pagename = pn
	end
	
	local cpagename = 'Kategori:'..pagename --limited-Lua-regex workaround
	
	local season  = mw.ustring.match(cpagename, '[:%s%(](%d+[–-]%d+)[%)%s]') or --split in 2 b/c %f[%s$] doesn't work
					mw.ustring.match(cpagename, '[:%s](%d+[–-]%d+)$')
					
	local ordinal = mw.ustring.match(cpagename, '[:%s](%d+[snrt][tdh])[-%s]') or
					mw.ustring.match(cpagename, '[:%s](%d+[snrt][tdh])$')
					
	local decade  = mw.ustring.match(cpagename, '[:%s](%d+s)[%s-]') or
					mw.ustring.match(cpagename, '[:%s](%d+s)$')
					
	local year    = mw.ustring.match(cpagename, '[:%s](%d+)%s') or
					mw.ustring.match(cpagename, '[:%s](%d+)$')
					
	local all4 = (season or '')..','..(ordinal or '')..','..(decade or '')..','..(year or '')
	
	if (season == nil and ordinal == nil and decade == nil and year == nil) or
		string.match(all4, '%d%d%d%d%d')
	then
		errors = p.errorclass('Function var_season can\'t recognize a season, ordinal, decade, nor year for category "'..pagename..'".')
		return p.failedcat(errors, 'S')
	end
	
	--return in order of decreasing complexity
	if season  then return season  end
	if ordinal then return ordinal end
	if decade  then return decade  end
	if year    then return year    end
end


--[[==========================================================================]]
--[[                                   Main                                   ]]
--[[==========================================================================]]

function p.navseasoncats( frame )
	local args = frame:getParent().args
	local dby         = args['decade-below-year'] --used by {{Navseasoncats with decades below year}}
	local cbd         = args['century-below-decade'] --used by {{Navseasoncats with centuries below decade}} (proposed)
	local cat         = args['cat'] --'testcase' alias
	local testcase    = args['testcase']
	local testcasegap = args['testcasegap']
	local minyear = args['min']
	local maxyear = args['max']
	
	if dby then
		navborder = false
		dby = string.gsub(dby, '&#32;', ' ') --unicodify forced whitespace
	end
	if cbd then
		navborder = false
		cbd = string.gsub(cbd, '&#32;', ' ') --unicodify forced whitespace
	end
	
	if currtitle.nsText == 'Kategori' then
		if cat      then misctrackingcats[1] = '[['..testcasecolon..'Kategori:Navseasoncats using cat parameter]]' end
		if testcase then misctrackingcats[2] = '[['..testcasecolon..'Kategori:Navseasoncats using testcase parameter]]' end
	end
	
	local pagename = testcase or cat or dby or cbd or currtitle.baseText
	
	local varseason = p.var_season(pagename)
	if errors ~= '' then return varseason..table.concat(misctrackingcats) end --some error checking in var_season()
	
	local firstpart, lastpart = string.match(pagename, '^(.*)'..varseason..'(.*)$')
	firstpart = mw.text.trim(firstpart or '')
	lastpart  = mw.text.trim(lastpart or '')
	
	local start = string.match(varseason, '^%d+')
	local hyphen, finish = mw.ustring.match(varseason, '%d([–-])(%d+)') --ascii 150 & 45 (ndash & keyboard hyphen); mw req'd
	
	--determine the appropriate nav function
	
	if hyphen and finish then                             --e.g. "1–4", "1999–2000", "2001–02", "2001–2002", "2005–2010", etc.
		return navhyphen( start, hyphen, finish, firstpart, lastpart, minyear, maxyear, testcasegap )..table.concat(misctrackingcats)
		
	elseif string.match(varseason, '%d[snrt][tdh]$') then --e.g. "4th"
		return navordinal( firstpart, start, lastpart, minyear, maxyear )..table.concat(misctrackingcats)
		
	elseif string.match(varseason, '%ds$') then           --e.g. "0s", "2010s"
		return navdecade( firstpart, start, lastpart, minyear, maxyear )..table.concat(misctrackingcats)
		
	elseif string.match(varseason, '^%d+$') then          --e.g. "500", "2001"
		return navyear( firstpart, start, lastpart, minyear, maxyear )..table.concat(misctrackingcats)
		
	else                                                  --malformed
		errors = p.errorclass('Failed to determine the appropriate nav function from malformed season "'..varseason..'". ')
		return p.failedcat(errors, 'N')..table.concat(misctrackingcats)
	end
end

return p