require ('strict');

local p = {}



p.trim = function(frame)

	return mw.text.trim(frame.args1 or "")

end



p.sentence = function (frame)

	-- {{lc:}} is strip-marker safe, string.lower is not.

	frame.args1 = frame:callParserFunction('lc', frame.args1])

	return p.ucfirst(frame)

end



p.ucfirst = function (frame )

	local s = frame.args1];

	if not s or '' == s or s:match ('^%s+$') then								-- when <s> is nil, empty, or only whitespace

		return s;																-- abandon because nothing to do

	end



	s =  mw.text.trim( frame.args1 or "" )

	local s1 = ""



	local prefix_patterns_t = {													-- sequence of prefix patterns

		'^\127[^\127]*UNIQ%-%-%a+%-%x+%-QINU[^\127]*\127',						-- stripmarker

		'^([%*;:#]+)',															-- various list markup

		'^(\'\'\'*)',															-- bold / italic markup

		'^(%b<>)',																-- html-like tags because some templates render these

		'^(&%a+;)',																-- html character entities because some templates render these

		'^(&#%d+;)',															-- html numeric (decimal) entities because some templates render these

		'^(&#x%x+;)',															-- html numeric (hexadecimal) entities because some templates render these

		'^(%s+)',																-- any whitespace characters

		'^([%(%)%-%+%?%.%%!~!@%$%^&_={}/`,‘’„“”ʻ|\"\'\\]+)',					-- miscellaneous punctuation

		}

	

	local prefixes_t = {};														-- list, bold/italic, and html-like markup, & whitespace saved here



	local function prefix_strip (s)												-- local function to strip prefixes from <s>

		for _, pattern in ipairs (prefix_patterns_t) do							-- spin through <prefix_patterns_t> 

			if s:match (pattern) then											-- when there is a match

				local prefix = s:match (pattern);								-- get a copy of the matched prefix

				table.insert (prefixes_t, prefix);								-- save it

				s = s:sub (prefix:len() + 1);									-- remove the prefix from <s>

				return s, true;													-- return <s> without prefix and flag; force restart at top of sequence because misc punct removal can break stripmarker

			end

		end

		return s;																-- no prefix found; return <s> with nil flag

	end



	local prefix_removed;														-- flag; boolean true as long as prefix_strip() finds and removes a prefix

	

	repeat																		-- one by one remove list, bold/italic, html-like markup, whitespace, etc from start of <s>

		s, prefix_removed = prefix_strip (s);

	until (not prefix_removed);													-- until <prefix_removed> is nil



	s1 = table.concat (prefixes_t);												-- recreate the prefix string for later reattachment



	local first_text = mw.ustring.match (s, '^%[%[[^%]]+%]%]');					-- extract wikilink at start of string if present; TODO: this can be string.match()?



	local upcased;

	if first_text then

		if first_text:match ('^%[%[[^|]+|[^%]]+%]%]') then						-- if <first_text> is a piped link

			upcased = mw.ustring.match (s, '^%[%[[^|]+|%W*(%w)');				-- get first letter character

			upcased = mw.ustring.upper (upcased);								-- upcase first letter character

			s = mw.ustring.gsub (s, '^(%[%[[^|]+|%W*)%w', '%1' .. upcased);		-- replace

		else																	-- here when <first_text> is a wikilink but not a piped link

			upcased = mw.ustring.match (s, '^%[%[%W*%w');						-- get '[[' and first letter

			upcased = mw.ustring.upper (upcased);								-- upcase first letter character

			s = mw.ustring.gsub (s, '^%[%[%W*%w', upcased);						-- replace; no capture needed here

		end



	elseif s:match ('^%[%S+%s+[^%]]+%]') then									-- if <s> is a ext link of some sort; must have label text

		upcased = mw.ustring.match (s, '^%[%S+%s+%W*(%w)');						-- get first letter character

		upcased = mw.ustring.upper (upcased);									-- upcase first letter character

		s = mw.ustring.gsub (s, '^(%[%S+%s+%W*)%w', '%1' .. upcased);			-- replace

	

	elseif s:match ('^%[%S+%s*%]') then											-- if <s> is a ext link without label text; nothing to do

		return s1 .. s;															-- reattach prefix string (if present) and done



	else																		-- <s> is not a wikilink or ext link; assume plain text

		upcased = mw.ustring.match (s, '^%W*%w');								-- get the first letter character

		upcased = mw.ustring.upper (upcased);									-- upcase first letter character

		s = mw.ustring.gsub (s, '^%W*%w', upcased);								-- replace; no capture needed here

	end



	return s1 .. s;																-- reattach prefix string (if present) and done

end





p.title = function (frame )

	-- http://grammar.yourdictionary.com/capitalization/rules-for-capitalization-in-titles.html

	-- recommended by The U.S. Government Printing Office Style Manual:

	-- "Capitalize all words in titles of publications and documents,

	-- except a, an, the, at, by, for, in, of, on, to, up, and, as, but, or, and nor."

	local alwayslower = {['a' = 1, 'an' = 1, 'the' = 1,

		'and' = 1, 'but' = 1, 'or' = 1, 'for' = 1,

		'nor' = 1, 'on' = 1, 'in' = 1, 'at' = 1, 'to' = 1,

		'from' = 1, 'by' = 1, 'of' = 1, 'up' = 1 }

	local res = ''

	local s =  mw.text.trim( frame.args1 or "" )

	local words = mw.text.split( s, " ")

	for i, s in ipairs(words) do

		-- {{lc:}} is strip-marker safe, string.lower is not.

		s = frame:callParserFunction('lc', s)

		if i == 1 or alwayslowers ~= 1 then

			s = mw.getContentLanguage():ucfirst(s)

		end

		wordsi = s

	end

	return table.concat(words, " ")

end



-- findlast finds the last item in a list

-- the first unnamed parameter is the list

-- the second, optional unnamed parameter is the list separator (default = comma space)

-- returns the whole list if separator not found

p.findlast = function(frame)

	local s =  mw.text.trim( frame.args1 or "" )

	local sep = frame.args2 or ""

	if sep == "" then sep = ", " end

	local pattern = ".*" .. sep .. "(.*)"

	local a, b, last = s:find(pattern)

	if a then

		return last

	else

		return s

	end

end



-- stripZeros finds the first number and strips leading zeros (apart from units)

-- e.g "0940" -> "940"; "Year: 0023" -> "Year: 23"; "00.12" -> "0.12"

p.stripZeros = function(frame)

	local s = mw.text.trim(frame.args1 or "")

	local n = tonumber( string.match( s, "%d+" ) ) or ""

	s = string.gsub( s, "%d+", n, 1 )

	return s

end



-- nowiki ensures that a string of text is treated by the MediaWiki software as just a string

-- it takes an unnamed parameter and trims whitespace, then removes any wikicode

p.nowiki = function(frame)

	local str = mw.text.trim(frame.args1 or "")

	return mw.text.nowiki(str)

end



-- split splits text at boundaries specified by separator

-- and returns the chunk for the index idx (starting at 1)

-- #invoke:String2 |split |text |separator |index |true/false

-- #invoke:String2 |split |txt=text |sep=separator |idx=index |plain=true/false

-- if plain is false/no/0 then separator is treated as a Lua pattern - defaults to plain=true

p.split = function(frame)

	local args = frame.args

	if not(args1 or args.txt) then args = frame:getParent().args end

	local txt = args1 or args.txt or ""

	if txt == "" then return nil end

	local sep = (args2 or args.sep or ""):gsub('"', '')

	local idx = tonumber(args3 or args.idx) or 1

	local plain = (args4 or args.plain or "true"):sub(1,1)

	plain = (plain ~= "f" and plain ~= "n" and plain ~= "0")

	local splittbl = mw.text.split( txt, sep, plain )

	if idx < 0 then idx = #splittbl + idx + 1 end

	return splittblidx

end



-- val2percent scans through a string, passed as either the first unnamed parameter or |txt=

-- it converts each number it finds into a percentage and returns the resultant string.

p.val2percent = function(frame)

	local args = frame.args

	if not(args1 or args.txt) then args = frame:getParent().args end

	local txt = mw.text.trim(args1 or args.txt or "")

	if txt == "" then return nil end

	local function v2p (x)

		x = (tonumber(x) or 0) * 100

		if x == math.floor(x) then x = math.floor(x) end

		return x .. "%"

	end

	txt = txt:gsub("%d[%d%.]*", v2p) -- store just the string

	return txt

end



-- one2a scans through a string, passed as either the first unnamed parameter or |txt=

-- it converts each occurrence of 'one ' into either 'a ' or 'an ' and returns the resultant string.

p.one2a = function(frame)

	local args = frame.args

	if not(args1 or args.txt) then args = frame:getParent().args end

	local txt = mw.text.trim(args1 or args.txt or "")

	if txt == "" then return nil end

	txt = txt:gsub(" one ", " a "):gsub("^one", "a"):gsub("One ", "A "):gsub("a ([aeiou])", "an %1"):gsub("A ([aeiou])", "An %1")

	return txt

end



-- findpagetext returns the position of a piece of text in a page

-- First positional parameter or |text is the search text

-- Optional parameter |title is the page title, defaults to current page

-- Optional parameter |plain is either true for plain search (default) or false for Lua pattern search

-- Optional parameter |nomatch is the return value when no match is found; default is nil

p._findpagetext = function(args)

	-- process parameters

	local nomatch = args.nomatch or ""

	if nomatch == "" then nomatch = nil end

	--

	local text = mw.text.trim(args1 or args.text or "")

	if text == "" then return nil end

	--

	local title = args.title or ""

	local titleobj

	if title == "" then

		titleobj = mw.title.getCurrentTitle()

	else

		titleobj = mw.title.new(title)

	end

	--

	local plain = args.plain or ""

	if plain:sub(1, 1) == "f" then plain = false else plain = true end

	-- get the page content and look for 'text' - return position or nomatch

	local content = titleobj and titleobj:getContent()

	return content and mw.ustring.find(content, text, 1, plain) or nomatch

end

p.findpagetext = function(frame)

	local args = frame.args

	local pargs = frame:getParent().args

	for k, v in pairs(pargs) do

		argsk = v

	end

	if not (args1 or args.text) then return nil end

	-- just the first value

	return (p._findpagetext(args))

end



-- returns the decoded url. Inverse of parser function {{urlencode:val|TYPE}}

-- Type is:

-- QUERY decodes + to space (default)

-- PATH does no extra decoding

-- WIKI decodes _ to space

p._urldecode = function(url, type)

	url = url or ""

	type = (type == "PATH" or type == "WIKI") and type

	return mw.uri.decode( url, type )

end

-- {{#invoke:String2|urldecode|url=url|type=type}}

p.urldecode = function(frame)

	return mw.uri.decode( frame.args.url, frame.args.type )

end



-- what follows was merged from Module:StringFunc



-- helper functions

p._GetParameters = require('Module:GetParameters')



-- Argument list helper function, as per Module:String

p._getParameters = p._GetParameters.getParameters



-- Escape Pattern helper function so that all characters are treated as plain text, as per Module:String

function p._escapePattern( pattern_str )

	return mw.ustring.gsub( pattern_str, "([%(%)%.%%%+%-%*%?%[%^%$%]])", "%%%1" )

end



-- Helper Function to interpret boolean strings, as per Module:String

p._getBoolean = p._GetParameters.getBoolean



--[[

Strip



This function Strips characters from string



Usage:

{{#invoke:String2|strip|source_string|characters_to_strip|plain_flag}}



Parameters

	source: The string to strip

	chars:  The pattern or list of characters to strip from string, replaced with ''

	plain:  A flag indicating that the chars should be understood as plain text. defaults to true.



Leading and trailing whitespace is also automatically stripped from the string.

]]

function p.strip( frame )

	local new_args = p._getParameters( frame.args,  {'source', 'chars', 'plain'} )

	local source_str = new_args'source' or ''

	local chars = new_args'chars' or '' or 'characters'

	source_str = mw.text.trim(source_str)

	if source_str == '' or chars == '' then

		return source_str

	end

	local l_plain = p._getBoolean( new_args'plain' or true )

	if l_plain then

		chars = p._escapePattern( chars )

	end

	local result

	result = mw.ustring.gsub(source_str, "["..chars.."]", '')

	return result

end



--[[

Match any

Returns the index of the first given pattern to match the input. Patterns must be consecutively numbered.

Returns the empty string if nothing matches for use in {{#if:}}



Usage:

	{{#invoke:String2|matchAll|source=123 abc|456|abc}} returns '2'.



Parameters:

	source: the string to search

	plain:  A flag indicating that the patterns should be understood as plain text. defaults to true.

	1, 2, 3, ...: the patterns to search for

]]

function p.matchAny(frame)

	local source_str = frame.args'source' or error('The source parameter is mandatory.')

	local l_plain = p._getBoolean( frame.args'plain' or true )

	for i = 1, math.huge do

		local pattern = frame.argsi

		if not pattern then return '' end

		if mw.ustring.find(source_str, pattern, 1, l_plain) then

			return tostring(i)

		end

	end

end



--[[--------------------------< H Y P H E N _ T O _ D A S H >--------------------------------------------------



Converts a hyphen to a dash under certain conditions.  The hyphen must separate

like items; unlike items are returned unmodified.  These forms are modified:

	letter - letter (A - B)

	digit - digit (4-5)

	digit separator digit - digit separator digit (4.1-4.5 or 4-1-4-5)

	letterdigit - letterdigit (A1-A5) (an optional separator between letter and

		digit is supported – a.1-a.5 or a-1-a-5)

	digitletter - digitletter (5a - 5d) (an optional separator between letter and

		digit is supported – 5.a-5.d or 5-a-5-d)



any other forms are returned unmodified.



str may be a comma- or semicolon-separated list



]]

function p.hyphen_to_dash( str, spacing )

	if (str == nil or str == '') then

		return str

	end



	local accept



	str = mw.text.decode(str, true )											-- replace html entities with their characters; semicolon mucks up the text.split



	local out = {}

	local list = mw.text.split (str, '%s*[,;]%s*')								-- split str at comma or semicolon separators if there are any



	for _, item in ipairs (list) do												-- for each item in the list

		item = mw.text.trim(item)												-- trim whitespace

		item, accept = item:gsub ('^%(%((.+)%)%)$', '%1')

		if accept == 0 and mw.ustring.match (item, '^%w*[%.%-]?%w+%s*[%-–—]%s*%w*[%.%-]?%w+$') then	-- if a hyphenated range or has endash or emdash separators

			if item:match ('^%a+[%.%-]?%d+%s*%-%s*%a+[%.%-]?%d+$') or			-- letterdigit hyphen letterdigit (optional separator between letter and digit)

				item:match ('^%d+[%.%-]?%a+%s*%-%s*%d+[%.%-]?%a+$') or			-- digitletter hyphen digitletter (optional separator between digit and letter)

				item:match ('^%d+[%.%-]%d+%s*%-%s*%d+[%.%-]%d+$') or			-- digit separator digit hyphen digit separator digit

				item:match ('^%d+%s*%-%s*%d+$') or								-- digit hyphen digit

				item:match ('^%a+%s*%-%s*%a+$') then							-- letter hyphen letter

					item = item:gsub ('(%w*[%.%-]?%w+)%s*%-%s*(%w*[%.%-]?%w+)', '%1–%2')	-- replace hyphen, remove extraneous space characters

			else

				item = mw.ustring.gsub (item, '%s*[–—]%s*', '–')				-- for endash or emdash separated ranges, replace em with en, remove extraneous whitespace

			end

		end

		table.insert (out, item)												-- add the (possibly modified) item to the output table

	end



	local temp_str = table.concat (out, ',' .. spacing)							-- concatenate the output table into a comma separated string

	temp_str, accept = temp_str:gsub ('^%(%((.+)%)%)$', '%1')					-- remove accept-this-as-written markup when it wraps all of concatenated out

	if accept ~= 0 then

		temp_str = str:gsub ('^%(%((.+)%)%)$', '%1')							-- when global markup removed, return original str; do it this way to suppress boolean second return value

	end

	return temp_str

end



function p.hyphen2dash( frame )

	local str = frame.args1 or ''

	local spacing = frame.args2 or ' ' -- space is part of the standard separator for normal spacing (but in conjunction with templates r/rp/ran we may need a narrower spacing



	return p.hyphen_to_dash(str, spacing)

end



-- Similar to [[Module:String#endswith]]

function p.startswith(frame)

	return (frame.args1]:sub(1, frame.args2]:len()) == frame.args2]) and 'yes' or ''

end



return p