local m_str_utils = require("Module:string utilities")

local codepoint = m_str_utils.codepoint
local find = m_str_utils.find
local get_section = require("Module:pages").get_section
local gsub = m_str_utils.gsub
local sub = m_str_utils.sub

local m_links = require("Module:links")
local m_script_utils = require("Module:script utilities")

local export = {}

local PAGENAME = mw.loadData("Module:headword/data").pagename

local cangjie = {
	A = "日", B = "月", C = "金", D = "木", E = "水", F = "火", G = "土", H = "竹", I = "戈", J = "十", K = "大", L = "中", M = "一", N = "弓", O = "人", P = "心", Q = "手", R = "口", S = "尸", T = "廿", U = "山", V = "女", W = "田", X = "難", Y = "卜", Z = "重"
}

local radicals = {
	"一","丨","丶","丿","乙","亅",
	"二","亠","人","儿","入","八","冂","冖","冫","几","凵","刀","力","勹","匕","匚","匸","十","卜","卩","厂","厶","又",
	"口","囗","土","士","夂","夊","夕","大","女","子","宀","寸","小","尢","尸","屮","山","巛","工","己","巾","干","幺","广","廴","廾","弋","弓","彐","彡","彳",
	"心","戈","戶","手","支","攴","文","斗","斤","方","无","日","曰","月","木","欠","止","歹","殳","毋","比","毛","氏","气","水","火","爪","父","爻","爿","片","牙","牛","犬",
	"玄","玉","瓜","瓦","甘","生","用","田","疋","疒","癶","白","皮","皿","目","矛","矢","石","示","禸","禾","穴","立",
	"竹","米","糸","缶","网","羊","羽","老","而","耒","耳","聿","肉","臣","自","至","臼","舌","舛","舟","艮","色","艸","虍","虫","血","行","衣","襾",
	"見","角","言","谷","豆","豕","豸","貝","赤","走","足","身","車","辛","辰","辵","邑","酉","釆","里",
	"金","長","門","阜","隶","隹","雨","靑","非",
	"面","革","韋","韭","音","頁","風","飛","食","首","香",
	"馬","骨","高","髟","鬥","鬯","鬲","鬼",
	"魚","鳥","鹵","鹿","麥","麻",
	"黃","黍","黑","黹",
	"黽","鼎","鼓","鼠",
	"鼻","齊",
	"齒",
	"龍","龜",
	"龠"
}

local simplified_radical = {
	='言',='門',='食',='飛',='馬',='見',='貝',='糸',='車',='長',='韋',='風',='金',='鳥',='龍',='龍',='頁',='齊',='齊',='麥',='龜',='龜',='魚',='黽',='鼠',='齒',='齒',='鹵',='龜',='爿',='黑',='黃',
}

local codes = {
	c = 'simplified Chinese', m = 'mainland China',
	j = 'Japanese', k = 'Korean'
}

-- Letters in "as" or "sn" parameter names follow these criteria:
-- There must be 1 or 2 of them.
-- They must be c, m, j, or k.
-- They must be in the order jk.
local function validate_letters(letters)
	local letter_count = #letters
	return letter_count == 3 and (letters == 'mjk' or letters == 'cjk')
		or letter_count == 2 and (letters == 'jk' or letters == 'cj' or letters == 'mj')
		or letter_count == 1 and codes
end

local function mul_link(term)
	return m_links.full_link({lang = require('Module:languages').getByCode('zh'), term = term.."//", tr="-"})
end

-- Description:
-- This box links to one of the 214 categories Radical ###-0 on Wikimedia
-- Commons, from the ~300 pages "※" (※ stands for any of the 214 radical
-- glyphs and its variants).
--
-- Purpose:
-- At Commons, each Chinese radical (and each other glyph) category has a direct
-- link to the character entry at English Wiktionary, where it is well explained.
-- The back link from each Wiktionary radikal article to its equivalent Commons
-- category eases the browsing of Chinese characters.
-- 
-- The box was formerly housed at ].
local function radical(name,number,variant)
	number = number or 1
	local padleft = ("%03d"):format(number)
	local text = '<div class="noprint standard-box nowrap" style="margin:0;font-size:90%;width:fit-content;text-align:left;float:right"><div style="float:left; margin-right:0.5em">]</div>]</div>"
	if name == PAGENAME or (variant and variant ~= '') then
		text = text .. ']'
	else
		text = text .. ']'
	end
	return text
end

function export.simp(frame)
	local args = frame:getParent().args
	
	local trad = args or ''
	if trad == '' then
		require('Module:debug').track("zh-han-simp-no-arg1")
		trad = mw.loadData("Module:zh/data/st") or PAGENAME
	end
	
	local nocap = args or ''
	local alt = args or ''
	local from = {args or '',args or ''}
	local to = {args or '',args or ''}
	if from == '' and to ~= '' then from = trad end
	local text = {}
	local result = ''
	result = (nocap == '' and 'S' or 's') .. 'implified from ' .. mul_link(trad)
	if alt ~= '' then
		result = result .. ' and ' .. mul_link(alt)
	end
	for i=1,2 do
		if from ~= '' then
			if to == '' then
				table.insert(text,mul_link(from) .. " → a component which cannot be displayed independently")
			elseif to == ' ' or to == '&nbsp;' then
				table.insert(text,'elimination of ' .. mul_link(from))
			else
				table.insert(text,mul_link(from) .. ' → ' .. mul_link(to))
			end
		end
	end
	if #text > 0 then
		result = result .. ' (' .. table.concat(text,' and '):gsub('and elimination of','and') .. ')'
	end
	return result
end

-- NOTE: added 2023 Nov as a sanity check for {{Han ref}}
function export.cp()
	return string.format('%.4X', codepoint(PAGENAME))
end

do
	local function check_translingual_only()
		for _, sec in pairs(mw.loadData("Module:headword/data").page.L2_sections) do
			if sec ~= "Translingual" then
				return
			end
		end
		require('Module:debug').track('zh-han/translingual-only character')
	end
	
	function export.character(frame)
		local args = {}
		for arg, val in pairs(frame:getParent().args) do -- Set empty args to nil.
			if val ~= '' then
				args = val
			end
		end
		if radicals)] ~= (simplified_radical] or args) then
			error('Radical number (rn) and radical (rad) do not match')
		end
		local text = { insert = table.insert }
		local categories = { insert = table.insert }
		local as = tostring(tonumber(args or '-1'))
		if as == '0' then
			text:insert(radical(args, args, (args or '')))
		end
		
		-- Creating headword with ] ensures that page title is script-tagged with Hani (generic Han).
		-- This assumes that {{Han char}} is only used in Translingual sections.
		local mul = require("Module:languages").getByCode("mul")
		local Hani = require("Module:scripts").getByCode("Hani")
		local sort_key = args .. args .. PAGENAME
		text:insert(
			require("Module:headword").full_headword{
				lang = mul,
				sc = Hani,
				heads = { args },
				categories = {},
				pos_category = "symbols",
				sort_key = sort_key,
			}
		)
		text:insert(" (''] " .. (args or '') .. ", ''  or '') .. '|' .. (args or ' ') .. ']]+' .. as)
		if args then
			text:insert(" ''in Chinese'', " .. (args or '') .. '+' .. tonumber(args) .. " ''in Japanese''")
		end
		if args then
			text:insert(" ''in traditional Chinese'', " .. (args or '') .. '+' .. tonumber(args) .. " ''in simplified Chinese''")
		end
		if args then
			text:insert(" ''in Chinese'', " .. (args or '') .. '+' .. tonumber(args) .. " ''in Korean''")
		end
		if args then
			text:insert(" ''in Chinese'', " .. (args or '') .. '+' .. tonumber(args) .. " ''in Japanese and Korean''")
		end
		if args then
			text:insert(" ''in Chinese and Korean'', " .. (args or '') .. '+' .. tonumber(args) .. " ''in Japanese''")
		end
		if args then
			text:insert(" ''in Chinese and Japanese'', " .. (args or '') .. '+' .. tonumber(args) .. " ''in Korean''")
		end
		if args then
			text:insert(" ''in traditional Chinese and Japanese'', " .. (args or '') .. '+' .. tonumber(args) .. " ''in simplified Chinese''")
		end
		if args then
			text:insert(" ''in traditional Chinese, Japanese and Korean'', " .. (args or '') .. '+' .. tonumber(args) .. " ''in simplified Chinese''")
		end
		if args then
			text:insert(" ''in traditional Chinese'', " .. (args or '') .. '+' .. tonumber(args) .. " ''in simplified Chinese and Japanese''")
		end
		if args then
			text:insert(" ''in traditional Chinese and Korean'', " .. (args or '') .. '+' .. tonumber(args) .. " ''in simplified Chinese and Japanese''")
		end
		if args then
			text:insert(" ''in traditional Chinese'', " .. (args or '') .. '+' .. tonumber(args) .. " ''in mainland China''")
		end
		if args then
			text:insert(" ''in traditional Chinese'', " .. (args or '') .. '+' .. tonumber(args) .. " ''in mainland China and Japanese''")
		end
		if args then
			text:insert(" ''in traditional Chinese and Korean'', " .. (args or '') .. '+' .. tonumber(args) .. " ''in mainland China and Japanese''")
		end
		if args then
			text:insert(" ''in traditional Chinese and Japanese'', " .. (args or '') .. '+' .. tonumber(args) .. " ''in mainland China''")
		end
		if args then
			text:insert(" ''in traditional Chinese, Japanese and Korean'', " .. (args or '') .. '+' .. tonumber(args) .. " ''in mainland China''")
		end
		if args then
			text:insert(" ''in traditional Chinese'', " .. (args or '') .. '+' .. tonumber(args) .. " ''in simplified Chinese, Japanese and Korean''")
		end
		if args then
			text:insert(" ''in traditional Chinese'', " .. (args or '') .. '+' .. tonumber(args) .. " ''in mainland China, Japanese and Korean''")
		end
		if args then
			text:insert(" ''in traditional Chinese (Taiwan)'', " .. (args or '') .. '+' .. tonumber(args) .. " ''in Chinese (mainland China, Hong Kong), Japanese and Korean''")
		end
		text:insert(", " .. (args or '') .. " stroke")
		-- To do: fix handling of multiple additional stroke numbers;
		-- search query:
		-- hastemplate:"Module:zh-han" insource:/\|sn?\+*=+\|sn?\+*=+/
		if args ~= '1' then
			text:insert('s')
		end
		if args then
			text:insert(" ''in Chinese''")
		end
		if args then
			text:insert(" ''in traditional Chinese''")
		end
		if args then
			text:insert(" ''in Chinese''")
		end
		if args then
			text:insert(" ''in Chinese''")
		end
		if args then
			text:insert(" ''in Chinese and Korean''")
		end
		if args then
			text:insert(" ''in Chinese and Japanese''")
		end
		if args then
			text:insert(" ''in traditional Chinese and Japanese''")
		end
		if args then
			text:insert(" ''in traditional Chinese, Japanese and Korean''")
		end
		if args then
			text:insert(" ''in traditional Chinese''")
		end
		if args then
			text:insert(" ''in traditional Chinese and Korean''")
		end
		if args then
			text:insert(" ''in traditional Chinese''")
		end
		if args then
			text:insert(" ''in traditional Chinese''")
		end
		if args then
			text:insert(" ''in traditional Chinese and Korean''")
		end
		if args then
			text:insert(" ''in traditional Chinese and Japanese''")
		end
		if args then
			text:insert(" ''in traditional Chinese, Japanese and Korean''")
		end
		if args then
			text:insert(" ''in traditional Chinese''")
		end
		if args then
			text:insert(" ''in traditional Chinese''")
		end
		if args then
			text:insert(" ''in traditional Chinese (Taiwan)''")
		end
		
		-- Find parameters specifying additional stroke numbers and add notes for
		-- them.
		for param_name, value in pairs(args) do
			if type(param_name) == "string" then
				local letters = param_name:match("^sn(%l+)%+*$")
				if letters then
					if validate_letters(letters) then
						if value and value ~= '' then
							local label = {}
							for letter in letters:gmatch(".") do
								table.insert(label, codes) -- Already checked that letters are valid.
							end
							label = table.concat(label, " and ")
							
							text:insert(", " .. value .. " stroke")
							if value ~= '1' then
								text:insert('s')
							end
							text:insert(" ''in " .. label .. "''")
						end
					else
						require("Module:debug").track('zh-han/incorrect stroke number parameter')
						-- return error("Unrecognized stroke number parameter name " .. param_name .. ".")
					end
				end
			end
		end
		
		if args then
			local canj = args
			local canj_split = mw.text.split(canj,',')
			for i = 1, #canj_split do
				if canj_split:match('^%u+$') then
					canj_split = canj_split:gsub('','')
					canj_split = m_script_utils.tag_text(canj_split:gsub('%u',cangjie), mul, Hani) .. ' (:sub(1,1):lower() .. '|' .. canj_split .. ']])'
				else
					return error('The value of "canj" parameter is invalid.')
				end
			end
			text:insert(", '']'' " .. table.concat(canj_split,' or '))
			if #canj_split > 1 then
				categories:insert("]")
			end
		end
		if args then
			local four = args
			local four_split = mw.text.split(four,',')
			for i=1,#four_split do
				if not four_split:match('') then
					four_split = four_split:gsub('(%d)(%d%d%d)%.?(%d?)',']')
				else
					return error('The value of "four" parameter is invalid.')
				end
			end
			text:insert(", '']'' " .. table.concat(four_split,' or '))
			if #four_split > 1 then
				categories:insert("]")
			end
		end
		if args then
			local ids = args
			local ids_split = mw.text.split(ids,',')
			for i=1, #ids_split do
				if not ids_split:match(']') then
					if find(ids_split, '^(.)%1%1$') then
						categories:insert(']')
					end
					if find(ids_split, '^(.)%1$') then
						categories:insert(']')
					end
					local before = {}
					ids_split = gsub(ids_split, "()",
						function (character)
							if not before then
								before = true
								return "]"
							else
								return character
							end
						end)
					ids_split = ids_split:gsub("^(.-)%f(.*)",
						function(m1, m2)
							local m1 = m_links.embedded_language_links{term = m1, lang = mul, sc = Hani}
							m1 = m_script_utils.tag_text(m1, mul, Hani)
							local letters = {
								G = '<span class="explain" title="Mainland China">G</span>',
								H = '<span class="explain" title="Hong Κong">H</span>',
								T = '<span class="explain" title="Taiwan">T</span>',
								J = '<span class="explain" title="Japan">J</span>',
								K = '<span class="explain" title="Korea">K</span>',
								V = '<span class="explain" title="Vietnam">V</span>'
							}
							return m1 .. m2:gsub(".", letters)
						end)
				end
			end
			text:insert(", '']'' " .. table.concat(ids_split,' or '))
			if #ids_split > 1 then
				categories:insert("]")
			end
		end
		text:insert(')')
		if args then
			if mw.title.getCurrentTitle().nsText == '' then
				categories:insert("]")
			end
		else
			if mw.title.getCurrentTitle().nsText == '' then
				categories:insert("]")
			end
		end
		local params_to_check = { "as", "rn", "sn", "ids", "four", "canj" }
		local sortkey = args and "|" .. args or ""
		for _, param in pairs(params_to_check) do
			if not args or args == '' then
				categories:insert("]")
			end
		end
		
		if type(args) == "string" and sub(args,1,1) == '0' then
			return error('Please remove leading zeros from the "sn" parameter.')
		end
		
		check_translingual_only()
		
		if (get_section(mw.title.getCurrentTitle():getContent(), "Translingual", 2) or ""):match("%f#*%S") then
			categories:insert("]")
		end
		
		return table.concat(text) .. table.concat(categories)
	end
end

return export