require('strict');
local p = {}

-- common label prepping to make loop more readable
local function prep_label(result, label, show_labels, out, i)
	if show_labels ~= 'no' then
		-- labels for every case except for optional first term outside parentheses
		if (out ~= 'yes') or (out == 'yes' and i > 1) then
			table.insert(result, label)
		end
	end
	return result
end

-- function to generate error message
local function format_error(message)
	local result = {
		'<span class="error" style="border:inherit; padding:inherit;">{{[[Template:Korean/auto|Korean/auto]]}} error. ',
		message,
		' ([[Template:Korean/auto|Help]])</span>',
		'[[Category:Korean/auto template errors]]'
	}
	return table.concat(result)
end

function p.ko(frame)
	local getArgs = require('Module:Arguments').getArgs
	return p._ko(getArgs(frame))
end

function p._ko(args)
	local lang_module = require('Module:Lang')      -- for wrapping non-English text
	local utils_module = require('Module:Ko-utils/sandbox') -- for a function to check hangul
	local translit = require('Module:Ko-translit/sandbox')  -- for automatic romanization
	local ipa_module = require('Module:IPA')        -- for IPA (duh)
	local template = 'Korean'
	
	-- assign positional params
	local hangul, hanja
	if args['hangul'] then hangul = args['hangul'] else hangul = args[1] end
	if args['hanja'] then hanja = args['hanja'] else hanja = args[2] end
	
	-- assign named params
	local lit, rr, mr = args['lit'], args['rr'], args['mr']
	local hangulref, hanjaref, en_iparef, ko_iparef, litref = args['hangulref'], args['hanjaref'], args['en_iparef'], args['ko_iparef'], args['litref']
	local en_ipa, ko_ipa = args['en_ipa'], args['ko_ipa']
	local out, en_out, order = args['out'], args['en_out'], args['order']
	local show_labels, show_links = args['labels'], args['links']
	local capitalize, namemode = args['capitalize'], args['namemode']
	
	-- validate input
	if not hangul then return format_error('<code>hangul</code> must not be empty.') end
	if not utils_module.contains_hangul(hangul) then
		return format_error('<code>hangul</code> must contain at least one Hangul character.')
	end
	if utils_module.contains_reference(hangul) then
		return format_error('<code>hangul</code> should not contain a reference; use <code>hangulref</code> for that.')
	end
	if utils_module.hangul_contains_syntax(hangul) and not (rr or mr) then
		return format_error('<code>hangul</code> contains special syntax but romanization not enabled; remove or escape (<code>\\</code>) special syntax.')
	end
	if hanjaref and not hanja then
		return format_error('<code>hanja</code> cannot be empty when <code>hanjaref</code> is given.')
	end
	if en_iparef and not en_ipa then
		return format_error('<code>en_ipa</code> cannot be empty when <code>en_iparef</code> is given.')
	end
	if ko_iparef and not ko_ipa then
		return format_error('<code>ko_ipa</code> cannot be empty when <code>ko_iparef</code> is given.')
	end
	if litref and not lit then
		return format_error('<code>lit</code> cannot be empty when <code>litref</code> is given.')
	end
	if ((out == "yes" or en_out == "yes") and not (lit or rr or mr or en_ipa or ko_ipa)) then
		return format_error('If <code>out=yes</code>, a parameter other than <code>hangul</code> or <code>hangulref</code> must be provided.')
	end
	if en_out == 'yes' then
		if out == 'no' then return format_error('If <code>en_out=yes</code>, <code>out</code> cannot be <code>no</code>') end
		if en_out == 'yes' then out = 'yes' end -- set out if it wasn't already specified 
		if not lit then return format_error('<code>en_out</code> specified but no <code>lit</code> was provided.') end
		if (order and string.sub(order, 1, 1) ~= 'l') then
			return format_error('If giving both <code>en_out</code> and <code>order</code>, <code>l</code> should come first in <code>order</code>.')
		end
	end
	if (namemode == 'yes' and not (rr or mr)) then
		return format_error('If <code>namemode=yes</code>, <code>rr</code> or <code>mr</code> should be <code>yes</code>.')
	end
	if (namemode == 'yes' and string.sub(hangul, 1, 1) == "%") then
		return format_error('If <code>namemode=yes</code>, <code>%</code> is not needed at beginning of <code>hangul</code> input.')
	end
	if (capitalize == 'yes' and not (rr or mr)) then
		return format_error('If <code>capitalize=yes</code>, <code>rr</code> or <code>mr</code> should be <code>yes</code>.')
	end
	if (capitalize == 'yes' and string.sub(hangul, 1, 1) == "^") then
		return format_error('If <code>capitalize=yes</code>, <code>^</code> is not needed at beginning of <code>hangul</code> input.')
	end
	
	-- apply name mode
	if namemode == 'yes' then
		hangul = '%' .. hangul
	end
	
	-- apply capitalization
	if capitalize == 'yes' then
		hangul = '^' .. hangul
	end
	
	-- romanize
	local rr_out
	if rr == 'yes' then
		rr_out = translit.rr({hangul})                                          -- generate automatic RR
		rr_out = lang_module._xlit({'ko', 'rr', rr_out, ['template']=template}) -- wrap in {{translit|ko|rr}}
	end
	local mr_out
	if mr == 'yes' then
		mr_out = translit.mr({hangul})
		mr_out = lang_module._xlit({'ko', 'mr', mr_out, ['template']=template})
	end
	
	-- prep hangul for display
	hangul = translit.clean_hangul({hangul})                                    -- remove syntax characters
	hangul = lang_module._lang({'ko', hangul, ['template']=template})           -- wrap in lang template
	
	-- prep hanja for display
	if hanja then
		hanja = lang_module._lang({'ko', hanja, ['template']=template})
	end
	
	-- prep ipas
	local ipa_label
	if ko_ipa or en_ipa then
		if show_labels ~= 'no' then
			ipa_label = 'pronounced'
		else
			ipa_label = ''
		end
	end
	if ko_ipa then
		ko_ipa = ipa_module._main({'ko', ko_ipa, ['label'] = ipa_label})
	end
	if en_ipa then
		en_ipa = ipa_module._main({'en', en_ipa, ['label'] = ipa_label})
	end
	
	-- prep display order string
	if order then
		-- for en_out mode, add english ipa after literal if wasn't specified
		if (en_out == 'yes' and en_ipa and not string.find(order, 'e')) then
			order = string.sub(order, 1, 1) .. 'e' .. string.sub(order, 2, #order)
		end
		
		-- check if order is malformed
		if not string.match(order, '^[hzrmkle]+$') then return format_error('<code>order</code> contains invalid characters.') end
		-- check if any characters duplicated
		for _, c in ipairs({'h', 'z', 'r', 'm', 'e', 'k', 'l'}) do
			local _, count = string.gsub(order, c, '')
			if count > 1 then return format_error('<code>order</code> contains more than one <code>"' .. c .. '"</code>.') end
		end
		if not string.find(order, 'h') then return format_error('<code>order</code> is missing "<code>h</code>".') end
		if (hanja and not string.find(order, 'z')) or (not hanja and string.find(order, 'z')) then return format_error('<code>order</code> is missing "<code>z</code>" or <code>hanja</code> is empty.') end
		if (rr == 'yes' and not string.find(order, 'r')) then
			return format_error('<code>order</code> is missing "<code>r</code>".')
		end
		if (rr ~= 'yes' and string.find(order, 'r')) then
			return format_error('<code>order</code> contains "<code>r</code>" but <code>rr</code> is not <code>yes</code>.')
		end
		if (mr == 'yes' and not string.find(order, 'm')) then
			return format_error('<code>order</code> is missing "<code>m</code>".')
		end
		if (mr ~= 'yes' and string.find(order, 'm')) then
			return format_error('<code>order</code> contains "<code>m</code>" but <code>mr</code> is not <code>yes</code>.')
		end
		-- "i" and "l" are optional to specify, so only check if order is given but not value
		if (string.find(order, 'e') and not en_ipa) then return format_error('<code>order</code> has "<code>e</code>" but <code>en_ipa</code> is empty.') end
		if (string.find(order, 'k') and not ko_ipa) then return format_error('<code>order</code> has "<code>k</code>" but <code>ko_ipa</code> is empty.') end
		if (string.find(order, 'l') and not lit) then return format_error('<code>order</code> has "<code>l</code>" but <code>lit</code> is empty.') end
	elseif en_out == 'yes' then
		-- if no order was provided but en_out was given, build default order
		-- lit[litref] (en_ipa[en_iparef]; hangul[hangulref]; hanja[hanjaref]; rr; mr; ko_ipa[ko_iparef])
		order = 'l'
		if en_ipa then order = order .. 'eh' else order = order .. 'h' end -- hangul also added here
		if hanja then order = order .. 'z' end
		if rr_out then order = order .. 'r' end
		if mr_out then order = order .. 'm' end
		if ko_ipa then order = order .. 'k' end
	else
		-- default order
		-- en_ipa[en_ipa]; hangul[hangulref]; hanja[hanjaref]; rr; mr; ko_ipa[ko_iparef]; lit[litref]
		if en_ipa then order = 'eh' else order = 'h' end -- hangul also added here
		if hanja then order = order .. 'z' end
		if rr_out then order = order .. 'r' end
		if mr_out then order = order .. 'm' end
		if ko_ipa then order = order .. 'k' end
		if lit then order = order .. 'l' end
	end
	-- add optional order parameters (k, l) to end if not already there
	if (ko_ipa and not string.find(order, 'k')) then order = order .. 'k' end
	if (lit and not string.find(order, 'l')) then order = order .. 'l' end
	
	-- iterate through the order and add elements to output
	local result = {}
	local c, label
	for i = 1, #order do
	    c = string.sub(order, i, i)
	    
	    -- hangul processing
	    if c == 'h' then
	    	-- language label insertion (more complicated conditionals in function)
	    	if show_links == 'no' then
	    		label = 'Korean: '
    		else
    			label = '[[Korean language|Korean]]: '
			end
	    	result = prep_label(result, label, show_labels, out, i)
	    	
    		-- hangul insertion
	    	table.insert(result, hangul)
	    	
	    	-- hangul ref insertion
	    	if hangulref then table.insert(result, hangulref) end
    	end
    	
	    -- hanja processing
	    if c == 'z' then
	    	if show_links == 'no' then
	    		label = 'Hanja: '
    		else
    			label = '[[Hanja]]: '
			end
	    	result = prep_label(result, label, show_labels, out, i)
	    	table.insert(result, hanja)
	    	if hanjaref then table.insert(result, hanjaref) end
    	end
    	
    	-- rr processing
	    if c == 'r' then
	    	if show_links == 'no' then
	    		label = '<abbr title="Revised Romanization of Korean">RR</abbr>: '
    		else
    			label = '[[Revised Romanization of Korean|RR]]: '
			end
	    	result = prep_label(result, label, show_labels, out, i)
	    	table.insert(result, rr_out)
    	end

    	-- mr processing
	    if c == 'm' then
	    	if show_links == 'no' then
	    		label = '<abbr title="McCune–Reischauer">MR</abbr>: '
    		else
    			label = '[[McCune–Reischauer|MR]]: '
			end
	    	result = prep_label(result, label, show_labels, out, i)
	    	table.insert(result, mr_out)
    	end
    	
		-- en_ipa processing
    	if c == 'e' then
			table.insert(result, en_ipa)
			table.insert(result, en_iparef)
    	end
    	
		-- ko_ipa processing
    	if c == 'k' then
			table.insert(result, ko_ipa)
			table.insert(result, ko_iparef)
    	end
    	
    	-- literal translation processing
    	if c == 'l' then
			label = '<abbr style="font-size:85%;" title="literal translation">lit.</abbr> '
			lit = "'" .. lit .. "'" -- single quotes around gloss
			result = prep_label(result, label, show_labels, out, i)
			table.insert(result, lit)
			table.insert(result, litref)
    	end
	
	    -- add semicolon
	    if i < #order then
	    	if not (out == 'yes' and i == 1) then
	    		table.insert(result, '; ')
    		end
    	end
	    -- add parentheses if needed 
		if (i == 1 and out == 'yes') then table.insert(result, ' (') end
		if (i == #order and out == 'yes') then table.insert(result, ')') end
	end
	return unpack(result)
end

return p