local p = {}

local azupper = mw.text.split('ABCDEFGHIJKLMNOPQRSTUVWXYZ','')
local azlower = mw.text.split('abcdefghijklmnopqrstuvwxyz','')
local aejot = mw.text.split('aejot','')

local function main(toc_type)
	local toc_frame = mw.html.create('div')
		:addClass('large-cat-toc')
		:addClass('plainlinks')
		:addClass('toc')
		-- :attr('id','toc')
		
	-- Contains "Content: Top 0-9 A - Z"
	local header = toc_frame:tag('div')
		:attr('class', 'toctitle')
	
	-- Contains all the rest
	local body_wrapper
	local body = toc_frame:tag('div')
		:addClass('large-cat-toc-body')
		
	local jumpy_collapse = mw.html.create('div')
		:addClass('large-cat-toc-jumpy-title')
	
	if toc_type == 'collapsible' then
		toc_frame:addClass('mw-collapsible mw-collapsed')
		body:addClass('mw-collapsible-content')
		
	elseif toc_type == 'scrollable' then
		toc_frame:addClass('large-cat-toc-scroll')
	end
	
	local pageurl = mw.title.getCurrentTitle():fullUrl()
	local header_content = {
		string.format(
			'<span class="large-cat-toc-title">%s:</span> [%s Top] [%s?from=0 0–9]',
			mw.message.new('Toc'):plain(),
			pageurl,
			pageurl
		)
	}
	
	for _, v in ipairs(azupper) do
		table.insert(header_content, string.format(
			' [%s?from=%s %s]', pageurl, v, v
		))
	end
	
	if toc_type == 'collapsible' then
		jumpy_collapse:wikitext(table.concat(header_content))
		header:node(jumpy_collapse)
	else
		header:wikitext(table.concat(header_content))
	end
	
	local body_content = {}
	if toc_type ~= 'collapsible' then
		table.insert(body_content, ' <span class="large-cat-toc-anum">['..pageurl..'?from=* *]</span>')
	end
	
	table.insert(body_content, ' <span class="large-cat-toc-anum">#</span>')
	body_wrapper = body:tag('span')
	
	for i=0,9 do
		table.insert(body_content,string.format(' [%s?from=%s %s]',pageurl,i,i))
	end
	
	local function atoz(letter)
		local azlist = {}
		local letterlist
		if toc_type == 'aejot' then
			letterlist = aejot
		else
			letterlist = azlower
		end
				
		if toc_type == 'aejot' or toc_type == 'scrollable' then
			table.insert(azlist,' • <span class="large-cat-toc-anum">'..letter..'</span>')
		else
			table.insert(azlist,' <br /><span class="large-cat-toc-anum">'..letter..'</span>')
		end
			
        for i, v in ipairs(letterlist) do
            local lead = (i == 1) and '&nbsp;' or ' '  -- non-breaking space before the first link
            table.insert(azlist, string.format(
                '%s[%s?from=%s%s %s%s]', lead, pageurl, letter, v, letter, v
            ))
        end

		return table.concat(azlist)
	end
	
	for _, v in ipairs(azupper) do
		table.insert(body_content, atoz(v))
	end
	
	body_wrapper:wikitext(table.concat(body_content))
	
	return '__NOTOC__\n' .. mw.getCurrentFrame():extensionTag{
		name = 'templatestyles', args = { src = 'Module:Large category TOC/styles.css' }
	} .. tostring(toc_frame)
end

function p.scrollable(frame)
	return main('scrollable')
end

function p.collapsible(frame)
	return main('collapsible')
end

function p.aejot(frame)
	return main('aejot')
end

return p