local p = {}

local math_module = require("Module:Math")

local function rnd(num, digits)
	-- This function implements {{rnd}}
	return math_module._precision_format(tostring(num), digits)
end

function p.ifexists(frame)
	page = frame.args[1]
	if not page then return (frame.args['no'] or '') end
    if mw.title.new(page).exists then return (frame.args['yes'] or 'yes') end
	return (frame.args['no'] or '')
end

function p.lists(frame)
	local s = '\n' .. (frame.args[1] or '') .. '\n'
	s = mw.ustring.gsub(s, '([\r\n])%*([^\r\n]*)', '%1<ul><li>%2</li></ul>')
	s = mw.ustring.gsub(s, '([\r\n])#([^\r\n]*)', '%1<ol><li>%2</li></ol>')
	s = mw.ustring.gsub(s, '</ol>%s*([\r\n]*)<ol>', '%1')
	s = mw.ustring.gsub(s, '</ul>%s*([\r\n]*)<ul>', '%1')
	s = mw.ustring.gsub(s, '^[\r\n](.*)[\r\n]$', '%1')
	return s
end

function p.precision(frame)
	return math_module._precision(frame.args[1])
end

function p.wpct(frame)
	local w = tonumber(frame.args[1]) or 0
	local l = tonumber(frame.args[2]) or 0
	local pct = '–'
	if (w + l) > 0 then
		pct = rnd(w / (w + l), 3):gsub('^0', '')
	end
	return pct
end

function p.extractcolor(frame)
	local str = frame.args[1] or ''
	local color = mw.ustring.match(';' .. str .. ';', '.*;%s*([Cc][Oo][Ll][Oo][Rr]%s*:%s*.-)%s*;')
	return color or 'NO MATCH'
end

local function trim(s)
	return s:match('^%s*(.-)%s*$')
end

function p.timeline(frame)
	local args = frame.args
	local width = 600
	local height = 340
	local scaleminor = 50
	local scalemajor = 100
	local rawoutput = false
	local data = {}
	for k, v in pairs(args) do
		if type(k) == 'number' then
			data[k] = trim(v)
		elseif k:find('^width$') then
			width = tonumber(v)
		elseif k:find('^height$') then
			height = tonumber(v)
		elseif k:find('^rawoutput$') then
			if trim(v) ~= '' then
				rawoutput = true
			end
		end
	end
	
	-- find some data limits
	local minyear, maxyear, maxpop = 999999, 0, 0
	for i = 1, #data, 2 do
		local year = tonumber(data[i] or '0')
		local pop = tonumber(data[i+1] or '0')
		minyear = (year < minyear) and year or minyear
		maxyear = (year > maxyear) and year or maxyear
		maxpop = (pop > maxpop) and pop or maxpop
	end
	local logbound = 10^(math.floor(math.log(maxpop)/math.log(10)+1))
	local scalemajor = logbound/10
	local scaleminor = scalemajor/2
	maxpop = scalemajor*(math.floor(maxpop/scalemajor + 1))

	local timeline = {
		'Colors=',
		'  id:lightgrey value:gray(0.9)',
		'  id:darkgrey value:gray(0.3)',
		'  id:sfondo value:rgb(1,1,1)',
		'  id:barra value:rgb(0.664, 0.664, 0.930)', -- dark lavender
		'',
		'ImageSize = width:' .. tostring(width) .. ' height:' .. tostring(height),
		'PlotArea = left:44 bottom:40 top:10 right:10',
		'DateFormat = x.y',
		'Period = from:0 till:' .. tostring(maxpop),
		'TimeAxis = orientation:vertical',
		'AlignBars = justify',
		'ScaleMajor = gridcolor:darkgrey increment:' .. tostring(scalemajor) .. ' start:0',
		'ScaleMinor = gridcolor:lightgrey increment:' .. tostring(scaleminor) .. ' start:0',
		'BackgroundColors = canvas:sfondo',
		'BarData='
		}
	local yearscale = math.max(math.floor((maxyear - minyear)/10),1)
	yearscale = 5*(math.floor(yearscale / 5))
	
	minyear = yearscale*math.floor(minyear/yearscale)
	maxyear = yearscale*math.ceil(maxyear/yearscale)
	
	for year = minyear,maxyear do
		local text = ( (year % yearscale) == 0) and ' text:' .. year or ''
		table.insert(timeline, '  bar:' .. year .. text)
	end
	table.insert(timeline,'\nPlotData=\n  color:barra width:7 align:left\n')
	for i = 1, #data, 2 do
		local year = data[i] or ''
		local pop = data[i+1] or ''
		table.insert(timeline, '  bar:' .. year .. ' from: 0 till:' .. pop)
	end
	-- table.insert(timeline,'\nPlotData=\n')
	--for i = 1, #data, 2 do
	--	local year = data[i] or ''
	--	local pop = data[i+1] or ''
	--	table.insert(timeline, '  bar:' .. year .. ' at:' .. pop .. ' fontsize:XS text: ' .. pop .. ' shift:(-8.5)')
	-- end
	if rawoutput then
		return frame:extensionTag{ name = 'pre', content = '\n' .. table.concat(timeline,'\n') .. '\n' }
	end
	return frame:extensionTag{ name = 'timeline', content = '\n' .. table.concat(timeline,'\n') .. '\n' }
end

local function getBestStatement(item_id, property_id)
	if not(item_id) or not(mw.wikibase.isValidEntityId(item_id)) or not(mw.wikibase.entityExists(item_id)) then
		return false
	end
	local statements = mw.wikibase.getBestStatements(item_id, property_id)
	if not statements or #statements == 0 then
		return false
	end
	local hasNoValue = ( statements[1].mainsnak and statements[1].mainsnak.snaktype == 'novalue' )
	if hasNoValue then
		return false
	end
	return statements[1]
end

function p.hasOSM(frame)
	return getBestStatement(mw.wikibase.getEntityIdForCurrentPage(), 'P402') and 'yes' or 'no'
end

function p.chart(frame)
	local chart = require('Module:Chart')['bar-chart']
	
	return chart(frame)
end

function p.main(frame)
	local getArgs = require('Module:Arguments').getArgs
	local args = getArgs(frame, {parentFirst = true,
	valueFunc = function (key, val)
		if key == 'text_IPS' then
			return nil
		end
		if type(val) == 'string' then
			val = val:match('^%s*(.-)%s*$')
			if val == '' then
				return nil
			else
				return val
			end
		else
			return val
		end
	end
	})
	local team_list = {}
	local ii = 1
	while args['team'..ii] ~= nil do
		team_list[args['team'..ii]] = ii
		ii = ii + 1
	end
	local max_team = ii - 1
	
	local first_team, last_team = 1, max_team
	if args['showteam'] and team_list[args['showteam']] then
		first_team = team_list[args['showteam']] - 2
		last_team = first_team + 4
		if first_team < 1 then
			first_team = 1
			last_team = first_team + 4
		end
		if last_team > max_team then
			last_team = max_team
			first_team = max_team - 4
		end
		if first_team < 1 then first_team = 1 end
	end
		
	local hasnotes = false
	
	local ii = first_team
	local res = '{| class="wikitable"\n'
	res = res .. '! Pos. !! Team !! Result\n'
	while args['team'..ii] ~= nil and (ii <= last_team) do
		res = res .. '|-\n'
		res = res .. '| ' .. ii .. '\n'
		res = res .. '| ' .. (args['name_'..args['team' .. ii]] or '') .. '\n'
		local text_result = args['result'..ii] and args['text_'..args['result'..ii]] or ''
		local style_text = ''
		if text_result:match('fbmulticompefn') then
			hasnotes = true
			style_text = style_text .. 'padding:0;'
		end
		style_text = style_text .. (args['result'..ii] and ('background:' .. args['col_'..args['result'..ii]]) or '')
		res = res .. '| style="' .. style_text .. '" | ' .. text_result .. '\n'
		ii = ii + 1
	end
	res = res .. '|}'
	
	if hasnotes == true then
		res = res .. '<b>Table notes:</b>' .. frame:expandTemplate{ title = 'notelist'}
	end
	
	-- Generate tracking
	if not args['notracking'] then
		-- Step 1: Generate a team and result list
		for k,v in pairs(args) do
			-- nothing
		end
	end

	return res
end

return p