require('strict')

local conf = require( "Module:Taxonbar/conf" )

local function getIdsFromWikidata( item, property )
	local ids = {}
	if not item.claims[property] then
		return ids
	end
	for _, statement in pairs( item.claims[property] ) do
		if statement.mainsnak.datavalue then
			table.insert( ids, statement.mainsnak.datavalue.value )
		end
	end
	return ids
end

local function getLink( property, val )
	local link = ""
	if mw.ustring.find( val, '//' ) then
		link = val
	else
		if type(property) == 'number' then
			local entityObject = mw.wikibase.getEntity('P'..property)
			local dataType = entityObject.datatype
			if dataType == "external-id" then
				local formatterURL = entityObject:getBestStatements('P1630')[1]
				if formatterURL then link = formatterURL.mainsnak.datavalue.value end
			elseif dataType == "url" then
				local subjectItem = entityObject:getBestStatements('P1629')[1]
				if subjectItem then
					local officialWebsite = mw.wikibase.getEntityObject(subjectItem.mainsnak.datavalue.value.id):getBestStatements('P856')[1]
					if officialWebsite then	link = officialWebsite.mainsnak.datavalue.value end
				end
			elseif dataType == "string" then
				local formatterURL = entityObject:getBestStatements('P1630')[1]
				if formatterURL then
					link = formatterURL.mainsnak.datavalue.value
				else
					local subjectItem = entityObject:getBestStatements('P1629')[1]
					if subjectItem then
						local officialWebsite = mw.wikibase.getEntityObject(subjectItem.mainsnak.datavalue.value.id):getBestStatements('P856')[1]
						if officialWebsite then	link = officialWebsite.mainsnak.datavalue.value end
					end
				end
			end
		elseif type(property) == 'string' then
			link = property
		end
		link = mw.ustring.gsub(link, '$1', val)
	end
	link = mw.ustring.gsub(link, '^[Hh][Tt][Tt][Pp]([Ss]?)://', 'http%1://') -- fix wikidata URL
	val = mw.ustring.match(val, '([^=/]*)/?$') -- get display name from end of URL
	if mw.ustring.find( link, '//' ) then
		return '['..link..' '..val..']'
	elseif link == "" then
		return val
	else
		return '<span class="external">[['..link..'|'..val..']]</span>'
	end
end

local function createRow( id, label, rawValue, link, withUid )
	if link then
		local outStr = '*<span style="white-space:nowrap;">' .. label .. ' <span'
		if withUid then outStr = outStr..' class="uid"' end
		return outStr..'>' .. link .. '</span></span>\n'
	else
		return '* <span class="error">The identifier ' .. id .. ' ' .. rawValue .. ' is not valid.</span>\n'
	end
end

local function copyTable(inTable)
	if type(inTable) ~= 'table' then return inTable end
	local outTable = setmetatable({}, getmetatable(inTable))
	for key, value in pairs (inTable) do outTable[copyTable(key)] = copyTable(value) end
	return outTable
end

local p = {}

function p.authorityControlTaxon( frame )
	local parentArgs = copyTable(frame:getParent().args)
	local stringArgs = false
	local fromTitleCount, firstRow, rowCount = 1, 0, 0
	--Cleanup args
	for k, v in pairs( frame:getParent().args ) do
		if type(k) == 'string' then
			--make args case insensitive
			local lowerk = mw.ustring.lower(k)
			if not parentArgs[lowerk] or parentArgs[lowerk] == '' then
				parentArgs[k] = nil
				parentArgs[lowerk] = v
			end
			--remap abc to abc1
			if not mw.ustring.find(lowerk,"%d$") then --if no number at end of param
				if not parentArgs[lowerk..'1'] or parentArgs[lowerk..'1'] == '' then
					parentArgs[lowerk] = nil
					lowerk = lowerk..'1'
					parentArgs[lowerk] = v
				end
			end
			if v and v ~= '' then
				--remap "for" to "title"
				if mw.ustring.sub(lowerk,1,3) == "for" then
					local forTitle = mw.ustring.gsub(lowerk,"^for","title",1)
					if parentArgs[forTitle] == '' or not parentArgs[forTitle] then
						parentArgs[lowerk] = nil
						lowerk = forTitle
						parentArgs[lowerk] = v
					end
				end
				--find highest from or title param
				if mw.ustring.sub(lowerk,1,4) == "from" then
					local fromNumber = tonumber(mw.ustring.sub(lowerk,5,-1))
					if fromNumber and fromNumber >= fromTitleCount then fromTitleCount = fromNumber end
				elseif mw.ustring.sub(lowerk,1,3) == "title" then
					local titleNumber = tonumber(mw.ustring.sub(lowerk,4,-1))
					if titleNumber and titleNumber >= fromTitleCount then fromTitleCount = titleNumber end
				elseif mw.ustring.lower(v) ~= 'no' and lowerk ~= 'for' then
					stringArgs = true
				end
			end
		end
	end

	--Setup navbox
	local navboxParams = {
		name  = 'Taxonbar',
		bodyclass = 'hlist',
		listclass = '',
		groupstyle = 'text-align: left;',
	}

	local currentTitle = mw.title.getCurrentTitle()

	for f = 1,fromTitleCount,1
	do
		local elements, title = {}, nil
		--cleanup parameters
		if parentArgs['from'..f] == '' then parentArgs['from'..f] = nil end
		if parentArgs['title'..f] == '' then parentArgs['title'..f] = nil end
		--remap aliases
		for _, a in pairs( conf.aliases ) do
			local alias, name = mw.ustring.lower(a[1]), mw.ustring.lower(a[2])
			if parentArgs[alias..f] and not parentArgs[name..f] then
				parentArgs[name..f] = parentArgs[alias..f]
				parentArgs[alias..f] = nil
			end
		end
		--Fetch Wikidata item
		local item = mw.wikibase.getEntity(parentArgs['from'..f])
		local label = nil
		if item then
			local statements = item:getBestStatements('P225')[1]
			if statements then
				local datavalue = statements.mainsnak.datavalue
				if datavalue then
					label = datavalue.value
				end
			end
			label = label or item:getLabel()
		end
		if label and label ~= '' then
			title = mw.title.new(label)
		end
		if not title and parentArgs['title'..f] then
			title = mw.title.new(parentArgs['title'..f])
		end
		if not title and f == 1 then
			title = currentTitle
		end

		if title then
			if (not parentArgs['wikidata'..f] or parentArgs['wikidata'..f] == '') and (title.namespace == 0) then
				if parentArgs['from'..f] then parentArgs['wikidata'..f] = parentArgs['from'..f] elseif item then parentArgs['wikidata'..f] = item.id end
			end
			if title.namespace == 0 or stringArgs then --Only in the main namespace or if there are manual overrides
				local sourcesFound = false
				for _, params in pairs( conf.databases ) do
					params[1] = mw.ustring.lower(params[1])
					--Wikidata fallback if requested
					if (item ~= nil and item.claims ~= nil) and params[3] ~= 0 and (not parentArgs[params[1]..f] or parentArgs[params[1]..f] == '') then
						local wikidataIds = getIdsFromWikidata( item, 'P' .. params[3] )
						if wikidataIds[1] then
							parentArgs[params[1]..f] = wikidataIds[1]
						end
					end
					local val = parentArgs[params[1]..f]
					if val and val ~= '' and mw.ustring.lower(val) ~= 'no' and params[3] ~= 0 then
						table.insert( elements, createRow( params[1], params[2] .. ':', val, getLink( params[3], val ), true ) )
						if params[1] ~= 'wikidata' then sourcesFound = true end
					end
				end

				--Generate navbox title
				if sourcesFound then
					rowCount = rowCount + 1
					if firstRow == 0 then firstRow = f end
					--set title from wikidata if it doesn't exist
					if parentArgs['title'..f] == '' or not parentArgs['title'..f] then
						parentArgs['noTitle'..f] = true
						parentArgs['title'..f] = title.text
					end
					--if it exists now, set row heading to title
					if parentArgs['title'..f] and parentArgs['title'..f] ~= '' then
						navboxParams['group'..f] = "''" .. parentArgs['title'..f] .. "''"
					else
						navboxParams['group'..f] = ""
					end
					navboxParams['list'..f] = table.concat( elements )
				end
			end
		end
	end

	if rowCount > 0 then
		local Navbox = require('Module:Navbox')
		if rowCount > 1 then
			--remove duplicates and move page title to top
			local rowIDs = {}
			for f = 1,fromTitleCount,1
			do
				if parentArgs['title'..f] and parentArgs['title'..f] ~= '' then
					if rowIDs[parentArgs['wikidata'..f]] then --remove duplicate
						navboxParams['group'..f] = nil
						navboxParams['list'..f] = nil
					else
						rowIDs[parentArgs['wikidata'..f]] = true
						if f > firstRow and (parentArgs['title'..f] == currentTitle.text or parentArgs['wikidata'..f] == mw.wikibase.getEntityIdForCurrentPage()) then --move item linked to page to top
							if navboxParams['group'..f] and navboxParams['group'..f] ~= '' and navboxParams['list'..f] and navboxParams['list'..f] ~= '' then
								local tempGroup, tempList = navboxParams['group'..f], navboxParams['list'..f]
								navboxParams['group'..f], navboxParams['list'..f] = navboxParams['group'..firstRow], navboxParams['list'..firstRow]
								navboxParams['group'..firstRow], navboxParams['list'..firstRow] = tempGroup, tempList
							end
						end
					end
				end
			end
			--adjust navbox for number of rows
			navboxParams['title'] = "[[Help:Taxon identifiers|Taxon identifiers]]"
			if rowCount > 2 then
				navboxParams['navbar'] = 'plain'
			else
				navboxParams['state'] = 'off'
				navboxParams['navbar'] = 'off'
			end
		elseif parentArgs['noTitle'..firstRow] then
			navboxParams['group'..firstRow] = '[[Help:Taxon identifiers|Taxon identifiers]]'
		else
			navboxParams['group'..firstRow] = '[[Help:Taxon identifiers|Taxon identifiers]]<br />' .. navboxParams['group'..firstRow]
		end
		return Navbox._navbox(navboxParams)
	else
		return ""
	end
end

return p