local languages = {}

local lang_lua = {
	keywords = {
		["if"] = "Keyword.Control.If";
		["else"] = "Keyword.Control.Else";
		["elseif"] = "Keyword.Control.Elseif";

		["repeat"] = "Keyword.Loop.Repeat";
		["while"] = "Keyword.Loop.While";

		["for"] = "Keyword.Loop.For";
		["in"] = "Keyword";

		["and"] = "Operator.And";
		["or"] = "Operator.Or";
		["not"] = "Operator.Not";

		["break"] = "Keyword.Control.Break";
		["return"] = "Keyword.Control.Return";

		["do"] = "Keyword";
		["then"] = "Keyword";
		["until"] = "Keyword";
		["end"] = "Keyword.Control";

		["function"] = "Keyword.Function";

		["local"] = "Keyword.Declare";

		["true"] = "Constant.Boolean";
		["false"] = "Constant.Boolean";
		["nil"] = "Constant.Null";
	};

	symbols = {
		["="] = "Symbol";

		["["] = "Symbol.Bracket.Square";
		["]"] = "Symbol.Bracket.Square";
		["("] = "Symbol.Bracket.Round";
		[")"] = "Symbol.Bracket.Round";
		["{"] = "Symbol.Bracket.Curly";
		["}"] = "Symbol.Bracket.Curly";

		["+"] = "Operator.Math.Add";
		["-"] = "Operator.Math.Sub";
		["*"] = "Operator.Math.Mul";
		["/"] = "Operator.Math.Div";
		["%"] = "Operator.Math.Mod";
		["^"] = "Operator.Math.Pow";

		["=="] = "Operator.Compare.Eq";
		["~="] = "Operator.Compare.Neq";
		[">="] = "Operator.Compare.Gte";
		["<="] = "Operator.Compare.Lte";
		[">"] = "Operator.Compare.Gt";
		["<"] = "Operator.Compare.Lt";

		["#"] = "Operator.Len";

		["."] = "Symbol.Index";
		[":"] = "Symbol.Index";

		[","] = "Symbol.Sep";
		[";"] = "Symbol.Sep";
	};

	comments = {
		start = {
			line = "%-%-";
			multiline = "%-%-%[(=*)%[";
		};
		finish = {
			line = "\n";
			multiline = "%]%1%]";
		};
	};

	strings = {
		start = {
			line = "[\"\']";
			multiline = "%[(=*)%[";
		};
		finish = {
			line = "%1";
			multiline = "%]%1%]";
		};
		escape = {
			line = "\\";
			multiline = nil;
		};
	};
}

local function findEndingMatch( text, initial, final, escape, position )
	if not final then error("hey", 2)end
	local escaped = false
	local close = "^" .. initial:gsub( "^(.*)$", final )
	local esc = escape and "^" .. initial:gsub( "^(.*)$", escape )

	while position <= #text do
		if escaped then
			escaped = false
		elseif escape and text:find( esc, position ) then
			position = select( 2, text:find( esc, position ) )
			escaped = true
		else
			local s, f = text:find( close, position )
			if s then
				return f
			end
		end

		position = position + 1
	end
end

local function longestOf( text, position, a, b, c, d, A, B, C, D )
	local t = {
		{ a, text:match( "^" .. a:gsub( "%(", "" ):gsub( "%)", "" ), position ) };
		{ b, text:match( "^" .. b:gsub( "%(", "" ):gsub( "%)", "" ), position ) };
		{ c, text:match( "^" .. c:gsub( "%(", "" ):gsub( "%)", "" ), position ) };
		{ d, text:match( "^" .. d:gsub( "%(", "" ):gsub( "%)", "" ), position ) };
	}
	local l = 0
	local n = 0

	for i = 1, #t do
		if t[i][2] and #t[i][2] > l then
			n = i
		end
	end

	return n > 0 and text:match( "^" .. t[n][1], position ), n > 0 and ({A, B, C, D})[n]
end

local function formatText( text )
	return text:gsub( "\\", "\\\\" ):gsub( "{", "\\{" ):gsub( "}", "\\}" )
end

local function createLanguageFormatter(lang)
	return function(state, line)

		local i = 1
		local res = ""

		if state.in_section then
			local index = state.in_section:match "_(.+)"
			local sindex = (state.in_section == "comment_line" or state.in_section == "comment_multiline") and "comments" or "strings"
			local ending = findEndingMatch( line, state.string_match, lang[sindex].finish[index], lang[sindex].escape and lang[sindex].escape[index], 1 )

			if ending then
				state.in_section = false
				i = ending + 1
				res = (sindex == "strings" and "{Constant.String:" or "{Comment:") .. formatText( line:sub( 1, ending ) ) .. "}"
			else
				return (sindex == "strings" and "{Constant.String:" or "{Comment:") .. formatText( line ) .. "}"
			end
		end

		while i <= #line do
			local pat, fullindex = longestOf( line, i,
				lang.strings.start.line, lang.strings.start.multiline,
				lang.comments.start.line, lang.comments.start.multiline,
				"string_line", "string_multiline",
				"comment_line", "comment_multiline"
			)

			if pat then
				local index = fullindex:match "_(.+)"
				local sindex = (fullindex == "string_line" or fullindex == "string_multiline") and "strings" or "comments"
				local ending = findEndingMatch( line, pat, lang[sindex].finish[index], lang[sindex].escape and lang[sindex].escape[index], i + #pat )

				if ending then
					res = res .. (sindex == "strings" and "{Constant.String:" or "{Comment:") .. formatText( line:sub( i, ending ) ) .. "}"
					i = ending + 1
				elseif fullindex == "comment_line" then
					res = res .. (sindex == "strings" and "{Constant.String:" or "{Comment:") .. formatText( line:sub( i ) ) .. "}"
					return res
				else
					state.in_section = fullindex
					state.string_match = pat
					res = res .. (sindex == "strings" and "{Constant.String:" or "{Comment:") .. formatText( line:sub( i ) ) .. "}"
					return res
				end

			elseif line:find( "^%d*%.?%d", i ) then
				local match = line:match( "^%d*%.?%d+e[%+%-]%d+", i ) or line:match( "^%d*%.?%d+", i )
				res = res .. "{Constant.Number:" .. match .. "}"
				i = i + #match

			elseif line:find( "^0x%x", i ) then
				local match = line:match( "^0x%x+", i )
				res = res .. "{Constant.Number:" .. match .. "}"
				i = i + #match

			elseif line:find( "^[%w_]", i ) then
				local match = line:match( "^[%w_]+", i )

				if lang.keywords[match] then
					res = res .. "{" .. lang.keywords[match] .. ":" .. match .. "}"
				else
					res = res .. "{Constant.Identifier:" .. match .. "}"
				end
				i = i + #match

			else
				local l, v = 0
				for k, sv in pairs( lang.symbols ) do
					if line:sub( i, i + #k - 1 ) == k then
						if #k > l then
							l = #k
							v = sv
						end
					end
				end

				if l > 0 then
					res = res .. "{" .. v .. ":" .. formatText( line:sub( i, i + l - 1 ) ) .. "}"
				else
					res = res .. formatText( line:sub( i, i ) )
				end

				i = i + 1
			end
		end

		return res

	end, {
		in_section = false;
		string_match = "";
	}
end

languages.lua = lang_lua