-- SLAXML parser
-- Adapted for Anomaly usage by demonized

--[=====================================================================[
v0.8 Copyright © 2013-2018 Gavin Kistner <!@phrogz.net>; MIT Licensed
See http://github.com/Phrogz/SLAXML for details.
--]=====================================================================]
function SLAXML()
	local SLAXML = {
		VERSION = "0.8",
		_call = {
			pi = function(target, content)
				print(string.format("<?%s %s?>", target, content))
			end,
			comment = function(content)
				print(string.format("<!-- %s -->", content))
			end,
			startElement = function(name, nsURI, nsPrefix)
				io.write("<")
				if nsPrefix then
					io.write(nsPrefix, ":")
				end
				io.write(name)
				if nsURI then
					io.write(" (ns='", nsURI, "')")
				end
				print(">")
			end,
			attribute = function(name, value, nsURI, nsPrefix)
				io.write("  ")
				if nsPrefix then
					io.write(nsPrefix, ":")
				end
				io.write(name, "=", string.format("%q", value))
				if nsURI then
					io.write(" (ns='", nsURI, "')")
				end
				io.write("\n")
			end,
			text = function(text, cdata)
				print(string.format("  %s: %q", cdata and "cdata" or "text", text))
			end,
			closeElement = function(name, nsURI, nsPrefix)
				io.write("</")
				if nsPrefix then
					io.write(nsPrefix, ":")
				end
				print(name .. ">")
			end,
		},
		_defcall = {
			startElement = function(name, nsURI, nsPrefix) end, -- When "<foo" or <x:foo is seen
			attribute = function(name, value, nsURI, nsPrefix) end, -- attribute found on current element
			closeElement = function(name, nsURI) end, -- When "</foo>" or </x:foo> or "/>" is seen
			text = function(text, cdata) end, -- text and CDATA nodes (cdata is true for cdata nodes)
			comment = function(content) end, -- comments
			pi = function(target, content) end, -- processing instructions e.g. "<?yes mon?>"
		},
	}

	function SLAXML:parser(callbacks)
		return { _call = callbacks or self._defcall, parse = self.parse }
	end

	-- demonized
	-- Sanitize xml before parsing
	local function sanitize(s)
		-- Add spaces between attributes
		s = s:gsub("<([%a_][%w_.-]*)( )(.-)(/?>)", function(a, b, c, d)
			local new_c = c:gsub('([:%a_][:%w_.-]*)%s*=%s*"(.-)"', function(a, b)
				return string.format('%s="%s" ', a, b)
			end)
			new_c = one_space(new_c)

			-- Add quotes to attributes where they are absent
			new_c = new_c:gsub("([:%a_][:%w_.-]*=)([%w_]+)([ />]?)", [[%1"%2"%3]])
			return one_space("<" .. a .. b .. " " .. new_c .. d)
		end)

		return s
	end

	local function loadFile(path)
		local file_reader = getFS():r_open('$game_config$', path)
		return file_reader
	end

	local parse_include_line
	local parse_includes

	parse_include_line = function(line)
		if line:sub(1, 1) == "#" and line:find("#include") then
			local include_file = line:match('"(.*)"')
			if include_file then
				-- printf("parsing include %s", include_file)
				local include_file_xml = loadFile(include_file)
				if include_file_xml then
					line = parse_includes(include_file_xml, false)
				end
			end
		end
		return line
	end

	parse_includes = function(s, rootFile)
		local res = ""
		if rootFile then
			for line in s:gmatch('[^\r\n]+') do
				res = res .. parse_include_line(line) .. "\n"
			end
		else
			local lua_s = ""
			while not s:r_eof() do
				lua_s = lua_s .. string.char(s:r_u8())
			end
			-- getFS():r_close(s)
			for line in lua_s:gmatch('[^\r\n]+') do
				res = res .. parse_include_line(line) .. "\n"
			end
		end
		-- res = sanitize(res)
		-- printf("%s", res)
		return res
	end

	function SLAXML:parse(xml, options)
		if not options then
			options = { stripWhitespace = false, parseIncludes = false }
		end

		xml = sanitize(xml)
		if options.parseIncludes then
			xml = parse_includes(xml, true)
			-- printf("%s", xml)
		end

		-- Cache references for maximum speed
		local find, sub, gsub, char, push, pop, concat =
			string.find, string.sub, string.gsub, string.char, table.insert, table.remove, table.concat
		local first, last, match1, match2, match3, pos2, nsURI
		local unpack = unpack or table.unpack
		local pos = 1
		local state = "text"
		local textStart = 1
		local currentElement = {}
		local currentAttributes = {}
		local currentAttributeCt -- manually track length since the table is re-used
		local nsStack = {}
		local anyElement = false

		local utf8markers = { { 0x7FF, 192 }, { 0xFFFF, 224 }, { 0x1FFFFF, 240 } }
		local function utf8(decimal) -- convert unicode code point to utf-8 encoded character string
			if decimal < 128 then
				return char(decimal)
			end
			local charbytes = {}
			for bytes, vals in ipairs(utf8markers) do
				if decimal <= vals[1] then
					for b = bytes + 1, 2, -1 do
						local mod = decimal % 64
						decimal = (decimal - mod) / 64
						charbytes[b] = char(128 + mod)
					end
					charbytes[1] = char(vals[2] + decimal)
					return concat(charbytes)
				end
			end
		end
		local entityMap = { ["lt"] = "<", ["gt"] = ">", ["amp"] = "&", ["quot"] = '"', ["apos"] = "'" }
		local entitySwap = function(orig, n, s)
			return entityMap[s] or n == "#" and utf8(tonumber("0" .. s)) or orig
		end
		local function unescape(str)
			return gsub(str, "(&(#?)([%d%a]+);)", entitySwap)
		end

		local function finishText()
			if first > textStart and self._call.text then
				local text = sub(xml, textStart, first - 1)
				if options.stripWhitespace then
					text = gsub(text, "^%s+", "")
					text = gsub(text, "%s+$", "")
					if #text == 0 then
						text = nil
					end
				end
				if text then
					self._call.text(unescape(text), false)
				end
			end
		end

		local function findPI()
			first, last, match1, match2 = find(xml, "^<%?([:%a_][:%w_.-]*) ?(.-)%?>", pos)
			if first then
				finishText()
				if self._call.pi then
					self._call.pi(match1, match2)
				end
				pos = last + 1
				textStart = pos
				return true
			end
		end

		local function findComment()
			first, last, match1 = find(xml, "^<!%-%-(.-)%-%->", pos)
			if first then
				finishText()
				if self._call.comment then
					self._call.comment(match1)
				end
				pos = last + 1
				textStart = pos
				return true
			end
		end

		local function nsForPrefix(prefix)
			if prefix == "xml" then
				return "http://www.w3.org/XML/1998/namespace"
			end -- http://www.w3.org/TR/xml-names/#ns-decl
			for i = #nsStack, 1, -1 do
				if nsStack[i][prefix] then
					return nsStack[i][prefix]
				end
			end
			error(("Cannot find namespace for prefix %s"):format(prefix))
		end

		local function startElement()
			anyElement = true
			first, last, match1 = find(xml, "^<([%a_][%w_.-]*)", pos)
			if first then
				currentElement[2] = nil -- reset the nsURI, since this table is re-used
				currentElement[3] = nil -- reset the nsPrefix, since this table is re-used
				finishText()
				pos = last + 1
				first, last, match2 = find(xml, "^:([%a_][%w_.-]*)", pos)
				if first then
					currentElement[1] = match2
					currentElement[3] = match1 -- Save the prefix for later resolution
					match1 = match2
					pos = last + 1
				else
					currentElement[1] = match1
					for i = #nsStack, 1, -1 do
						if nsStack[i]["!"] then
							currentElement[2] = nsStack[i]["!"]
							break
						end
					end
				end
				currentAttributeCt = 0
				push(nsStack, {})
				return true
			end
		end

		local function findAttribute()
			first, last, match1 = find(xml, "^%s+([:%a_][:%w_.-]*)%s*=%s*", pos)
			if first then
				pos2 = last + 1
				first, last, match2 = find(xml, '^"([^<"]*)"', pos2) -- FIXME: disallow non-entity ampersands
				if first then
					pos = last + 1
					match2 = unescape(match2)
				else
					first, last, match2 = find(xml, "^'([^<']*)'", pos2) -- FIXME: disallow non-entity ampersands
					if first then
						pos = last + 1
						match2 = unescape(match2)
					end
				end
			end
			if match1 and match2 then
				local currentAttribute = { match1, match2 }
				local prefix, name = string.match(match1, "^([^:]+):([^:]+)$")
				if prefix then
					if prefix == "xmlns" then
						nsStack[#nsStack][name] = match2
					else
						currentAttribute[1] = name
						currentAttribute[4] = prefix
					end
				else
					if match1 == "xmlns" then
						nsStack[#nsStack]["!"] = match2
						currentElement[2] = match2
					end
				end
				currentAttributeCt = currentAttributeCt + 1
				currentAttributes[currentAttributeCt] = currentAttribute
				return true
			end
		end

		local function findCDATA()
			first, last, match1 = find(xml, "^<!%[CDATA%[(.-)%]%]>", pos)
			if first then
				finishText()
				if self._call.text then
					self._call.text(match1, true)
				end
				pos = last + 1
				textStart = pos
				return true
			end
		end

		local function closeElement()
			first, last, match1 = find(xml, "^%s*(/?)>", pos)
			if first then
				state = "text"
				pos = last + 1
				textStart = pos

				-- Resolve namespace prefixes AFTER all new/redefined prefixes have been parsed
				if currentElement[3] then
					currentElement[2] = nsForPrefix(currentElement[3])
				end
				if self._call.startElement then
					self._call.startElement(unpack(currentElement))
				end
				if self._call.attribute then
					for i = 1, currentAttributeCt do
						if currentAttributes[i][4] then
							currentAttributes[i][3] = nsForPrefix(currentAttributes[i][4])
						end
						self._call.attribute(unpack(currentAttributes[i]))
					end
				end

				if match1 == "/" then
					pop(nsStack)
					if self._call.closeElement then
						self._call.closeElement(unpack(currentElement))
					end
				end
				return true
			end
		end

		local function findElementClose()
			first, last, match1, match2 = find(xml, "^</([%a_][%w_.-]*)%s*>", pos)
			if first then
				nsURI = nil
				for i = #nsStack, 1, -1 do
					if nsStack[i]["!"] then
						nsURI = nsStack[i]["!"]
						break
					end
				end
			else
				first, last, match2, match1 = find(xml, "^</([%a_][%w_.-]*):([%a_][%w_.-]*)%s*>", pos)
				if first then
					nsURI = nsForPrefix(match2)
				end
			end
			if first then
				finishText()
				if self._call.closeElement then
					self._call.closeElement(match1, nsURI)
				end
				pos = last + 1
				textStart = pos
				pop(nsStack)
				return true
			end
		end

		while pos < #xml do
			if state == "text" then
				if not (findPI() or findComment() or findCDATA() or findElementClose()) then
					if startElement() then
						state = "attributes"
					else
						first, last = find(xml, "^[^<]+", pos)
						pos = (first and last or pos) + 1
					end
				end
			elseif state == "attributes" then
				if not findAttribute() then
					if not closeElement() then
						error("Was in an element and couldn't find attributes or the close.")
					end
				end
			end
		end

		if not anyElement then
			error("Parsing did not discover any elements")
		end
		if #nsStack > 0 then
			error("Parsing ended with unclosed elements")
		end
	end

	function SLAXML:dom(xml, opts)
		if not opts then
			opts = {}
		end
		local rich = not opts.simple
		local push, pop = table.insert, table.remove
		local doc = { type = "document", name = "#doc", kids = {} }
		local current, stack = doc, { doc }
		local builder = self:parser({
			startElement = function(name, nsURI, nsPrefix)
				local el = {
					type = "element",
					name = name,
					kids = {},
					el = rich and {} or nil,
					attr = {},
					nsURI = nsURI,
					nsPrefix = nsPrefix,
					parent = rich and current or nil,
				}
				if current == doc then
					if doc.root then
						printf(
							("Encountered element '%s' when the document already has a root '%s' element"):format(
								name,
								doc.root.name
							)
						)
					else
						doc.root = rich and el or nil
					end
				end
				push(current.kids, el)
				if current.el then
					push(current.el, el)
				end
				current = el
				push(stack, el)
			end,
			attribute = function(name, value, nsURI, nsPrefix)
				if not current or current.type ~= "element" then
					error(("Encountered an attribute %s=%s but I wasn't inside an element"):format(name, value))
				end
				local attr = {
					type = "attribute",
					name = name,
					nsURI = nsURI,
					nsPrefix = nsPrefix,
					value = value,
					parent = rich and current or nil,
				}
				if rich then
					current.attr[name] = value
				end
				push(current.attr, attr)
			end,
			closeElement = function(name)
				if current.name ~= name or current.type ~= "element" then
					error(
						("Received a close element notification for '%s' but was inside a '%s' %s"):format(
							name,
							current.name,
							current.type
						)
					)
				end
				pop(stack)
				current = stack[#stack]
			end,
			text = function(value, cdata)
				-- documents may only have text node children that are whitespace: https://www.w3.org/TR/xml/#NT-Misc
				if current.type == "document" and not value:find("^%s+$") then
					error(
						("Document has non-whitespace text at root: '%s'"):format(
							value:gsub("[\r\n\t]", { ["\r"] = "\\r", ["\n"] = "\\n", ["\t"] = "\\t" })
						)
					)
				end
				push(current.kids, {
					type = "text",
					name = "#text",
					cdata = cdata and true or nil,
					value = value,
					parent = rich and current or nil,
				})
			end,
			comment = function(value)
				push(
					current.kids,
					{ type = "comment", name = "#comment", value = value, parent = rich and current or nil }
				)
			end,
			pi = function(name, value)
				push(current.kids, { type = "pi", name = name, value = value, parent = rich and current or nil })
			end,
		})
		builder:parse(xml, opts)
		return doc
	end

	local escmap = {
		["<"] = "&lt;",
		[">"] = "&gt;",
		["&"] = "&amp;",
		['"'] = "&quot;",
		["'"] = "&apos;",
	}
	local function esc(s)
		return s:gsub('[<>&"]', escmap)
	end

	-- opts.indent: number of spaces, or string
	function SLAXML:xml(n, opts)
		opts = opts or {}
		local out = {}
		local tab = opts.indent and (type(opts.indent) == "number" and string.rep(" ", opts.indent) or opts.indent)
			or ""
		local ser = {}
		local omit = {}
		if opts.omit then
			for _, s in ipairs(opts.omit) do
				omit[s] = true
			end
		end

		function ser.document(n)
			for _, kid in ipairs(n.kids) do
				if ser[kid.type] then
					ser[kid.type](kid, 0)
				end
			end
		end

		function ser.pi(n, depth)
			depth = depth or 0
			table.insert(out, tab:rep(depth) .. "<?" .. n.name .. " " .. n.value .. "?>")
		end

		function ser.element(n, depth)
			if n.nsURI and omit[n.nsURI] then
				return
			end
			depth = depth or 0
			local indent = tab:rep(depth)
			local name = n.nsPrefix and n.nsPrefix .. ":" .. n.name or n.name
			local result = indent .. "<" .. name
			if n.attr and n.attr[1] then
				local sorted = n.attr
				if opts.sort then
					sorted = {}
					for i, a in ipairs(n.attr) do
						sorted[i] = a
					end
					table.sort(sorted, function(a, b)
						if a.nsPrefix and b.nsPrefix then
							return a.nsPrefix == b.nsPrefix and a.name < b.name or a.nsPrefix < b.nsPrefix
						elseif not (a.nsPrefix or b.nsPrefix) then
							return a.name < b.name
						elseif b.nsPrefix then
							return true
						else
							return false
						end
					end)
				end

				local attrs = {}
				for _, a in ipairs(sorted) do
					if (not a.nsURI or not omit[a.nsURI]) and not (omit[a.value] and a.name:find("^xmlns:")) then
						attrs[#attrs + 1] = " "
							.. (a.nsPrefix and (a.nsPrefix .. ":") or "")
							.. a.name
							.. '="'
							.. esc(a.value)
							.. '"'
					end
				end
				result = result .. table.concat(attrs, "")
			end
			result = result .. (n.kids and n.kids[1] and ">" or "/>")
			table.insert(out, result)
			if n.kids and n.kids[1] then
				for _, kid in ipairs(n.kids) do
					if ser[kid.type] then
						ser[kid.type](kid, depth + 1)
					end
				end
				table.insert(out, indent .. "</" .. name .. ">")
			end
		end

		function ser.text(n, depth)
			if n.cdata then
				table.insert(out, tab:rep(depth) .. "<![CDATA[" .. n.value .. "]]>")
			else
				table.insert(out, tab:rep(depth) .. esc(n.value))
			end
		end

		function ser.comment(n, depth)
			table.insert(out, tab:rep(depth) .. "<!--" .. n.value .. "-->")
		end

		ser[n.type](n, 0)

		return table.concat(out, opts.indent and "\n" or "")
	end

	-- demonized
	-- Simple dom and xml for stalker needs
	function SLAXML:simple_dom(xml, opts)
		if not opts then
			opts = {}
		end
		local push, pop = table.insert, table.remove
		local doc = { el = "!doc", kids = {} }
		local current, stack = doc, { doc }
		local builder = self:parser({
			startElement = function(name, nsURI, nsPrefix)
				local el = {
					el = "<" .. name,
					kids = {},
					parent = current,
				}
				push(current.kids, el)
				push(stack, el)
				current = el
			end,
			attribute = function(name, value, nsURI, nsPrefix)
				current.el = current.el .. " " .. name .. "=" .. value
			end,
			closeElement = function(name)
				pop(stack)
				current = stack[#stack]
			end,
			text = function(value, cdata)
				local el = {
					el = "#" .. value,
					parent = current,
				}
				push(current.kids, el)
			end,
			comment = function(value)
				-- Strip comments
			end,
			pi = function(name, value)
				local el = {
					el = "?xml " .. trim(value),
				}
				push(current.kids, el)
			end,
		})
		builder:parse(xml, opts)
		return doc
	end

	function SLAXML:sanitize_attr_list(s)
		local res
		local t = str_explode_lim(s, " ", 1)
		if not t[2] then
			return s
		end

		if trim(t[2]) == "" then
			return s
		end

		res = t[1]
		t = str_explode(t[2], " ")
		for i, v in ipairs(t) do
			local attr = str_explode(v, "=")
			if attr[2] then
				res = res .. " " .. attr[1] .. '="' .. attr[2] .. '"'
			end
		end
		return res
	end

	-- opts.indent: number of spaces, or string
	function SLAXML:simple_xml(n, opts)
		opts = opts or {}
		local out = {}
		local tab = opts.indent and (type(opts.indent) == "number" and string.rep(" ", opts.indent) or opts.indent)
			or ""
		local ser = {}
		local omit = {}
		if opts.omit then
			for _, s in ipairs(opts.omit) do
				omit[s] = true
			end
		end

		ser["!"] = function(n)
			for _, kid in ipairs(n.kids) do
				local t = kid.el:sub(1, 1)
				if ser[t] then
					ser[t](kid, 0)
				end
			end
		end

		ser["?"] = function(n, depth)
			depth = depth or 0
			local el = n.el:sub(2)
			table.insert(out, tab:rep(depth) .. "<?" .. el .. "?>")
		end

		ser["<"] = function(n, depth)
			depth = depth or 0
			local indent = tab:rep(depth)
			local el = self:sanitize_attr_list(n.el:sub(2))
			local result = indent .. "<" .. el
			result = result .. (n.kids and n.kids[1] and ">" or "/>")
			table.insert(out, result)
			if n.kids and n.kids[1] then
				for _, kid in ipairs(n.kids) do
					local t = kid.el:sub(1, 1)
					if ser[t] then
						ser[t](kid, depth + 1)
					end
				end
				local tag = str_explode(el, " ")[1]
				table.insert(out, indent .. "</" .. tag .. ">")
			end
		end

		ser["#"] = function(n, depth)
			local el = n.el:sub(2)
			table.insert(out, tab:rep(depth) .. esc(el))
		end

		local t = n.el:sub(1, 1)
		ser[t](n, 0)

		return table.concat(out, opts.indent and "\n" or "")
	end

	return SLAXML
end