local array = require "util.array";

local jid = require "util.jid";

local json = require "util.json";

local st = require "util.stanza";

local xml = require "util.xml";

local simple_types = {

	-- basic message

	body = "text_tag",

	subject = "text_tag",

	thread = "text_tag",

	-- basic presence

	show = "text_tag",

	status = "text_tag",

	priority = "text_tag",

	state = {"name", "http://jabber.org/protocol/chatstates"},

	nick = {"text_tag", "http://jabber.org/protocol/nick", "nick"},

	delay = {"attr", "urn:xmpp:delay", "delay", "stamp"},

	replace = {"attr", "urn:xmpp:message-correct:0", "replace", "id"},

	-- XEP-0045 MUC

	-- TODO history, password, ???

	join = {"bool_tag", "http://jabber.org/protocol/muc", "x"},

	-- XEP-0071

	html = {

		"func", "http://jabber.org/protocol/xhtml-im", "html",

		function (s) --> json string

			return (tostring(s:get_child("body", "http://www.w3.org/1999/xhtml")):gsub(" xmlns='[^']*'","", 1));

		end;

		function (s) --> xml

			if type(s) == "string" then

				return assert(xml.parse([[<x:html xmlns:x='http://jabber.org/protocol/xhtml-im' xmlns='http://www.w3.org/1999/xhtml'>]]..s..[[</x:html>]]));

			end

		end;

	};

	-- XEP-0199: XMPP Ping

	ping = {"bool_tag", "urn:xmpp:ping", "ping"},

	-- XEP-0092: Software Version

	version = {"func", "jabber:iq:version", "query",

		function (s)

			return {

				name = s:get_child_text("name");

				version = s:get_child_text("version");

				os = s:get_child_text("os");

			}

		end,

		function (s)

			local v = st.stanza("query", { xmlns = "jabber:iq:version" });

			if type(s) == "table" then

				v:text_tag("name", s.name);

				v:text_tag("version", s.version);

				if s.os then

					v:text_tag("os", s.os);

				end

			end

			return v;

		end

	};

	-- XEP-0030

	disco = {

		"func", "http://jabber.org/protocol/disco#info", "query",

		function (s) --> array of features

			local identities, features = array(), array();

			for tag in s:childtags() do

				if tag.name == "identity" and tag.attr.category and tag.attr.type then

					identities:push({ category = tag.attr.category, type = tag.attr.type, name = tag.attr.name });

				elseif tag.name == "feature" and tag.attr.var then

					features:push(tag.attr.var);

				end

			end

			return { node = s.attr.node, identities = identities, features = features, };

		end;

		function  (s)

			if type(s) == "table" and s ~= json.null then

				local disco = st.stanza("query", { xmlns = "http://jabber.org/protocol/disco#info", node = s.node });

				if s.identities then

					for _, identity in ipairs(s.identities) do

						disco:tag("identity", { category = identity.category, type = identity.type, name = identity.name }):up();

					end

				end

				if s.features then

					for _, feature in ipairs(s.features) do

						disco:tag("feature", { var = feature }):up();

					end

				end

				return disco;

			else

				return st.stanza("query", { xmlns = "http://jabber.org/protocol/disco#info", });

			end

		end;

	};

	items = {

		"func", "http://jabber.org/protocol/disco#items", "query",

			local items = array();

			for item in s:childtags("item") do

				items:push({ jid = item.attr.jid, node = item.attr.node, name = item.attr.name });

			end

			return items;

		end;

		function  (s)

			if type(s) == "table" and s ~= json.null then

				for _, item in ipairs(s) do

					if type(item) == "string" then

						disco:tag("item", { jid = item });

					elseif type(item) == "table" then

						disco:tag("item", { jid = item.jid, node = item.node, name = item.name });

					end

				end

			end

		end;

	};

	-- XEP-0066: Out of Band Data

	oob_url = {"func", "jabber:iq:oob", "query",

		function (s)

			return s:get_child_text("url");

		end;

		function (s)

			if type(s) == "string" then

				return st.stanza("query", { xmlns = "jabber:iq:oob" }):text_tag("url", s);

			end

		end;

	};

	-- XEP-XXXX: User-defined Data Transfer

	payload = {"func", "urn:xmpp:udt:0", "payload",

		function (s)

			local rawjson = s:get_child_text("json", "urn:xmpp:json:0");

			if not rawjson then return nil, "missing-json-payload"; end

			local parsed, err = json.decode(rawjson);

			if not parsed then return nil, err; end

			return {

				datatype = s.attr.datatype;

				data = parsed;

			};

		end;

		function (s)

			if type(s) == "table" then

				return st.stanza("payload", { xmlns = "urn:xmpp:udt:0", datatype = s.datatype })

					:tag("json", { xmlns = "urn:xmpp:json:0" }):text(json.encode(s.data));

			end;

		end

	};

};

local implied_kinds = {

	disco = "iq",

	items = "iq",

	ping = "iq",

	version = "iq",

	body = "message",

	html = "message",

	replace = "message",

	state = "message",

	subject = "message",

	thread = "message",

	join = "presence",

	priority = "presence",

	show = "presence",

	status = "presence",

}

local kind_by_type = {

	get = "iq", set = "iq", result = "iq",

	normal = "message", chat = "message", headline = "message", groupchat = "message",

	available = "presence", unavailable = "presence",

	subscribe = "presence", unsubscribe = "presence",

	subscribed = "presence", unsubscribed = "presence",

}

local function st2json(s)

	local t = {

		kind = s.name,

		type = s.attr.type,

		to = s.attr.to,

		from = s.attr.from,

		id = s.attr.id,

	};

	if s.name == "presence" and not s.attr.type then

		t.type = "available";

	end

	if t.to then

		t.to = jid.prep(t.to);

		if not t.to then return nil, "invalid-jid-to"; end

	end

	if t.from then

		t.from = jid.prep(t.from);

		if not t.from then return nil, "invalid-jid-from"; end

	end

	if t.type == "error" then

		local error = s:get_child("error");

		local err_typ, err_condition, err_text = s:get_error();

		t.error = {

			type = err_typ,

			condition = err_condition,

			text = err_text,

			by = error.attr.by,

		};

		return t;

	end

	for k, typ in pairs(simple_types) do

		if typ == "text_tag" then

			t[k] = s:get_child_text(k);

		elseif typ[1] == "text_tag" then

			t[k] = s:get_child_text(typ[3], typ[2]);

		elseif typ[1] == "name" then

			local child = s:get_child(nil, typ[2]);

			if child then

				t[k] = child.name;

			end

		elseif typ[1] == "attr" then

			local child = s:get_child(typ[3], typ[2])

			if child then

				t[k] = child.attr[typ[4]];

			end

		elseif typ[1] == "bool_tag" then

			if s:get_child(typ[3], typ[2]) then

				t[k] = true;

			end

		elseif typ[1] == "func" then

			local child = s:get_child(typ[3], typ[2] or k);

			-- TODO handle err

			if child then

				t[k] = typ[4](child);

			end

		end

	end

	return t;

end

local function str(s)

	if type(s) == "string" then

		return s;

	end

end

local function json2st(t)

	if type(t) ~= "table" or not str(next(t)) then

		return nil, "invalid-json";

	end

	local kind = str(t.kind) or kind_by_type[str(t.type)];

	if not kind then

		for k, implied in pairs(implied_kinds) do

			if t[k] then

				kind = implied;

				break

			end

		end

	end

	local s = st.stanza(kind or "message", {

		type = t.type ~= "available" and str(t.type) or nil,

		to = str(t.to) and jid.prep(t.to);

		from = str(t.to) and jid.prep(t.from);

		id = str(t.id),

	});

	if t.to and not s.attr.to then

		return nil, "invalid-jid-to";

	end

	if t.from and not s.attr.from then

		return nil, "invalid-jid-from";

	end

	if kind == "iq" and not s.attr.type then

		s.attr.type = "get";

	end

	if type(t.error) == "table" then

		return st.error_reply(st.reply(s), str(t.error.type), str(t.error.condition), str(t.error.text), str(t.error.by));

	elseif t.type == "error" then

		s:text_tag("error", t.body, { code = t.error_code and tostring(t.error_code) });

		return s;

	end

	for k, v in pairs(t) do

		local typ = simple_types[k];

		if typ then

			if typ == "text_tag" then

				s:text_tag(k, v);

			elseif typ[1] == "text_tag" then

				s:text_tag(typ[3] or k, v, typ[2] and { xmlns = typ[2] });

			elseif typ[1] == "name" then

				s:tag(v, { xmlns = typ[2] }):up();

			elseif typ[1] == "attr" then

				s:tag(typ[3] or k, { xmlns = typ[2], [ typ[4] or k ] = v }):up();

			elseif typ[1] == "bool_tag" then

				s:tag(typ[3] or k, { xmlns = typ[2] }):up();

			elseif typ[1] == "func" then

				s:add_child(typ[5](v)):up();

			end

		end

	end

	s:reset();

	return s;

end

return {

	st2json = st2json;

	json2st = json2st;

};