local condition_handlers = {};

local jid = require "util.jid";

-- Return a code string for a condition that checks whether the contents

-- of variable with the name 'name' matches any of the values in the

-- comma/space/pipe delimited list 'values'.

local function compile_comparison_list(name, values)

	local conditions = {};

	for value in values:gmatch("[^%s,|]+") do

		table.insert(conditions, ("%s == %q"):format(name, value));

	end

	return table.concat(conditions, " or ");

end

function condition_handlers.KIND(kind)

	return compile_comparison_list("name", kind), { "name" };

end

local wildcard_equivs = { ["*"] = ".*", ["?"] = "." };

local function compile_jid_match_part(part, match)

	if not match then

		return part.." == nil"

	end

	local pattern = match:match("<(.*)>");

	-- TODO: Support Lua pattern matching (main issue syntax... << >>?)

	if pattern then

		if pattern ~= "*" then

			return ("%s:match(%q)"):format(part, pattern:gsub(".", wildcard_equivs));

		end

	else

		return ("%s == %q"):format(part, match);

	end

end

local function compile_jid_match(which, match_jid)

	local match_node, match_host, match_resource = jid.split(match_jid);

	local conditions = {

		compile_jid_match_part(which.."_node", match_node);

		compile_jid_match_part(which.."_host", match_host);

		match_resource and compile_jid_match_part(which.."_resource", match_resource) or nil;

	};

	return table.concat(conditions, " and ");

end

function condition_handlers.TO(to)

	return compile_jid_match("to", to), { "split_to" };

end

function condition_handlers.FROM(from)

	return compile_jid_match("from", from), { "split_from" };

end

function condition_handlers.TYPE(type)

	return compile_comparison_list("type", type), { "type" };

end

function condition_handlers.ENTERING(zone)

	return ("(zones[%q] and (zones[%q][to_host] or "

		.."zones[%q][to] or "

		.."zones[%q][bare_to]))"

		)

		:format(zone, zone, zone, zone), { "split_to", "bare_to" };

end

function condition_handlers.LEAVING(zone)

	return ("zones[%q] and (zones[%q][from_host] or "

		.."(zones[%q][from] or "

		.."zones[%q][bare_from]))")

		:format(zone, zone, zone, zone), { "split_from", "bare_from" };

end

function condition_handlers.PAYLOAD(payload_ns)

	return ("stanza:get_child(nil, %q)"):format(payload_ns);

end

function condition_handlers.FROM_GROUP(group_name)

	return ("group_contains(%q, bare_from)"):format(group_name), { "group_contains", "bare_from" };

end

function condition_handlers.TO_GROUP(group_name)

	return ("group_contains(%q, bare_to)"):format(group_name), { "group_contains", "bare_to" };

end

function condition_handlers.FROM_ADMIN_OF(host)

	return ("is_admin(bare_from, %s)"):format(host ~= "*" and host or nil), { "is_admin", "bare_from" };

end

function condition_handlers.TO_ADMIN_OF(host)

	return ("is_admin(bare_to, %s)"):format(host ~= "*" and host or nil), { "is_admin", "bare_to" };

end

return condition_handlers;