--luacheck: globals meta idsafe

local condition_handlers = {};

local jid = require "util.jid";

-- Helper to convert user-input strings (yes/true//no/false) to a bool

local function string_to_boolean(s)

	s = s:lower();

	return s == "yes" or s == "true";

end

-- 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("^<(.*)>$");

	if pattern then

		if pattern == "*" then

			return part;

		end

		if pattern:find("^<.*>$") then

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

		else

			pattern = pattern:gsub("%p", "%%%0"):gsub("%%(%p)", wildcard_equivs);

		end

		return ("(%s and %s:find(%q))"):format(part, part, "^"..pattern.."$");

	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 = {};

	conditions[#conditions+1] = compile_jid_match_part(which.."_node", match_node);

	conditions[#conditions+1] = compile_jid_match_part(which.."_host", match_host);

	if match_resource then

		conditions[#conditions+1] = compile_jid_match_part(which.."_resource", match_resource);

	end

	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.FROM_EXACTLY(from)

	local metadeps = {};

	return ("from == %s"):format(metaq(from, metadeps)), { "from", unpack(metadeps) };

end

function condition_handlers.TO_EXACTLY(to)

	local metadeps = {};

	return ("to == %s"):format(metaq(to, metadeps)), { "to", unpack(metadeps) };

end

function condition_handlers.TO_SELF()

end

function condition_handlers.TYPE(type)

	return compile_comparison_list("(type or (name == 'message' and 'normal') or (name == 'presence' and 'available'))", type), { "type", "name" };

end

local function zone_check(zone, which)

	local which_not = which == "from" and "to" or "from";

	return ("(zone_%s[%s_host] or zone_%s[%s] or zone_%s[bare_%s]) "

		.."and not(zone_%s[%s_host] or zone_%s[%s] or zone_%s[bare_%s])"

		)

		:format(zone, which, zone, which, zone, which,

		zone, which_not, zone, which_not, zone, which_not), {

			"split_to", "split_from", "bare_to", "bare_from", "zone:"..zone

		};

end

function condition_handlers.ENTERING(zone)

	return zone_check(zone, "to");

end

function condition_handlers.LEAVING(zone)

	return zone_check(zone, "from");

end

-- IN ROSTER? (parameter is deprecated)

function condition_handlers.IN_ROSTER(yes_no)

	local in_roster_requirement = string_to_boolean(yes_no or "yes"); -- COMPAT w/ older scripts

	return "not "..(in_roster_requirement and "not" or "").." roster_entry", { "roster_entry" };

end

function condition_handlers.IN_ROSTER_GROUP(group)

	return ("not not (roster_entry and roster_entry.groups[%q])"):format(group), { "roster_entry" };

end

function condition_handlers.SUBSCRIBED()

	return "rostermanager.is_contact_subscribed(to_node, to_host, bare_from)",

	       { "rostermanager", "split_to", "bare_from" };

end

function condition_handlers.PAYLOAD(payload_ns)

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

end

function condition_handlers.INSPECT(path)

	if path:find("=") then

		local query, match_type, value = path:match("(.-)([~/$]*)=(.*)");

		if not(query:match("#$") or query:match("@[^/]+")) then

			error("Stanza path does not return a string (append # for text content or @name for value of named attribute)", 0);

		end

		local meta_deps = {};

		local quoted_value = ("%q"):format(value);

		if match_type:find("$", 1, true) then

			match_type = match_type:gsub("%$", "");

			quoted_value = meta(quoted_value, meta_deps);

		end

		if match_type == "~" then -- Lua pattern match

			return ("(stanza:find(%q) or ''):match(%s)"):format(query, quoted_value), meta_deps;

		elseif match_type == "/" then -- find literal substring

			return ("(stanza:find(%q) or ''):find(%s, 1, true)"):format(query, quoted_value), meta_deps;

		elseif match_type == "" then -- exact match

			return ("stanza:find(%q) == %s"):format(query, quoted_value), meta_deps;

		else

			error("Unrecognised comparison '"..match_type.."='", 0);

		end

	end

	return ("stanza:find(%q)"):format(path);

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

function condition_handlers.FROM_ADMIN()

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

end

function condition_handlers.TO_ADMIN()

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

end

local day_numbers = { sun = 0, mon = 2, tue = 3, wed = 4, thu = 5, fri = 6, sat = 7 };

local function current_time_check(op, hour, minute)

	hour, minute = tonumber(hour), tonumber(minute);

	local adj_op = op == "<" and "<" or ">="; -- Start time inclusive, end time exclusive

	if minute == 0 then

		return "(current_hour"..adj_op..hour..")";

	else

		return "((current_hour"..op..hour..") or (current_hour == "..hour.." and current_minute"..adj_op..minute.."))";

	end

end

local function resolve_day_number(day_name)

	return assert(day_numbers[day_name:sub(1,3):lower()], "Unknown day name: "..day_name);

end

function condition_handlers.DAY(days)

	local conditions = {};

	for day_range in days:gmatch("[^,]+") do

		local day_start, day_end = day_range:match("(%a+)%s*%-%s*(%a+)");

		if day_start and day_end then

			local day_start_num, day_end_num = resolve_day_number(day_start), resolve_day_number(day_end);

			local op = "and";

			if day_end_num < day_start_num then

				op = "or";

			end

			table.insert(conditions, ("current_day >= %d %s current_day <= %d"):format(day_start_num, op, day_end_num));

		elseif day_range:find("%a") then

			local day = resolve_day_number(day_range:match("%a+"));

			table.insert(conditions, "current_day == "..day);

		else

			error("Unable to parse day/day range: "..day_range);

		end

	end

	assert(#conditions>0, "Expected a list of days or day ranges");

	return "("..table.concat(conditions, ") or (")..")", { "time:day" };

end

function condition_handlers.TIME(ranges)

	local conditions = {};

	for range in ranges:gmatch("([^,]+)") do

		local clause = {};

		range = range:lower()

			:gsub("(%d+):?(%d*) *am", function (h, m) return tostring(tonumber(h)%12)..":"..(tonumber(m) or "00"); end)

			:gsub("(%d+):?(%d*) *pm", function (h, m) return tostring(tonumber(h)%12+12)..":"..(tonumber(m) or "00"); end);

		local start_hour, start_minute = range:match("(%d+):(%d+) *%-");

		local end_hour, end_minute = range:match("%- *(%d+):(%d+)");

		local op = tonumber(start_hour) > tonumber(end_hour) and " or " or " and ";

		if start_hour and end_hour then

			table.insert(clause, current_time_check(">", start_hour, start_minute));

			table.insert(clause, current_time_check("<", end_hour, end_minute));

		end

		if #clause == 0 then

			error("Unable to parse time range: "..range);

		end

		table.insert(conditions, "("..table.concat(clause, " "..op.." ")..")");

	end

	return table.concat(conditions, " or "), { "time:hour,min" };

end

function condition_handlers.LIMIT(spec)

	local name, param = spec:match("^(%w+) on (.+)$");

	local meta_deps = {};

	if not name then

		name = spec:match("^%w+$");

		if not name then

			error("Unable to parse LIMIT specification");

		end

	else

		param = meta(("%q"):format(param), meta_deps);

	end

	if not param then

		return ("not global_throttle_%s:poll(1)"):format(name), { "globalthrottle:"..name, unpack(meta_deps) };

	end

	return ("not multi_throttle_%s:poll_on(%s, 1)"):format(name, param), { "multithrottle:"..name, unpack(meta_deps) };	

end

function condition_handlers.ORIGIN_MARKED(name_and_time)

	local name, time = name_and_time:match("^%s*([%w_]+)%s+%(([^)]+)s%)%s*$");

	if not name then

		name = name_and_time:match("^%s*([%w_]+)%s*$");

	end

	if not name then

		error("Error parsing mark name, see documentation for usage examples");

	end

	if time then

		return ("(current_timestamp - (session.firewall_marked_%s or 0)) < %d"):format(idsafe(name), tonumber(time)), { "timestamp" };

	end

	return ("not not session.firewall_marked_"..idsafe(name));

end

function condition_handlers.SENT_DIRECTED_PRESENCE_TO_SENDER()

	return "not not session.directed[from]", { "from" };

end

function condition_handlers.TO_FULL_JID()

	return "not not full_sessions[to]", { "to" };

end

-- CHECK LIST: spammers contains $<@from>

function condition_handlers.CHECK_LIST(list_condition)

	local list_name, expr = list_condition:match("(%S+) contains (.+)$");

	if not (list_name and expr) then

		error("Error parsing list check, syntax: LISTNAME contains EXPRESSION");

	end

	local meta_deps = {};

	expr = meta(("%q"):format(expr), meta_deps);

	return ("list_%s:contains(%s) == true"):format(list_name, expr), { "list:"..list_name, unpack(meta_deps) };

end

-- SCAN: body for word in badwords

function condition_handlers.SCAN(scan_expression)

	local search_name, pattern_name, list_name = scan_expression:match("(%S+) for (%S+) in (%S+)$");

	if not (search_name) then

		error("Error parsing SCAN expression, syntax: SEARCH for PATTERN in LIST");

	end

	return ("scan_list(list_%s, %s)"):format(list_name, "tokens_"..search_name.."_"..pattern_name), { "scan_list", "tokens:"..search_name.."_"..pattern_name, "list:"..list_name };

end

local valid_comp_ops = { [">"] = ">", ["<"] = "<", ["="] = "==", ["=="] = "==", ["<="] = "<=", [">="] = ">=" };

function condition_handlers.COUNT(count_expression)

	local pattern_name, search_name, comparator_expression = count_expression:match("(%S+) in (%S+) (.+)$");

	if not (pattern_name) then

		error("Error parsing COUNT expression, syntax: PATTERN in SEARCH COMPARATOR");

	end

	local value;

	comparator_expression = comparator_expression:gsub("%d+", function (value_string)

		value = tonumber(value_string);

		return "";

	end);

	if not value then

		error("Error parsing COUNT expression, expected value");

	end

	local comp_op = comparator_expression:gsub("%s+", "");

	assert(valid_comp_ops[comp_op], "Error parsing COUNT expression, unknown comparison operator: "..comp_op);

	return ("it_count(search_%s:gmatch(pattern_%s)) %s %d"):format(search_name, pattern_name, comp_op, value), { "it_count", "search:"..search_name, "pattern:"..pattern_name };

end

return condition_handlers;