-- Prosody IM

-- Copyright (C) 2008-2010 Matthew Wild

-- Copyright (C) 2008-2010 Waqas Hussain

--

-- This project is MIT/X11 licensed. Please see the

-- COPYING file in the source package for more information.

--

local debug = require "prosody.util.debug";

-- Helper functions for debugging

local log = require "prosody.util.logger".init("util.debug");

local function log_events(events, name, logger)

	local f = events.fire_event;

	if not f then

		error("Object does not appear to be a util.events object");

	end

	logger = logger or log;

	name = name or tostring(events);

	function events.fire_event(event, ...)

		logger("debug", "%s firing event: %s", name, event);

		return f(event, ...);

	end

	local function event_handler_hook(handler, event_name, event_data)

		logger("debug", "calling handler for %s: %s", event_name, handler);

		local ok, ret = pcall(handler, event_data);

		if not ok then

			logger("error", "error in event handler %s: %s", handler, ret);

			error(ret);

		end

		if ret ~= nil then

			logger("debug", "event chain ended for %s by %s with result: %s", event_name, handler, ret);

		end

		return ret;

	end

	events.set_debug_hook(event_handler_hook);

	events[events.fire_event] = f;

	return events;

end

local function revert_log_events(events)

	events.fire_event, events[events.fire_event] = events[events.fire_event], nil; -- :))

	events.set_debug_hook(nil);

end

local function log_host_events(host)

	return log_events(prosody.hosts[host].events, host);

end

local function revert_log_host_events(host)

	return revert_log_events(prosody.hosts[host].events);

end

local function show_events(events, specific_event)

	local event_handlers = events._handlers;

	local events_array = {};

	local event_handler_arrays = {};

	for event, priorities in pairs(events._event_map) do

		local handlers = event_handlers[event];

		if handlers and (event == specific_event or not specific_event) then

			table.insert(events_array, event);

			local handler_strings = {};

			for i, handler in ipairs(handlers) do

				local upvals = debug.string_from_var_table(debug.get_upvalues_table(handler));

				handler_strings[i] = "  "..(priorities[handler] or "?")..": "..tostring(handler)..(upvals and ("\n        "..upvals) or "");

			end

			event_handler_arrays[event] = handler_strings;

		end

	end

	table.sort(events_array);

	local i = 1;

	while i <= #events_array do

		local handlers = event_handler_arrays[events_array[i]];

		for j=#handlers, 1, -1 do

			table.insert(events_array, i+1, handlers[j]);

		end

		if i > 1 then events_array[i] = "\n"..events_array[i]; end

		i = i + #handlers + 1

	end

	return table.concat(events_array, "\n");

end

local function get_upvalue(f, get_name)

	local i, name, value = 0;

	repeat

		i = i + 1;

		name, value = debug.getupvalue(f, i);

	until name == get_name or name == nil;

	return value;

end

return {

	log_host_events = log_host_events;

	revert_log_host_events = revert_log_host_events;

	log_events = log_events;

	revert_log_events = revert_log_events;

	show_events = show_events;

	get_upvalue = get_upvalue;

};