-- IN-BAND BYTESTREAMS (XEP-0047)

-- library

require 'lm'

require 'base64'

-- public

ibb = {

	block_size    = 4096,

	streamhandler =

		function ( accept, reject )

			reject ()

		end,

}

local ibb_sid = 0 -- private

function ibb.send ( conn, to, success, fail, id )

	local bs    = ibb.block_size -- local instance

	local sid   = id

	if not sid then

		ibb_sid = ibb_sid + 1

		sid     = 'ibb_' .. ibb_sid

	end

	iq.send ( conn, to, 'set',

		{

			open = { sid = sid, ['block-size'] = bs, xmlns = 'http://jabber.org/protocol/ibb' }

		},

		function ()

			local seq   = 0

			local noerr = true

			success (

				function ( data, success, fail )

					if not data  then

						iq.send ( conn, to, 'set',

							{

								close = { sid = sid, xmlns = 'http://jabber.org/protocol/ibb' },

							},

							function ()

								success ( 'end' ) -- XXX

							end,

							fail )

					elseif data ~= '' then

						local encoded = base64.encode ( data )

						while encoded:len () > 0 and noerr do

							local chunk = encoded:sub ( 1, bs )

							local cseq  = seq -- local instance for closure

							encoded     = encoded:sub ( bs + 1 )

							seq         = seq + 1

							iq.send ( conn, to, 'set',

								{

									data = { sid = sid, xmlns = 'http://jabber.org/protocol/ibb', seq = cseq,

										chunk,

									},

								},

								function ()

									success ( cseq )

								end,

								function ( mesg )

									noerr = false

									fail ( mesg )

								end )

						end

					end

				end )

		end,

		fail )

end

-- private

local ibb_files               = {}

local ibb_handler_registered  = false

local ibb_incoming_iq_handler = lm.message_handler.new ( 

	function ( conn, mess )

		local mtype, smtype = mess:type ()

		if smtype ~= 'set' then

			return false

		end

		local child = mess:children ()

		if not child or child:attribute ( 'xmlns' ) ~= 'http://jabber.org/protocol/ibb' then

			return false

		end

		local id     = mess:attribute ( 'id' )

		local from   = mess:attribute ( 'from' )

		local action = child:name ()

		local sid    = child:attribute ( 'sid' )

		if action == 'open' then

			if not ibb_files[sid] then

				ibb.streamhandler ( from,

					function ( success, fail )

						ibb_files[sid] = { from = from, success = success, fail = fail }

						conn:send ( lm.message.create { to = from, mtype = 'iq-result', id = id } )

					end,

					function ()

						conn:send (

							lm.message.create { to = from, mtype = 'iq-error', id = id,

								error = { code = '405', type = 'cancel',

									['not-allowed'] = { xmlns = 'urn:ietf:params:xml:ns:xmpp-stanzas' }

								}

							} )

					end )

			else

				conn:send (

					lm.message.create { to = from, mtype = 'iq-error', id = id,

						error = { code = '409', type = 'cancel',

							conflict = { xmlns = 'urn:ietf:params:xml:ns:xmpp-stanzas' }

						}

					} )

			end

		elseif action == 'data' then

			local seq = child:attribute ( 'seq' )

			if ibb_files[sid] and from == ibb_files[sid].from and not ibb_files[sid][tonumber(seq)+1] then

				local data = child:value ()

				conn:send ( lm.message.create { to = from, mtype = 'iq-result', id = id } )

				ibb_files[sid][tonumber(seq)+1] = data

-- XXX			ibb_files[sid].success ( seq )

			else

				if ibb_files[sid] then

					ibb_files[sid].fail ( 'conflict' )

					ibb_files[sid] = nil -- invalidate session

					conn:send (

						lm.message.create { to = from, mtype = 'iq-error', id = id,

							error = { code = '409', type = 'cancel',

								conflict = { xmlns = 'urn:ietf:params:xml:ns:xmpp-stanzas' }

							}

						} )

				else

					conn:send (

						lm.message.create { to = from, mtype = 'iq-error', id = id,

							error = { code = '404', type = 'cancel', -- XXX: check

								['item-not-found'] = { xmlns = 'urn:ietf:params:xml:ns:xmpp-stanzas' }

							}

						} )

				end

			end

		elseif action == 'close' then

			if ibb_files[sid] and from == ibb_files[sid].from then

				local data = ''

				for seq, chunk in ipairs ( ibb_files[sid] ) do

					data = data .. chunk

				end

				local decoded = base64.decode ( data )

				ibb_files[sid].success ( decoded )

				conn:send ( lm.message.create { to = from, mtype = 'iq-result', id = id } )

				ibb_files[sid] = nil

			else

				if ibb_files[sid] then

					ibb_files[sid].fail ( 'conflict' )

					ibb_files[sid] = nil -- invalidate session

					conn:send (

						lm.message.create { to = from, mtype = 'iq-error', id = id,

							error = { code = '409', type = 'cancel',

								conflict = { xmlns = 'urn:ietf:params:xml:ns:xmpp-stanzas' }

							}

						} )

				else

					conn:send (

						lm.message.create { to = from, mtype = 'iq-error', id = id,

							error = { code = '404', type = 'cancel', -- XXX: check

								['item-not-found'] = { xmlns = 'urn:ietf:params:xml:ns:xmpp-stanzas' }

							}

						} )

				end

			end

		else

			return false

		end

		return true

	end )

-- mcabber

local mc_incoming_files = { }

ibb.streamhandler =

	function ( from, accept, reject )

		local fid = #mc_incoming_files + 1

		mc_incoming_files[fid] = {

				from   = from,

				accept =

					function ( name )

						mc_incoming_files[fid].name = name

						accept (

							function ( data )

								local h = io.open ( mc_incoming_files[fid].name, 'w' )

								if not h then

									print ( 'Cannot open output file: ' .. mc_incoming_files[fid].name )

									return

								end

								h:write ( data )

								h:close ()

								print ( 'Stream ' .. fid .. ' successfully saved to ' .. mc_incoming_files[fid].name )

								mc_incoming_files[fid] = nil

							end,

							function ( mesg )

								main.print_info ( from, 'Stream error: ' .. mesg )

								mc_incoming_files[fid] = nil -- XXX

							end )

					end,

				reject =

					function ()

						reject ()

						print ( 'Stream ' .. fid .. ' rejected' )

						mc_incoming_files[fid] = nil

					end,

		}

		main.print_info ( from, from .. ' wants you to receive stream. Use /ibb [accept|reject] ' .. fid .. ' to process his request.' )

	end

main.command ( 'ibb',

	function ( args )

		local action = args[1]

		if action == 'send' then

			local who

			if args.t then

				who = args.t

			else

				who = main.full_jid ()

			end

			local fname = args[2]

			ibb.send ( lm.connection.bless ( main.connection () ), who,

				function ( sender )

					main.print_info ( who, 'Stream accepted' )

					local noerr = true

					local h     = io.open ( fname, 'r' )

					if not h then

						print ( 'Cannot open file ' .. fname )

						return

					end

					local data = h:read ( '*a' ) -- In fact, it is better to read it in chunks :/

					h:close ()

					local fail =

						function ( mesg )

							noerr = false

							main.print_info ( who, 'Stream error: ' .. mesg )

						end

					sender ( data,

						function ( seq )

							main.print_info ( who, 'Delivery notification of chunk #' .. seq )

						end, fail )

					if noerr then

						sender ( nil,

							function ( seq )

								main.print_info ( who, 'Stream finalizing notification' )

							end, fail )

					end

					if noerr then

						main.print_info ( who, 'Stream sent' )

					else

						main.print_info ( who, 'Stream error occured' )

					end

				end,

				function ( mesg )

					main.print_info ( who, 'Stream initiation error: ' .. mesg )

				end )

		elseif action == 'accept' then

			local id = tonumber(args[2])

			if mc_incoming_files[id] then

				mc_incoming_files[id].accept ( args[3] )

			end

		elseif action == 'reject' then

			local id = tonumber(args[2])

			if mc_incoming_files[id] then

				mc_incoming_files[id].reject ()

			end

		else

			local text = ''

			for sid, data in pairs ( mc_incoming_files ) do

				text = text .. '\n' ..  sid .. ': ' .. data.from .. ' --> ' .. ( data.name or '?' )

			end

			if text ~= '' then

				print ( 'List of incoming streams:' .. text )

			else

				print ( 'No streams' )

			end

		end

	end, true, { "send", "accept", "reject" } )

commands_help['ibb'] = "[[-t target_jid] send filename | accept sid filename | reject sid]\n\nRequests, accepts or rejects sending file via in-band bytestream."

hooks_d['hook-post-connect'].ibb =

	function ( args )

		lm.connection.bless( main.connection () ):handler ( ibb_incoming_iq_handler, 'iq', 'normal' )

		ibb_handler_registered = true

		hooks_d['hook-post-connect'].ibb = nil

		hooks_d['hook-quit'].ibb =

			function ( args )

				if ibb_handler_registered then

					lm.connection.bless( main.connection () ):handler ( ibb_incoming_iq_handler, 'iq' )

				end

			end

	end

main.add_feature ( 'http://jabber.org/protocol/ibb' )

-- vim: se ts=4: --