-- IN-BAND BYTESTREAMS (XEP-0047)

-- TODO bidirectionality

--        thus, on stream accept we can add our sid to incoming files structure,

--        as if we received and accepted incoming request.

--      message stanzas

-- library

local lm     = require 'lm'

local iq     = require 'iq'

local base64 = require 'base64'

--

local F = { }

local M = { }

M.__index = M

local O = {

	handler =

		function ( accept, reject )

			reject ()

		end,

}

function F.new ( conn, to, bs, sid )

	local obj = {

		conn = conn,

		to   = to,

		sbs  = bs,

		bs   = math.floor ( bs * 3 / 4 ),

		sid  = sid,

		seq  = 0,

	}

	setmetatable ( obj, M )

	return obj

end

function M.open ( obj, success, fail )

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

		{

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

		}, success, fail )

end

function M.send ( obj, data, success, fail )

	if data and data ~= '' then

		local start = 0

		while start < data:len () do

			local chunk = base64.encode ( data:sub ( start, obj.bs ) )

			local cseq  = obj.seq -- local instance

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

				{

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

						chunk,

					},

				},

				function ()

					success ( cseq )

				end,

				function ( mesg )

					noerr = false

					fail ( mesg )

				end )

			start   = start + obj.bs

			obj.seq = obj.seq + 1

		end

	end

end

function M.close ( obj, success, fail )

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

		{

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

		}, success, fail )

end

function F.handler ( handler )

	O.handler = handler

end

local ibb_files = {}

function F.iq_handler ( conn, mess )

	local mtype, smtype = mess:type ()

	if smtype ~= 'set' then

		return false

	end

	local child = mess:child ()

	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

			O.handler ( 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

return F

-- vim: se ts=4: --