NTNet P2P Transfer client

- Adds simple NTNet P2P transfer client, that allows users to send files via NTNet.
- This client can act either as actual client (downloading files), or as a server, providing one file at time.
- This may (not guaranteed) be expanded in future, to allow sharing of multiple files at once, possibly even having some sort of dedicated server architecture
- Transfer speed is calculated as lower value of connection speed of both devices (weakest link in the chain)
- Server may be protected using rudimentary password that, if set, must be entered to download the file.

code/modules/modular_computers/file_system/programs/file_browser.dm

@@ -71,7 +71,8 @@
 		var/datum/computer_file/data/F = HDD.find_file_by_name(open_file)
 		if(!F || !istype(F))
 			return
-		var/newtext = sanitize(html_decode(input(usr, "Editing file [open_file]. You may use most tags used in paper formatting:", "Text Editor", F.stored_data) as message))
+		// 16384 is the limit for file length in characters. Currently, papers have value of 2048 so this is 8 times as long, since we can't edit parts of the file independently.
+		var/newtext = sanitize(html_decode(input(usr, "Editing file [open_file]. You may use most tags used in paper formatting:", "Text Editor", F.stored_data) as message), 16384)
 		if(F)
 			var/datum/computer_file/data/backup = F.clone()
 			HDD.remove_file(F)

code/modules/modular_computers/file_system/programs/ntdownloader.dm

@@ -127,6 +127,9 @@
 		data["disk_used"] = my_computer.hard_drive.used_capacity
 		var/list/all_entries[0]
 		for(var/datum/computer_file/program/P in ntnet_global.available_station_software)
+			// Only those programs our user can run will show in the list
+			if(!P.can_run(user))
+				continue
 			all_entries.Add(list(list(
 			"filename" = P.filename,
 			"filedesc" = P.filedesc,

code/modules/modular_computers/file_system/programs/nttransfer.dm

@@ -0,0 +1,196 @@
+var/global/nttransfer_uid = 0
+
+/datum/computer_file/program/nttransfer
+	filename = "nttransfer"
+	filedesc = "NTNet P2P Transfer Client"
+	program_icon_state = "generic"
+	size = 1
+	requires_ntnet = 1
+	requires_ntnet_feature = NTNET_PEERTOPEER
+	network_destination = "other device via P2P tunnel"
+	available_on_ntnet = 1
+	nanomodule_path = /datum/nano_module/computer_nttransfer/
+
+	var/error = ""										// Error screen
+	var/server_password = ""							// Optional password to download the file.
+	var/datum/computer_file/provided_file = null		// File which is provided to clients.
+	var/datum/computer_file/downloaded_file = null		// File which is being downloaded
+	var/list/connected_clients = list()					// List of connected clients.
+	var/datum/computer_file/program/nttransfer/remote	// Client var, specifies who are we downloading from.
+	var/download_completion = 0							// Download progress in GQ
+	var/download_netspeed = 0							// Our connectivity speed in GQ/s
+	var/actual_netspeed = 0								// Displayed in the UI, this is the actual transfer speed.
+	var/unique_token 									// UID of this program
+	var/upload_menu = 0									// Whether we show the program list and upload menu
+
+/datum/computer_file/program/nttransfer/New()
+	unique_token = nttransfer_uid
+	nttransfer_uid++
+	..()
+
+/datum/computer_file/program/nttransfer/process_tick()
+	// Server mode
+	update_netspeed()
+	if(provided_file)
+		for(var/datum/computer_file/program/nttransfer/C in connected_clients)
+			// Transfer speed is limited by device which uses slower connectivity.
+			// We can have multiple clients downloading at same time, but let's assume we use some sort of multicast transfer
+			// so they can all run on same speed.
+			C.actual_netspeed = min(C.download_netspeed, download_netspeed)
+			C.download_completion += C.actual_netspeed
+			if(C.download_completion >= provided_file.size)
+				C.finish_download()
+	else if(downloaded_file) // Client mode
+		if(!remote)
+			crash_download("Connection to remote server lost")
+
+/datum/computer_file/program/nttransfer/kill_program(var/forced = 0)
+	if(downloaded_file) // Client mode, clean up variables for next use
+		finalize_download()
+
+	if(provided_file) // Server mode, disconnect all clients
+		for(var/datum/computer_file/program/nttransfer/P in connected_clients)
+			P.crash_download("Connection terminated by remote server")
+		downloaded_file = null
+	..(forced)
+
+
+
+/datum/computer_file/program/nttransfer/proc/update_netspeed()
+	download_netspeed = 0
+	switch(ntnet_status)
+		if(1)
+			download_netspeed = NTNETSPEED_LOWSIGNAL
+		if(2)
+			download_netspeed = NTNETSPEED_HIGHSIGNAL
+		if(3)
+			download_netspeed = NTNETSPEED_ETHERNET
+
+// Finishes download and attempts to store the file on HDD
+/datum/computer_file/program/nttransfer/proc/finish_download()
+	if(!computer || !computer.hard_drive || !computer.hard_drive.store_file(downloaded_file))
+		error = "I/O Error:  Unable to save file. Check your hard drive and try again."
+	finalize_download()
+
+//  Crashes the download and displays specific error message
+/datum/computer_file/program/nttransfer/proc/crash_download(var/message)
+	error = message ? message : "An unknown error has occured during download"
+	finalize_download()
+
+// Cleans up variables for next use
+/datum/computer_file/program/nttransfer/proc/finalize_download()
+	if(remote)
+		remote.connected_clients.Remove(src)
+	downloaded_file = null
+	remote = null
+	download_completion = 0
+
+
+
+
+
+/datum/nano_module/computer_nttransfer
+	name = "NTNet P2P Transfer Client"
+
+/datum/nano_module/computer_nttransfer/ui_interact(mob/user, ui_key = "main", var/datum/nanoui/ui = null, var/force_open = 1, var/datum/topic_state/state = default_state)
+	if(!program)
+		return
+	var/datum/computer_file/program/nttransfer/PRG = program
+	if(!istype(PRG))
+		return
+
+	var/list/data = program.get_header_data()
+
+	if(PRG.error)
+		data["error"] = PRG.error
+	else if(PRG.downloaded_file)
+		data["downloading"] = 1
+		data["download_size"] = PRG.downloaded_file.size
+		data["download_progress"] = PRG.download_completion
+		data["download_netspeed"] = PRG.actual_netspeed
+		data["download_name"] = "[PRG.downloaded_file.filename].[PRG.downloaded_file.filetype]"
+	else if (PRG.provided_file)
+		data["uploading"] = 1
+		data["upload_uid"] = PRG.unique_token
+		data["upload_clients"] = PRG.connected_clients.len
+		data["upload_haspassword"] = PRG.server_password ? 1 : 0
+		data["upload_filename"] = "[PRG.provided_file.filename].[PRG.provided_file.filetype]"
+	else if (PRG.upload_menu)
+		var/list/all_files[0]
+		for(var/datum/computer_file/F in PRG.computer.hard_drive.stored_files)
+			all_files.Add(list(list(
+			"uid" = F.uid,
+			"filename" = "[F.filename].[F.filetype]",
+			"size" = F.size
+			)))
+		data["upload_filelist"] = all_files
+	else
+		var/list/all_servers[0]
+		for(var/datum/computer_file/program/nttransfer/P in ntnet_global.fileservers)
+			all_servers.Add(list(list(
+			"uid" = P.unique_token,
+			"filename" = "[P.provided_file.filename].[P.provided_file.filetype]",
+			"size" = P.provided_file.size,
+			"haspassword" = P.server_password ? 1 : 0
+			)))
+		data["servers"] = all_servers
+
+	ui = nanomanager.try_update_ui(user, src, ui_key, ui, data, force_open)
+	if (!ui)
+		ui = new(user, src, ui_key, "ntnet_transfer.tmpl", "NTNet P2P Transfer Client", 575, 700, state = state)
+		ui.auto_update_layout = 1
+		ui.set_initial_data(data)
+		ui.open()
+		ui.set_auto_update(1)
+
+/datum/computer_file/program/nttransfer/Topic(href, href_list)
+	if(..())
+		return 1
+	if(href_list["PRG_downloadfile"])
+		for(var/datum/computer_file/program/nttransfer/P in ntnet_global.fileservers)
+			if("[P.unique_token]" == href_list["PRG_downloadfile"])
+				remote = P
+				break
+		if(!remote || !remote.provided_file)
+			return
+		if(remote.server_password)
+			var/pass = sanitize(input(usr, "Code 401 Unauthorized. Please enter password:", "Password required"))
+			if(pass != remote.server_password)
+				error = "Incorrect Password"
+				return
+		downloaded_file = remote.provided_file.clone()
+		remote.connected_clients.Add(src)
+		return
+	if(href_list["PRG_reset"])
+		error = ""
+		upload_menu = 0
+		finalize_download()
+		if(src in ntnet_global.fileservers)
+			ntnet_global.fileservers.Remove(src)
+		for(var/datum/computer_file/program/nttransfer/T in connected_clients)
+			T.crash_download("Remote server has forcibly closed the connection")
+		provided_file = null
+		return
+	if(href_list["PRG_setpassword"])
+		var/pass = sanitize(input(usr, "Enter new server password. Leave blank to cancel, input 'none' to disable password.", "Server security", "none"))
+		if(!pass)
+			return
+		if(pass == "none")
+			server_password = ""
+			return
+		server_password = pass
+		return
+	if(href_list["PRG_uploadfile"])
+		for(var/datum/computer_file/F in computer.hard_drive.stored_files)
+			if("[F.uid]" == href_list["PRG_uploadfile"])
+				if(F.unsendable)
+					error = "I/O Error: File locked."
+					return
+				provided_file = F
+				ntnet_global.fileservers.Add(src)
+				return
+		error = "I/O Error: Unable to locate file on hard drive."
+		return
+	if(href_list["PRG_uploadmenu"])
+		upload_menu = 1
+	return 0