# (C) 2010-2018 magicant

# Completion script for the "ssh" command.
# Completion function "completion/ssh" is used for the "scp" and "sftp" commands
# as well.
# Supports OpenSSH 7.7.

function completion/ssh {

	typeset OPTIONS ARGOPT PREFIX
	OPTIONS=( #>#
	#"1; use the protocol version 1 only"
	#"2; use the protocol version 2 only"
	"4; use IPv4 addresses only"
	"6; use IPv6 addresses only"
	"C; enable data compression"
	"c:; specify the encryption algorithm"
	"F:; specify the configuration file"
	"i:; specify the private key (identity) file"
	"o:; specify an option in the configuration file format"
	"v; print debugging messages"
	) #<#

	case ${WORDS[1]} in
	(ssh)
		OPTIONS=("$OPTIONS" #>#
		"A; enable authentication agent forwarding"
		"a; disable authentication agent forwarding"
		"B:; specify the network interface to connect from"
		"b:; specify the local IP address to connect from"
		"D:; specify a port for local dynamic application-level port forwarding"
		"E:; specify the log file"
		"e:; specify the escape character"
		"f; run in the background after authentication"
		"G; print the configuration"
		"g; allow remote hosts to connect to local forwarded ports"
		"I:; specify the PKCS#11 shared library"
		"J:; specify jump hosts"
		"K; enable GSSAPI-based authentication and forwarding"
		"k; disable GSSAPI-based authentication and forwarding"
		"L:; specify a local port and a remote host/port to forward"
		"l:; specify the user name to log in as"
		"M; run in the master mode for connection sharing"
		"m:; specify MACs (message authentication codes)"
		"N; don't run any remote command"
		"n; redirect the standard input of the remote command to /dev/null"
		"O:; specify a command to control the master process"
		"p:; specify the port to connect to"
		"Q:; specify the feature to query"
		"q; suppress warning and diagnostic messages"
		"R:; specify a remote port and a local host/port to forward"
		"S:; specify the control socket for connection sharing"
		"s; run the command as the SSH2 subsystem"
		"T; run the command without a pseudo-terminal"
		"t; run the command in a pseudo-terminal"
		"V; print version info"
		"W:; specify a remote host/port to directly connect to"
		"w:; specify the tunnel device to forward"
		"X; enable X11 forwarding"
		"x; disable X11 forwarding"
		"Y; enable trusted X11 forwarding"
		"y; use syslog for logging"
		) #<#
		;;
	(scp)
		OPTIONS=("$OPTIONS" #>#
		"3; copy via local host between remote source and destination"
		"B; batch mode: don't ask for passwords/phrases"
		) #<#
		;;
	(sftp)
		OPTIONS=("$OPTIONS" #>#
		"a; continue on interruption"
		"B:; specify the buffer size in bytes"
		"b:; batch mode: specify the file to read commands from"
		"D:; specify the path of local sftp server to connect to"
		"R:; specify the max number of outstanding requests"
		"s:; specify the SSH2 subsystem or the path for the remote sftp server"
		) #<#
		;;
	(*)
		return 1
		;;
	esac
	case ${WORDS[1]} in (scp|sftp)
		OPTIONS=("$OPTIONS" #>#
		"l:; specify the max bandwidth in Kbps"
		"P:; specify the port to connect to"
		"p; preserve file attributes"
		"q; suppress progress bar and warning and diagnostic messages"
		"r; recursively copy directories"
		"S:; specify the connection program used instead of ssh"
		) #<#
	esac

	command -f completion//parseoptions
	case $ARGOPT in
	(-)
		command -f completion//completeoptions
		;;
	([BDPp])
		;;
	(b)
		case ${WORDS[1]} in
		(sftp)
			complete -P "$PREFIX" -f
			;;
		esac
		;;
	([Fi])
		complete -P "$PREFIX" -f
		;;
	(c)
		#TODO
		;;
	(e) #>>#
		complete -P "$PREFIX" '~'
		complete -P "$PREFIX" -D "none" none
		;; #<<#
	(I)
		#TODO
		;;
	(J)
		PREFIX=${TARGETWORD%"${${TARGETWORD#"$PREFIX"}##*,}"}
		command -f completion/${WORDS[1]}::operand
		;;
	(L)
		#TODO
		;;
	(l)
		case ${WORDS[1]} in
		(ssh)
			complete -P "$PREFIX" -u
			;;
		esac
		;;
	(m)
		#TODO
		;;
	(O) #>>#
		complete -P "$PREFIX" -D "request the master process to stop port forwarding" cancel
		complete -P "$PREFIX" -D "check that the master process is running" check
		complete -P "$PREFIX" -D "request the master process to exit" exit
		complete -P "$PREFIX" -D "request forwarding without command execution" forward
		complete -P "$PREFIX" -D "request the master process to accept no more connections" stop
		;; #<<#
	(o)
		#TODO
		;;
	(Q) #>>#
		complete -P "$PREFIX" -D "supported symmetric ciphers" cipher
		complete -P "$PREFIX" -D "supported symmetric ciphers that support authenticated encryption" cipher-auth
		complete -P "$PREFIX" -D "key exchange algorithms" kex
		complete -P "$PREFIX" -D "key types" key
		complete -P "$PREFIX" -D "certificate key types" key-cert
		complete -P "$PREFIX" -D "non-certificate key types" key-plain
		complete -P "$PREFIX" -D "supported message integrity codes" mac
		complete -P "$PREFIX" -D "supported SSH protocol versions" protocol-version
		;; #<<#
	(R)
		#TODO
		;;
	(S)
		case ${WORDS[1]} in
		(ssh)
			complete -P "$PREFIX" -f
			;;
		(scp|sftp)
			WORDS=()
			command -f completion//reexecute -e
			;;
		esac
		;;
	(W)
		#TODO
		;;
	(w)
		#TODO
		;;
	('')
		command -f completion/${WORDS[1]}::operand
		;;
	esac

}

function completion/ssh::operand {
	typeset config ssh sshopts cmd="${WORDS[1]}"
	command -f completion/ssh::parseconfig
	if [ ${WORDS[#]} -gt 0 ]; then
		# complete the command
		WORDS=("${WORDS[2,-1]}")
		command -f completion//reexecute
	else
		command -f completion/ssh::completehostname
	fi
}

function completion/scp::operand {
	typeset config ssh sshopts cmd="${WORDS[1]}"
	command -f completion/ssh::parseconfig

	case $TARGETWORD in
	(${cmd}://*/*)
		typeset path="${TARGETWORD#"${cmd}"://*/}"
		command -f completion/ssh::completeremotepath
		;;
	(${cmd}://*)
		command -f completion/ssh::completehostname -T -S /
		;;
	(*:*)
		case ${TARGETWORD%%:*} in
		(*/*) # a host name cannot contain a slash
			command -f completion/ssh::completelocalpath
			;;
		(*)
			typeset path="${TARGETWORD#*:}"
			command -f completion/ssh::completeremotepath
			;;
		esac
		;;
	(*)
		command -f completion/ssh::completehostname -T -S :
		command -f completion/ssh::completelocalpath
		;;
	esac
}

function completion/sftp::operand {
	command -f completion/scp::operand
}

function completion/ssh::parseconfig {
	typeset i=2
	config=${HOME:+"$HOME/.ssh/config"}
	ssh=ssh sshopts=()
	while [ $i -le ${WORDS[#]} ]; do
		case ${WORDS[i]} in
			(-F*)
				sshopts=("$sshopts" "${WORDS[i]}")
				config=${WORDS[i]#-F} ;;
			(-[1246BCiJo]*)
				sshopts=("$sshopts" "${WORDS[i]}") ;;
			(-P*)
				sshopts=("$sshopts" -p"${WORDS[i]#-P}") ;;
			(-S*)
				case ${WORDS[1]} in (scp|sftp)
					ssh=${WORDS[1]#-S}
				esac
				;;
			(--)
				i=$((i+1)); break ;;
			(-*)
				;;
			(*)
				break ;;
		esac
		i=$((i+1))
	done
	WORDS=("${WORDS[i,-1]}")
}

function completion/ssh::completehostname {
	case ${TARGETWORD#"$PREFIX"} in (${cmd}://*)
		PREFIX=${PREFIX}${cmd}://
	esac
	case ${TARGETWORD#"$PREFIX"} in (*@*)
		PREFIX=${TARGETWORD%"${${TARGETWORD#"$PREFIX"}#*@}"}
	esac
	typeset key values file words host
	while read -Ar key values; do
		case $key in ([Hh][Oo][Ss][Tt])
			complete -P "$PREFIX" -R '*[*?]*' -R '!*' "$@" -- \
				"$values"
		esac
	done <(sed -e 's/#.*//' -e 's/[Hh][Oo][Ss][Tt][[:blank:]]*=/host /' "$config" 2>/dev/null)
	# currently, we always read known-hosts files from the default location
	for file in /etc/ssh/ssh_known_hosts ~/.ssh/known_hosts; do
		if ! [ -r "$file" ]; then
			continue
		fi
		while read -Ar words; do
			case ${words[1]} in
			(\#*)
				continue
				;;
			(@*)
				words=("${words[2,-1]}")
				;;
			esac
			for host in ${words[1]//,/ }; do
				case $host in
				([\|!]*|*[*?]*) ;;
				(\[*]:*)
					complete -P "$PREFIX" "$@" -- "${{host#\[}%]:*}"
					;;
				(*)
					complete -P "$PREFIX" "$@" -- "$host"
					;;
				esac
			done
			hosts=(${words[1]//,/ })
			case $key in
			(\|*) ;;
			(*)
				complete -P "$PREFIX" "$@" -- ${key//,/ }
			esac
		done <"$file"
	done
}

function completion/ssh::completeremotepath
	case $cmd in (scp|sftp|rsync)
		PREFIX=${TARGETWORD%"$path"}
		typeset host="${${PREFIX%[/:]}/#${cmd}:\/\//ssh:\/\/}"
		typeset name="${path##*/}"
		typeset dir="${path%"$name"}"
		typeset filter f flags
		if [ -o dotglob ]; then
			filter=()
		else
			case $name in
				(.*) filter=(-A '.*') ;;
				(*)  filter=(-R '.*') ;;
			esac
		fi
		while read -r f; do
			case $f in
				(*/) flags='-T' ;;
				(*)  flags=     ;;
			esac
			complete -P "$PREFIX$dir" "$filter" $flags -- "$f"
		done <("$ssh" "$sshopts" -o BatchMode=yes -- "$host" "ls -ap -- '${${dir:-.}//\'/\'\\\'\'}'" <>/dev/null 2>&0)
	esac

function completion/ssh::completelocalpath
	case $cmd in (scp|rsync)
		typeset slash=false
		case $TARGETWORD in (*/*)
			slash=
		esac
		complete ${slash:+-R '*:*'} -f
	esac


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