#! /bin/bash

IP=$1
PORT=$2
FILE=$3
REF=$4
INSTANCE=$5

PATH=$PATH:/sbin:/usr/sbin:/usr/local/sbin

set -e

is() {
    local prog=$1
    shift

    eval "_is_$prog" "$@" 2>/dev/null >/dev/null
}

compare() {
    cmp "$REF" output
}

## tftp-hpa
_is_tftp_hpa_fedora() {
    type -p tftp || return 1

    tftp -V | grep "^tftp-hpa 5\."
}

run_tftp_hpa_fedora() {
    is tftp_hpa_fedora || return 23

    tftp -m binary "$IP" "$PORT" -c get "$FILE" output
}

## busybox tftp
_is_tftp_busybox() {
    type -p busybox || return 1
    busybox --list | grep -q '^tftp$' || return 1
}

run_tftp_busybox() {
    is tftp_busybox || return 23

    busybox tftp -g -l output -r "$FILE" ${1:+-b $1} "$IP" "$PORT"
}

## curl
_is_curl() {
    type -p curl || return 1
    curl --version | grep -q -i '^protocols:.*\<tftp\>' || return 1
}

run_curl() {
    local uri

    is curl || return 23

    case $IP in
      *:*)	uri="[$IP]:$PORT";;
      *)	uri="$IP:$PORT";;
    esac

    curl --silent tftp://"$uri"/"$FILE" -o output "$@"
}

rm -f output
test -w .

case $INSTANCE in
  0)
	## test the test code...
	exit 23
	;;

  1)
	## fedora tftp client
	run_tftp_hpa_fedora
	compare
	;;

  2)
	## busybox tftp client with 512 blocksize
	run_tftp_busybox
	compare
	;;

  3)
	## busybox tftp client with 1400 blocksize
	run_tftp_busybox 1400
	compare
	;;

  4)
	## curl fails to download empty files
	test "$REF" != input_0 || exit 0

	run_curl --tftp-blksize 50000
	compare
	;;

  5)
	## curl fails to download empty files
	test "$REF" != input_0 || exit 0

	run_curl --tftp-no-options
	compare
	;;

  6)
	exit 42
esac