#! /bin/bash
#
# Flash an esp8266 over wifi. This communicates with the esphttpd's /flash handlers
# and POSTS the correct binary depending on the parittion that needs to be flashed
# next.
#
# ----------------------------------------------------------------------------
# "THE BEER-WARE LICENSE" (Revision 42):
# Thorsten von Eicken wrote this file. As long as you retain 
# this notice you can do whatever you want with this stuff. If we meet some day, 
# and you think this stuff is worth it, you can buy me a beer in return. 
# ----------------------------------------------------------------------------

show_help() {
  cat <<EOT
Usage: ${0##*/} [-options...] hostname user1.bin user2.bin
Flash the esp8266 running esphttpd at <hostname> with either <user1.bin> or <user2.bin>
depending on its current state. Reboot the esp8266 after flashing and wait for it to come
up again.
  -v                    Be verbose
  -h                    show this help

Example: ${0##*/} -v esp8266 firmware/user1.bin firmware/user2.bin
         ${0##*/} 192.168.4.1 firmware/user1.bin firmware/user2.bin
EOT
}

if ! which curl >/dev/null; then
  echo "ERROR: Cannot find curl: it is required for this script." >&2
  exit 1
fi

start=`date +%s`

# ===== Parse arguments

verbose=

while getopts "hvx:" opt; do
  case "$opt" in
    h) show_help; exit 0 ;;
    v) verbose=1 ;;
    x) foo="$OPTARG" ;;
    '?') show_help >&2; exit 1 ;;
  esac
done

# Shift off the options and optional --.
shift "$((OPTIND-1))"

# Get the fixed arguments
if [[ $# != 3 ]]; then
	show_help >&2
	exit 1
fi
hostname=$1
user1=$2
user2=$3

re='[-A-Za-z0-9.]+'
if [[ ! "$hostname" =~ $re ]]; then
	echo "ERROR: hostname ${hostname} is not a valid hostname or ip address" >&2
	exit 1
fi

if [[ ! -r "$user1" ]]; then
	echo "ERROR: cannot read user1 firmware file ($user1)" >&2
	exit 1
fi

if [[ ! -r "$user2" ]]; then
	echo "ERROR: cannot read user2 firmware file ($user2)" >&2
	exit 1
fi

# ===== Retrieve the 'next' firmware required

fw=
while true; do
	[[ -n "$verbose" ]] && echo "Fetching http://$hostname/flash/next" >&2
	v=; [[ -n "$verbose" ]] && v=-v
	next=`curl -m 10 $v -s "http://$hostname/flash/next"`
	if [[ $? != 0 ]]; then
		echo "Error retrieving http://$hostname/flash/next" >&2
		break
	fi
	case "$next" in
	user1.bin)
	  echo "Flashing user1.bin"  >&2
		fw="$user1"
		break;;
	user2.bin)
	  echo "Flashing user2.bin"  >&2
		fw="$user2"
		break;;
	*)
	  echo "Cannot parse result of retrieving http://$hostname/flash/next" >&2
		sleep 2
		;;
	esac
done

silent=-s
[[ -n "$verbose" ]] && silent=
res=`curl $silent -XPOST --data-binary "@$fw" "http://$hostname/flash/upload"`
if [[ $? != 0 ]]; then
	echo "Error flashing $fw" >&2
	exit 1
fi

sleep 2
echo "Rebooting into new firmware" >&2
curl -m 10 -s "http://$hostname/flash/reboot"

sleep 2
echo "Waiting for ESP8266 to come back"
while true; do
	[[ -n "$verbose" ]] && echo "Fetching http://$hostname/flash/next" >&2
	next2=`curl -m 10 $v -s "http://$hostname/flash/next"`
	[[ -n "$verbose" ]] && echo "got: $next2"
	re='user[12]\.bin'
	if [[ "$next2" =~ $re ]]; then
		if [[ "$next2" != "$next" ]]; then
			sec=$(( `date +%s` - $start ))
			echo "Success, took $sec seconds" >&2
			exit 0
		else
			echo "Flashing seems to have failed and it reverted to the old firmware?" >&2
			exit 1
		fi
	fi
	sleep 1
done