#!/bin/bash
##
##   olyWifiSync - Mirror Olympus camera via WIFI
##
##   Usage: olyWifiSync [-d|-n|-f|-p|-h] ESSID PASSWORD [wifidevice]
##      -d download only, don't try to configure the WIFI device)
##      -n no disconnect, do not disconnect the WIFI on completion
##      -f full download, do not skip over files that already exist
##      -p power off camera at end of transfer
##      -h help
##
##   Examples: 
##       olyWifiSync E-M5II-P-XYZZY123 12341234 wlan0
##
##   Mirrors SD contents to $HOME/SD-Mirror/$CAMERA_NET_ESSID
##   Only copies files they are not already in the destination folder.
##   The ESSID and PASSWORD are those displayed on the camera LCD 
##   when wifi is enabled.  Defaults to wlan0.
##
##   Requires full root sudo access if configuring the WIFI device.
##   Wifidevice defaults to wlan0. Pass -d to skip WIFI configuration,
##   in which case root is not required.
##
##   Limitations: Sometimes wpa_supplicant can fail to exit or just be
##   cranky - if this occurs, try sudo killall wpa_supplicant (but only
##   if you have one WIFI device).  The test of file existence is just
##   by name match - resetting the numbering sequence would defeat this
##   simple approach.  The camera can timeout if there are too many
##   files to transfer.  The camera sometimes seems to stop responding
##   over the wifi and its wifi will have to be restarted.  Needs more
##   error handling and error trapping.
##
##   Notes: to find out what commands a camera supports do:
##   wget -O cmdlist.txt http://192.168.0.10/get_commandlist.cgi
##   (see https://www.dpreview.com/forums/post/57165274 )
##   Originally based on reading the C++ code at: 
##   https://sourceforge.net/projects/wifi-downloader-for-oly-e-m1/
##   that project looks like a good GUI if you don't need WIFI 
##   to be configured.  This script was written on OpenSUSE 42.3,
##   but should run elsewhere too.
##
##   MIT License
##   
##   Copyright (c) 2018 Michael Hamilton
##   
##   Permission is hereby granted, free of charge, to any person obtaining a copy
##   of this software and associated documentation files (the "Software"), to deal
##   in the Software without restriction, including without limitation the rights
##   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
##   copies of the Software, and to permit persons to whom the Software is
##   furnished to do so, subject to the following conditions:
##   
##   The above copyright notice and this permission notice shall be included in all
##   copies or substantial portions of the Software.
##   
##   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
##   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
##   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
##   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
##   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
##   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
##   SOFTWARE.Copyright 2018 Michael Hamilton
##
DOWNLOAD_ONLY=N
NO_DISCONNECT=N
FULL_DOWNLOAD=N
POWER_OFF_CAMERA=N
 
while [[ "$1" =~ ^-[dhnpf] ]]
do
    [ "$1" == "-d" ] && DOWNLOAD_ONLY=Y
    [ "$1" == "-n" ] && NO_DISCONNECT=Y
    [ "$1" == "-f" ] && FULL_DOWNLOAD=Y
    [ "$1" == "-p" ] && POWER_OFF_CAMERA=Y
    [ "$1" == "-h" ] && egrep "^##" $0 && exit 0
    shift
done

CAMERA_NET_ESSID=${1:-E-M1MKII-P-DefaultSerialNumber}
CAMERA_NET_PASSWORD=${2:-DefaultWifiPassword}
CAMERA_NET_PREFIX=192.168.0
CAMERA_NET_CAMERA_ADDRESS=$CAMERA_NET_PREFIX.10
CAMERA_NET_PC_ADDRESS=$CAMERA_NET_PREFIX.5
CAMERA_NET_DEVICE=${3:-wlan0}

MIRROR_DIR="$HOME/SD-mirror/$CAMERA_NET_ESSID"

WPA_CTL=/tmp/wpa_ctl_$CAMERA_NET_ESSID
WPA_PID_FILE=/tmp/wpa_pid_$CAMERA_NET_ESSID

function download {
    if ! ping -c 1 $CAMERA_NET_CAMERA_ADDRESS
    then
        echo "ERROR: no device responding at IP address CAMERA_NET_CAMERA_ADDRESS"
        return 1
    fi
    echo "INFO: mirroring to $MIRROR_DIR"
    mkdir -p $MIRROR_DIR
    url="http://$CAMERA_NET_CAMERA_ADDRESS/get_imglist.cgi?DIR=/DCIM/100OLYMP"
    echo "INFO: retrieving file list via $url" 
    downloadCount=0
    wget -q "$url" -O - | while read line 
    do
        IFS=, read dir filename rest <<< $line
        if [ -n "$filename" ]
        then
            if [ $FULL_DOWNLOAD == "N" -a -f $MIRROR_DIR/$filename ]
            then
                echo "WARN: skipping existing file: $filename"
            else
                url="http://$CAMERA_NET_CAMERA_ADDRESS/DCIM/100OLYMP/$filename"
                echo "INFO: downloading $filename"
                wget -O $MIRROR_DIR/$filename "$url" || return
                downloadCount=$[downloadCount + 1]
            fi
        fi
    done
    echo "INFO: downloaded $downloadCount files"
    if [ $POWER_OFF_CAMERA == "Y" ]
    then
        url="http://$CAMERA_NET_CAMERA_ADDRESS/exec_pwoff.cgi"
        wget "$url" -O -
    fi
}

function connect_wifi {
    
    [ $DOWNLOAD_ONLY == "Y" ] && return 0

    # Do Linux WIFI configuration for a WIFI device dedicated to the camera.
    sudo ifconfig $CAMERA_NET_DEVICE up
    sleep 2

    if sudo iwlist $CAMERA_NET_DEVICE scan | egrep "ESSID:\"$CAMERA_NET_ESSID\""
    then
        sudo bash -c "wpa_supplicant -B -g $WPA_CTL -P $WPA_PID_FILE -i $CAMERA_NET_DEVICE -c <(/usr/sbin/wpa_passphrase $CAMERA_NET_ESSID $CAMERA_NET_PASSWORD)"
        sleep 2
        sudo ifconfig $CAMERA_NET_DEVICE $CAMERA_NET_PC_ADDRESS netmask 255.255.255.0
        sleep 2
    else
        echo "ERROR: failed to connect to WIFI for $CAMERA_NET_DEVICE $CAMERA_NET_ESSID" && return 1
    fi    
}

function disconnect_wifi {

    [ $DOWNLOAD_ONLY == "Y" ] && return
    [ $NO_DISCONNECT == "Y" ] && return
    
    sudo ifconfig $CAMERA_NET_DEVICE down
    [ -f $WPA_CTL ] && sudo wpa_cli -g $WPA_CTL terminate
    sleep 2
    sudo kill `cat $WPA_PID_FILE`
    sudo rm $WPA_CTL $WPA_PID_FILE
}

connect_wifi && download && disconnect_wifi