#!/bin/bash

# Library to install software on Raspbian ARM through QEMU
#
# Copyleft 2017 by Ignacio Nunez Hernanz <nacho _a_t_ ownyourbits _d_o_t_ com>
# GPL licensed (see end of file) * Use at your own risk!
#
# More at ownyourbits.com
#


IMGNAME=$( basename $IMGFILE .img )_$( basename $INSTALL_SCRIPT .sh ).img
CFGOUT=config_$( basename $INSTALL_SCRIPT .sh ).txt
DBG=x

# $IMGOUT will contain the name of the last step
function launch_install_qemu()
{
  local IMG=$1
  local IP=$2
  [[ "$IP"      == ""  ]] && { echo "usage: launch_install_qemu <script> <img> <IP>"; return 1; }
  test -f $IMG            || { echo "input file $IMG not found";                      return 1; }

  local BASE=$( sed 's=-stage[[:digit:]]=='         <<< $IMG )
  local NUM=$(  sed 's=.*-stage\([[:digit:]]\)=\1=' <<< $IMG )
  [[ "$BASE" == "$IMG" ]] && NUM=0

  local NUM_REBOOTS=$( grep -c reboot $INSTALL_SCRIPT )
  while [[ $NUM_REBOOTS != -1 ]]; do
    NUM=$(( NUM+1 ))
    IMGOUT="$BASE-stage$NUM"
    cp -v $IMG $IMGOUT || return 1 # take a copy of the input image for processing ( append "-stage1" )

    pgrep qemu-system-arm &>/dev/null && { echo -e "QEMU instance already running. Abort..."; return 1; }
    launch_qemu $IMGOUT &
    sleep 10
    wait_SSH $IP
    launch_installation_qemu $IP || return 1
    wait 
    IMG="$IMGOUT"
    NUM_REBOOTS=$(( NUM_REBOOTS-1 ))
  done
  echo "$IMGOUT generated successfully"
}

function launch_qemu()
{
  local IMG=$1
  test -f $1 || { echo "Image $IMG not found"; return 1; }
  test -d qemu-raspbian-network || git clone https://github.com/nachoparker/qemu-raspbian-network.git
  sed -i '30s/NO_NETWORK=1/NO_NETWORK=0/' qemu-raspbian-network/qemu-pi.sh
  sed -i '35s/NO_GRAPHIC=0/NO_GRAPHIC=1/' qemu-raspbian-network/qemu-pi.sh
  echo "Starting QEMU image $IMG"
  ( cd qemu-raspbian-network && sudo ./qemu-pi.sh ../$IMG 2>/dev/null )
}

function ssh_pi()
{
  local IP=$1
  local ARGS=${@:2}
  local PIUSER=${PIUSER:-pi}
  local PIPASS=${PIPASS:-raspberry}
  local SSH=( ssh -q  -o UserKnownHostsFile=/dev/null\
                      -o StrictHostKeyChecking=no\
                      -o ServerAliveInterval=20\
                      -o ConnectTimeout=20\
                      -o LogLevel=quiet                  )
  type sshpass &>/dev/null && local SSHPASS=( sshpass -p$PIPASS )
  if [[ "${SSHPASS[@]}" == "" ]]; then
    ${SSH[@]} ${PIUSER}@$IP $ARGS; 
  else
    ${SSHPASS[@]} ${SSH[@]} ${PIUSER}@$IP $ARGS 
    local RET=$?
    [[ $RET -eq 5 ]] && { ${SSH[@]} ${PIUSER}@$IP $ARGS; return $?; }
    return $RET
  fi
}

function wait_SSH()
{
  local IP=$1
  echo "Waiting for SSH to be up on $IP..."
  while true; do
    ssh_pi $IP : && break
    sleep 1
  done
  echo "SSH is up"
}

function launch_installation()
{
  local IP=$1
  [[ "$INSTALLATION_CODE"  == "" ]] && { echo "Need to run config first"    ; return 1; }
  [[ "$INSTALLATION_STEPS" == "" ]] && { echo "No installation instructions"; return 1; }
  local PREINST_CODE="
set -e$DBG
sudo su
set -e$DBG
"
  echo "Launching installation"
  echo -e "$PREINST_CODE\n$INSTALLATION_CODE\n$INSTALLATION_STEPS" | ssh_pi $IP || { echo "Installation to $IP failed" && return 1; }
  echo "configuration saved to $CFGOUT"
}

function launch_installation_qemu()
{
  local IP=$1
  [[ "$NO_CFG_STEP"  != "1" ]] && local CFG_STEP=configure
  [[ "$NO_CLEANUP"   != "1" ]] && local CLEANUP_STEP=cleanup
  [[ "$NO_HALT_STEP" != "1" ]] && local HALT_STEP="nohup halt &>/dev/null &"
  local INSTALLATION_STEPS="
install
$CFG_STEP
$CLEANUP_STEP
$HALT_STEP
"
  launch_installation $IP
}

function launch_installation_online()
{
  local IP=$1
  [[ "$NO_CFG_STEP" != "1" ]]  && local CFG_STEP=configure
  local INSTALLATION_STEPS="
install
$CFG_STEP
"
  launch_installation $IP
}

# Initializes $INSTALLATION_CODE
function config()
{
  local INSTALL_SCRIPT="$1"
  local BACKTITLE="NextCloudPi installer configuration"

  type dialog &>/dev/null || { echo "please, install dialog for interactive configuration"; return 1; }

  test -f "$INSTALL_SCRIPT" || { echo "file "$INSTALL_SCRIPT" not found"; return 1; }
  local VARS=( $( grep "^[[:alpha:]]\+_=" "$INSTALL_SCRIPT" | cut -d= -f1 | sed 's|_$||' ) )
  local VALS=( $( grep "^[[:alpha:]]\+_=" "$INSTALL_SCRIPT" | cut -d= -f2 ) )

  [[ "$NO_CONFIG" == "1" ]] || test ${#VARS[@]} -eq 0 && { INSTALLATION_CODE="$( cat "$INSTALL_SCRIPT" )"; return; }

  for i in `seq 1 1 ${#VARS[@]} `; do
    local PARAM+="${VARS[$((i-1))]} $i 1 ${VALS[$((i-1))]} $i 15 60 0 "
  done

  local DIALOG_OK=0
  local DIALOG_CANCEL=1
  local DIALOG_ERROR=254
  local DIALOG_ESC=255
  local RET=0

  while test $RET != 1 && test $RET != 250; do
    local value
    value=$( dialog --ok-label "Start" \
                    --no-lines --backtitle "$BACKTITLE" \
                    --form "Enter the desired configuration for $( basename "$INSTALL_SCRIPT" .sh )" \
                    20 70 0 $PARAM \
             3>&1 1>&2 2>&3 )
    RET=$?

    case $RET in
      $DIALOG_CANCEL)
        return 1
        ;;
      $DIALOG_OK)
        local RET=( $value )
        for i in `seq 0 1 $(( ${#RET[@]} - 1 )) `; do
          local SEDRULE+="s|^${VARS[$i]}_=.*|${VARS[$i]}_=${RET[$i]}|;"
          local CONFIG+="${VARS[$i]}=${RET[$i]}\n"
        done
        break
        ;;
      $DIALOG_ERROR)
        echo "ERROR!$value"
        return 1
        ;;
      $DIALOG_ESC)
        echo "ESC pressed."
        return 1
        ;;
      *)
        echo "Return code was $RET"
        return 1
        ;;
    esac
  done

  INSTALLATION_CODE="$( sed $SEDRULE "$INSTALL_SCRIPT" )"
  [[ "$CFGOUT" != "" ]] && echo -e "$CONFIG" > "$CFGOUT"
}

function install_script()
{
  (
    local SCRIPT=$1
    source ./$SCRIPT 
    echo -e "Installing \e[1m$( basename $SCRIPT .sh )\e[0m"
    set +x
    install
  )
}

function activate_script()
{
  (
    local SCRIPT=$1
    source ./$SCRIPT 
    echo -e "Activating \e[1m$( basename $SCRIPT .sh )\e[0m"
    set +x
    configure
  )
}

function info_script()
{
  (
    local SCRIPT=$1
    cd /usr/local/etc/nextcloudpi-config.d/
    unset show_info
    source ./$SCRIPT
    [[ $( type -t show_info ) == function ]] || return 0
    [[ $( type -t show_info ) == function ]] && show_info 
  )
}

function configure_script()
{
  (
    local SCRIPT=$1
    cd /usr/local/etc/nextcloudpi-config.d/
    config $SCRIPT || return 1                 # writes "$INSTALLATION_CODE"
    echo -e "$INSTALLATION_CODE" > $SCRIPT     # save configuration
    source ./$SCRIPT                           # load configuration
    echo -e "Launching \e[1m$( basename $SCRIPT .sh )\e[0m"
    set +x
    configure
    return 0
  )
}

function copy_to_image()
{
  local IMG=$1
  local DST=$2
  local SRC=${@: 3 }
  local SECTOR=$( fdisk -l $IMG | grep Linux | awk '{ print $2 }' )
  local OFFSET=$(( SECTOR * 512 ))

  [ -f "$IMG" ] || { echo "no image"; return 1; }
  mkdir -p tmpmnt
  sudo mount $IMG -o offset=$OFFSET tmpmnt || return 1
  sudo cp -v $SRC tmpmnt/$DST || return 1
  sudo umount -l tmpmnt
  rmdir tmpmnt &>/dev/null
}

function download_resize_raspbian_img()
{
  local SIZE=$1
  local IMGFILE=$2
  local IMG=raspbian_lite_latest

  test -f $IMGFILE && \
    echo -e "INFO: $IMGFILE already exists. Skipping download ..." && return 0 

  test -f $IMG.zip || \
    wget https://downloads.raspberrypi.org/$IMG -O $IMG.zip || return 1

  unzip -o $IMG.zip && \
    mv *-raspbian-*.img $IMGFILE && \
    qemu-img resize -f raw $IMGFILE +$SIZE  && \
    return 0
}

function pack_image()
{
  local IMGOUT="$1"
  local IMGNAME="$2"
  local TARNAME=$( basename $IMGNAME .img ).tar.bz2
  echo "copying $IMGOUT → $IMGNAME"
  cp "$IMGOUT" "$IMGNAME" || return 1
  echo "packing $IMGNAME → $TARNAME"
  tar -I pbzip2 -cvf $TARNAME "$IMGNAME" &>/dev/null && \
    echo -e "$TARNAME packed successfully"
}

# License
#
# This script is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This script is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this script; if not, write to the
# Free Software Foundation, Inc., 59 Temple Place, Suite 330,
# Boston, MA  02111-1307  USA