#!/bin/bash

# based on https://github.com/Stadicus/guides/blob/master/raspibolt/raspibolt_30_bitcoin.md#installation

# set version (change if update is available)
# https://bitcoincore.org/en/download/
bitcoinVersion="0.21.0"

# needed to check code signing
laanwjPGP="01EA5486DE18A882D4C2684590C8019E36C2E964"

echo "Detecting CPU architecture ..."
isARM=$(uname -m | grep -c 'arm')
isAARCH64=$(uname -m | grep -c 'aarch64')
isX86_64=$(uname -m | grep -c 'x86_64')
if [ ${isARM} -eq 0 ] && [ ${isAARCH64} -eq 0 ] && [ ${isX86_64} -eq 0 ]; then
  echo "!!! FAIL !!!"
  echo "Can only build on ARM, aarch64, x86_64 or i386 not on:"
  uname -m
  exit 1
else
 echo "OK running on $(uname -m) architecture."
fi

echo "Checking if LND is up-to-date..."
lndVersion=$(lnd --version | awk '{print $3}' | cut -d'-' -f1 | sed 's/\.//g')
if [ ${lndVersion} -ge 081 ]; then
  echo "LND is up-to-date."
else
  echo
  echo "LND is not up-to-date."
  echo "LND < v0.8.1 is incompatible with Bitcoin Core v0.19.0.1 and above"
  echo "Please update LND via the update script found here:"
  echo "https://github.com/openoms/lightning-node-management/tree/master/lnd.updates"
 exit 1
fi

echo
echo "*** PREPARING BITCOIN ***"

# prepare directories
sudo rm -rf /home/admin/download 2>/dev/null
sudo -u admin mkdir /home/admin/download 2>/dev/null
cd /home/admin/download

# download, check and import signer key
sudo -u admin wget https://bitcoin.org/laanwj-releases.asc
if [ ! -f "./laanwj-releases.asc" ]
then
  echo "!!! FAIL !!! Download laanwj-releases.asc not success."
  exit 1
fi
gpg ./laanwj-releases.asc
fingerprint=$(gpg ./laanwj-releases.asc 2>/dev/null | grep "${laanwjPGP}" -c)
if [ ${fingerprint} -lt 1 ]; then
  echo
  echo "!!! BUILD WARNING --> Bitcoin PGP author not as expected"
  echo "Should contain laanwjPGP: ${laanwjPGP}"
  echo "PRESS ENTER to TAKE THE RISK if you think all is OK"
  read key
fi
gpg --import ./laanwj-releases.asc

# download signed binary sha256 hash sum file and check
sudo -u admin wget https://bitcoin.org/bin/bitcoin-core-${bitcoinVersion}/SHA256SUMS.asc
verifyResult=$(gpg --verify SHA256SUMS.asc 2>&1)
goodSignature=$(echo ${verifyResult} | grep 'Good signature' -c)
echo "goodSignature(${goodSignature})"
correctKey=$(echo ${verifyResult} |  grep "using RSA key ${laanwjPGP: -16}" -c)
echo "correctKey(${correctKey})"
if [ ${correctKey} -lt 1 ] || [ ${goodSignature} -lt 1 ]; then
  echo
  echo "!!! BUILD FAILED --> PGP Verify not OK / signature(${goodSignature}) verify(${correctKey})"
  exit 1
else
  echo
  echo "****************************************"
  echo "OK --> BITCOIN MANIFEST IS CORRECT"
  echo "****************************************"
  echo
fi

# get the sha256 value for the corresponding platform from signed hash sum file
if [ ${isARM} -eq 1 ] ; then
  bitcoinOSversion="arm-linux-gnueabihf"
fi
if [ ${isAARCH64} -eq 1 ] ; then
  bitcoinOSversion="aarch64-linux-gnu"
fi
if [ ${isX86_64} -eq 1 ] ; then
  bitcoinOSversion="x86_64-linux-gnu"
fi
bitcoinSHA256=$(grep -i "$bitcoinOSversion" SHA256SUMS.asc | cut -d " " -f1)

echo
echo "*** BITCOIN v${bitcoinVersion} for ${bitcoinOSversion} ***"

# download resources
binaryName="bitcoin-${bitcoinVersion}-${bitcoinOSversion}.tar.gz"
sudo -u admin wget https://bitcoin.org/bin/bitcoin-core-${bitcoinVersion}/${binaryName}
if [ ! -f "./${binaryName}" ]
then
    echo "!!! FAIL !!! Download BITCOIN BINARY not success."
    exit 1
fi

# check binary checksum test
binaryChecksum=$(sha256sum ${binaryName} | cut -d " " -f1)
if [ "${binaryChecksum}" != "${bitcoinSHA256}" ]; then
  echo "!!! FAIL !!! Downloaded BITCOIN BINARY not matching SHA256 checksum: ${bitcoinSHA256}"
  exit 1
else
  echo
  echo "****************************************"
  echo "OK --> VERIFIED BITCOIN CHECKSUM CORRECT"
  echo "****************************************"
  echo
fi

echo "Stopping bitcoind and lnd"
sudo systemctl stop lnd
sudo systemctl stop bitcoind
echo

echo "Installing Bitcoin Core v${bitcoinVersion}"
sudo -u admin tar -xvf ${binaryName}
sudo install -m 0755 -o root -g root -t /usr/local/bin/ bitcoin-${bitcoinVersion}/bin/*
sleep 3
installed=$(sudo -u admin bitcoind --version | grep "${bitcoinVersion}" -c)
if [ ${installed} -lt 1 ]; then
  echo
  echo "!!! BUILD FAILED --> Was not able to install bitcoind version(${bitcoinVersion})"
  exit 1
fi

sudo systemctl start bitcoind
sleep 2

echo
echo "Installed $(sudo -u admin bitcoind --version | grep version)"
echo 

sudo systemctl start lnd
sleep 10

echo "Unlock lnd with the Password C"
lncli unlock
echo 
echo "A restart is recommended to bring all services back online. Use: 'restart' or 'sudo shutdown now -r'"
echo