# Download and run this script on the RaspiBlitz:
# $ wget https://github.com/openoms/bitcoin-tutorials/raw/master/electrs/electrs_to_RaspiBlitz.sh && bash electrs_to_RaspiBlitz.sh

# https://github.com/romanz/electrs/blob/master/doc/usage.md

echo ""
echo "***"
echo "Creating the electrs user"
echo "***"
echo ""
sudo adduser --disabled-password --gecos "" electrs
cd /home/electrs

echo ""
echo "***"
echo "Installing Rust"
echo "***"
echo ""
sudo -u electrs curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sudo -u electrs sh -s -- -y
#source $HOME/.cargo/env
sudo apt update
sudo apt install -y clang cmake  # for building 'rust-rocksdb'

echo ""
echo "***"
echo "Downloading and building electrs. This will take ~30 minutes" # ~22 min on an Odroid XU4
echo "***"
echo ""
sudo -u electrs git clone https://github.com/romanz/electrs
cd /home/electrs/electrs
sudo -u electrs /home/electrs/.cargo/bin/cargo build --release

echo ""
echo "***"
echo "The electrs database will be built in /mnt/hdd/electrs/db. Takes ~18 hours and ~50Gb diskspace"
echo "***"
echo ""
sudo mkdir /mnt/hdd/electrs 2>/dev/null
sudo chown -R electrs:electrs /mnt/hdd/electrs

echo ""
echo "***"
echo "getting RPC credentials from the bitcoin.conf"
echo "***"
echo ""
#echo "Type the PASSWORD B of your RaspiBlitz followed by [ENTER] (needed for Electrs to access the bitcoind RPC):"
#read PASSWORD_B
RPC_USER=$(sudo cat /mnt/hdd/bitcoin/bitcoin.conf | grep rpcuser | cut -c 9-)
PASSWORD_B=$(sudo cat /mnt/hdd/bitcoin/bitcoin.conf | grep rpcpassword | cut -c 13-)
echo "Done"

echo ""
echo "***"
echo "generating electrs.toml setting file with the RPC passwords"
echo "***"
echo ""
# generate setting file: https://github.com/romanz/electrs/issues/170#issuecomment-530080134
# https://github.com/romanz/electrs/blob/master/doc/usage.md#configuration-files-and-environment-variables

sudo rm -f /home/electrs/.electrs/config.toml 
sudo -u electrs mkdir /home/electrs/.electrs 2>/dev/null

touch /home/admin/config.toml
chmod 600 /home/admin/config.toml || exit 1 
cat > /home/admin/config.toml <<EOF
verbose = 4
timestamp = true
jsonrpc_import = true
db_dir = "/mnt/hdd/electrs/db"
cookie = "$RPC_USER:$PASSWORD_B"
EOF
sudo mv /home/admin/config.toml /home/electrs/.electrs/config.toml
sudo chown electrs:electrs /home/electrs/.electrs/config.toml

echo ""
echo "***"
echo "Open port 50001 on UFW "
echo "***"
echo ""
sudo ufw allow 50001

echo ""
echo "***"
echo "Checking for config.toml"
echo "***"
echo ""
if [ ! -f "/home/electrs/.electrs/config.toml" ]
    then
        echo "Failed to create config.toml"
        exit 1
    else
        echo "OK"
fi

echo ""
echo "***"
echo "installing Nginx"
echo "***"
echo ""

sudo apt-get install -y nginx
sudo /etc/init.d/nginx start

echo ""
echo "***"
echo "Create a self signed SSL certificate"
echo "***"
echo ""

#https://www.humankode.com/ssl/create-a-selfsigned-certificate-for-nginx-in-5-minutes
#https://stackoverflow.com/questions/8075274/is-it-possible-making-openssl-skipping-the-country-common-name-prompts

echo "
[req]
prompt=no
default_bits       = 2048
default_keyfile    = localhost.key
distinguished_name = req_distinguished_name
req_extensions     = req_ext
x509_extensions    = v3_ca

[req_distinguished_name]
countryName                 = Country Name (2 letter code)
countryName_default         = US
stateOrProvinceName         = State or Province Name (full name)
stateOrProvinceName_default = New York
localityName                = Locality Name (eg, city)
localityName_default        = Rochester
organizationName            = Organization Name (eg, company)
organizationName_default    = localhost
organizationalUnitName      = organizationalunit
organizationalUnitName_default = Development
commonName                  = Common Name (e.g. server FQDN or YOUR name)
commonName_default          = localhost
commonName_max              = 64

[req_ext]
subjectAltName = @alt_names

[v3_ca]
subjectAltName = @alt_names

[alt_names]
DNS.1   = localhost
DNS.2   = 127.0.0.1
" | sudo tee /mnt/hdd/electrs/localhost.conf

cd /mnt/hdd/electrs
sudo openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout localhost.key -out localhost.crt -config localhost.conf

sudo cp localhost.crt /etc/ssl/certs/localhost.crt
sudo cp localhost.key /etc/ssl/private/localhost.key

echo ""
echo "***"
echo "Setting up nginx.conf"
echo "***"
echo ""

isElectrs=$(sudo cat /etc/nginx/nginx.conf 2>/dev/null | grep -c 'upstream electrs')
if [ ${isElectrs} -gt 0 ]; then
        echo "electrs is already configured with Nginx. To edit manually run \`sudo nano /etc/nginx/nginx.conf\`"

elif [ ${isElectrs} -eq 0 ]; then

        isStream=$(sudo cat /etc/nginx/nginx.conf 2>/dev/null | grep -c 'stream {')
        if [ ${isStream} -eq 0 ]; then

        echo "
stream {
        upstream electrs {
                server 127.0.0.1:50001;
        }
        server {
                listen 50002 ssl;
                proxy_pass electrs;
                ssl_certificate /etc/ssl/certs/localhost.crt;
                ssl_certificate_key /etc/ssl/private/localhost.key;
                ssl_session_cache shared:SSL-electrs:1m;
                ssl_session_timeout 4h;
                ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
                ssl_prefer_server_ciphers on;
        }
}" | sudo tee -a /etc/nginx/nginx.conf

        elif [ ${isStream} -eq 1 ]; then
                sudo truncate -s-2 /etc/nginx/nginx.conf
                echo "

        upstream electrs {
                server 127.0.0.1:50001;
        }
        server {
                listen 50002 ssl;
                proxy_pass electrs;
                ssl_certificate /etc/ssl/certs/localhost.crt;
                ssl_certificate_key /etc/ssl/private/localhost.key;
                ssl_session_cache shared:SSL-electrs:1m;
                ssl_session_timeout 4h;
                ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
                ssl_prefer_server_ciphers on;
        }
}" | sudo tee -a /etc/nginx/nginx.conf

        elif [ ${isStream} -gt 1 ]; then

                echo " Too many \`stream\` commands in nginx.conf. Please edit manually: \`sudo nano /etc/nginx/nginx.conf\` and retry"
                exit 1
        fi
fi

echo "allow port 50002 on ufw"
sudo ufw allow 50002

sudo systemctl enable nginx
sudo systemctl restart nginx

echo ""
echo "***"
echo "Installing the systemd service"
echo "***"
echo ""

sudo systemctl stop electrs
sudo systemctl disable electrs
sudo rm /etc/systemd/system/electrs.service

# sudo nano /etc/systemd/system/electrs.service 
echo "
[Unit]
Description=Electrs
After=bitcoind.service

[Service]
WorkingDirectory=/home/electrs/electrs
ExecStart=/home/electrs/electrs/target/release/electrs --index-batch-size=10 --electrum-rpc-addr=\"0.0.0.0:50001\"
User=electrs
Group=electrs
Type=simple
KillMode=process
TimeoutSec=60
Restart=always
RestartSec=60

[Install]
WantedBy=multi-user.target
" | sudo tee -a /etc/systemd/system/electrs.service 

# Hidden Service for electrs if Tor active

source /mnt/hdd/raspiblitz.conf

if [ "${runBehindTor}" = "on" ]; then
    isElectrsTor=$(sudo cat /etc/tor/torrc 2>/dev/null | grep -c 'electrs')
    if [ ${isElectrsTor} -eq 0 ]; then
        echo "
        # Hidden Service for Electrum Server
        HiddenServiceDir /mnt/hdd/tor/electrs
        HiddenServiceVersion 3
        HiddenServicePort 50001 127.0.0.1:50001
        " | sudo tee -a /etc/tor/torrc

        sudo systemctl restart tor
        sudo systemctl restart tor@default
    fi
    TOR_ADDRESS=$(sudo cat /mnt/hdd/tor/electrs/hostname)
    echo ""
    echo "***"
    echo "The hidden service address for electrs is:"
    echo "$TOR_ADDRESS"
    echo "***"
    echo "" 
fi

echo ""
echo "***"
echo "Starting electrs in the background"
echo "***"
echo ""
# sudo -u electrs /home/electrs/.cargo/bin/cargo run --release -- --index-batch-size=10 --electrum-rpc-addr="0.0.0.0:50001"
sudo systemctl enable electrs
sudo systemctl start electrs

echo ""
echo "To connect from outside of the local network make sure the port 50002 is forwarded on the router"
echo "Electrum wallet: start with the options \`electrum --oneserver --server RaspiBlitz_IP:50002:s"
echo ""