#!/bin/bash

INSTALL_DIR="${PWD}"

# Check system requirements: Git, Node & NPM
EXC_GIT="$(/usr/bin/which git)"
if [ -z "$EXC_GIT" ]; then
  echo "[ERROR] Missing required system dependency 'git'." >&2
  echo "Please install using \"apt install git\"" >&2
  exit 1
fi

EXC_NPM="$(/usr/bin/which npm)"
if [ -z "$EXC_NPM" ]; then
  echo "[ERROR] Missing required system dependency 'npm'." >&2
  echo "Please install following the official install documentation." >&2
  exit 1
fi

EXC_NODE="$(/usr/bin/which node)"
if [ -z "$EXC_NODE" ]; then
  echo "[ERROR] Missing required system dependency 'node'." >&2
  echo "Please install following the official install documentation." >&2
  exit 1
fi

# exit on error exit codes
set -e

# Ensure SSH-Agent is started and id_rsa loaded, 
# git and npm will do a lot of stuff via ssh and 
# ask for id passphrase multiple times if there's
# no agent
echo "[INSTALL] Starting SSH agent"
eval $(ssh-agent)
ssh-add ~/.ssh/id_rsa

TMPFOLDER="/tmp/hbbq/monitoring/$(date +'%Y%m%d%H%M%S')"

echo "[INSTALL] Cloning entire project into temp folder $TMPFOLDER"
mkdir -p "$TMPFOLDER"
git clone ssh://git@gogs.hostbbq.com:8301/hostbbq/hostbbq-monitoring.git "$TMPFOLDER"

cd "$TMPFOLDER/daemon"

echo "[INSTALL] Installing npm build dependencies for daemon project"
$EXC_NPM install

echo "[INSTALL] Transpiling typescript sources of daemon project"
$EXC_NPM run build

echo "[INSTALL] Installing daemon service application"
cp -rv "dist" "$INSTALL_DIR/"
cp -v ".env.default" "$INSTALL_DIR/.env"
cp -v "cpu.sh" "$INSTALL_DIR/"
cp -v "hdd.sh" "$INSTALL_DIR/"
cp -v "ram.sh" "$INSTALL_DIR/"
cp -v "package.json" "$INSTALL_DIR/"

cd "$INSTALL_DIR"

echo "[INSTALL] Installing npm runtime dependencies"
$EXC_NPM install --omit=dev

echo "[INSTALL] Creating and enabling systemd unit \"monitoring@daemon.service\""
SVC_FILE="/etc/systemd/system/monitoring@daemon.service"

ACTION="update"
if [ ! -f "$SVC_FILE" ]; then
  ACTION="install"
fi

sudo cat > $SVC_FILE << EOF
[Unit]
Description=HostBBQ Monitoring Daemon Service
After=network.target

[Service]
Type=simple
WorkingDirectory="$INSTALL_DIR"
ExecStart=node .
ExecStop=/bin/kill -TERM \$MAINPID

[Install]
WantedBy=multi-user.target
Alias=monitoring@daemon.service
EOF

if [[ "$ACTION" = "install" ]]; then
  sudo systemctl enable monitoring@daemon.service
else
  sudo systemctl restart monitoring@daemon.service
fi

echo "[CLEANUP] Removing temp folder $TMPFOLDER"
rm -rf "$TMPFOLDER"

echo "[SUCCESS] HostBBQ Monitoring Daemon installed and activated successfully"