#!/bin/bash

# INFOS
# n (Node version management) utilise la variable PATH pour stocker le path de la version de node à utiliser.
# C'est ainsi qu'il change de version
# ynh_install_nodejs installe la version de nodejs demandée en argument, avec n
# ynh_use_nodejs active une version de nodejs dans le script courant
# 3 variables sont mises à disposition, et 2 sont stockées dans la config de l'app
# - nodejs_path: Le chemin absolu de cette version de node
# Utilisé pour des appels directs à node.
# - nodejs_version: Simplement le numéro de version de nodejs pour cette application
# - nodejs_use_version: Un alias pour charger une version de node dans le shell courant.
# Utilisé pour démarrer un service ou un script qui utilise node ou npm
# Dans ce cas, c'est $PATH qui contient le chemin de la version de node. Il doit être propagé sur les autres shell si nécessaire.

n_install_dir="/opt/node_n"
node_version_path="/opt/node_n/n/versions/node"
# N_PREFIX est le dossier de n, il doit être chargé dans les variables d'environnement pour n.
export N_PREFIX="$n_install_dir"

ynh_install_n () {
	echo "Installation of N - Node.js version management" >&2
	# Build an app.src for n
	mkdir -p "../conf"
	echo "SOURCE_URL=https://github.com/tj/n/archive/v2.1.7.tar.gz
SOURCE_SUM=2ba3c9d4dd3c7e38885b37e02337906a1ee91febe6d5c9159d89a9050f2eea8f" > "../conf/n.src"
	# Download and extract n
	ynh_setup_source "$n_install_dir/git" n
	# Install n
	(cd "$n_install_dir/git"
	PREFIX=$N_PREFIX make install 2>&1)
}

ynh_use_nodejs () {
	nodejs_version=$(ynh_app_setting_get $app nodejs_version)

	load_n_path="[[ :$PATH: == *\":$n_install_dir/bin:\"* ]] || PATH=\"$n_install_dir/bin:$PATH\"; N_PREFIX="$n_install_dir""

	nodejs_use_version="$n_install_dir/bin/n -q $nodejs_version"

	# "Load" a version of node
	eval $load_n_path; $nodejs_use_version

	# Get the absolute path of this version of node
	nodejs_path="$(n bin $nodejs_version)"

	# Make an alias for node use
	ynh_node_exec="eval $load_n_path; n use $nodejs_version"
}

ynh_install_nodejs () {
	# Use n, https://github.com/tj/n to manage the nodejs versions
	nodejs_version="$1"
	local n_install_script="https://git.io/n-install"

	# Create $n_install_dir
	mkdir -p "$n_install_dir"

	# Load n path in PATH
	CLEAR_PATH="$n_install_dir/bin:$PATH"
	# Remove /usr/local/bin in PATH in case of node has already setup.
	PATH=$(echo $CLEAR_PATH | sed 's@/usr/local/bin:@@')

	# Move an existing node binary, to avoid to block n.
	test -x /usr/bin/node && mv /usr/bin/node /usr/bin/node_n
	test -x /usr/bin/npm && mv /usr/bin/npm /usr/bin/npm_n

	# If n is not previously setup, install it
	if ! test n --version > /dev/null 2>&1
	then
		ynh_install_n
	fi

	# Modify the default N_PREFIX in n script
	ynh_replace_string "^N_PREFIX=\${N_PREFIX-.*}$" "N_PREFIX=\${N_PREFIX-$N_PREFIX}" "$n_install_dir/bin/n"

	# Restore /usr/local/bin in PATH
	PATH=$CLEAR_PATH

	# And replace the old node binary.
	test -x /usr/bin/node_n && mv /usr/bin/node_n /usr/bin/node
	test -x /usr/bin/npm_n && mv /usr/bin/npm_n /usr/bin/npm

	# Install the requested version of nodejs
	n $nodejs_version

	# Find the last "real" version for this major version of node.
	real_nodejs_version=$(find $node_version_path/$nodejs_version* -maxdepth 0 | sort --version-sort | tail --lines=1)
	real_nodejs_version=$(basename $real_nodejs_version)

	# Create a symbolic link for this major version. If the file doesn't already exist
	if [ ! -e "$node_version_path/$nodejs_version" ]
	then
		ln --symbolic --force --no-target-directory $node_version_path/$real_nodejs_version $node_version_path/$nodejs_version
	fi

	# Store the ID of this app and the version of node requested for it
	echo "$YNH_APP_ID:$nodejs_version" | tee --append "$n_install_dir/ynh_app_version"

	# Store nodejs_version into the config of this app
	ynh_app_setting_set $app nodejs_version $nodejs_version

	# Build the update script and set the cronjob
	ynh_cron_upgrade_node

	ynh_use_nodejs
}

ynh_remove_nodejs () {
	ynh_use_nodejs

	# Remove the line for this app
	sed --in-place "/$YNH_APP_ID:$nodejs_version/d" "$n_install_dir/ynh_app_version"

	# If none another app uses this version of nodejs, remove it.
	if ! grep --quiet "$nodejs_version" "$n_install_dir/ynh_app_version"
	then
		n rm $nodejs_version
	fi

	# If none another app uses n, remove n
	if [ ! -s "$n_install_dir/ynh_app_version" ]
	then
		ynh_secure_remove "$n_install_dir"
		ynh_secure_remove "/usr/local/n"
		sed --in-place "/N_PREFIX/d" /root/.bashrc
	fi
}

ynh_cron_upgrade_node () {
	# Build the update script
	cat > "$n_install_dir/node_update.sh" << EOF
#!/bin/bash
version_path="$node_version_path"
n_install_dir="$n_install_dir"
# Log the date
date
# List all real installed version of node
all_real_version="\$(find \$version_path/* -maxdepth 0 -type d | sed "s@\$version_path/@@g")"
# Keep only the major version number of each line
all_real_version=\$(echo "\$all_real_version" | sed 's/\..*\$//')
# Remove double entries
all_real_version=\$(echo "\$all_real_version" | sort --unique)
# Read each major version
while read version
do
	echo "Update of the version \$version"
	sudo \$n_install_dir/bin/n \$version
	# Find the last "real" version for this major version of node.
	real_nodejs_version=\$(find \$version_path/\$version* -maxdepth 0 | sort --version-sort | tail --lines=1)
	real_nodejs_version=\$(basename \$real_nodejs_version)
	# Update the symbolic link for this version
	sudo ln --symbolic --force --no-target-directory \$version_path/\$real_nodejs_version \$version_path/\$version
done <<< "\$(echo "\$all_real_version")"
EOF

	chmod +x "$n_install_dir/node_update.sh"

	# Build the cronjob
	cat > "/etc/cron.daily/node_update" << EOF
#!/bin/bash
$n_install_dir/node_update.sh >> $n_install_dir/node_update.log
EOF

	chmod +x "/etc/cron.daily/node_update"
}