#!/bin/bash

n_version=7.0.2
n_install_dir="/opt/node_n"
node_version_path="$n_install_dir/n/versions/node"
# N_PREFIX is the directory of n, it needs to be loaded as a environment variable.
export N_PREFIX="$n_install_dir"

# Install Node version management
#
# [internal]
#
# usage: ynh_install_n
#
# Requires YunoHost version 2.7.12 or higher.
ynh_install_n () {
    ynh_print_info --message="Installation of N - Node.js version management"
    # Build an app.src for n
    echo "SOURCE_URL=https://github.com/tj/n/archive/v${n_version}.tar.gz
SOURCE_SUM=fa80a8685f0fb1b4187fc0a1228b44f0ea2f244e063fe8f443b8913ea595af89" > "$YNH_APP_BASEDIR/conf/n.src"
    # Download and extract n
    ynh_setup_source --dest_dir="$n_install_dir/git" --source_id=n
    # Install n
    (cd "$n_install_dir/git"
    PREFIX=$N_PREFIX make install 2>&1)
}

# Load the version of node for an app, and set variables.
#
# ynh_use_nodejs has to be used in any app scripts before using node for the first time.
# This helper will provide alias and variables to use in your scripts.
#
# To use npm or node, use the alias `ynh_npm` and `ynh_node`
# Those alias will use the correct version installed for the app
# For example: use `ynh_npm install` instead of `npm install`
#
# With `sudo` or `ynh_exec_as`, use instead the fallback variables `$ynh_npm` and `$ynh_node`
# And propagate $PATH to sudo with $ynh_node_load_PATH
# Exemple: `ynh_exec_as $app $ynh_node_load_PATH $ynh_npm install`
#
# $PATH contains the path of the requested version of node.
# However, $PATH is duplicated into $node_PATH to outlast any manipulation of $PATH
# You can use the variable `$ynh_node_load_PATH` to quickly load your node version
#  in $PATH for an usage into a separate script.
# Exemple: $ynh_node_load_PATH $final_path/script_that_use_npm.sh`
#
#
# Finally, to start a nodejs service with the correct version, 2 solutions
#  Either the app is dependent of node or npm, but does not called it directly.
#  In such situation, you need to load PATH
#    `Environment="__NODE_ENV_PATH__"`
#    `ExecStart=__FINALPATH__/my_app`
#     You will replace __NODE_ENV_PATH__ with $ynh_node_load_PATH
#
#  Or node start the app directly, then you don't need to load the PATH variable
#    `ExecStart=__YNH_NODE__ my_app run`
#     You will replace __YNH_NODE__ with $ynh_node
#
#
# 2 other variables are also available
#   - $nodejs_path: The absolute path to node binaries for the chosen version.
#   - $nodejs_version: Just the version number of node for this app. Stored as 'nodejs_version' in settings.yml.
#
# usage: ynh_use_nodejs
#
# Requires YunoHost version 2.7.12 or higher.
ynh_use_nodejs () {
    nodejs_version=$(ynh_app_setting_get --app=$app --key=nodejs_version)

    # Get the absolute path of this version of node
    nodejs_path="$node_version_path/$nodejs_version/bin"

    # Allow alias to be used into bash script
    shopt -s expand_aliases

    # Create an alias for the specific version of node and a variable as fallback
    ynh_node="$nodejs_path/node"
    alias ynh_node="$ynh_node"
    # And npm
    ynh_npm="$nodejs_path/npm"
    alias ynh_npm="$ynh_npm"

    # Load the path of this version of node in $PATH
    if [[ :$PATH: != *":$nodejs_path"* ]]; then
        PATH="$nodejs_path:$PATH"
    fi
    node_PATH="$PATH"
    # Create an alias to easily load the PATH
    ynh_node_load_PATH="PATH=$node_PATH"
}

# Install a specific version of nodejs
#
# ynh_install_nodejs will install the version of node provided as argument by using n.
#
# usage: ynh_install_nodejs --nodejs_version=nodejs_version
# | arg: -n, --nodejs_version=      - Version of node to install. When possible, your should prefer to use major version number (e.g. 8 instead of 8.10.0). The crontab will then handle the update of minor versions when needed.
#
# n (Node version management) uses the PATH variable to store the path of the version of node it is going to use.
# That's how it changes the version
#
# Refer to ynh_use_nodejs for more information about available commands and variables
#
# Requires YunoHost version 2.7.12 or higher.
ynh_install_nodejs () {
    # Use n, https://github.com/tj/n to manage the nodejs versions

    # Declare an array to define the options of this helper.
    local legacy_args=n
    local -A args_array=( [n]=nodejs_version= )
    local nodejs_version
    # Manage arguments with getopts
    ynh_handle_getopts_args "$@"

    # Create $n_install_dir
    mkdir --parents "$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 prior installation
    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 ! $n_install_dir/bin/n --version > /dev/null 2>&1
    then
        ynh_install_n
    elif dpkg --compare-versions "$($n_install_dir/bin/n --version)" lt $n_version
    then
        ynh_install_n
    fi

    # Modify the default N_PREFIX in n script
    ynh_replace_string --match_string="^N_PREFIX=\${N_PREFIX-.*}$" --replace_string="N_PREFIX=\${N_PREFIX-$N_PREFIX}" --target_file="$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
    uname=$(uname --machine)
    if [[ $uname =~ aarch64 || $uname =~ arm64 ]]
    then
        n $nodejs_version --arch=arm64
    else
        n $nodejs_version
    fi

    # 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 "$YNH_APP_INSTANCE_NAME:$nodejs_version" | tee --append "$n_install_dir/ynh_app_version"

    # Store nodejs_version into the config of this app
    ynh_app_setting_set --app=$app --key=nodejs_version --value=$nodejs_version

    # Build the update script and set the cronjob
    ynh_cron_upgrade_node

    ynh_use_nodejs
}

# Remove the version of node used by the app.
#
# This helper will check if another app uses the same version of node,
# if not, this version of node will be removed.
# If no other app uses node, n will be also removed.
#
# usage: ynh_remove_nodejs
#
# Requires YunoHost version 2.7.12 or higher.
ynh_remove_nodejs () {
    nodejs_version=$(ynh_app_setting_get --app=$app --key=nodejs_version)

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

    # If no other app uses this version of nodejs, remove it.
    if ! grep --quiet "$nodejs_version" "$n_install_dir/ynh_app_version"
    then
        $n_install_dir/bin/n rm $nodejs_version
    fi

    # If no other app uses n, remove n
    if [ ! -s "$n_install_dir/ynh_app_version" ]
    then
        ynh_secure_remove --file="$n_install_dir"
        ynh_secure_remove --file="/usr/local/n"
        sed --in-place "/N_PREFIX/d" /root/.bashrc
        rm --force /etc/cron.daily/node_update
    fi
}

# Set a cron design to update your node versions
#
# [internal]
#
# This cron will check and update all minor node versions used by your apps.
#
# usage: ynh_cron_upgrade_node
#
# Requires YunoHost version 2.7.12 or higher.
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"
}