#!/bin/bash

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"

_ynh_load_nodejs_in_path_and_other_tweaks() {

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

    # Load the path of this version of node in $PATH
    if [[ :$PATH: != *":$nodejs_path"* ]]; then
        PATH="$nodejs_path:$PATH"
    fi

    # Export PATH such that it's available through sudo -E / ynh_exec_as $app
    export PATH

    # This is in full lowercase such that it gets replaced in templates
    path_with_nodejs="$PATH"
    PATH_with_nodejs="$PATH"

    # Prevent yet another Node and Corepack madness, with Corepack wanting the user to confirm download of Yarn
    export COREPACK_ENABLE_DOWNLOAD_PROMPT=0
}

# Install a specific version of nodejs, using 'n'
#
# The installed version is defined by $nodejs_version which should be defined as global prior to calling this helper
#
# usage: ynh_install_nodejs
#
# `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
#
# Adds the appropriate, specific version of nodejs to the PATH variable (which
# is also exported, to ease the use of ynh_exec_as_app). Also define variable
# PATH_with_nodejs to be used in the systemd config
# (Environment="PATH=__PATH_WITH_NODEJS__")
#
# Requires YunoHost version 2.7.12 or higher.
ynh_install_nodejs() {
    # Use n, https://github.com/tj/n to manage the nodejs versions

    [[ -n "${nodejs_version:-}" ]] || ynh_die --message="\$nodejs_version should be defined prior to calling ynh_install_nodejs"

    # 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

    # Install (or update if YunoHost vendor/ folder updated since last install) n
    mkdir -p $n_install_dir/bin/
    cp "$YNH_HELPERS_DIR/vendor/n/n" $n_install_dir/bin/n
    # Tweak for n to understand it's installed in $N_PREFIX
    ynh_replace --match="^N_PREFIX=\${N_PREFIX-.*}$" --replace="N_PREFIX=\${N_PREFIX-$N_PREFIX}" --file="$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 --key=nodejs_version --value=$nodejs_version

    # Build the update script and set the cronjob
    ynh_cron_upgrade_node

    _ynh_load_nodejs_in_path_and_other_tweaks
}

# Remove the version of node used by the app.
#
# usage: ynh_remove_nodejs
#
# 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.
#
# Requires YunoHost version 2.7.12 or higher.
ynh_remove_nodejs() {

    [[ -n "${nodejs_version:-}" ]] || ynh_die --message="\$nodejs_version should be defined prior to calling ynh_install_nodejs"

    # 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 "$n_install_dir/ynh_app_version" ]; then
        ynh_safe_rm "$n_install_dir"
        ynh_safe_rm "/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"
}