#!/bin/bash

readonly N_INSTALL_DIR="/opt/node_n"
# N_PREFIX is the directory of n, it needs to be loaded as a environment variable.
export N_PREFIX="$N_INSTALL_DIR"

# [internal]
_ynh_load_nodejs_in_path_and_other_tweaks() {

    # Get the absolute path of this version of node
    nodejs_dir="$N_INSTALL_DIR/n/versions/node/$nodejs_version/bin"

    # Load the path of this version of node in $PATH
    if [[ :$PATH: != *":$nodejs_dir"* ]]; then
        PATH="$nodejs_dir:$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 `$nodejs_version` which should be defined as global prior to calling this helper
#
# usage: ynh_nodejs_install
#
# `n` (Node version management) uses the `PATH` variable to store the path of the version of node it is going to use.
# That's how it changes the version
#
# The helper adds the appropriate, specific version of nodejs to the `$PATH` variable (which
# is preserved when calling ynh_exec_as_app). Also defines:
# - `$path_with_nodejs` to be used in the systemd config (`Environment="PATH=__PATH_WITH_NODEJS__"`)
# - `$nodejs_dir`, the directory containing the specific version of nodejs, which may be used in the systemd config too (e.g. `ExecStart=__NODEJS_DIR__/node foo bar`)
ynh_nodejs_install() {
    # Use n, https://github.com/tj/n to manage the nodejs versions

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

    # 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 $N_INSTALL_DIR/n/versions/node/$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 "$N_INSTALL_DIR/n/versions/node/$nodejs_version" ]; then
        ln --symbolic --force --no-target-directory \
            $N_INSTALL_DIR/n/versions/node/$real_nodejs_version \
            $N_INSTALL_DIR/n/versions/node/$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

    _ynh_load_nodejs_in_path_and_other_tweaks
}

# Remove the version of node used by the app.
#
# usage: ynh_nodejs_remove
#
# 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.
ynh_nodejs_remove() {

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

    # 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"
        sed --in-place "/N_PREFIX/d" /root/.bashrc
    fi
}