pimp

#!/bin/bash

show_help() {
    printf "\
╔═╗╦╔╦╗╔═╗ ══════════════════════════════════════════╗
╠═╝║║║║╠═╝  Plexamp Installation Management Program  ║
╩  ╩╩ ╩╩ ════════════════════════════════════════════╝

Usage: pimp [-h] [-d <path/to/dir>] [-n <node version>]

Optional arguments:
   -h   show this help message and exit
   -d   the directory where Plexamp should reside
   -n   the major version of Node.js required. i.e. 20
"
}

cd $HOME || exit 1
export NVM_DIR="${HOME}/.nvm"
endpoint="https://plexamp.plex.tv/headless/version.json"
response=$(curl -s $endpoint)
latest=$(echo "$response" | jq -r '.latestVersion')
service="${HOME}/.config/systemd/user/plexamp.service"
declare -a node
declare -a log
modified=0

setup_node() {
    # Install the node version manager if not already available.
    # Then proceed to install & load the required version of nodejs.
    if [ ! -d "$NVM_DIR" ]; then
        mkdir "$NVM_DIR"
        curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/master/install.sh | bash
        [ -s "${NVM_DIR}/nvm.sh" ] && \. "${NVM_DIR}/nvm.sh"
        log+=("Node version manager installed for ${USER} under ${NVM_DIR}.")
    fi
    nvm install $reqd_node && log+=("Node version $(nvm version) installed.")
    modified=$((modified+2))
}

which_node() {
    # If the user supplied a node version, it is already in the node array.
    # We now check the node requirements of each included module & append them.
    # Finally, all versions are compared and the highest is returned.
    readarray -d '' modules < <(find "${1}/node_modules" -name package.json)
    for module in "${modules[@]}"; do
        node+=("$(jq -r '.devDependencies."@types\/node"' $module | cut -c 2-3)")
    done
    printf '%s\n' "${node[@]}" | sort -n | tail -1
}

download_latest() {
    # Identify, download & extract the latest Plexamp release.
    # Note this removes any prior install at the same path.
    download=$(echo "$response" | jq -r '.updateUrl')
    curl $download -o plexamp.tar.bz2
    rm -rf "${dir}/plexamp"
    tar xfj plexamp.tar.bz2 -C "${dir}"
    rm plexamp.tar.bz2
    chown -R "${USER}:${USER}" "${dir}/plexamp"
    echo $latest > "${dir}/plexamp/version"
    log+=("Plexamp v${latest} installed under ${dir}.")
    modified=$((modified+1))
}

check_version() {
    # Check what version (if any) is already installed.
    # If we can't derive a current version, assume update required.
    # Plexamp versions may vary in digit length, i.e. 4.1 - 4.11.1
    # Split on period and compare from most to least significant number.
    read -r current < "${dir}/plexamp/version"
    if [ -z $current ]; then download_latest
    else
        # Create arrays from parameter expansion.
        l=(${latest//./ })
        c=(${current//./ })
        for i in "${!l[@]}"; do
            if [[ ${l[i]} -gt ${c[i]} ]]; then
                download_latest; break
            fi
        done
        log+=("Plexamp is at the latest version ($current).")
    fi
}

configure_service() {
# Heredoc creates & configures plexamp service for current user.
mkdir -p "$(dirname ${service})"
cat << EOF > "${service}"
[Unit]
Description=Plexamp
Wants=sound.target
After=sound.target
Wants=network-online.target
After=network-online.target

[Service]
WorkingDirectory=${dir}/plexamp
ExecStart=${NVM_DIR}/versions/node/$(nvm version)/bin/node ${dir}/plexamp/js/index.js
Restart=on-failure
RestartSec=10

[Install]
WantedBy=default.target
EOF
log+=("Plexamp service created for user ${USER}.")
}

quit() {
    # Provide user output on what's happened & whether the service is running.
    printf '%s\n' "${log[@]}"
    if [ -s "${service}" ]; then
        printf '%b\n' "Plexamp may be evoked manually with the following command:" \
        "\e[33m$(cat ${service} | grep ExecStart | cut -d= -f2) \e[0m" \
        "(This may be useful if you need to set up your claim code, i.e. on first use)." \
        "Once claimed, access plexamp at \e[34mhttp://$(hostname).local:32500\e[0m"
        systemctl --user is-active --quiet plexamp
        if [ $? -eq 0 ]; then printf "Happy listening! \U1F60A\U1F3B5\n"
        else printf "Service failed...\U1F622 Check with 'systemctl --user status plexamp'\n"; fi
    fi
    exit 0
}

# Parse any given arguments.
opts=$(getopt -o 'hd:n:' -- "$@")
eval set -- "$opts"
while true; do
    case $1 in
        -h) show_help && exit ;;
        -d) shift; dir=$(realpath "$1") ;;
        -n) shift; node+=("$1") ;;
        --) shift; break ;;
    esac
    shift
done

# Check for missing requirements needed to run this script.
missing=0
[ ! -f /usr/bin/curl ] && missing=$((missing+1))
[ ! -f /usr/bin/jq ] && missing=$((missing+2))
case $missing in
    1) echo "Please install curl before continuing." && exit 1 ;;
    2) echo "Please install jq before continuing." && exit 1 ;;
    3) echo "Please install curl and jq before continuing." && exit 1 ;;
esac

# Set & make default installation directory
[ -z "$dir" ] && dir=$HOME
mkdir -p "$dir" || exit 1

# Check current version if exist, or go straight to download
[ -d "${dir}/plexamp" ] && check_version || download_latest

# Set-up nodejs
reqd_node=$(which_node ${dir}/plexamp)
[ -s "${NVM_DIR}/nvm.sh" ] && \. "${NVM_DIR}/nvm.sh"
inst_node=$(nvm version | cut -c 2-3)
[[ $reqd_node -ne $inst_node ]] && setup_node || log+=("Node requirements met.")

# Configure a systemd service file after updating
[[ $modified -gt 0 ]] && configure_service || log+=("Nothing changed.")

case $modified in
    0)  # Nothing changed
        quit
        ;;
    1)  # Plexamp updated
        systemctl --user restart plexamp
        log+=("Plexamp service restarted.")
        ;;
    2)  # Node updated
        systemctl --user daemon-reload && systemctl --user restart plexamp
        log+=("Units reloaded & Plexamp service restarted.")
        ;;
    3)  # Both Plexamp & Node updated
        systemctl --user daemon-reload && systemctl --user enable --now plexamp.service
        log+=("Units reloaded - Plexamp service enabled & started.")
        ;;
esac

quit