#!/usr/bin/env bash
#
# install-synology-prompt.sh
#
# Universal installer for Synology SysAdmin Prompt.
#
# -------------------------------------------------------------------------------
# USAGE
# -------------------------------------------------------------------------------
#
# Recommended:
#
#   bash install-synology-prompt.sh
#
# Do NOT normally run this installer using:
#
#   sudo bash install-synology-prompt.sh
#
# The script will request sudo privileges itself when required.
#
#
# What this installer does:
#
#   1. Verifies that the machine looks like Synology DSM.
#   2. Verifies that Bash is available.
#   3. Downloads synology-prompt.sh.
#   4. Installs it as:
#
#        /etc/synology-prompt.sh
#
#      with:
#
#        owner: root
#        group: root
#        mode : 0644
#
#   5. Adds a small loader to the current user's ~/.profile.
#   6. Preserves existing user configuration.
#   7. Adds root integration to /root/.profile.
#   8. Preserves Synology's original root profile.
#   9. Makes "sudo -i" use Bash + the same prompt.
#
#
# Requirements:
#
#   - Synology DSM
#   - Bash
#   - sudo access
#   - wget or curl
#
#
# Nerd Font:
#
#   Nerd Font is NOT installed on Synology.
#   Install/use a Nerd Font in your SSH client or terminal.
#
# -------------------------------------------------------------------------------


set -u


# ==============================================================================
# CONFIGURATION
# ==============================================================================

PROMPT_URL="https://gist.darto.id/dartokloning/d0bd9f4e277a4242acbc7fb153c9a440/download/HEAD/synology-prompt.sh"

PROMPT_FILE="/etc/synology-prompt.sh"

USER_MARKER_BEGIN="# >>> Synology SysAdmin Prompt >>>"
USER_MARKER_END="# <<< Synology SysAdmin Prompt <<<"

ROOT_MARKER_BEGIN="# >>> Synology SysAdmin Prompt - Root >>>"
ROOT_MARKER_END="# <<< Synology SysAdmin Prompt - Root <<<"


# ==============================================================================
# OUTPUT HELPERS
# ==============================================================================

info()
{
    printf '\n== %s ==\n' "$1"
}


ok()
{
    printf '  -> %s\n' "$1"
}


warn()
{
    printf 'WARNING: %s\n' "$1" >&2
}


die()
{
    printf 'ERROR: %s\n' "$1" >&2
    exit 1
}


# ==============================================================================
# DETECT CURRENT USER
# ==============================================================================

# The installer is intended to be launched as the normal DSM user.
if [ "$(id -u)" -eq 0 ]; then
    die "Jalankan installer sebagai user DSM biasa, bukan dengan 'sudo bash'. Gunakan: bash install-synology-prompt.sh"
fi

CURRENT_USER="$(id -un)"
CURRENT_HOME="${HOME:-}"

[ -n "$CURRENT_HOME" ] ||
    die "HOME untuk user ${CURRENT_USER} tidak ditemukan."

[ -d "$CURRENT_HOME" ] ||
    die "Home directory tidak ditemukan: ${CURRENT_HOME}"


# ==============================================================================
# VERIFY SYNOLOGY DSM
# ==============================================================================

info "1. Memeriksa Synology DSM"

if [ ! -f /etc.defaults/VERSION ]; then
    die "File /etc.defaults/VERSION tidak ditemukan. Mesin ini tidak terlihat seperti Synology DSM."
fi

DSM_VERSION="$(
    sed -n 's/^productversion="\([^"]*\)".*/\1/p' \
        /etc.defaults/VERSION 2>/dev/null |
    head -n 1
)"

DSM_BUILD="$(
    sed -n 's/^buildnumber="\([^"]*\)".*/\1/p' \
        /etc.defaults/VERSION 2>/dev/null |
    head -n 1
)"

ok "Synology DSM terdeteksi."

if [ -n "$DSM_VERSION" ]; then
    ok "DSM version: ${DSM_VERSION}"
fi

if [ -n "$DSM_BUILD" ]; then
    ok "DSM build: ${DSM_BUILD}"
fi

ok "User: ${CURRENT_USER}"
ok "Home: ${CURRENT_HOME}"


# ==============================================================================
# VERIFY BASH
# ==============================================================================

info "2. Memeriksa Bash"

command -v bash >/dev/null 2>&1 ||
    die "Bash tidak ditemukan."

BASH_PATH="$(command -v bash)"

ok "Bash ditemukan: ${BASH_PATH}"

BASH_VERSION_TEXT="$(
    bash --version 2>/dev/null |
    head -n 1
)"

[ -n "$BASH_VERSION_TEXT" ] &&
    ok "$BASH_VERSION_TEXT"


# ==============================================================================
# VERIFY SUDO
# ==============================================================================

info "3. Memeriksa sudo"

command -v sudo >/dev/null 2>&1 ||
    die "sudo tidak ditemukan."

printf '  -> Meminta privilege sudo...\n'

sudo -v ||
    die "Tidak mendapatkan privilege sudo."

ok "sudo siap digunakan."


# ==============================================================================
# VERIFY DOWNLOAD TOOL
# ==============================================================================

info "4. Memeriksa downloader"

if command -v wget >/dev/null 2>&1; then

    DOWNLOAD_TOOL="wget"
    ok "Menggunakan wget."

elif command -v curl >/dev/null 2>&1; then

    DOWNLOAD_TOOL="curl"
    ok "Menggunakan curl."

else

    die "wget maupun curl tidak ditemukan."
fi


# ==============================================================================
# VERIFY URL
# ==============================================================================

if [ "$PROMPT_URL" = "PASTE_RAW_GIST_URL_HERE" ] ||
   [ -z "$PROMPT_URL" ]; then

    die "PROMPT_URL belum diisi. Edit installer dan isi URL raw/download synology-prompt.sh dari Gist."
fi


# ==============================================================================
# TEMPORARY DIRECTORY
# ==============================================================================

TMP_DIR="$(mktemp -d)" ||
    die "Tidak dapat membuat temporary directory."

TMP_PROMPT="${TMP_DIR}/synology-prompt.sh"

cleanup()
{
    rm -rf "$TMP_DIR"
}

trap cleanup EXIT


# ==============================================================================
# DOWNLOAD PROMPT
# ==============================================================================

info "5. Download synology-prompt.sh"

if [ "$DOWNLOAD_TOOL" = "wget" ]; then

    wget -q -O "$TMP_PROMPT" "$PROMPT_URL" ||
        die "Gagal download: ${PROMPT_URL}"

else

    curl -fsSL "$PROMPT_URL" -o "$TMP_PROMPT" ||
        die "Gagal download: ${PROMPT_URL}"
fi


[ -s "$TMP_PROMPT" ] ||
    die "File hasil download kosong."


# Basic sanity check.
if ! grep -q 'Synology DSM SysAdmin Prompt\|Universal Powerline-style SysAdmin prompt' "$TMP_PROMPT"; then

    warn "File berhasil didownload tetapi signature prompt tidak ditemukan."
    warn "Periksa PROMPT_URL sebelum melanjutkan."

    exit 1
fi

ok "Prompt berhasil didownload."


# ==============================================================================
# INSTALL SYSTEM-WIDE PROMPT
# ==============================================================================

info "6. Install system-wide prompt"

sudo cp "$TMP_PROMPT" "$PROMPT_FILE" ||
    die "Gagal menyalin prompt ke ${PROMPT_FILE}."

sudo chown root:root "$PROMPT_FILE" ||
    die "Gagal mengatur ownership ${PROMPT_FILE}."

sudo chmod 0644 "$PROMPT_FILE" ||
    die "Gagal mengatur permission ${PROMPT_FILE}."

ok "Installed: ${PROMPT_FILE}"
ok "Owner: root:root"
ok "Mode: 0644"


# ==============================================================================
# USER PROFILE
# ==============================================================================

info "7. Konfigurasi user ${CURRENT_USER}"

USER_PROFILE="${CURRENT_HOME}/.profile"

# Create profile if it does not exist.
if [ ! -e "$USER_PROFILE" ]; then

    touch "$USER_PROFILE" ||
        die "Tidak dapat membuat ${USER_PROFILE}."

    ok "Membuat ${USER_PROFILE}."
fi


# Backup only once.
USER_BACKUP="${USER_PROFILE}.before-synology-prompt"

if [ ! -e "$USER_BACKUP" ]; then

    cp -a "$USER_PROFILE" "$USER_BACKUP" ||
        die "Gagal membuat backup ${USER_BACKUP}."

    ok "Backup dibuat: ${USER_BACKUP}"

else

    ok "Backup user profile sudah ada, tidak ditimpa."
fi


# Remove an existing managed block, making installation idempotent.
USER_TMP="${TMP_DIR}/user-profile"

awk \
    -v begin="$USER_MARKER_BEGIN" \
    -v end="$USER_MARKER_END" '
        $0 == begin { skip=1; next }
        $0 == end   { skip=0; next }
        !skip       { print }
    ' "$USER_PROFILE" > "$USER_TMP" ||
    die "Gagal memproses ${USER_PROFILE}."


cat >> "$USER_TMP" <<'EOF'

# >>> Synology SysAdmin Prompt >>>
#
# Start Bash for interactive sessions and load the system-wide prompt.
#
case "$-" in
    *i*)
        if [ -z "${SYNO_USER_PROMPT:-}" ]; then
            export SYNO_USER_PROMPT=1
            exec bash --noprofile --rcfile /etc/synology-prompt.sh -i
        fi
        ;;
esac
# <<< Synology SysAdmin Prompt <<<
EOF


cp "$USER_TMP" "$USER_PROFILE" ||
    die "Gagal memperbarui ${USER_PROFILE}."

ok "User profile dikonfigurasi."


# ==============================================================================
# ROOT PROFILE
# ==============================================================================

info "8. Konfigurasi root"

ROOT_PROFILE="/root/.profile"
ROOT_BACKUP="/root/.profile.before-synology-prompt"

# DSM normally has /root/.profile, but create it safely if absent.
if ! sudo test -e "$ROOT_PROFILE"; then

    sudo touch "$ROOT_PROFILE" ||
        die "Gagal membuat ${ROOT_PROFILE}."

    sudo chown root:root "$ROOT_PROFILE"
    sudo chmod 0600 "$ROOT_PROFILE"

    ok "Membuat ${ROOT_PROFILE}."
fi


# Backup only once.
if ! sudo test -e "$ROOT_BACKUP"; then

    sudo cp -a "$ROOT_PROFILE" "$ROOT_BACKUP" ||
        die "Gagal membuat backup ${ROOT_BACKUP}."

    ok "Backup dibuat: ${ROOT_BACKUP}"

else

    ok "Backup root profile sudah ada, tidak ditimpa."
fi


ROOT_TMP="${TMP_DIR}/root-profile"

sudo cat "$ROOT_PROFILE" |
awk \
    -v begin="$ROOT_MARKER_BEGIN" \
    -v end="$ROOT_MARKER_END" '
        $0 == begin { skip=1; next }
        $0 == end   { skip=0; next }
        !skip       { print }
    ' > "$ROOT_TMP" ||
    die "Gagal memproses ${ROOT_PROFILE}."


cat >> "$ROOT_TMP" <<'EOF'

# >>> Synology SysAdmin Prompt - Root >>>
#
# Preserve Synology's original root initialization above.
# For interactive root login (for example: sudo -i),
# replace ash with Bash and load the system-wide prompt.
#
case "$-" in
    *i*)
        if [ -z "${SYNO_ROOT_PROMPT:-}" ]; then
            export SYNO_ROOT_PROMPT=1
            cd /root 2>/dev/null || true
            exec bash --noprofile --rcfile /etc/synology-prompt.sh -i
        fi
        ;;
esac
# <<< Synology SysAdmin Prompt - Root <<<
EOF


sudo cp "$ROOT_TMP" "$ROOT_PROFILE" ||
    die "Gagal memperbarui ${ROOT_PROFILE}."

sudo chown root:root "$ROOT_PROFILE"

ok "Root profile dikonfigurasi."


# ==============================================================================
# VERIFY
# ==============================================================================

info "9. Verifikasi"

if sudo test -r "$PROMPT_FILE"; then
    ok "${PROMPT_FILE} readable."
else
    die "${PROMPT_FILE} tidak dapat dibaca."
fi


if grep -Fq "$USER_MARKER_BEGIN" "$USER_PROFILE"; then
    ok "User loader ditemukan."
else
    die "User loader tidak ditemukan."
fi


if sudo grep -Fq "$ROOT_MARKER_BEGIN" "$ROOT_PROFILE"; then
    ok "Root loader ditemukan."
else
    die "Root loader tidak ditemukan."
fi


# ==============================================================================
# DONE
# ==============================================================================

printf '\n'
printf '====================================================================\n'
printf ' Synology SysAdmin Prompt berhasil di-install\n'
printf '====================================================================\n'
printf '\n'

printf 'Prompt file:\n'
printf '  %s\n' "$PROMPT_FILE"

printf '\nUser:\n'
printf '  %s\n' "$CURRENT_USER"

printf '\nCara menggunakan:\n'
printf '\n'
printf '  1. Logout dari SSH lalu login kembali.\n'
printf '\n'
printf '     ATAU untuk test tanpa logout:\n'
printf '\n'
printf '       exec bash --noprofile --rcfile %s -i\n' "$PROMPT_FILE"
printf '\n'
printf '  2. Untuk masuk ke root:\n'
printf '\n'
printf '       sudo -i\n'
printf '\n'
printf '     Root otomatis menggunakan warning palette merah/kuning.\n'
printf '\n'
printf '  3. Jika icon Powerline/Nerd Font tidak tampil dengan benar,\n'
printf '     gunakan Nerd Font pada terminal CLIENT, bukan pada Synology.\n'
printf '\n'
printf 'Contoh prompt user:\n'
printf '\n'
printf '  ╭  user   NAS   ~   52%%   Selasa, 29 September 2026   14:00:00 \n'
printf '  ╰> $\n'
printf '\n'
printf 'Contoh root:\n'
printf '\n'
printf '  sudo -i\n'
printf '\n'
printf '  ╭  root   NAS   ~   24%%  ...\n'
printf '  ╰> #\n'
printf '\n'
printf 'Backup:\n'
printf '  User : %s\n' "$USER_BACKUP"
printf '  Root : %s\n' "$ROOT_BACKUP"
printf '\n'
printf 'Selesai.\n'