#!/usr/bin/env bash
# Fenris — interactive menu for the NVMe wear monitor & dashboard.
# Created by Bongbetic.

set -euo pipefail
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PY="$SCRIPT_DIR/fenris.py"
PORT_DEFAULT=8420
INTERVAL_DEFAULT=300

banner() {
  cat <<'EOF'
 _____           _
|   __|___ ___ _| |___
|   __| -_|   | . |  _|
|__|  |___|_|_|_|___|_|

 NVMe wear monitor & live dashboard
 Created by Bongbetic
EOF
}

pause() { read -rp "Press Enter to continue..." _; }

detect_device() {
  # Query Python's auto-detect for the default device.
  python3 -c "import sys; sys.path.insert(0,'$SCRIPT_DIR'); from fenris import detect_device; print(detect_device())" 2>/dev/null || echo /dev/nvme0
}

menu() {
  clear
  banner
  echo
  echo "  1) Start monitoring (background daemon + dashboard)"
  echo "  2) Stop monitoring"
  echo "  3) Status / current wear stats"
  echo "  4) Take one sample right now"
  echo "  5) Open dashboard URL"
  echo "  ---"
  echo "  h) Help / how this works"
  echo "  q) Exit"
  echo
  read -rp "Choose an option: " choice
  echo
  case "$choice" in
    1) start_flow ;;
    2) python3 "$PY" stop; pause ;;
    3) python3 "$PY" status; pause ;;
    4) read -rp "Device [default: auto-detect]: " dev
       if [ -z "$dev" ]; then python3 "$PY" sample; else python3 "$PY" sample --device "$dev"; fi
       pause ;;
    5) show_url; pause ;;
    h|H) help_text; pause ;;
    q|Q) echo "Bye. — Fenris, by Bongbetic"; exit 0 ;;
    *) echo "Invalid choice."; pause ;;
  esac
}

start_flow() {
  read -rp "NVMe device [Enter = auto-detect]: " dev
  read -rp "Sample interval in seconds [Enter = ${INTERVAL_DEFAULT}]: " interval
  read -rp "Dashboard port [Enter = ${PORT_DEFAULT}]: " port
  interval="${interval:-$INTERVAL_DEFAULT}"
  port="${port:-$PORT_DEFAULT}"

  args=(start --interval "$interval" --port "$port")
  if [ -n "${dev:-}" ]; then args+=(--device "$dev"); fi

  echo
  echo "Note: reading NVMe SMART data needs root."
  echo "Fenris runs 'sudo -n smartctl ...' (no-prompt sudo). If this fails,"
  echo "either run this menu with sudo, or allow passwordless smartctl via:"
  echo "  sudo visudo   ->   youruser ALL=(root) NOPASSWD: /usr/sbin/smartctl"
  echo

  python3 "$PY" "${args[@]}"
  pause
}

show_url() {
  if [ -f "$SCRIPT_DIR/data/fenris.pid" ]; then
    # Try to read actual port from running process cmdline, else guess default.
    local pid port
    pid=$(<"$SCRIPT_DIR/data/fenris.pid")
    port=$(tr '\0' '\n' < /proc/"$pid"/cmdline 2>/dev/null | grep -A1 -- '--port' | tail -1 || true)
    port="${port:-$PORT_DEFAULT}"
    echo "Dashboard: http://localhost:${port}"
  else
    echo "Fenris is not currently running. Start it first (option 1)."
  fi
}

help_text() {
  cat <<EOF
What Fenris does:
  - Periodically reads your NVMe drive's SMART health data (via smartctl),
    including "percentage_used" (the drive's own wear indicator), total
    bytes written/read, temperature, spare capacity, and error counts.
  - Logs every sample to: $SCRIPT_DIR/data/history.jsonl
    and per-hour aggregates to: $SCRIPT_DIR/data/hourly.jsonl (GB/hour,
    rebuilt from history on restart). Used for the trailing-24h bar chart
    and exact rolling-24h write volume.
  - Serves a live HTML dashboard (dense layout, interval-synced polling)
    with wear-over-time and trailing-24h hourly-write charts, plus a
    projected life-remaining estimate in hours/days/years derived from
    your actual rolling-24h write rate and implied TBW endurance.

Requirements:
  - smartmontools (smartctl) installed.
  - Root access to read NVMe SMART logs — either run Fenris via sudo,
    or set up passwordless sudo for smartctl (see option 1).

CLI usage (equivalent to this menu):
  python3 fenris.py start    [--device /dev/nvme0] [--interval 300] [--port 8420]
  python3 fenris.py stop
  python3 fenris.py status
  python3 fenris.py sample   [--device /dev/nvme0]

Leave it running in the background (option 1) and check back after a
few days/weeks of normal use — more samples = a more accurate lifespan
estimate.

Fenris — created by Bongbetic.
EOF
}

# Loop instead of recurse to avoid stack overflow.
while true; do menu; done