#!/usr/bin/env bash
set -euo pipefail

# sync-nextcloud-ecosystem-conf.sh
#
# Pull/push a fixed set of server files under /data to a local git-tracked tree,
# preserving folder structure but stripping the leading "/data".
#
# Requires: rsync, ssh
#
# Examples:
#   ./sync-nextcloud-ecosystem-conf.sh pull
#   ./sync-nextcloud-ecosystem-conf.sh push --dry-run
#   ./sync-nextcloud-ecosystem-conf.sh pull --host henrov@nextcloud.data-pro.nu --port 22
#
# Notes:
# - Uses remote sudo via: --rsync-path="sudo rsync"
# - Allocates a TTY for sudo prompting with ssh -tt
# - Transfers ONLY the listed files (push and pull)

DEFAULT_HOST="henrov@nextcloud.data-pro.nu"
DEFAULT_PORT="22"
DEFAULT_REMOTE_BASE="/data"
DEFAULT_LOCAL_ROOT="$HOME/Repos/nextcloud_ecosystem/conf"

usage() {
  cat <<'USAGE'
Usage:
  sync-nextcloud-ecosystem-conf.sh <pull|push> [--host USER@HOST] [--port N] [--local-root PATH] [--dry-run]

Options:
  --host USER@HOST     SSH target (default: henrov@nextcloud.data-pro.nu)
  --port N             SSH port (default: 22)
  --local-root PATH    Local destination root (default: ~/Repos/nextcloud_ecosystem/conf)
  --dry-run            Show what would change without writing (rsync -n + itemize)
  -h, --help           Show this help

Behavior:
  pull: server:/data/<paths> -> local-root/<paths>
  push: local-root/<paths>   -> server:/data/<paths>

Always overwrites destination files (as rsync updates them). Preserves timestamps.

USAGE
}

MODE="${1:-}"
shift || true

HOST="$DEFAULT_HOST"
PORT="$DEFAULT_PORT"
REMOTE_BASE="$DEFAULT_REMOTE_BASE"
LOCAL_ROOT="$DEFAULT_LOCAL_ROOT"
DRY_RUN=0

while [[ $# -gt 0 ]]; do
  case "$1" in
    --host) HOST="${2:?missing value for --host}"; shift 2 ;;
    --port) PORT="${2:?missing value for --port}"; shift 2 ;;
    --local-root) LOCAL_ROOT="${2:?missing value for --local-root}"; shift 2 ;;
    --dry-run) DRY_RUN=1; shift ;;
    -h|--help) usage; exit 0 ;;
    *) echo "Unknown argument: $1" >&2; usage; exit 2 ;;
  esac
done

if [[ "$MODE" != "pull" && "$MODE" != "push" ]]; then
  echo "Error: first argument must be 'pull' or 'push'." >&2
  usage
  exit 2
fi

mkdir -p "$LOCAL_ROOT"

# File list is RELATIVE to /data, so /data is effectively "stripped" on local.
# Only these files are transferred in either direction.
read -r -d '' FILES_FROM <<'EOF' || true
caddy/Caddyfile
nextcloud/config/config.php
nextcloud/php/conf.d/opcache.ini
signaling/config/server.conf
janus/janus.transport.http.jcfg
janus/janus.transport.websockets.jcfg
gitlab/config/gitlab.rb
EOF

tmp_files_from="$(mktemp)"
cleanup() { rm -f "$tmp_files_from"; }
trap cleanup EXIT
printf "%s\n" "$FILES_FROM" > "$tmp_files_from"

# rsync options:
# -a : archive (recursive, preserve perms, etc.)
# -t : preserve times (also included in -a, but explicit for clarity)
# -v : verbose
# --itemize-changes: useful output, especially with --dry-run
# --files-from: copy only specified files
# --relative not needed because paths are already relative to REMOTE_BASE/LOCAL_ROOT
#
# Excludes (mostly relevant if you ever extend this to directories):
# *~ , *.swp / *.sw? , *.tmp
RSYNC_OPTS=(
  -avt
  --itemize-changes
  --files-from="$tmp_files_from"
  --exclude='*~'
  --exclude='*.swp'
  --exclude='*.sw?'
  --exclude='*.tmp'
)

if [[ "$DRY_RUN" -eq 1 ]]; then
  RSYNC_OPTS+=(
    --dry-run
  )
fi

# Use ssh with a TTY so sudo can prompt on the remote end if needed.
SSH_CMD=(ssh -T -p "$PORT")

# Remote sudo for rsync (read/write privileged files)

# Preflight: ensure sudo won't prompt during rsync
if ! ssh -p "$PORT" "$HOST" 'sudo -n true' >/dev/null 2>&1; then
  echo "[warn] Remote sudo needs authentication. Running 'sudo -v' interactively once..."
  ssh -t -p "$PORT" "$HOST" 'sudo -v'
fi

REMOTE_RSYNC_PATH='sudo -n rsync'

REMOTE_SRC="${HOST}:${REMOTE_BASE}/"
REMOTE_DST="${HOST}:${REMOTE_BASE}/"

LOCAL_SRC="${LOCAL_ROOT}/"
LOCAL_DST="${LOCAL_ROOT}/"

echo "[info] mode=$MODE host=$HOST port=$PORT"
echo "[info] remote_base=$REMOTE_BASE"
echo "[info] local_root=$LOCAL_ROOT"
[[ "$DRY_RUN" -eq 1 ]] && echo "[info] dry-run enabled"

if [[ "$MODE" == "pull" ]]; then
  # server -> local
  rsync "${RSYNC_OPTS[@]}" \
    -e "${SSH_CMD[*]}" \
    --rsync-path="$REMOTE_RSYNC_PATH" \
    "$REMOTE_SRC" "$LOCAL_DST"
else
  # local -> server
  rsync "${RSYNC_OPTS[@]}" \
    -e "${SSH_CMD[*]}" \
    --rsync-path="$REMOTE_RSYNC_PATH" \
    "$LOCAL_SRC" "$REMOTE_DST"
fi

echo "[ok] done"