#!/bin/bash
# Sync (copy) this project to another location, excluding git-ignored files,
# the .git directory, and local-only cruft.
#
# Respects every .gitignore in the tree (root and nested, e.g. ui/.gitignore)
# via rsync's per-directory merge filter, so node_modules/, build output,
# output/ runs, samples/, local-run.sh, etc. are never copied. Tracked files
# (including the .gitignore files themselves) are copied so the destination is
# a clean, working copy of the project.
#
# Usage:
#   ctrl/sync.sh [-n] [-d] <destination>
#
#   <destination>   local path or rsync target
#                   (e.g. ../meetus-copy, /mnt/backup/meetus, host:~/meetus)
#   -n              dry run — list what would change, copy nothing
#   -d              mirror mode — also delete files in <destination> that are
#                   not in the source (destructive; off by default)
#
# Examples:
#   ctrl/sync.sh ../meetus-copy
#   ctrl/sync.sh -n /mnt/backup/meetus       # preview
#   ctrl/sync.sh -d server:~/projects/meetus # exact mirror
set -euo pipefail

PROJECT_DIR="$(cd "$(dirname "$0")/.." && pwd)"

usage() {
  # Print the header comment block (skip shebang, stop at first code line).
  awk 'NR==1{next} /^#/{sub(/^# ?/,""); print; next} {exit}' "$0"
}

DRY_RUN=""
DELETE=""
DEST=""

while [ $# -gt 0 ]; do
  case "$1" in
    -n) DRY_RUN="--dry-run" ;;
    -d) DELETE="--delete" ;;
    -h|--help) usage; exit 0 ;;
    --) shift; break ;;
    -*) echo "Unknown option: $1" >&2; usage >&2; exit 1 ;;
    *)  if [ -z "$DEST" ]; then DEST="$1"; else echo "Unexpected argument: $1" >&2; exit 1; fi ;;
  esac
  shift
done

# Any trailing args after -- are the destination too (support one).
if [ -z "$DEST" ] && [ $# -gt 0 ]; then DEST="$1"; fi

if [ -z "$DEST" ]; then
  echo "Error: destination required." >&2
  echo "Usage: ctrl/sync.sh [-n] [-d] <destination>" >&2
  exit 1
fi

echo "Syncing project -> $DEST"
[ -n "$DRY_RUN" ] && echo "  (dry run: no changes will be made)"
[ -n "$DELETE" ]  && echo "  (mirror mode: extraneous files in destination will be DELETED)"

# --filter ':- .gitignore'  reads a .gitignore in every directory rsync visits
#                           and applies its ignore patterns to that subtree.
rsync -ah --info=stats1 $DRY_RUN $DELETE \
    --exclude='.git/' \
    --exclude='.DS_Store' \
    --filter=':- .gitignore' \
    "$PROJECT_DIR"/ "$DEST"/

echo "Sync complete."