#!/usr/bin/env bash
# sentinel-snapshot: Copy room/STATE.md to room/.snapshots/STATE-YYYY-MM-DD.md
# Creates a point-in-time snapshot for drift detection by sentinel-health-check
# Part of Sentinel Intelligence (SENT-07)

set -euo pipefail

ROOM_DIR="${1:-./room}"

if [ ! -d "$ROOM_DIR" ]; then
  echo "ERROR: Room directory not found: $ROOM_DIR" >&2
  exit 1
fi

if [ ! -f "$ROOM_DIR/STATE.md" ]; then
  echo "ERROR: No STATE.md found in $ROOM_DIR" >&2
  exit 1
fi

# Ensure .snapshots/ directory exists
SNAPSHOTS_DIR="$ROOM_DIR/.snapshots"
mkdir -p "$SNAPSHOTS_DIR"

# Generate snapshot filename with today's date
TODAY=$(date -u +"%Y-%m-%d")
SNAPSHOT_FILE="$SNAPSHOTS_DIR/STATE-${TODAY}.md"

# Copy STATE.md to snapshot
cp "$ROOM_DIR/STATE.md" "$SNAPSHOT_FILE"

echo "SNAPSHOT_CREATED:${SNAPSHOT_FILE}"
echo "SNAPSHOT_DATE:${TODAY}"

# Clean up old snapshots (keep last 12 weeks)
SNAPSHOT_COUNT=$(find "$SNAPSHOTS_DIR" -name "STATE-*.md" 2>/dev/null | wc -l | tr -d ' ')
if [ "$SNAPSHOT_COUNT" -gt 12 ]; then
  # Remove oldest snapshots beyond the 12-week window
  find "$SNAPSHOTS_DIR" -name "STATE-*.md" 2>/dev/null | sort | head -n $(( SNAPSHOT_COUNT - 12 )) | while read -r old_snap; do
    rm "$old_snap"
    echo "SNAPSHOT_PRUNED:$(basename "$old_snap")"
  done
fi