#!/usr/bin/env bash
# Snapshot loadavg + RSS groups inside a podman container (for landing stats).
# Usage: collect_container_resources.sh CONTAINER [OUT.json]
# Prints JSON to stdout (and writes OUT when given).
set -euo pipefail

CTR="${1:-}"
OUT="${2:-}"
if [ -z "$CTR" ]; then
  echo "usage: $0 CONTAINER [OUT.json]" >&2
  exit 2
fi

ADMIN_LOG="${ADMIN_LOG:-${HOME}/src/koopa/koopa-admin-log}"
MEM_SRC="${MEM_SNAPSHOT_SRC:-$ADMIN_LOG/scripts/taler-shared/mem-snapshot.sh}"
MEM_DST="${MEM_SNAPSHOT_DST:-/usr/local/lib/landing-mem-snapshot.sh}"

if ! podman inspect -f '{{.State.Running}}' "$CTR" 2>/dev/null | grep -qx true; then
  echo "{\"ok\":false,\"error\":\"container not running: $CTR\"}" 
  exit 1
fi

if [ -f "$MEM_SRC" ]; then
  podman exec "$CTR" mkdir -p "$(dirname "$MEM_DST")" 2>/dev/null || true
  podman cp "$MEM_SRC" "${CTR}:${MEM_DST}"
fi

# Run emit inside container (needs /proc + cgroup of that container)
set +e
raw=$(podman exec "$CTR" bash -c '
  set -e
  export PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
  if [ ! -f /usr/local/lib/landing-mem-snapshot.sh ]; then
    echo "{\"ok\":false,\"error\":\"mem-snapshot helper missing\"}"
    exit 1
  fi
  # shellcheck disable=SC1091
  . /usr/local/lib/landing-mem-snapshot.sh
  if ! declare -F mem_snapshot_emit >/dev/null 2>&1; then
    # older helper without emit — synthesize
    mem_snapshot_json
    loadavg=""
    [ -r /proc/loadavg ] && loadavg=$(awk "{print \$1\",\"\$2\",\"\$3}" /proc/loadavg)
    printf "{\"ok\":true,\"source\":\"mem-snapshot-legacy\",\"loadavg\":%s,\"memory\":{%s}}\n" \
      "\"$loadavg\"" "$MEM_JSON"
  else
    mem_snapshot_emit
  fi
' 2>/tmp/landing-mem-err.$$)
ec=$?
set -e

if [ "$ec" -ne 0 ] || [ -z "$raw" ]; then
  err=$(tr '\n' ' ' </tmp/landing-mem-err.$$ 2>/dev/null | head -c 200 || true)
  rm -f /tmp/landing-mem-err.$$
  printf '{"ok":false,"error":"podman exec failed: %s"}\n' "${err//\"/\'}"
  exit 1
fi
rm -f /tmp/landing-mem-err.$$

# Validate JSON
if ! printf '%s' "$raw" | python3 -c 'import json,sys; json.load(sys.stdin)' 2>/dev/null; then
  printf '{"ok":false,"error":"invalid json from container"}\n'
  exit 1
fi

if [ -n "$OUT" ]; then
  printf '%s\n' "$raw" >"$OUT"
fi
printf '%s\n' "$raw"