#!/usr/bin/env bash
# CASAN shared log helper (source me, do not execute).
# Taxonomy (shared with scripts/casan-log.mjs): error < warn < info < debug < trace.
# CASAN_LOG_LEVEL selects the threshold (default: info). All log lines go to
# stderr so stdout contracts (CASAN_HARNESS_COMPLETE, cache=..., evidence
# .stdout files) stay byte-identical.

casan_log_num() {
  case "$1" in
    error) echo 0 ;;
    warn)  echo 1 ;;
    info)  echo 2 ;;
    debug) echo 3 ;;
    trace) echo 4 ;;
    *)     echo 2 ;;
  esac
}

CASAN_LOG_LEVEL="${CASAN_LOG_LEVEL:-info}"
CASAN_LOG_THRESHOLD="$(casan_log_num "$CASAN_LOG_LEVEL")"

# casan_log <level> <component> <message...>
casan_log() {
  local lvl="$1" comp="$2"
  shift 2
  [ "$(casan_log_num "$lvl")" -le "$CASAN_LOG_THRESHOLD" ] || return 0
  # SEC-27 (X-02): log messages carry attacker-influenced data (action names, tool
  # output snippets). Strip control chars — ESC/CSI (terminal-escape injection that
  # rewrites a reviewer's screen) and CR/LF (fake-log-line injection) — keeping tab.
  local msg; msg="$(printf '%s' "$*" | tr -d '\000-\010\012-\037\177')"
  printf '[%s] %s [%s] %s\n' \
    "$(printf '%s' "$lvl" | tr '[:lower:]' '[:upper:]')" \
    "$(date -u +"%Y-%m-%dT%H:%M:%SZ")" \
    "$comp" "$msg" >&2
}