#!/usr/bin/env bash
# Require every crates/ or legacy src/ change to carry a changed binding page.
# Read one changed path per line on stdin. With --index, inspect candidate wiki
# pages from Git's staged snapshot rather than the possibly different worktree.
set -euo pipefail
cd "$(dirname "$0")/.."

mode=worktree
case "${1:-}" in
  "") ;;
  --worktree) ;;
  --index) mode=index ;;
  *) echo "usage: $0 [--worktree|--index] < changed-paths" >&2; exit 2 ;;
esac

changed=$(cat)
[ -n "$changed" ] || {
  echo "No files changed"
  exit 0
}

grep -qE '^(crates/|src/)' <<< "$changed" || {
  echo "No crates/ or src/ files changed"
  exit 0
}

is_binding_page() {
  local path="$1"
  case "$path" in
    wiki/*.md) ;;
    *) return 1 ;;
  esac

  if [ "$mode" = index ]; then
    git cat-file -e ":$path" 2>/dev/null || return 1
    git grep --cached -qE '^Type: (law|spec)$' -- "$path"
  else
    [ -f "$path" ] && grep -qE '^Type: (law|spec)$' "$path"
  fi
}

while IFS= read -r path; do
  [ -n "$path" ] || continue
  if is_binding_page "$path"; then
    echo "Design corpus check passed"
    exit 0
  fi
done <<< "$changed"

echo "DESIGN CORPUS VIOLATION"
echo "  A crates/ (or src/) change must amend a changed Type: law or Type: spec"
echo "  page under wiki/. Root DESIGN.md does not count."
exit 1