#!/usr/bin/env bash
set -euo pipefail

root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
cd "$root"

if [[ ! -d rfcs ]]; then
  echo "missing RFC tree: rfcs/" >&2
  exit 1
fi

# Git does not track empty directories, so a state directory with no RFCs in
# it yet (most commonly rfcs/archive) will not exist in a fresh clone. That is
# a legitimate condition, not an error: treat an absent state directory as an
# empty one rather than failing.
state_dirs=()
for dir in rfcs/proposed rfcs/done rfcs/archive; do
  if [[ -d "$dir" ]]; then
    state_dirs+=("$dir")
  fi
done

if [[ ${#state_dirs[@]} -eq 0 ]]; then
  exit 0
fi

numbers="$(find "${state_dirs[@]}" -type f -name '[0-9][0-9][0-9]-*.md' -printf '%f\n' | cut -d- -f1 | sort)"
duplicates="$(printf '%s\n' "$numbers" | uniq -d)"
if [[ -n "$duplicates" ]]; then
  echo "duplicate RFC number(s):" >&2
  printf '%s\n' "$duplicates" >&2
  exit 1
fi

while IFS= read -r file; do
  case "$file" in
    rfcs/proposed/*) expected="Proposed" ;;
    rfcs/done/*) expected="Implemented" ;;
    rfcs/archive/*) expected="Withdrawn|Superseded" ;;
    *) continue ;;
  esac

  # Consult only the file's real frontmatter Status line, not the whole body.
  # RFCs that discuss the Status convention (e.g. RFC 000) may quote
  # **Status.** lines as prose examples later in the file; those must not
  # satisfy this check.
  status_line="$(grep -m1 -E '^\*\*Status\.\*\* ' "$file" || true)"
  if [[ -z "$status_line" ]] || ! grep -Eq "^\*\*Status\.\*\* ($expected)" <<<"$status_line"; then
    echo "RFC status does not match folder: $file" >&2
    exit 1
  fi
done < <(find "${state_dirs[@]}" -type f -name '[0-9][0-9][0-9]-*.md' | sort)

for file in $(find "${state_dirs[@]}" -type f -name '[0-9][0-9][0-9]-*.md' | sort); do
  if ! grep -q "$(basename "$file")" rfcs/README.md && ! grep -q "$(basename "$file" .md)" rfcs/README.md; then
    echo "RFC missing from index: $file" >&2
    exit 1
  fi
done