#!/usr/bin/env bash
#
# check-no-vanity-metrics.sh
#
# Blocks codebase-state numbers from landing in Markdown surfaces.
# Run by the no-vanity-metrics CI workflow and (optionally) by a
# local pre-commit hook (`scripts/install-hooks.sh`).
#
# Why: counts of crates / tests / LOC / adapters drift on every code
# change and create permanent sync debt between the website, the
# GitHub READMEs, and any memory document. The open-standards posture
# is "describe the shape, not the size."
#
# Opt-out: append `<!-- allow-vanity: <reason> -->` to the END of a
# line whose number is genuinely structural (a fact about an EXTERNAL
# spec, not a count of TX-side artefacts). The marker MUST give a
# reason. Misuse is caught by a separate audit.
#
# What gets flagged (the regex catches every count we've actually had
# to fix; tuned to avoid false positives on codec / RFC / spec
# references):
#
#   - "N crates", "N+ crates"
#   - "N tests passing", "N tests"
#   - "N LOC", "~Nk LOC", "Nk LOC"
#   - "N+ samplers"
#   - "N+ adapters"
#   - "N+ backends"
#   - "N+ integrations"
#
# Identity-class numbers (spec versions like "JCR-1 v1", algorithm
# names like "Ed25519", RFC numbers, codec generation tags like
# "MPEG-4 Part 2") are NOT matched by the regex.

set -euo pipefail

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

# The vanity-metric pattern. Anchored to the keyword set with a
# trailing punctuation/space/EOL requirement so it doesn't fire on
# "Test-vector", "lockstep", "MPEG-4", RFC numbers, or version tags.
# The leading (^|[^[:alnum:]_-]) requires the count to be a standalone
# number, so a digit inside an identifier (e.g. "JR-2 tests", where
# "tests" is a verb) is not mistaken for a metric.
PATTERN='(^|[^[:alnum:]_-])[0-9][0-9,]*[+kKMG]?[+ ]*([Cc]rates?|[Tt]ests?|LOC|loc|[Ss]amplers?|[Aa]dapters?|[Bb]ackends?|[Ii]ntegrations?)([ .,;:!?)$]|$)'

# Build the file list — marketing / spec / governance surfaces only.
# Historical progress notes (docs/*-progress.md), changelogs, and
# external corpora are EXEMPT by design (they're snapshots, not the
# message we're keeping in sync). Research and notes dirs also exempt.
# Portable: read into an array without `mapfile` so macOS bash 3.2 works.
files=()
while IFS= read -r f; do
  case "$f" in
    *-progress.md|*/docs/*-progress.md|*/CHANGELOG.md|*/conformance/*|*/research/*|*/notes/*|*/notes-*/*)
      continue ;;
  esac
  files+=("$f")
done < <(git ls-files '*.md')

if [ ${#files[@]} -eq 0 ]; then
  echo "no Markdown files to scan"
  exit 0
fi

# Scan. A hit-line is exempted iff it ends with an `allow-vanity:`
# marker with a non-empty reason.
hits=0
while IFS= read -r line; do
  # `line` is "path:lineno:content"
  content="${line#*:}"
  content="${content#*:}"
  if echo "$content" | grep -qE 'allow-vanity:[[:space:]]*[^[:space:]]'; then
    continue
  fi
  if [ $hits -eq 0 ]; then
    echo "::error::Vanity metric(s) found — see scripts/check-no-vanity-metrics.sh for the policy and opt-out marker."
    echo ""
  fi
  echo "$line"
  hits=$((hits + 1))
done < <(grep -nE "$PATTERN" "${files[@]}" 2>/dev/null || true)

if [ $hits -gt 0 ]; then
  echo ""
  echo "Total hits: $hits"
  echo ""
  echo "Fix: replace the count with a shape description"
  echo "  (e.g. 'a multi-crate Rust workspace', 'covered by a test suite',"
  echo "  'the diffusion sampler catalog'), OR if the number is genuinely"
  echo "  structural (describes an external spec, not TX state) append"
  echo "  '<!-- allow-vanity: <reason> -->' to the end of the line."
  exit 1
fi

echo "✓ No vanity metrics found across $(echo "${files[@]}" | wc -w | tr -d ' ') Markdown files"