#!/usr/bin/env bash
#
# Fetch the trivia-invariant-layout gate corpora (TODO.md, S0) into `corpora/`
# at the repository root, pinned to exact commits so every stage's gate run
# (`badness debug format --checks all|trivia --report .`) is reproducible.
# The directory is gitignored; re-running is a fast no-op when a corpus is
# already checked out at its pin.
#
# The latex3/latex3 pin is the SHA the S1-S4 stage gates in TODO.md are
# measured against; the other two were recorded at the S0 baseline run.

set -euo pipefail

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

# name|owner/repo|commit
PINS="
latex3|latex3/latex3|3d1d347d8937863c0786988b14d307a6091ee397
latex2e|latex3/latex2e|3a9fdd88bdc53f16a0c2158aa70d259607de333a
pgf|pgf-tikz/pgf|1c7fc0fdc3ec8a6bdcfd68785c6bbd43ec110178
"

mkdir -p "${CORPORA_DIR}"

while IFS='|' read -r name repo sha; do
  [ -z "${name}" ] && continue
  dir="${CORPORA_DIR}/${name}"
  if [ -d "${dir}/.git" ] && [ "$(git -C "${dir}" rev-parse HEAD)" = "${sha}" ]; then
    echo "${name}: already at ${sha}"
    continue
  fi
  echo "${name}: fetching ${repo} @ ${sha}"
  rm -rf "${dir}"
  mkdir -p "${dir}"
  git -C "${dir}" init --quiet
  git -C "${dir}" remote add origin "https://github.com/${repo}.git"
  # A shallow single-commit fetch: reproducible, no history download.
  git -C "${dir}" fetch --quiet --depth 1 origin "${sha}"
  git -C "${dir}" checkout --quiet FETCH_HEAD
  echo "${name}: checked out $(git -C "${dir}" rev-parse HEAD)"
done <<EOF
${PINS}
EOF

echo "Gate corpora ready under ${CORPORA_DIR}"