#!/usr/bin/env bash
# Chain the ops-log attribution hook into .git/hooks/post-commit.
#
# ⚠ PREPENDS, and that is the whole point. The first version APPENDED, so as
# not to disturb graphify's hook — and thereby made attribution a subordinate
# clause of graphify's control flow. graphify's block owns EIGHT `exit 0`
# paths (rebase / merge / cherry-pick in progress, GRAPHIFY_SKIP_HOOK, no
# changed files, graphify-out-only, no python found), and every one of them
# returned before ever reaching the appended line.
#
# Measured 2026-09-19, after infra-hermes reported commits going unlogged:
# eaaacc1 touched only graphify-out/GRAPH_REPORT.md and hit the
# graphify-out-only exit; an empty probe commit hit the no-changed-files exit.
# Neither was recorded. It looked like a flaky hook or a lock race. It was
# ordering, and it was deterministic.
#
# Attribution must not depend on another hook's opinion about whether a commit
# is interesting, so it runs FIRST and unconditionally.
#
# Still an append-style install in spirit: graphify's block is preserved
# byte-for-byte below ours, and core.hooksPath is deliberately NOT used because
# it would disable graphify outright. Idempotent — safe to re-run.
set -euo pipefail
REPO="$(git rev-parse --show-toplevel)"
HOOK="$REPO/.git/hooks/post-commit"

BLOCK='# ── ops-log attribution — MUST RUN FIRST ──────────────────────────────────
# Records which althing handle made this commit. PREPENDED on purpose: see
# scripts/git-hooks/install.sh for why appending silently dropped commits.
"$(git rev-parse --show-toplevel)/scripts/git-hooks/post-commit-ops-log" || true
# ──────────────────────────────────────────────────────────────────────────'

if [ ! -f "$HOOK" ]; then
  printf '#!/bin/sh\n\n%s\n' "$BLOCK" > "$HOOK"
  chmod +x "$HOOK"
  echo "installed (new hook file)"
  exit 0
fi

if grep -q "post-commit-ops-log" "$HOOK"; then
  echo "already installed"
  exit 0
fi

# Insert immediately after the shebang so no other block can exit before us.
tmp=$(mktemp)
head -1 "$HOOK" > "$tmp"
printf '\n%s\n\n' "$BLOCK" >> "$tmp"
tail -n +2 "$HOOK" >> "$tmp"
cat "$tmp" > "$HOOK"
rm -f "$tmp"
chmod +x "$HOOK"
echo "installed — attribution now runs FIRST in the post-commit chain"