#!/usr/bin/env bash
# reflect-git-history.sh — Phase-0 experiment P2 ("only-self-reflection" bucket)
#
# Question: of the failures visible in git history, what fraction would ONLY
# have been caught by end-of-run self-reflection — i.e. NOT by CI and NOT by
# independent human review? If that bucket is near-empty, the closed
# calibration / skill-synthesis loop (design §7–§8) is not worth building.
#
# Method: scan `git log` over a window for failure signals (reverts, and
# fix:/hotfix commits landing shortly after a feature merge). Classify each by
# the gate most likely to have caught it, using a pre-registered heuristic.
# This is a HARNESS + RUBRIC; the classifier is deliberately simple and the
# real corpus/labelling is wired later. It emits a structured tally.
#
# Usage:
#   scripts/analysis/reflect-git-history.sh [--repo PATH] [--since SINCE] [--json|--md]
#
# Options:
#   --repo PATH   repo to analyse (default: current repo)
#   --since SINCE git log --since value (default: "6 months ago")
#   --json        emit JSON (default)
#   --md          emit markdown
#
# Requirements: git, awk.
#
# PRE-REGISTERED KILL CONDITION:
#   bucket "only_self_reflection" is near-empty (< 10% of classified failures)
#   ⇒ do NOT build design §7–§8 (closed loop). Caveat-notes capture only.

set -euo pipefail

REPO="."
SINCE="6 months ago"
FORMAT="json"

while [[ $# -gt 0 ]]; do
  case "$1" in
    --repo) REPO="$2"; shift 2 ;;
    --since) SINCE="$2"; shift 2 ;;
    --json) FORMAT="json"; shift ;;
    --md) FORMAT="md"; shift ;;
    -h|--help) sed -n '2,30p' "$0"; exit 0 ;;
    *) echo "unknown arg: $1" >&2; exit 2 ;;
  esac
done

KILL_CONDITION='bucket only_self_reflection < 10% of classified failures ⇒ do NOT build §7–§8'
echo "# pre-registered kill condition: ${KILL_CONDITION}" >&2

command -v git >/dev/null 2>&1 || { echo "git required" >&2; exit 3; }

# Collect candidate failure commits: reverts + fix/hotfix subjects.
mapfile -t LINES < <(
  git -C "$REPO" log --since="$SINCE" --pretty='%H%x09%s' 2>/dev/null \
    | grep -iE 'revert|hotfix|hot-fix|regression|fix(\(|:|!| )' || true
)

total=0; ci=0; human=0; selfonly=0
for line in "${LINES[@]}"; do
  [[ -z "$line" ]] && continue
  subj="${line#*$'\t'}"
  total=$((total + 1))
  # Pre-registered classification heuristic (gate most likely to have caught it):
  #   - build/test/lint/type/ci signals → CI would have caught it
  #   - security/auth/permission/data/migration → human review would flag it
  #   - everything else (logic/UX/assumption/edge) → only-self-reflection bucket
  if printf '%s' "$subj" | grep -qiE 'test|lint|type|build|ci|compile|typo'; then
    ci=$((ci + 1))
  elif printf '%s' "$subj" | grep -qiE 'security|auth|permission|rbac|secret|migration|data|sql|injection'; then
    human=$((human + 1))
  else
    selfonly=$((selfonly + 1))
  fi
done

pct() { awk "BEGIN{ if ($2==0) print \"0.0\"; else printf \"%.1f\", 100*$1/$2 }"; }
self_pct="$(pct "$selfonly" "$total")"
verdict="$(awk "BEGIN{print ($self_pct < 10.0) ? \"KILL §7–§8\" : \"signal present — proceed to deeper labelling\"}")"

if [[ "$FORMAT" == "md" ]]; then
  cat <<EOF
## P2 — git-history failure-gate attribution

- window: \`${SINCE}\` · repo: \`${REPO}\`
- classified failures: **${total}**

| gate | count | share |
|---|---:|---:|
| CI would catch | ${ci} | $(pct "$ci" "$total")% |
| human review would catch | ${human} | $(pct "$human" "$total")% |
| only-self-reflection | ${selfonly} | ${self_pct}% |

- kill condition: ${KILL_CONDITION}
- verdict: **${verdict}**
EOF
else
  awk -v t="$total" -v c="$ci" -v h="$human" -v s="$selfonly" -v sp="$self_pct" \
      -v v="$verdict" -v since="$SINCE" -v repo="$REPO" -v kc="$KILL_CONDITION" 'BEGIN{
    printf "{\n"
    printf "  \"experiment\": \"P2-git-history\",\n"
    printf "  \"repo\": \"%s\",\n", repo
    printf "  \"since\": \"%s\",\n", since
    printf "  \"classified_failures\": %d,\n", t
    printf "  \"buckets\": { \"ci\": %d, \"human_review\": %d, \"only_self_reflection\": %d },\n", c, h, s
    printf "  \"only_self_reflection_pct\": %s,\n", sp
    printf "  \"kill_condition\": \"%s\",\n", kc
    printf "  \"verdict\": \"%s\"\n", v
    printf "}\n"
  }'
fi