#!/usr/bin/env bash
# gstack-worktree-audit — read-only audit of every git worktree beside the main
# one: size, age of its last commit, whether its head is merged into the base,
# tracked edits vs untracked scratch, remote state, the PR on its branch, the
# newest Claude Code chat that ran in it, and a suggested bucket. One TSV row
# per worktree, largest first. It never deletes, prunes, checks out or edits a
# worktree or a branch; its one write is the best-effort fetch of the base ref
# (skip it with --no-fetch). Removing a worktree stays a step a person takes
# after reading the table.
#
# Ported from pstack's poteto-mode/scripts/worktree-audit.sh (Copyright Lauren
# Tan, MIT; https://github.com/cursor/plugins, pstack/skills/poteto-mode at
# 99b609a7). Changes from the source: the PR column comes from gh alone through
# its own --jq (no jq binary) and ignores fork PRs, LAST_CHAT reads Claude
# Code's per-worktree transcript directory instead of Cursor's, worktree paths
# may contain spaces, a registered worktree whose directory is gone gets a
# `prunable` row, `safe` also requires a clean tree with nothing unpushed, and
# --no-fetch is new. License
# text: licenses/MIT-pstack.txt; NOTICE.md carries the entry.
#
# Usage: gstack-worktree-audit [-b|--base <ref>] [--no-fetch] [repo-path]
#   repo-path defaults to the repository the current directory is in.
#   -b sets the ref the MERGED column checks against (origin/integration, say).
#      Without it the base is origin/HEAD, then origin/main, then origin/master,
#      and a warn line says which one was picked: origin/HEAD is the remote's
#      default branch, not necessarily the branch PRs merge into.
#   --no-fetch skips the best-effort fetch of the base before the merge check.
#
# Columns: SIZE AGE MERGED DIRTY REMOTE PR LAST_CHAT BUCKET WORKTREE
#   MERGED    YES when the worktree's head is an ancestor of the base. A
#             squash-merged branch is never an ancestor, so read PR with it.
#   DIRTY     clean | wip:<n> (tracked edits) | scratch:<n> (untracked only) |
#             missing (registered, directory gone: `git worktree prune` territory)
#   REMOTE    pushed | ahead<n> | no-remote | detached
#   PR        #<n>/<state> from gh (open, merged, closed; an open PR wins when a
#             branch name has several, fork PRs are ignored), or - without gh
#   LAST_CHAT date of the newest Claude Code transcript under
#             ${CLAUDE_CONFIG_DIR:-~/.claude}/projects/<worktree slug>/, or -
#   BUCKET    prunable (directory gone) > hold-wip (tracked edits) >
#             hold-open-pr > verify-recent-chat (a chat in the last 4 days) >
#             safe (clean tree, and either merged into the base or its PR is
#             closed or merged with every commit pushed) > review (anything
#             else: unpushed commits, untracked files, nothing says it is done)
set -u

base=""
fetch=1
while [ $# -gt 0 ]; do
  case "$1" in
  -b|--base) [ $# -ge 2 ] || { echo "gstack-worktree-audit: $1 needs a ref" >&2; exit 2; }; base="$2"; shift 2 ;;
  --no-fetch) fetch=0; shift ;;
  -h|--help) sed -n '2,/^set -u/p' "$0" | sed '$d; s/^# \{0,1\}//'; exit 0 ;;
  -*) echo "gstack-worktree-audit: unknown option: $1" >&2; exit 2 ;;
  *) break ;;
  esac
done

repo="${1:-$(git rev-parse --show-toplevel 2>/dev/null)}"
[ -z "$repo" ] && { echo "gstack-worktree-audit: not in a git repository; pass a repo path" >&2; exit 1; }
cd "$repo" || exit 1
git rev-parse --git-dir >/dev/null 2>&1 || { echo "gstack-worktree-audit: not a git repository: $repo" >&2; exit 1; }

# The main worktree is the first entry; every other one is a candidate.
main_wt=$(git worktree list --porcelain | sed -n 's/^worktree //p' | head -1)

if [ -z "$base" ]; then
  for cand in "$(git symbolic-ref --short refs/remotes/origin/HEAD 2>/dev/null)" origin/main origin/master; do
    [ -n "$cand" ] && git rev-parse --verify --quiet "$cand^{commit}" >/dev/null && { base="$cand"; break; }
  done
  [ -z "$base" ] && { echo "gstack-worktree-audit: no base ref (origin/HEAD, origin/main, origin/master all missing); pass -b <ref>" >&2; exit 1; }
  echo "warn: no -b given; MERGED checks against $base" >&2
fi

# A stale base only makes MERGED conservative, so the fetch is best-effort. The
# explicit refspec creates the remote ref even in a single-branch clone.
if [ "$fetch" = 1 ]; then
  case "$base" in
  origin/*) GIT_TERMINAL_PROMPT=0 git fetch origin "+refs/heads/${base#origin/}:refs/remotes/$base" --quiet 2>/dev/null \
    || echo "warn: could not fetch $base; MERGED may be stale" >&2 ;;
  esac
fi
git rev-parse --verify --quiet "$base^{commit}" >/dev/null 2>&1 || { echo "gstack-worktree-audit: base ref not found: $base" >&2; exit 1; }

# GNU coreutils reads `stat -f` as file-system status and `date -r` as a file,
# so pick the stat and date spellings once.
if stat -c %Y / >/dev/null 2>&1; then
  stat_fmt=(-c '%Y %n'); fmt_day() { date -u -d "@$1" '+%Y-%m-%d'; }
else
  stat_fmt=(-f '%m %N'); fmt_day() { date -u -r "$1" '+%Y-%m-%d'; }
fi

# PR state per branch, read once as "<branch>\t<number>\t<state>" lines through
# gh's own --jq; a fork's PR says nothing about a local branch of the same name,
# so cross-repository PRs are dropped. Empty when gh is missing or cannot read
# this repository.
prs=$(mktemp)
trap 'rm -f "$prs"' EXIT
if command -v gh >/dev/null 2>&1; then
  gh pr list --state all --limit 1000 --json number,state,headRefName,isCrossRepository \
    --jq '.[] | select(.isCrossRepository | not) | [.headRefName, (.number|tostring), (.state|ascii_downcase)] | @tsv' > "$prs" 2>/dev/null \
    || { : > "$prs"; echo "warn: gh could not list this repository's PRs; PR column is -" >&2; }
else
  echo "warn: gh not on PATH; PR column is -" >&2
fi

projects="${CLAUDE_CONFIG_DIR:-$HOME/.claude}/projects"
now=$(date +%s)

echo "# base: $base"
printf 'SIZE\tAGE\tMERGED\tDIRTY\tREMOTE\tPR\tLAST_CHAT\tBUCKET\tWORKTREE\n'

git worktree list --porcelain | sed -n 's/^worktree //p' | while read -r wt; do
  [ "$wt" = "$main_wt" ] && continue
  if [ ! -d "$wt" ]; then
    printf '0\t?\t?\tmissing\t?\t-\t-\tprunable\t%s\n' "$wt"
    continue
  fi

  size=$(du -sh "$wt" 2>/dev/null | awk '{print $1}')
  head=$(git -C "$wt" rev-parse HEAD 2>/dev/null)
  head_ts=$(git -C "$wt" log -1 --format='%ct' HEAD 2>/dev/null || echo 0)
  age=$([ "$head_ts" -gt 0 ] 2>/dev/null && echo "$(( (now - head_ts) / 86400 ))d" || echo "?")

  git merge-base --is-ancestor "$head" "$base" 2>/dev/null && merged=YES || merged=no

  # Tracked edits are work in progress; untracked files alone are scratch.
  porcelain=$(git -C "$wt" status --porcelain 2>/dev/null)
  if [ -z "$porcelain" ]; then dirty=clean
  elif printf '%s\n' "$porcelain" | grep -qv '^??'; then
    dirty="wip:$(printf '%s\n' "$porcelain" | grep -cv '^??')"
  else dirty="scratch:$(printf '%s\n' "$porcelain" | grep -c '^??')"; fi

  branch=$(git -C "$wt" symbolic-ref --quiet --short HEAD 2>/dev/null || echo "")
  if [ -z "$branch" ]; then remote=detached
  elif git -C "$wt" show-ref --verify --quiet "refs/remotes/origin/$branch"; then
    [ "$(git -C "$wt" rev-parse "origin/$branch" 2>/dev/null)" = "$head" ] \
      && remote=pushed \
      || remote="ahead$(git -C "$wt" rev-list --count "origin/$branch..HEAD" 2>/dev/null)"
  else remote=no-remote; fi

  # Several PRs can share a branch name over time; an open one describes the
  # branch as it is now, so it wins over a closed or merged one.
  pr="-"
  [ -n "$branch" ] && [ -s "$prs" ] && pr=$(awk -F'\t' -v b="$branch" \
    '$1==b { if ($3=="open" || $3=="draft") { print "#" $2 "/" $3; exit } if (first=="") first="#" $2 "/" $3 } END { if (first!="") print first }' "$prs" | head -1)
  [ -z "$pr" ] && pr="-"

  # Newest transcript in this worktree's own Claude Code project directory
  # (the path with every non-alphanumeric byte replaced by -, as Claude names it).
  last="-"; last_ts=0
  chat_dir="$projects/$(printf '%s' "$wt" | sed 's/[^A-Za-z0-9]/-/g')"
  if [ -d "$chat_dir" ]; then
    f=$(find "$chat_dir" -type f -print0 2>/dev/null | xargs -0 stat "${stat_fmt[@]}" 2>/dev/null | sort -rn | head -1)
    if [ -n "$f" ]; then last_ts=$(echo "$f" | awk '{print $1}'); last=$(fmt_day "$last_ts" 2>/dev/null); fi
  fi
  recent=$([ "$last_ts" -gt 0 ] 2>/dev/null && [ $(( (now - last_ts) / 86400 )) -le 4 ] && echo yes || echo no)

  # safe means nothing in the worktree exists only there: a clean tree whose
  # head is in the base, or whose PR is closed or merged with every commit
  # pushed. Unpushed commits or untracked files on a merged branch are review.
  case "$dirty" in wip:*) bucket=hold-wip ;; *)
    case "$pr" in */open|*/draft) bucket=hold-open-pr ;; *)
      if [ "$recent" = yes ]; then bucket=verify-recent-chat
      elif [ "$dirty" = clean ] && { [ "$merged" = YES ] || { [ "$pr" != "-" ] && [ "$remote" = pushed ]; }; }; then bucket=safe
      else bucket=review; fi ;;
    esac ;;
  esac

  printf '%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\n' \
    "$size" "$age" "$merged" "$dirty" "$remote" "$pr" "$last" "$bucket" "$wt"
done | sort -t"$(printf '\t')" -k1,1 -rh