#!/usr/bin/env bash
#
# wt-clean.sh — tidy up worktrees whose branch has merged.
#
# WHAT it does (safe by default):
#   1. `git worktree prune` — drop admin entries for worktrees whose
#      directory is already gone.
#   2. For every *other* worktree (never the primary checkout, never the one
#      you're standing in) whose branch is fully merged into origin/main:
#      remove the worktree and delete the local branch.
#
# SAFETY: it refuses to remove a worktree with uncommitted changes (no
# --force) and only ever touches branches git confirms are merged into
# origin/main, so unmerged work is never lost. Run it whenever; it's not
# tied to any moment.
#
# USAGE
#   scripts/wt-clean.sh            # do it
#   scripts/wt-clean.sh --dry-run  # show what it would remove

set -euo pipefail

log() { printf '  wt-clean: %s\n' "$*" >&2; }

dry=0
[ "${1:-}" = "--dry-run" ] && dry=1

git rev-parse --git-dir >/dev/null 2>&1 || { echo "wt-clean: not in a git repo" >&2; exit 1; }

log "fetching origin/main"
git fetch --quiet --prune origin main || true

log "pruning stale worktree entries"
if (( dry )); then
  git worktree prune --dry-run -v
else
  git worktree prune -v
fi

# The primary checkout and the current worktree are off-limits.
main_wt="$(git worktree list --porcelain | awk '/^worktree /{print $2; exit}')"
here="$(git rev-parse --show-toplevel)"

# Branches fully merged into origin/main (whitespace-trimmed, sans markers).
merged="$(git branch --format='%(refname:short)' --merged origin/main)"
is_merged() { grep -qxF "$1" <<<"$merged"; }

removed=0
# Iterate worktrees: paired "worktree <path>" / "branch refs/heads/<name>".
path=""; while read -r key val; do
  case "$key" in
    worktree) path="$val" ;;
    branch)
      br="${val#refs/heads/}"
      if [ "$path" != "$main_wt" ] && [ "$path" != "$here" ] && is_merged "$br"; then
        if (( dry )); then
          log "would remove worktree $path (branch $br, merged)"
        else
          if git worktree remove "$path" 2>/dev/null; then
            git branch -d "$br" >/dev/null 2>&1 || true
            log "removed worktree $path + branch $br"
            removed=$((removed+1))
          else
            log "skipped $path — has uncommitted changes (remove it by hand)"
          fi
        fi
      fi
      ;;
  esac
done < <(git worktree list --porcelain)

(( dry )) || log "done — removed $removed merged worktree(s)"