# shellcheck shell=bash
# Worktrees for parallel agent sessions. Generic part here; project specifics (ports, .env,
# starting a stack, seeding) go into hooks:
#   .opencode-sandbox/hooks/wt-post-add   after `git worktree add`, cwd = the new worktree
#   .opencode-sandbox/hooks/wt-pre-rm     before removal (stop the stack), cwd = the worktree
# Hooks get WT_DIR, WT_BRANCH, WT_SLUG, MAIN_ROOT in the environment and the extra
# arguments of `wt add` / `wt rm` as their arguments. A failing hook aborts the command.

ocsb_wt_main_root() {
  git -C "${OCSB_PROJECT_DIR}" rev-parse --path-format=absolute --git-common-dir | sed 's|/\.git$||'
}

ocsb_wt_slug() {
  local branch=$1 slug=""
  if [[ -n ${OCSB_WT_SLUG_REGEX} && ${branch} =~ ${OCSB_WT_SLUG_REGEX} ]]; then
    slug=${BASH_REMATCH[1]}
  fi
  [[ -n ${slug} ]] || slug=$(printf '%s' "${branch}" | tr '/' '-' | tr -c 'a-zA-Z0-9._-' '-')
  echo "${slug}"
}

ocsb_wt_hook() {
  local name=$1 dir=$2
  shift 2
  local hook=${OCSB_PROJECT_DIR}/.opencode-sandbox/hooks/${name}
  [[ -x ${hook} ]] || return 0
  ocsb_info "hook ${name}"
  (cd "${dir}" && "${hook}" "$@")
}

ocsb_wt_add() {
  [[ $# -ge 1 ]] || ocsb_die "usage: opencode-sandbox wt add <branch> [hook args]"
  local branch=$1 main slug dir base
  shift
  git check-ref-format --branch "${branch}" >/dev/null 2>&1 || ocsb_die "invalid branch name: ${branch}"
  main=$(ocsb_wt_main_root)
  slug=$(ocsb_wt_slug "${branch}")
  dir=${OCSB_WORKTREES_DIR}/${OCSB_WT_PREFIX}${slug}
  [[ -e ${dir} ]] && ocsb_die "already exists: ${dir}"
  base=${OCSB_WT_BASE:-HEAD}
  if [[ ${base} != HEAD ]] && git -C "${main}" rev-parse -q --verify "origin/${base}" >/dev/null; then
    echo "  ${base} is $(git -C "${main}" rev-list --count "${base}..origin/${base}") commit(s) behind origin/${base} (git fetch if needed)"
  fi
  mkdir -p "${OCSB_WORKTREES_DIR}"
  git -C "${main}" worktree add -b "${branch}" "${dir}" "${base}"
  export WT_DIR=${dir} WT_BRANCH=${branch} WT_SLUG=${slug} MAIN_ROOT=${main}
  ocsb_wt_hook wt-post-add "${dir}" "$@"
  echo "✓ worktree ${dir} (branch ${branch}); remove: opencode-sandbox wt rm ${slug}"
}

ocsb_wt_rm() {
  [[ $# -ge 1 ]] || ocsb_die "usage: opencode-sandbox wt rm <name|path> [--force]"
  local name=$1 force=0 main dir branch status a extra=()
  shift
  for a in "$@"; do
    if [[ ${a} == --force ]]; then force=1; else extra+=("${a}"); fi
  done
  main=$(ocsb_wt_main_root)
  case "${name}" in
    /*) dir=${name} ;;
    *) dir=${OCSB_WORKTREES_DIR}/${OCSB_WT_PREFIX}${name} ;;
  esac
  [[ -d ${dir} ]] || ocsb_die "no such worktree: ${dir}"
  [[ $(realpath "${dir}") != "$(realpath "${main}")" ]] || ocsb_die "refusing to remove the main worktree"
  branch=$(git -C "${dir}" rev-parse --abbrev-ref HEAD 2>/dev/null || true)
  export WT_DIR=${dir} WT_BRANCH=${branch} WT_SLUG=${name##*/} MAIN_ROOT=${main}
  status=$(git -C "${dir}" status --porcelain)
  if [[ -n ${status} && ${force} -ne 1 ]]; then
    echo "${status}" >&2
    ocsb_die "worktree has uncommitted changes — commit them or pass --force (they will be lost)"
  fi
  ocsb_wt_hook wt-pre-rm "${dir}" "${extra[@]}"
  if [[ ${force} -eq 1 ]]; then
    git -C "${main}" worktree remove --force "${dir}"
  else
    git -C "${main}" worktree remove "${dir}"
  fi
  git -C "${main}" worktree prune
  echo "✓ removed ${dir} (branch ${branch:-?} kept)"
}

ocsb_wt() {
  local sub=${1:-list}
  [[ $# -gt 0 ]] && shift
  case "${sub}" in
    add) ocsb_wt_add "$@" ;;
    rm) ocsb_wt_rm "$@" ;;
    list) git -C "${OCSB_PROJECT_DIR}" worktree list ;;
    *) ocsb_die "wt: unknown subcommand ${sub} (add|rm|list)" ;;
  esac
}