#!/usr/bin/env bash
set -euo pipefail

BOOTSTRAP_SESSION="__resurrect_bootstrap__"
RESTORE_SCRIPT="${TMUX_RESURRECT_PLUGIN_SCRIPT:-$HOME/.tmux/plugins/tmux-resurrect/scripts/restore.sh}"

resurrect_dir() {
  if [[ -d "$HOME/.tmux/resurrect" ]]; then
    printf '%s\n' "$HOME/.tmux/resurrect"
  else
    printf '%s\n' "${XDG_DATA_HOME:-$HOME/.local/share}/tmux/resurrect"
  fi
}

LAST_FILE="${TMUX_RESURRECT_LAST_FILE:-$(resurrect_dir)/last}"

die() {
  printf 'tmux-resurrect: %s\n' "$*" >&2
  exit 1
}

tmux_has_sessions() {
  tmux list-sessions >/dev/null 2>&1
}

bootstrap_is_only_session() {
  local sessions
  sessions="$(tmux list-sessions -F '#{session_name}' 2>/dev/null || true)"
  [[ -n "$sessions" ]] && [[ "$sessions" == "$BOOTSTRAP_SESSION" ]]
}

post_restore() {
  [[ -x "$RESTORE_SCRIPT" ]] || die "restore script not found at $RESTORE_SCRIPT"
  [[ -e "$LAST_FILE" ]] || die "no resurrect file found at $LAST_FILE"

  if ! "$RESTORE_SCRIPT"; then
    tmux display-message "tmux restore failed"
    exec "${SHELL:-/bin/zsh}" -l
  fi

  if tmux list-sessions -F '#{session_name}' 2>/dev/null | grep -qv "^${BOOTSTRAP_SESSION}$"; then
    tmux kill-session -t "$BOOTSTRAP_SESSION" 2>/dev/null || true
  fi
}

usage() {
  cat <<'EOF'
Usage: tmux-resurrect

Restore the last tmux-resurrect snapshot, resume saved OpenCode panes,
and attach to tmux.
EOF
}

if [[ "${1:-}" == "--post-restore" ]]; then
  if [[ -n "${2:-}" ]]; then
    BOOTSTRAP_SESSION="$2"
  fi
  post_restore
  exit 0
fi

case "${1:-}" in
  "" )
    ;;
  -h|--help)
    usage
    exit 0
    ;;
  *)
    die "unknown option: $1"
    ;;
esac

if tmux_has_sessions; then
  if bootstrap_is_only_session; then
    tmux kill-session -t "$BOOTSTRAP_SESSION" 2>/dev/null || true
  else
    exec tmux attach-session
  fi
fi

[[ -x "$RESTORE_SCRIPT" ]] || die "restore script not found at $RESTORE_SCRIPT"
[[ -e "$LAST_FILE" ]] || die "no resurrect file found at $LAST_FILE"

SELF="$0"
if [[ "$SELF" != /* ]]; then
  SELF="$(command -v "$SELF" || true)"
fi
[[ -n "$SELF" ]] || die "could not resolve script path"

exec tmux new-session -A -s "$BOOTSTRAP_SESSION" "\"$SELF\" --post-restore \"$BOOTSTRAP_SESSION\""