resume

#!/usr/bin/env bash
# session.txt — resume helper
# Reads ./session.txt in the current folder and relaunches a saved session.
# Lines are runnable commands with an optional "# title" comment:
#   claude --resume <id>  # title
#   codex resume <id>  # title
# Tool-agnostic: it just runs the chosen line (minus the comment).
#
#   resume          start the newest session (last line)
#   resume -l       numbered list with titles (1 = oldest, at top)
#   resume N        start entry N            (e.g. resume 1 = oldest)
#   resume N show   print the full command for entry N (don't run it)
#   resume show     print the full command for the newest entry
#   resume -h       help
#
# On every run it self-cleans: entries whose session no longer exists on disk
# (no Claude transcript / no Codex rollout) are dropped from session.txt.

set -uo pipefail

file="${PWD}/session.txt"

usage() { sed -n '2,17p' "$0" | sed 's/^# \{0,1\}//'; }

# --- parse args: a number (index), a list flag, a show flag, in any order ---
LIST=0; SHOW=0; NUM=""
for a in "$@"; do
  case "$a" in
    -h|--help) usage; exit 0 ;;
    -l|--list|list) LIST=1 ;;
    -s|--show|-p|--print|show|print|cmd) SHOW=1 ;;
    *[0-9]) [[ "$a" =~ ^[0-9]+$ ]] && NUM="$a" ;;
  esac
done

[ -f "$file" ] || { echo "session.txt: no file in $PWD" >&2; exit 1; }

# --- helpers ----------------------------------------------------------------
# tool of a line = first token (claude, codex, opencode, pi, cursor-agent, agent, gemini)
line_tool() { awk '{print $1}' <<<"$1"; }
# id of a line. Handles both the spaced form (claude --resume <id>, codex resume
# <id>, ...) and the fused form (agent --resume=<id>, cursor-agent --resume=<id>).
line_id() {
  local l="$1"
  case "$l" in
    *--resume=*)  l="${l##*--resume=}";  printf '%s\n' "${l%% *}" ;;
    *--session=*) l="${l##*--session=}"; printf '%s\n' "${l%% *}" ;;
    *)            awk '{print $3}' <<<"$l" ;;
  esac
}
# title of a line (after "# "), empty if none
line_title() { case "$1" in *"#"*) echo "${1#*# }" ;; *) echo "" ;; esac; }
# command without the trailing "# title" comment
line_cmd()  { local c="${1%%#*}"; echo "${c%"${c##*[![:space:]]}"}"; }

# does the session still exist on disk? (checked against the current folder)
is_live() {
  local tool="$1" id="$2"
  [ -n "$id" ] || return 1
  case "$tool" in
    claude)
      find "$HOME/.claude/projects" -name "${id}.jsonl" -print -quit 2>/dev/null | grep -q . ;;
    codex)
      find "$HOME/.codex/sessions" -name "rollout-*-${id}.jsonl" -print -quit 2>/dev/null | grep -q . ;;
    opencode)
      local db="$HOME/.local/share/opencode/opencode.db" q
      command -v sqlite3 >/dev/null 2>&1 && [ -f "$db" ] || return 1
      q="${id//\'/\'\'}"
      [ -n "$(sqlite3 "$db" "SELECT 1 FROM session WHERE id='$q' LIMIT 1;" 2>/dev/null)" ] ;;
    pi)
      find "$HOME/.pi/agent/sessions" -name "*${id}*.jsonl" -print -quit 2>/dev/null | grep -q . ;;
    cursor-agent|agent)
      [ -n "$(find "$HOME/.cursor/chats" -maxdepth 2 -type d -name "$id" -print -quit 2>/dev/null)" ] ;;
    *)
      return 1 ;;
  esac
}

# --- load + prune dead entries ----------------------------------------------
live=()
while IFS= read -r l; do
  [ -n "$l" ] || continue
  if is_live "$(line_tool "$l")" "$(line_id "$l")"; then
    live+=("$l")
  fi
done < <(grep -vE '^[[:space:]]*$' "$file")

# rewrite session.txt with only the live entries
if [ "${#live[@]}" -eq 0 ]; then
  : > "$file"
  echo "session.txt: no resumable sessions left in $PWD" >&2
  exit 1
fi
printf '%s\n' "${live[@]}" > "$file"

n=${#live[@]}

# --- list -------------------------------------------------------------------
if [ "$LIST" -eq 1 ]; then
  i=1
  for l in "${live[@]}"; do
    id="$(line_id "$l")"; short="${id:0:8}"
    tool="$(line_tool "$l")"; title="$(line_title "$l")"
    printf '%2d  %-12s %-8s  %s\n' "$i" "$tool" "$short" "$title"
    i=$((i + 1))
  done
  exit 0
fi

# --- pick entry -------------------------------------------------------------
if [ -n "$NUM" ]; then
  idx=$(( NUM - 1 ))
  if [ "$idx" -lt 0 ] || [ "$idx" -ge "$n" ]; then
    echo "resume: no entry $NUM (1..$n)" >&2; exit 1
  fi
  sel="${live[$idx]}"
else
  sel="${live[$(( n - 1 ))]}"
fi

cmd="$(line_cmd "$sel")"
title="$(line_title "$sel")"

# --- show: print the full command instead of running it ---------------------
if [ "$SHOW" -eq 1 ]; then
  printf '%s\n' "$cmd"
  exit 0
fi

# --- run --------------------------------------------------------------------
echo "» ${title:-$cmd}" >&2
exec ${cmd}