#!/bin/sh
# rclaude <host> [dir]
#
# Durable Claude Code session, local or remote. Two layers of resilience:
#
#   1. tmux on <host> survives terminal/transport drops (network, lid close,
#      ssh kill, terminal crash) — works even when <host> is the local box
#      because the local terminal can also die independently.
#   2. `claude --continue` resumes the per-directory session from disk after
#      anything kills the host itself (reboot, crash, OOM).
#
# Re-running with the same <host> + <dir> always lands you back in the same
# conversation: tmux reattaches if alive, claude --continue picks up from
# ~/.claude/projects/<encoded-cwd>/ otherwise.
#
# <host> can be:
#   - any ssh-reachable target (Host alias, user@hostname, IP)
#   - "local", "localhost", or the local short/long hostname → no ssh,
#     just a local tmux session (still detachable with Ctrl-b d)
#
# Permission mode: --dangerously-skip-permissions is on by default — these
# are sessions on hosts you own. Override with RCLAUDE_PERMS=default (or any
# other --permission-mode value) if you want prompts back.
#
# Usage:
#   rclaude                                  # local, current pwd (shorthand)
#   rclaude .                                # same
#   rclaude apricot                          # remote home dir on apricot
#   rclaude apricot ~/Code/@projects/foo     # remote, specific dir
#   rclaude local .                          # local, current pwd (explicit)
#   rclaude local ~/Code/@projects/foo       # local, specific dir
#   rclaude $(hostname) ~                    # also local (hostname match)

set -eu

# Argument resolution:
#   `rclaude`        → local, $PWD
#   `rclaude .`      → local, $PWD
#   `rclaude <host>` → host, default dir (~ remote, $PWD local)
#   `rclaude <host> <dir>` → host, dir (with `.` resolving to $PWD)
if [ $# -eq 0 ] || [ "${1:-}" = "." ]; then
    host=local
    dir=$PWD
else
    host=$1
    dir=${2:-}
fi

is_local() {
    case $1 in
        local|localhost|127.0.0.1|::1) return 0 ;;
    esac
    [ "$1" = "$(hostname)" ] && return 0
    [ "$1" = "$(hostname -s 2>/dev/null)" ] && return 0
    return 1
}

# Defaults + `.` expansion now that we know whether we're local or remote.
if is_local "$host"; then
    case ${dir:-.} in
        .|"") dir=$PWD ;;
    esac
else
    if [ "$dir" = "." ]; then
        echo "error: '.' as dir requires a local target; pass an explicit remote path" >&2
        exit 2
    fi
    [ -z "$dir" ] && dir=\~
fi

slug=$(printf %s "$dir" | sed -e 's|^[~/]*||' -e 's|[^A-Za-z0-9]|-|g')
[ -z "$slug" ] && slug=home
session="claude-$(whoami)-${slug}"

perms=${RCLAUDE_PERMS:-bypass}
case $perms in
    bypass) flag="--dangerously-skip-permissions" ;;
    *)      flag="--permission-mode $perms" ;;
esac

if is_local "$host"; then
    # No ssh hop — local tmux. dir is already an absolute path here.
    cd "$dir"
    exec tmux new-session -A -s "$session" "exec claude --continue ${flag}"
fi

# Remote: tmux on the other side of an ssh -t. exec replaces the shell so
# the tmux pane dies cleanly when claude exits.
inner="cd ${dir} && exec claude --continue ${flag}"
exec ssh -t "$host" "tmux new-session -A -s '${session}' \"${inner}\""