#!/bin/bash
# claw-master-agent-setup USER [--restart] -- every Claude Code in this container uses the pool, not only the ones t-claude
# launches.
#
# t-claude starts a terminal Claude through `claw-master connect`, which gives that one process the pool's proxy. The Claude
# desktop app's SSH sessions start their own Claude Code in here (~/.claude/remote/ccd-cli/...) with the person's own login
# and no proxy, so they spent the person's own subscription, which the pool also spends: the app said "You've hit your weekly
# limit" while the terminal worked. For an ENROLLED account (its client certificate is readable) this runs the claw-master
# agent, claw-master-agent@USER (a proxy on loopback that reaches the server with the account's certificate), and puts its
# proxy, CA and loopback exemption in a managed settings drop-in, which every Claude Code here reads and which outranks the
# person's own and any project's settings. The container is one person's, so a machine-wide file is theirs alone; the
# person's ~/.claude/settings.json is never touched.
#
# `claw-master connect` accepts exactly those entries (they name its own client directory's agent.token and ca.pem), and
# t-claude's sessions keep their own forwarder: connect also sets the lowercase https_proxy, which Claude prefers. No fallback
# (owner, 2026-10-18): while the agent or the server is down, those requests fail rather than go to Anthropic on the
# person's own login.
#
# Not enrolled: no agent and no drop-in. Run by provision at every container boot (--restart after it installed a new
# claw-master), by claw-master-agent@USER.path when the certificate changes and hourly by claw-master-agent@USER.timer. The
# agent reads its certificate once, when it starts, so it is restarted whenever client.pem is not the certificate it was
# started with (enrolling and the daily renewal both swap a new directory in). The CM_AGENT_* variables are for the offline tests.
set -uo pipefail
U=${1:-}
RESTART=""
[ "${2:-}" = --restart ] && RESTART=1
case "$U" in ''|*[!a-z0-9_-]*) echo "usage: claw-master-agent-setup USER [--restart]" >&2; exit 2 ;; esac
H=${CM_AGENT_HOME:-/home/$U}
CONFIG=${CM_AGENT_CONFIG:-/opt/nextjs-ct/config.json}
CM=${CM_AGENT_BIN:-/usr/local/bin/claw-master}
ENVFILE=${CM_AGENT_ENVFILE:-/etc/nextjs-ct/claw-master-agent.env}
DROPIN=${CM_AGENT_DROPIN:-/etc/claude-code/managed-settings.d/50-claw-master-agent.json}
LISTEN=${CM_AGENT_LISTEN:-127.0.0.1:8445}
TRIES=${CM_AGENT_TRIES:-30}   # half a second each
DIR=$H/.config/claude-master
PEM=$DIR/client.pem
UNIT=claw-master-agent@$U.service
LOCK=${CM_AGENT_LOCK:-/run/claw-master-agent-setup.lock}
LOADED=${CM_AGENT_LOADED:-/run/claw-master-agent@$U.pem.sha256}   # the certificate the running agent was started with
USER_SETTINGS=$H/.claude/settings.json
as_user() { if [ "$(id -un)" = "$U" ]; then "$@"; else sudo -u "$U" -H env HOME="$H" "$@"; fi; }
say() { echo "claw-master-agent-setup: $*" >&2; }

# One run at a time: provision, the path unit and the timer can all start one at once (enabling the timer starts it).
exec 9>"$LOCK" && flock 9 || { say "cannot take $LOCK"; exit 1; }

# A renewal swaps the directory with two renames, so the certificate can be missing for a moment: only an absence that
# lasts is "not enrolled".
enrolled() {
  local _
  for _ in $(seq 1 "$TRIES"); do
    as_user test -r "$PEM" && return 0
    sleep 0.5
  done
  as_user test -r "$PEM"
}

if ! enrolled; then
  systemctl disable --now "$UNIT" >/dev/null 2>&1 || true
  rm -f "$DROPIN"
  echo "claw-master-agent-setup: $U is not enrolled; no agent"
  exit 0
fi

# Enrolled from here on: a fault keeps whatever drop-in is there, so Claude fails rather than use the person's own login.
[ -x "$CM" ] || { say "$CM is missing"; exit 1; }
SERVER=$(jq -r '.claw_master.server // empty' "$CONFIG" 2>/dev/null)
[ -n "$SERVER" ] || { say "no claw_master.server in $CONFIG"; exit 1; }
install -d -m 755 "$(dirname "$ENVFILE")" && printf 'CLAW_MASTER_SERVER=%s\nCLAW_MASTER_AGENT_LISTEN=%s\n' "$SERVER" "$LISTEN" > "$ENVFILE.new" \
  && mv -f "$ENVFILE.new" "$ENVFILE" || { say "could not write $ENVFILE"; exit 1; }
# Prints what Claude needs, and makes the agent's token (agent.token beside the certificate) on first use.
LINES=$(as_user "$CM" agent env --listen "$LISTEN" --server "$SERVER" --dir "$DIR") || { say "claw-master agent env failed"; exit 1; }
SETTINGS=$(printf '%s\n' "$LINES" | jq -Rn '{env: ([inputs | capture("^(?<key>[A-Z_]+)=(?<value>.+)$")] | from_entries)}') \
  && [ "$(jq -c '.env | keys' <<<"$SETTINGS")" = '["HTTPS_PROXY","NODE_EXTRA_CA_CERTS","NO_PROXY"]' ] \
  || { say "unexpected claw-master agent env output"; exit 1; }

systemctl enable "$UNIT" >/dev/null 2>&1 || { say "$UNIT not enabled"; exit 1; }
# Taken before the agent starts, so a certificate swapped in meanwhile reads as different next time and restarts it again.
SUM=$(as_user sha256sum "$PEM" | cut -d' ' -f1) && [ -n "$SUM" ] || { say "cannot read $PEM"; exit 1; }
if ! systemctl is-active --quiet "$UNIT"; then
  systemctl start "$UNIT" || { say "$UNIT did not start"; exit 1; }
elif [ -n "$RESTART" ] || [ "$(cat "$LOADED" 2>/dev/null)" != "$SUM" ]; then
  systemctl restart "$UNIT" || { say "$UNIT did not restart"; exit 1; }
fi
echo "$SUM" > "$LOADED" || { say "cannot write $LOADED"; exit 1; }

# The drop-in is written whether or not the agent came up: the unit keeps restarting it, and failing beats spending the
# person's own login. It carries the agent's token, so only the person (and root) can read it.
install -d -m 755 "$(dirname "$DROPIN")" || { say "cannot make $(dirname "$DROPIN")"; exit 1; }
if ! [ -f "$DROPIN" ] || [ "$(cat "$DROPIN")" != "$SETTINGS" ]; then
  TMP=$(mktemp "$(dirname "$DROPIN")/.claw-master-agent.XXXXXX") && printf '%s\n' "$SETTINGS" > "$TMP" \
    && chgrp "$(id -gn "$U")" "$TMP" && chmod 640 "$TMP" && mv -f "$TMP" "$DROPIN" \
    || { rm -f "${TMP:-}"; say "could not write $DROPIN"; exit 1; }
fi

# Spellings Claude takes over HTTPS_PROXY and NO_PROXY (it prefers lowercase), set in the person's own settings, would route
# around the agent; the drop-in cannot set them (connect accepts only the three it writes), so they are reported.
OTHER=$(jq -r '(.env | objects) // {} | keys[] | select(IN("https_proxy", "http_proxy", "HTTP_PROXY", "all_proxy", "ALL_PROXY", "no_proxy"))' \
  "$USER_SETTINGS" 2>/dev/null | tr '\n' ' ')
[ -z "$OTHER" ] || { say "$USER_SETTINGS sets ${OTHER% }, which Claude would use instead of the agent"; exit 1; }

# Ready means the unit's own process listens there: something else on the port would be handed every Claude request.
PORT=${LISTEN##*:}
for _ in $(seq 1 "$TRIES"); do
  PID=$(systemctl show -p MainPID --value "$UNIT")
  [ "${PID:-0}" != 0 ] && ss -Hltnp "sport = :$PORT" 2>/dev/null | grep -q "pid=$PID," && {
    echo "claw-master-agent-setup: $U uses the pool through $LISTEN"
    exit 0
  }
  sleep 0.5
done
say "$UNIT is not the listener on $LISTEN"
exit 1