#!/bin/bash
# @file agenthub-provision.sh
# @description Server mode, one Linux user per account (S3): the ONE root
# command the dashboard's host account may run (sudoers, written by
# install-system.sh; installed as /opt/agenthub/sbin/agenthub-provision).
#
#   agenthub-provision create  <name>   Linux user ah-<name>, home <USERS_ROOT>/<name>
#   agenthub-provision disable <name>   lock the account and end its processes
#   agenthub-provision enable  <name>   unlock it
#
# Nothing but an action and a name comes from the caller; every path comes
# from /etc/agenthub/server.conf (root's). It never deletes an account or a
# home, never touches an account that is not an AgentHub member (one that
# already exists outside group agenthub-members is refused), and never
# grants a member sudo.
# @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
set -euo pipefail
umask 022
cd /  # runuser keeps the cwd: one every account may enter

die() { echo "agenthub-provision: $*" >&2; exit "${2:-1}"; }
[ "$(id -u)" = 0 ] || die "must run as root (through sudo)"
[ $# -eq 2 ] || die "usage: agenthub-provision create|disable|enable <name>" 2

CONF=/etc/agenthub/server.conf
[ -f "$CONF" ] || die "$CONF is missing — run agenthub server install-system first"
USERS_ROOT=$(sed -n 's/^USERS_ROOT=//p' "$CONF")
[[ "$USERS_ROOT" == /* ]] || die "USERS_ROOT in $CONF is not absolute"

ACTION=$1 NAME=$2
# Lower case, starts with a letter, ≤ 29 so "ah-<name>" fits Linux's 32.
[[ "$NAME" =~ ^[a-z][a-z0-9_-]{0,28}$ ]] || die "invalid name: $NAME" 3
LOGIN="ah-$NAME"
HOME_DIR="$USERS_ROOT/$NAME"

is_member() { id -nG "$LOGIN" 2>/dev/null | tr ' ' '\n' | grep -qx agenthub-members; }

case "$ACTION" in
  create)
    if id "$LOGIN" >/dev/null 2>&1; then
      is_member || die "$LOGIN exists and is not an AgentHub member — refusing to adopt it" 4
    else
      [ ! -e "$HOME_DIR" ] || die "$HOME_DIR already exists" 5
      useradd --create-home --home-dir "$HOME_DIR" --shell /bin/bash --user-group \
        --groups agenthub-members --comment "AgentHub member $NAME" "$LOGIN"
    fi
    # Home: the member's, readable by the dashboard (group agenthub), nobody else.
    # The home itself sits in root's USERS_ROOT, so the member cannot swap it.
    chown "$LOGIN:agenthub" "$HOME_DIR"
    chmod 0750 "$HOME_DIR"
    # Nothing INSIDE the home is touched as root: the member owns every name
    # there and could have made one a link to a system file. Their tmux socket
    # folder and the folder the dashboard writes a pane's files to (through
    # write-as, as them) are made by the member.
    runuser -u "$LOGIN" -- mkdir -p -m 0700 "$HOME_DIR/.agenthub/tmux" "$HOME_DIR/.agenthub/handoff"
    # Claude Code's first run, as the member: onboarding done (the dashboard's
    # own setup chose theme and the rest) and the home trusted, which covers
    # every folder under it. Merged into what is there; a file that is not
    # JSON is the member's and is left alone.
    if [ -x /opt/agenthub/tools/bin/node ]; then
      runuser -u "$LOGIN" -- /opt/agenthub/tools/bin/node -e '
        const fs = require("fs"), home = process.argv[1], p = home + "/.claude.json";
        let d = {};
        try { d = JSON.parse(fs.readFileSync(p, "utf8")); } catch (e) { if (e.code !== "ENOENT") process.exit(0); }
        d.hasCompletedOnboarding = true;
        d.projects = d.projects || {};
        (d.projects[home] = d.projects[home] || {}).hasTrustDialogAccepted = true;
        fs.writeFileSync(p, JSON.stringify(d, null, 2) + "\n", { mode: 0o600 });
      ' "$HOME_DIR" || echo "agenthub-provision: Claude Code first run not seeded" >&2
    fi
    echo "created $LOGIN $HOME_DIR"
    ;;
  disable)
    is_member || die "$LOGIN is not an AgentHub member" 4
    usermod --lock --expiredate 1 "$LOGIN"
    pkill -KILL -u "$LOGIN" 2>/dev/null || true
    echo "disabled $LOGIN"
    ;;
  enable)
    is_member || die "$LOGIN is not an AgentHub member" 4
    usermod --expiredate "" "$LOGIN"
    # A member has no password (they never log in to the OS); unlocking one
    # that never had any is refused by usermod and changes nothing.
    usermod --unlock "$LOGIN" >/dev/null 2>&1 || true
    echo "enabled $LOGIN"
    ;;
  *) die "unknown action: $ACTION" 2 ;;
esac