#!/bin/bash
# capture-dsh-token.sh — start dsh-web, capture its token, update nginx
# Run on CT112 (tankodhs.sysloggh.net)
# This script:
# 1. Restarts the dsh-web service
# 2. Captures the token URL from the journal
# 3. Extracts the token value
# 4. Writes the token to /etc/dsh-web/launch-token
# 5. Creates an nginx config that exposes a /dsh-web-login endpoint
# 6. Reloads nginx

set -euo pipefail
umask 077

# Kill any existing dsh-web instance first
systemctl stop dsh-web 2>/dev/null || true
sleep 2

# Record the time we started the service (for --since filter)
START_TIME="$(date -u +%Y-%m-%dT%H:%M:%SZ)"

# Start dsh-web
systemctl start dsh-web

# Wait for the token to appear in the journal (up to 30 seconds)
TOKEN=""
for i in {1..30}; do
  TOKEN=$(journalctl -u dsh-web.service --since "$START_TIME" --output=cat 2>/dev/null | grep -m1 "dsh web: http://" | grep -oP "(?<=dsh web: )(https?://[^ ]+)" | head -1 || true)
  if [ -n "$TOKEN" ]; then
    break
  fi
  sleep 1
done

if [ -z "$TOKEN" ]; then
  echo "ERROR: token not captured within 30s" >&2
  exit 1
fi

# Extract the token value (everything after "?token=")
TOKEN_VALUE=$(echo "$TOKEN" | grep -oP "(?<=token=)[^ ]+")

# Reject tokens that could break nginx config or the request URI
if ! printf '%s' "$TOKEN_VALUE" | grep -qE '^[A-Za-z0-9._~+/=%:@-]+$'; then
  echo "ERROR: token contains unsupported characters" >&2
  exit 1
fi

# Write the token to a restricted file
mkdir -p /etc/dsh-web
printf '%s\n' "$TOKEN_VALUE" > /etc/dsh-web/launch-token
chmod 600 /etc/dsh-web/launch-token
echo "Captured dsh-web launch token"

# Create the nginx config with the token (using printf to control expansion)
NGINX_ENABLED="/etc/nginx/sites-enabled/dsh.token"
NGINX_STAGE_DIR="/etc/nginx/sites-available"
mkdir -p "$NGINX_STAGE_DIR"

TMP_CONFIG="$(mktemp "$NGINX_STAGE_DIR/dsh.token.XXXXXX")"
BACKUP=""
if [ -f "$NGINX_ENABLED" ]; then
  BACKUP="$(mktemp "$NGINX_STAGE_DIR/dsh.token.bak.XXXXXX")"
  cp -p "$NGINX_ENABLED" "$BACKUP"
fi

{
  printf "server {\n"
  printf "    listen 127.0.0.1:8081;\n"
  printf "    server_name _;\n"
  printf "    \n"
  printf "    location = /dsh-web-login {\n"
  printf "        proxy_pass http://127.0.0.1:3080/?token=%s;\n" "$TOKEN_VALUE"
  printf "        proxy_http_version 1.1;\n"
  printf "        proxy_set_header Host 127.0.0.1:3080;\n"
  printf "        proxy_set_header X-Real-IP \$remote_addr;\n"
  printf "        proxy_set_header X-Forwarded-For \$proxy_add_x_forwarded_for;\n"
  printf "    }\n"
  printf "    \n"
  printf "    location / {\n"
  printf "        proxy_pass http://127.0.0.1:3080;\n"
  printf "        proxy_http_version 1.1;\n"
  printf "        proxy_set_header Host 127.0.0.1:3080;\n"
  printf "        proxy_set_header X-Real-IP \$remote_addr;\n"
  printf "        proxy_set_header X-Forwarded-For \$proxy_add_x_forwarded_for;\n"
  printf "    }\n"
  printf "}\n"
} > "$TMP_CONFIG"
chmod 600 "$TMP_CONFIG"

mv "$TMP_CONFIG" "$NGINX_ENABLED"
CONFIG_APPLIED=1
restore_on_exit() {
  if [ "$CONFIG_APPLIED" -eq 1 ]; then
    if [ -n "$BACKUP" ]; then
      if cp -p "$BACKUP" "$NGINX_ENABLED" 2>/dev/null; then rm -f "$BACKUP"; fi
    else
      rm -f "$NGINX_ENABLED"
    fi
  fi
}
trap restore_on_exit EXIT

if nginx -t; then
  /usr/sbin/nginx -s reload
  CONFIG_APPLIED=0
  if [ -n "$BACKUP" ]; then rm -f "$BACKUP"; fi
  echo "Token captured and nginx reloaded"
else
  echo "ERROR: nginx config test failed; rolling back" >&2
  exit 1
fi