#!/usr/bin/env bash
set -euo pipefail

# Run chromium-browser with temporary per-host routes via eth1.
# For a passed URL, resolves target host (and www-host variant),
# adds temporary IPv4 routes via eth1, then removes them on exit.

VIA_GW="192.168.0.1"
DEV="eth1"

ROUTES=()

cleanup() {
  for ip in "${ROUTES[@]:-}"; do
    sudo ip route del "$ip" via "$VIA_GW" dev "$DEV" >/dev/null 2>&1 || true
  done
}
trap cleanup EXIT INT TERM

extract_host() {
  local url="$1"
  python3 - "$url" <<'PY'
import sys
from urllib.parse import urlparse
u = sys.argv[1]
p = urlparse(u)
print((p.hostname or '').strip())
PY
}

add_routes_for_host() {
  local host="$1"
  [[ -z "$host" ]] && return 0

  local ips
  ips=$(getent ahostsv4 "$host" 2>/dev/null | awk '{print $1}' | sort -u || true)
  [[ -z "$ips" ]] && return 0

  while IFS= read -r ip; do
    [[ -z "$ip" ]] && continue
    sudo ip route replace "$ip" via "$VIA_GW" dev "$DEV"
    ROUTES+=("$ip")
  done <<< "$ips"
}

TARGET_URL=""
for arg in "$@"; do
  if [[ "$arg" =~ ^https?:// ]]; then
    TARGET_URL="$arg"
    break
  fi
done

if [[ -n "$TARGET_URL" ]]; then
  HOST=$(extract_host "$TARGET_URL")
  if [[ -n "$HOST" ]]; then
    add_routes_for_host "$HOST"
    # add alternate host variant for common redirects
    if [[ "$HOST" == www.* ]]; then
      add_routes_for_host "${HOST#www.}"
    else
      add_routes_for_host "www.$HOST"
    fi
  fi
fi

chromium-browser "$@"