#!/bin/sh
# Policy routing: send traffic to specified domains via Starlink (wan2).
# No mwan3 required. Uses ip rule + custom table. Run on OpenWrt.
# Usage: run from hotplug (wan2 ifup) or manually after wan2 is up.
# Requires: ip, resolveip, ubus, jsonfilter (all default on OpenWrt).

TABLE_ID=100
WAN2_IF=wan2
DOMAINS="polymarket.com www.polymarket.com"

# Optional: set IPs manually if resolveip fails (e.g. no DNS yet). Space-separated.
# POLYMARKET_IPS="1.2.3.4 5.6.7.8"
POLYMARKET_IPS=""

get_wan2_gw() {
    local status
    status=$(ubus call network.interface."$WAN2_IF" status 2>/dev/null) || return 1
    echo "$status" | jsonfilter -e '@.route[0].nexthop' 2>/dev/null
}

get_wan2_dev() {
    local status
    status=$(ubus call network.interface."$WAN2_IF" status 2>/dev/null) || return 1
    echo "$status" | jsonfilter -e '@.device' 2>/dev/null
}

resolve_domains() {
    if [ -n "$POLYMARKET_IPS" ]; then
        echo "$POLYMARKET_IPS"
        return
    fi
    local list=""
    for d in $DOMAINS; do
        for ip in $(resolveip -4 -t 2 "$d" 2>/dev/null | grep -oE '[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+'); do
            [ -n "$ip" ] && list="$list $ip"
        done
    done
    echo "$list" | tr ' ' '\n' | sort -u | tr '\n' ' '
}

do_setup() {
    local gw dev ips ip
    gw=$(get_wan2_gw)
    dev=$(get_wan2_dev)
    if [ -z "$gw" ] || [ -z "$dev" ]; then
        logger -t starlink-policy "wan2 not ready (gw=$gw dev=$dev)"
        return 1
    fi
    ips=$(resolve_domains)
    if [ -z "$ips" ]; then
        logger -t starlink-policy "No IPs resolved for: $DOMAINS. Set POLYMARKET_IPS in script or check DNS."
        return 1
    fi
    for ip in $ips; do
        ip rule del to "$ip" table $TABLE_ID 2>/dev/null
    done
    ip route flush table $TABLE_ID 2>/dev/null
    ip route add default via "$gw" dev "$dev" table $TABLE_ID
    for ip in $ips; do
        ip rule add to "$ip" table $TABLE_ID
    done
    logger -t starlink-policy "Routes via wan2 ($dev): $ips"
}

do_remove() {
    local ips ip
    ips=$(resolve_domains)
    for ip in $ips; do
        ip rule del to "$ip" table $TABLE_ID 2>/dev/null
    done
    ip route flush table $TABLE_ID 2>/dev/null
    logger -t starlink-policy "Removed policy routes for table $TABLE_ID"
}

case "${1:-setup}" in
    setup)   do_setup ;;
    remove) do_remove ;;
    *)
        echo "Usage: $0 [setup|remove]"
        exit 1
        ;;
esac