#!/bin/bash
# Usage: ./init_adhoc.sh <PHYNAME> <DEVNAME> <SSID> <CHANNEL> <TXPOWER> <NOISEFLOOR> <NODES...>
# Example: ./init_adhoc.sh phy0 wlan0 adhocnet 36 1000 -95 0 1 2 3

set -e

### === INPUT ARGUMENTS ===
PHYNAME=$1
DEVNAME=$2
SSID=$3
CHANNEL=$4
TXPOWER=$5
NOISEFLOOR=$6
shift 6
NODES=($@)

source /opt/scripts/mesh/node_addresses.sh

# Check whether node is part of the network
HOSTNAME=$(uname -n | cut -d. -f1)
NODE_ID=$(echo "$HOSTNAME" | sed -E 's/[^0-9]*([0-9]+)$/\1/')
NODE_ID=$((10#$NODE_ID))
NODE_INDEX=-1
for idx in "${!NODES[@]}"; do
  [[ ${NODES[$idx]} -eq $NODE_ID ]] && NODE_INDEX=$idx && break
done
if [[ $NODE_INDEX -lt 0 ]]; then
  echo "[!] Node ID $NODE_ID not found in list."
  exit 1
fi

# Extract device number
dev_number=$(echo "$DEVNAME" | grep -o '[0-9]\+$')

### === PATHS ===
devPath="/sys/class/net/"
phyPath="/sys/kernel/debug/ieee80211/"

### === SYSTEM TUNING ===
echo "[*] Applying system optimizations..."
sysctl -w net.core.rmem_max=8388608
sysctl -w net.core.wmem_max=8388608
sysctl -w net.core.rmem_default=8388608
sysctl -w net.core.wmem_default=8388608
sysctl -w net.core.optmem_max=8388608
sysctl -w net.ipv4.tcp_mem="8388608 8388608 8388608"
sysctl -w net.ipv4.tcp_rmem="4096 87380 8388608"
sysctl -w net.ipv4.tcp_wmem="4096 65536 8388608"
sysctl -w net.ipv4.udp_mem="8388608 8388608 8388608"
sysctl -w net.ipv4.udp_rmem_min=4096
sysctl -w net.ipv4.udp_wmem_min=4096
sysctl -w net.core.netdev_max_backlog=5000
sysctl -w net.ipv4.tcp_max_syn_backlog=5000
sysctl -w net.ipv4.tcp_syn_retries=9
sysctl -w net.ipv4.tcp_synack_retries=9
sysctl -w net.ipv4.tcp_no_metrics_save=1
sysctl -w net.ipv4.route.flush=1
echo 0 > /sys/module/tcp_cubic/parameters/hystart
echo 0 > /sys/module/tcp_cubic/parameters/hystart_detect
sysctl -w net.ipv4.neigh.default.base_reachable_time_ms=1200000
sysctl -w net.ipv4.neigh.default.mcast_solicit=25
sysctl -w net.ipv4.neigh.default.ucast_solicit=25

### === CLEAN INTERFACES ===
if ip link show dev $DEVNAME &>/dev/null; then
  ip addr flush dev $DEVNAME
  ip link set $DEVNAME down || true
  iw dev $DEVNAME del || true
fi

phy_index=${PHYNAME//[!0-9]/}
current_dev_on_phy=$(iw dev | awk -v phy="$phy_index" '$0 ~ "phy#"phy {getline; while ($1 == "Interface") {print $2; getline}}')
if [[ ! -z "$current_dev_on_phy" ]]; then
  ip link set $current_dev_on_phy down || true
  iw dev $current_dev_on_phy del || true
fi

### === INTERFACE CONFIG ===
echo "[*] Creating IBSS interface $DEVNAME on $PHYNAME..."
iw phy $PHYNAME interface add $DEVNAME type ibss || {
  echo "[!] Failed to create interface. Ensure PHY is up."
  exit 1
}

ip addr flush dev $DEVNAME

### === FREQUENCY SETUP ===
source /opt/scripts/mesh/freq.sh
FREQ=${chan[$CHANNEL]}
if [[ -z "$FREQ" ]]; then
  echo "[!] Channel $CHANNEL not found in freq.sh mapping"
  exit 1
fi

### === PHY PARAMS BEFORE IFACE UP ===
iw dev $DEVNAME set type ibss
# These must be done *before* bringing interface up:
iw phy $PHYNAME set antenna 3 3
iw phy $PHYNAME set retry short 7 long 4
iw phy $PHYNAME set rts off
iw dev $DEVNAME set power_save off

### === BRING IFACE UP ===
ip link set $DEVNAME up
sleep 1

# Optional: ARP suppression after iface is up
sysctl -w net.ipv4.conf.$DEVNAME.arp_ignore=1
sysctl -w net.ipv4.conf.$DEVNAME.arp_announce=2

### === JOIN IBSS ===
BSSID="02:11:87:7B:5E:01"
echo "[*] Joining IBSS: SSID=$SSID FREQ=$FREQ MHz..."
# iw dev $DEVNAME ibss leave || true
sleep 1
# iw dev $DEVNAME ibss join $SSID $FREQ HT40 fixed-freq $BSSID || {
#   echo "Failed to join IBSS."
#   exit 1
# }

iw dev $DEVNAME ibss join "$SSID" "$FREQ" HT40+ beacon-interval 1000 basic-rates 54 mcast-rate 54 || {
  echo "[!] Failed to join IBSS with basic/mcast rates."
  exit 1
}


### === SET TX POWER ===
iw dev $DEVNAME set txpower fixed $TXPOWER

### === ASSIGN IP ===
if [[ $dev_number -eq 0 ]]; then
  IP_ADDR=${phy0IP[$HOSTNAME]}
  BROADCAST_IP=${phy0IP["broadcast"]}
elif [[ $dev_number -eq 1 ]]; then
  IP_ADDR=${phy1IP[$HOSTNAME]}
  BROADCAST_IP=${phy1IP["broadcast"]}
fi

if [[ -z "$IP_ADDR" ]]; then
  echo "[!] IP not found for $HOSTNAME"
  exit 1
fi

ip addr add ${IP_ADDR}/24 broadcast $BROADCAST_IP dev $DEVNAME

### === ENABLE IP FORWARDING ===
if (( NODE_INDEX > 0 && NODE_INDEX < ${#NODES[@]} - 1 )); then
  echo "Enabling IP forwarding..."
  sysctl -w net.ipv4.ip_forward=1
fi

### === ADD ROUTES ===
for target_idx in "${!NODES[@]}"; do
  target_node=${NODES[$target_idx]}
  [[ $target_node -eq $NODE_ID ]] && continue

  if (( target_idx < NODE_INDEX )); then
    next_hop=${NODES[$((NODE_INDEX - 1))]}
  else
    next_hop=${NODES[$((NODE_INDEX + 1))]}
  fi

  target_ip=${phy0IP["apu$(printf "%02d" $target_node)"]}
  next_ip=${phy0IP["apu$(printf "%02d" $next_hop)"]}

  [[ -n "$target_ip" && -n "$next_ip" ]] && ip route add "$target_ip/32" via "$next_ip" dev "$DEVNAME" 2>/dev/null || true

done

### === NOISE FLOOR ===
echo 0 > /sys/kernel/debug/ieee80211/${PHYNAME}/ath9k/ani
echo ${NOISEFLOOR} > /sys/kernel/debug/ieee80211/${PHYNAME}/ath9k/nf_override

### === FIXED RATE (Optional) ===
echo 198 > /sys/kernel/debug/ieee80211/${PHYNAME}/rc/fixed_rate_idx

echo "IBSS initialization complete for $DEVNAME ($IP_ADDR)"