#!/bin/bash

# ---- Configuration ----
source /opt/scripts/mesh/freq.sh
source /opt/scripts/mesh/node_addresses.sh

PHYNAME=$1
DEVNAME=$2
CHANNEL=${chan[$3]}
POWER=$4
NOISEFLOOR=$5

phy_number="${1//[!0-9]/}"
dev_number="${2//[!0-9]/}"
devPath="/sys/class/net/"
phyPath="/sys/kernel/debug/ieee80211/"

SSID="adhocnet"
BSSID="02:11:87:3A:4C:55"

# ---- Host validation ----
nodename="$(uname -n)"
host_valid=0
ALLNODES=${neighbors["all"]}

while [[ host_valid -eq 0 ]]; do
	for i in $ALLNODES; do
		if [[ $nodename == $i ]]; then
			host_valid=1
			echo "Hostname $nodename is valid"
			break
		fi
	done
	if [[ host_valid -eq 0 ]]; then
		sleep 1
		nodename="$(uname -n)"
	fi
done

echo "Configuring $nodename $DEVNAME on $PHYNAME"

# ---- Kernel/Network tuning ----
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

# ---- Check/clean interface ----
if [ ! -e "$phyPath$PHYNAME" ]; then
	echo "$PHYNAME not found in $phyPath, aborting."
	exit 1
fi

systemctl stop systemd-timesyncd.service

if [ -e "$devPath$DEVNAME" ]; then
	number=$(iw dev "$DEVNAME" info | awk '$1 == "wiphy" {print $2}')
	echo "Removing existing $DEVNAME from phy$number"
	ip link set $DEVNAME down
	iw dev $DEVNAME del
fi

# Delete existing interfaces on this phy
current_dev_on_phy=$(iw dev | awk -v phy="$phy_number" '$0 ~ "phy#"phy {getline; while ($1 ~ /^Interface/) {print $2; getline}}')
if [ ! -z "$current_dev_on_phy" ]; then
	echo "Removing $current_dev_on_phy from phy$phy_number"
	ip link set $current_dev_on_phy down
	iw dev $current_dev_on_phy del
fi

# ---- Create IBSS interface ----
iw phy ${PHYNAME} interface add ${DEVNAME} type ibss
ip link set ${DEVNAME} down
ip link set ${DEVNAME} up
iw dev ${DEVNAME} ibss join $SSID ${CHANNEL} HT40+ fixed-freq $BSSID

# ---- Set tx power and bitrate ----
iw dev ${DEVNAME} set txpower fixed $POWER
if [[ $3 -lt 15 ]]; then
	iw dev ${DEVNAME} set bitrates ht-mcs-2.4 6 sgi-2.4
else
	iw dev ${DEVNAME} set bitrates ht-mcs-5 6 sgi-5
fi

# ---- Set IP address ----
ip addr flush dev ${DEVNAME}

if [[ "$dev_number" -eq 0 ]]; then
	NODE_MESH_IP=${phy0IP["$nodename"]}
	BROADCAST_IP=${phy0IP["broadcast"]}
else
	NODE_MESH_IP=${phy1IP["$nodename"]}
	BROADCAST_IP=${phy1IP["broadcast"]}
fi

echo "Assigning IP: $NODE_MESH_IP"
ip addr add ${NODE_MESH_IP}/24 broadcast ${BROADCAST_IP} dev ${DEVNAME}

# ---- Done ----
echo "$DEVNAME is now in IBSS mode with IP $NODE_MESH_IP"