#!/bin/sh

case $1 in
    prereqs)
        exit 0
        ;;
esac

set -e

# Extract kernel parameters
set -- $(cat /proc/cmdline)
items=""
for x in "$@"; do
    case "$x" in
        Aboot=*)
            aboot_flag="${x#Aboot=}"
            ;;
        net_*)
            item="${x#net_}"
            items="$items $item"
            ;;
        platform=*)
            platform_flag="${x#platform=}"
            ;;
    esac
done

arista_net_rename() {
    local device_path="$1"
    local new_name="$2"
    local from_name="$3"
    for path in $(ls -d /sys/class/net/$from_name* 2>/dev/null); do
        local devid="$(realpath "$path/device")"
        if echo "$devid" | grep -q "$device_path"; then
            local cur_name="${path##*/}"
            ip link set "$cur_name" name "$new_name"
            return
        fi
    done
}

# Iterate over all the net_maX items found in the cmdline two times.
# First time renaming the interfaces to maX.
# The second time renaming them to their final name ethX.
if [ -n "$aboot_flag" -a "$platform_flag" == 'rook' ]; then
    for item in $items; do
        key="${item%=*}"
        value="${item#*=}"
        arista_net_rename "$value" "$key" eth
    done
    for item in $items; do
        key="${item%=*}"
        value="${item#*=}"
        index="${key#ma}"
        index="$(( $index - 1 ))"
        newKey="eth$index"
        arista_net_rename "$value" "$newKey" ma
    done
fi