#!/usr/bin/env bash

# Initialization supplies the real host sysfs and USB device paths.
generate_usb() {
    local sys=$1 dev=$2 entry vendor product bus number node
    local -a nodes=()
    for entry in "$sys"/*; do
        [[ -r $entry/idVendor && -r $entry/idProduct ]] || continue
        read -r vendor < "$entry/idVendor" || continue
        read -r product < "$entry/idProduct" || continue
        [[ $vendor == 046d ]] || continue
        case $product in c222|c225|c227|c22b|c22d|c22e) ;; *) continue ;; esac
        [[ -r $entry/busnum && -r $entry/devnum ]] || continue
        read -r bus < "$entry/busnum" || continue
        read -r number < "$entry/devnum" || continue
        [[ $bus =~ ^[0-9]{1,3}$ && $number =~ ^[0-9]{1,3}$ ]] || continue
        printf -v node '%s/%03d/%03d' "$dev" "$((10#$bus))" "$((10#$number))"
        [[ -c $node ]] || continue
        nodes+=("$node")
    done
    printf 'services:\n  dev:\n'
    if ((${#nodes[@]})); then
        printf '    devices:\n'
        for node in "${nodes[@]}"; do
            printf '      - "%s:%s:rw"\n' "$node" "$node"
        done
    else
        printf '    devices: []\n'
    fi
}