netdev 0.24.0

use crate::interface::InterfaceType;
use std::convert::TryFrom;
use std::fs::read_to_string;
use std::net::IpAddr;

const PATH_RESOLV_CONF: &str = "/etc/resolv.conf";

pub fn get_interface_type(if_name: String) -> InterfaceType {
    let if_type_path: String = format!("/sys/class/net/{}/type", if_name);
    let r = read_to_string(if_type_path);
    match r {
        Ok(content) => {
            let if_type_string = content.trim().to_string();
            match if_type_string.parse::<u32>() {
                Ok(if_type) => {
                    return InterfaceType::try_from(if_type).unwrap_or(InterfaceType::Unknown);
                }
                Err(_) => {
                    return InterfaceType::Unknown;
                }
            }
        }
        Err(_) => {
            return InterfaceType::Unknown;
        }
    };
}

pub fn get_interface_speed(if_name: String) -> Option<u64> {
    let if_speed_path: String = format!("/sys/class/net/{}/speed", if_name);
    let r = read_to_string(if_speed_path);
    match r {
        Ok(content) => {
            let if_speed_string = content.trim().to_string();
            match if_speed_string.parse::<u64>() {
                Ok(if_speed) => {
                    // Convert Mbps to bps
                    return Some(if_speed * 1000000);
                }
                Err(_) => {
                    return None;
                }
            }
        }
        Err(_) => {
            return None;
        }
    };
}

pub fn get_system_dns_conf() -> Vec<IpAddr> {
    let r = read_to_string(PATH_RESOLV_CONF);
    match r {
        Ok(content) => {
            let conf_lines: Vec<&str> = content.trim().split("\n").collect();
            let mut dns_servers = Vec::new();
            for line in conf_lines {
                let fields: Vec<&str> = line.split_whitespace().collect();
                if fields.len() >= 2 {
                    // field [0]: Configuration type (e.g., "nameserver", "domain", "search")
                    // field [1]: Corresponding value (e.g., IP address, domain name)
                    if fields[0] == "nameserver" {
                        if let Ok(ip) = fields[1].parse::<IpAddr>() {
                            dns_servers.push(ip);
                        } else {
                            eprintln!("Invalid IP address format: {}", fields[1]);
                        }
                    }
                }
            }
            dns_servers
        }
        Err(_) => {
            return Vec::new();
        }
    }
}