use std::env;
use std::str::FromStr;

use clap::{Parser, Subcommand};

use aardvark_dns::commands::{run, version};
use log::Level;
use syslog::{BasicLogger, Facility, Formatter3164};

#[derive(Parser, Debug)]
#[clap(version = env!("CARGO_PKG_VERSION"))]
struct Opts {
    /// Path to configuration directory
    #[clap(short, long)]
    config: Option<String>,
    /// Host port for aardvark servers, defaults to 5533
    #[clap(short, long)]
    port: Option<u32>,
    /// Filters search domain for backward compatiblity with dnsname/dnsmasq
    #[clap(short, long)]
    filter_search_domain: Option<String>,
    /// Aardvark-dns trig command
    #[clap(subcommand)]
    subcmd: SubCommand,
}

#[derive(Subcommand, Debug)]
enum SubCommand {
    /// Runs the aardvark dns server with the specified configuration directory.
    Run(run::Run),
    /// Display info about aardvark.
    Version(version::Version),
}

fn main() {
    let formatter = Formatter3164 {
        facility: Facility::LOG_USER,
        hostname: None,
        process: "aardvark-dns".into(),
        pid: 0,
    };

    let log_level = match env::var("RUST_LOG") {
        Ok(val) => match Level::from_str(&val) {
            Ok(level) => level,
            Err(e) => {
                eprintln!("aardvark-dns: failed to parse RUST_LOG level: {}", e);
                Level::Info
            }
        },
        // if env is not set default to info
        Err(_) => Level::Info,
    };

    // On error do nothing, running on system without syslog is fine and we should not clutter
    // logs with meaningless errors, https://github.com/containers/podman/issues/19809.
    if let Ok(logger) = syslog::unix(formatter) {
        if let Err(e) = log::set_boxed_logger(Box::new(BasicLogger::new(logger)))
            .map(|()| log::set_max_level(log_level.to_level_filter()))
        {
            eprintln!("aardvark-dns: failed to initialize syslog logger: {}", e)
        };
    }

    let opts = Opts::parse();

    let dir = opts.config.unwrap_or_else(|| String::from("/dev/stdin"));
    let port = opts.port.unwrap_or(5533_u32);
    let filter_search_domain = opts
        .filter_search_domain
        .unwrap_or_else(|| String::from(".dns.podman"));
    let result = match opts.subcmd {
        SubCommand::Run(run) => run.exec(dir, port, filter_search_domain),
        SubCommand::Version(version) => version.exec(),
    };

    match result {
        Ok(_) => {}
        Err(err) => {
            eprintln!("aardvark-dns: {}", err);
            std::process::exit(1);
        }
    }
}

#[cfg(test)]
mod test;
