extern crate getopts;
extern crate url;

use getopts::Options;
use url::Url;

use std::env;
use std::io::{self, Write};
use std::io::prelude::*;
use std::net::TcpListener;
use std::process::Command;

const DEFAULT_PORT: u16 = 37705;

fn open_stream(browser: String, port: u16) -> io::Result<()> {
    let listener = TcpListener::bind(
        format!("127.0.0.1:{}", port)
    )?;

    for stream in listener.incoming() {
        match stream {
            Ok(mut stream) => {
                let mut url = String::new();
                match stream.read_to_string(&mut url) {
                    Ok(_) => {},
                    Err(e) => writeln!(io::stderr(), "{}", e)?,
                };

                match Url::parse(url.as_str()) {
                    Ok(url) => {
                        match Command::new("open")
                            .arg("-a")
                            .arg(&browser)
                            .arg(&url.as_str())
                            .spawn() {
                            Ok(_) => {},
                            Err(e) => writeln!(io::stderr(), "{}", e)?,
                        };
                    },
                    Err(e) => writeln!(io::stderr(), "{}", e)?,
                };
            }
            Err(e) => {
                writeln!(io::stderr(), "{}", e)?;
            }
        }
    }

    Ok(())
}

fn print_usage(opts: Options) {
    let brief = "Usage: hearurl -b BROWSER";
    print!("{}", opts.usage(&brief));
}

fn main() {
    let args: Vec<String> = env::args().collect();

    let mut opts = Options::new();
    opts.optopt("b", "browser", "set browser", "BROWSER");
    opts.optopt("p", "port", "set port number", "PORT");
    opts.optflag("h", "help", "print this help menu");

    let opt_matches = match opts.parse(&args[1..]) {
        Ok(m) => m,
        Err(e) => panic!(e.to_string()),
    };

    if opt_matches.opt_present("h") {
        print_usage(opts);
        return
    }

    let browser = match opt_matches.opt_str("b") {
        Some(b) => b,
        None => {
            print_usage(opts);
            return
        },
    };

    let port: u16 = match opt_matches.opt_str("p") {
        Some(p) => p.parse().expect("Unable to parse specified port"),
        None => DEFAULT_PORT,
    };

    open_stream(browser, port).unwrap_or_else(|e| {
        writeln!(io::stderr(), "{}", e)
            .expect("Failed printing to stderr");
    });
}