extern crate static_http_cache;
extern crate reqwest;
extern crate env_logger;

use std::env;
use std::error::Error;
use std::fs;
use std::io;
use std::path;


fn parse_args<T: Iterator<Item=String>>(mut args: T)
    -> Result<fs::File, Box<dyn Error>>
{
    let cache_path = args.next()
        .map(|x| Ok(path::PathBuf::from(x)))
        .unwrap_or(Err("Cache directory argument required"))?;

    // Create the directory to hold persistent cache data.
    fs::DirBuilder::new()
        .recursive(true)
        .create(&cache_path)?;

    let raw_url = args.next()
        .map(Ok)
        .unwrap_or(Err("URL argument required"))?;
    let url = reqwest::Url::parse(&raw_url)?;

    let mut cache = static_http_cache::Cache::new(
        cache_path,
        reqwest::blocking::Client::new(),
    )?;

    cache.get(url)
}


fn main() {
    env_logger::init();

    match parse_args(env::args().skip(1)) {
        Ok(mut file) => {
            let stdout = io::stdout();
            io::copy(&mut file, &mut stdout.lock()).expect("could not write to stdout");
        },
        Err(e) => {
            eprintln!("Could not download URL: {:#?}", e);
        },
    }
}