use libc::{c_int, c_char};
use getopts::Options;
use std::process::exit;

mod radio;

const COPYRIGHT: &'static str = "Copyright (C) 2018 Serge Vakulenko KK6ABQ";
const VERSION: Option<&'static str> = option_env!("VERSION");

extern {
  fn old_c_main(argc: c_int, argv: *const *const c_char) -> c_int;
}

#[no_mangle]
pub extern "C" fn print_usage() {
  let version = VERSION.unwrap_or("-----");

  print!("DMR Config, Version {}, {}", version, COPYRIGHT);

  let msg = r#"
Usage:
    dmrconfig -r [-t]
                          Read codeplug from the radio to a file 'device.img'.
                          Save configuration to a text file 'device.conf'.
    dmrconfig -w [-t] file.img
                          Write codeplug to the radio.
    dmrconfig -v [-t] file.conf
                          Verify configuration script for the radio.
    dmrconfig -c [-t] file.conf
                          Apply configuration script to the radio.
    dmrconfig -c file.img file.conf
                          Apply configuration script to the codeplug image.
                          Store modified copy to a file 'device.img'.
    dmrconfig file.img
                          Display configuration from the codeplug image.
    dmrconfig -u [-t] file.csv
                          Update contacts database from CSV file.
Options:
    -r           Read codeplug from the radio.
    -w           Write codeplug to the radio.
    -c           Configure the radio from a text script.
    -v           Verify config file.
    -u           Update contacts database.
    -l           List all supported radios.
    -t           Trace USB protocol."#;
  print!("{}", msg);
  exit(-1);
}

fn get_options() -> Options {
  let mut opts = Options::new();
  opts.optflag("t", "", "Trace USB protocol.");
  opts.optflag("r", "", "Read codeplug from the radio to a file 'device.img'.\nSave configuration to a text file 'device.conf'.");
  opts.optflag("w", "", "Write codeplug to the radio.");
  opts.optflag("c", "", "Verify configuration script for the radio.");
  opts.optflag("u", "", "Update contacts database from CSV file.");
  opts.optflag("l", "", "List all supported radios.");
  opts.optflag("v", "", "Verify configuration script for the radio.");
  opts
}

#[no_mangle]
pub extern "C" fn rust_main(argc: c_int, argv: *const *const c_char) -> c_int {

  let args = std::env::args().skip(1);
  let matches = match get_options().parse(args) {
    Ok(m) => m,
    Err(fail) => {
      eprintln!("{}", fail);
      exit(-1);
    }
  };

  let list_flag = matches.opt_present("l");
  let verify_flag = matches.opt_present("v");
  let read_flag = matches.opt_present("r");
  let write_flag = matches.opt_present("w");
  let config_flag = matches.opt_present("c");
  let csv_flag = matches.opt_present("u");

  if list_flag {
    radio::list();
    exit(0);
  }

  if [read_flag, write_flag, config_flag, csv_flag, verify_flag].iter().filter(|x| **x).count() > 1 {
    eprintln!("Only one of -r, -w, -c, -v or -u options is allowed.");
    print_usage();
  }

  unsafe {
    old_c_main(argc, argv)
  }
}

#[cfg(test)]
mod tests {
    #[test]
    fn it_works() {
        assert_eq!(2 + 2, 4);
    }
}