extern crate clap;
extern crate time;
extern crate task1;
extern crate sys_info;

use std::sync::mpsc::channel;
use time::get_time;
use clap::{Arg, App, SubCommand};
use std::{process, thread};
use task1::verify_product;
use std::sync::Arc;

pub fn main() {
    let matches = create_app().get_matches();
    let base = matches.value_of("base").unwrap_or("1");
    let diff = Arc::new(matches.value_of("difficulty").unwrap_or("1").to_string());
    let cpus = sys_info::cpu_num().unwrap_or(1).to_string();
    let threads = matches.value_of("threads").unwrap_or(&cpus);
    let mut time_measurement = false;

    if diff.chars().any(|c| !c.is_digit(16)) {
        println!("Difficulty is not hexadecimal.");
        process::exit(1)
    }

    if let Some(ref sub_command) = matches.subcommand {
        if sub_command.name.eq("timings") {
            time_measurement = true;
        }
    }

    if true {
        println!("--------------------------------------------");
        println!(
            "Container:    : \"{}\"",
            sys_info::hostname().unwrap_or("-".to_string())
        );
        println!("Physical CPUs : {}", sys_info::cpu_num().unwrap_or(0));
        println!("Logical CPUs  : {}", sys_info::cpu_num().unwrap_or(0));
        println!("CPU Speed     : {}", sys_info::cpu_speed().unwrap_or(0));
        println!("Load Average  : {:?}", sys_info::loadavg().unwrap());
        println!("Processes     : {}", sys_info::proc_total().unwrap_or(0));
        println!("--------------------------------------------");
    }

    match (base.parse::<usize>(), threads.parse::<usize>()) {
        (Ok(b), Ok(t)) => {
            println!("Using base: {}", b);
            println!("Using difficulty: {}", diff);
            println!("Please wait...");
            let start = get_time();
            let max = <usize>::max_value();
            let mut children = vec![];

            let (tx, rx) = channel();

            for i in 0..t {
                let d = diff.clone();
                let tx = tx.clone();

                children.push(thread::spawn(move || {
                    let from = max / t * i;
                    let to = max / t * (i + 1);
                    println!("{} - {} | Thread {} | Difficulty is: {}", from, to, i, d);

                    for n in from..to {
                        if let Some(x) = verify_product(b, n, &d) {
                            let end = get_time();
                            println!("Number: {} --> hash: {}", x.number, x.hash);
                            if time_measurement {
                                let diff = end - start;
                                let s = diff.num_seconds();
                                let ms = diff.num_milliseconds();
                                let us = diff.num_microseconds().unwrap_or(ms * 1000);
                                println!("(Duration {}s / {}ms / {}us)", s, ms, us);
                            }
                            tx.send("Finished").unwrap();
                        }
                    }

                }));
            }

            match rx.recv() {
                Ok(msg) => {
                    println!("{}", msg);
                }
                Err(_) => {}
            }

            /*
            for child in children {
                let _ = child.join();
            } 
            */
        }
        (_, Err(_)) => {
            println!("Number of threads is not integer.");
            process::exit(1)
        }
        (Err(_), _) => {
            println!("Base is not integer.");
            process::exit(1)
        }
    };
}

fn create_app<'a, 'b>() -> App<'a, 'b> {
    App::new("Hash256")
        .version("1.0")
        .author("Lorenz Bung & Joshua Rutschmann")
        .about(
            "Calculates the Hashvalue of the given base, number and difficulty.",
        )
        .arg(
            Arg::with_name("base")
                .value_name("base")
                .help("The base of the hash to be calculated on.")
                .takes_value(true)
                .required(true),
        )
        .arg(
            Arg::with_name("difficulty")
                .value_name("difficulty")
                .help("The difficulty of the calculated hash.")
                .takes_value(true)
                .required(true),
        )
        .arg(
            Arg::with_name("threads")
                .value_name("threads")
                .help(
                    "Sets the number of the threads to use (default = number of cpus)",
                )
                .takes_value(true)
                .required(false),
        )
        .subcommand(
            SubCommand::with_name("timings")
                .about("controls timing features")
                .version("1.0")
                .author("Lorenz Bung & Joshua Rutschmann"),
        )
}