use chrono::{DateTime, NaiveDate, NaiveDateTime, NaiveTime, TimeDelta, Utc};
use clap::Parser;


#[derive(Parser, Debug)]
struct Args {
    time: Option<String>,
    // date: Option<String>,
    // time: Option<String>,
    // time: Option<NaiveTime>,
    // #[arg(long)]
    // zone: Ti
}

fn main() {
    let args = Args::parse();
    let stamp = if let Some(time) = args.time {
        let time = DateTime::parse_from_rfc2822(&time).unwrap();
        println!("time: {}", time);
        println!("time: {}", time.to_rfc2822());
        time.with_timezone(&Utc)
    } else {
        let now = Utc::now();
        println!("Now: {}", now.with_timezone(&chrono::Local));
        now
    };
    let unix = stamp.timestamp();
    let stamp = stamp.with_timezone(&chrono::Local);
    println!("<t:{}:F>  {}", unix, stamp.format("%A, %B %-d, %Y at %-H:%M %p"));
    println!("<t:{}:f>  {}", unix, stamp.format("%B %-d, %Y at %-H:%M %p"));
    println!("<t:{}:D>  {}", unix, stamp.format("%B %-d, %Y"));
    println!("<t:{}:d>  {}", unix, stamp.format("%-m/%-d/%y"));
    println!("<t:{}:T>  {}", unix, stamp.format("%-H:%M:%S %A"));
    println!("<t:{}:t>  {}", unix, stamp.format("%-H:%M %A"));
    let diff = stamp.with_timezone(&Utc) - Utc::now();
    let wrap = 
    if diff > TimeDelta::zero() {
        |num: i64, word: &str| format!("In {num} {word}")
    } else {
        |num: i64, word: &str| format!("{num} {word} ago")
    };
    let abs_diff = diff.abs();
    let words = if abs_diff.num_days() > 0 {
        wrap(abs_diff.num_days() + i64::from(abs_diff.num_hours() >= 12), "days")
    } else if abs_diff.num_hours() > 0 {
        wrap(abs_diff.num_hours(), "hours")
    } else if abs_diff.num_minutes() > 0 {
        wrap(abs_diff.num_minutes(), "minutes")
    } else if abs_diff.num_seconds() > 0 {
        wrap(abs_diff.num_seconds(), "seconds")
    } else {
        format!("now")
    };
    println!("<t:{}:R>  {}", unix, words);
}