use tokio::io::{self, AsyncReadExt};

use bytes::BytesMut;
use chrono::{DateTime, Datelike, Timelike};
use reqwest;
use serde::{Deserialize, Serialize};
use tokio::time::error::Error;
use tokio::time::{sleep, Duration};
use webbrowser::open_browser;

#[derive(Serialize, Deserialize, Debug)]
struct Appointment {
  locationId: u32,
  startTimestamp: String,
  endTimestamp: String,
  active: bool,
  duration: u32,
  remoteInd: bool,
}

const TIME: u64 = 3000;
const CHARLOTTE: u32 = 14321;
// const TESTING: u32 = 5023;

#[tokio::main]
async fn main() {
  let mut location_id: u32 = CHARLOTTE;
  let mut buf = [0, 0, 0, 0];

  println!(
    "Enter a location id to override the default (Charlotte, NC, {:?}): ",
    CHARLOTTE
  );
  io::stdin().read(&mut buf).await.unwrap();

  let loc = String::from_utf8(buf.to_vec()).unwrap().trim().parse();
  if loc.is_ok() {
    location_id = loc.unwrap();
  }

  println!("Looking for appointments at location id: {}", location_id);
  loop {
    look_for_appointments(location_id).await;
    println!(
      "No appointments found, trying again in {} seconds",
      TIME / 1000
    );
    sleep(Duration::from_millis(TIME)).await;
  }
}

async fn look_for_appointments(location_id: u32) {
  let data = get_data(location_id).await.unwrap();

  for appointment in data {
    let time = appointment.startTimestamp + ":00-05:00";
    let at = DateTime::parse_from_rfc3339(&time).unwrap();

    println!(
      "Appointment found on {}/{}/{} at {}:{}",
      at.day(),
      at.month(),
      at.year(),
      at.hour(),
      at.minute(),
    );
    open_browser(webbrowser::Browser::Default, "https://ttp.cbp.dhs.gov/credential/v1/login?app=GOES-prod&lang=en&state=en:IonIgXB4I9qt02S6cgKydMVA9HXHC1vq").unwrap();

    println!("Press any key to continue...");
    io::stdin()
      .read_buf(&mut BytesMut::with_capacity(10))
      .await
      .unwrap();
  }
}

async fn get_data(location_id: u32) -> Result<Vec<Appointment>, Error> {
  let res = reqwest::get(format!(
    "https://ttp.cbp.dhs.gov/schedulerapi/slots?orderBy=soonest&limit=3&locationId={}&minimum=1",
    location_id
  ))
  .await;
  let body: Vec<Appointment> = res.unwrap().json().await.unwrap();
  Ok(body)
}