use chrono::{Utc, DateTime, NaiveDateTime, Timelike};
use chrono_tz::Europe::Berlin;
/* @file straba.rs
 * @brief fetch next depature of light rail vehicle
 */
use serde_json::Value;
use serde::Deserialize;

const STATION_URL:&str = "https://www.rnv-online.de/rest/departure/2494";

/* ******************** JSON Description ****************************** */
#[derive(Default, Debug, Clone, PartialEq, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct Station {
    pub id: String,
    pub name: String,
    pub journeys: Vec<Journey>,
}

#[derive(Default, Debug, Clone, PartialEq, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct Line {
    pub id: String,
    pub text: String,
    pub icon_outlined: i64,
    pub icon_color: String,
    pub icon_text_color: i64,
}

#[derive(Default, Debug, Clone, PartialEq, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct Journey {
    pub line: Line,
    pub destination: String,
    pub barrier_level: String,
    pub loads_forecast_type: String,
    pub realtime_departure: Option<i64>,
    pub scheduled_departure: i64,
    pub difference: Option<i64>,
    pub canceled: bool,
}

// Return value
pub struct NextDeparture {
    pub rheinau: i64,
    pub schoenau: i64,
}

pub fn fetch_data() -> Option<&'static str> {
    let result = reqwest::blocking::get(STATION_URL);
    println!("Start Straba Crawler");

    if result.is_err() {
        println!("Could not read station response {:?}", result.err());  
        return Option::None;
    }
    let text = result.unwrap().text();
    if text.is_err() {
        println!("Could not convert response {:?}", text.err());
        return Option::None;
    }


    let body: std::result::Result<Station, serde_json::Error> = serde_json::from_str(&text.unwrap());

    if body.is_err() {
        println!("Could not parse json {:?}", body.err());  
        return Option::None;
    }

    let cur_time = DateTime::<Utc>::default();

    // parse JSON result.. serach of both directions
    let json = body.unwrap();
    for journey in (json.journeys) {
        let destination = (journey.destination).to_string();
        let departure = (journey.realtime_departure);
        let difference = (journey.difference);

        if (departure.is_some()) {
            // get current time
            let time_s = departure.unwrap();
            let local_time = NaiveDateTime::from_timestamp_millis(time_s*1000).unwrap();
            let zoned_time : DateTime<Utc> = DateTime::from_utc(local_time, Utc);
            let europe_time = zoned_time.with_timezone(&Berlin);
            
            let hour = europe_time.hour();
            let minute = europe_time.minute();
            println!("{0} {1}:{2}", destination, hour, minute);
        }
    }

    Some("")
}