use clap::Parser;
use derive_more::From;
use scraper::{Html, Selector};
use colored::Colorize;

#[derive(Default, Parser)]
#[clap(author, version, about)]
struct Arguments {
    #[clap(help = "Plume Labs location ID. For example, https://air.plumelabs.com/air-quality-in-XXX")]
    location: String,
    #[clap(short, long, help = "Display raw Air Quality Index")]
    raw: bool,
    #[clap(short, long, help = "Display AccuWeather Air Quality Index description")]
    description: bool,
}

#[derive(From, Debug)]
enum Error {
    ReqwestError(reqwest::Error),
    HttpError,
    InvalidResponse,
}

fn main() -> Result<(), Error> {
    let arguments = Arguments::parse();
    let response = reqwest::blocking::get(format!("https://air.plumelabs.com/air-quality-in-{}", arguments.location))?;
    if !response.status().is_success() {
        return Err(Error::HttpError);
    }
    let content = response.text_with_charset("utf-8")?;
    let document = Html::parse_document(&content);
    let selector = Selector::parse("span[data-role=\"current-pi\"]").unwrap();
    let aqi = match match document.select(&selector).next() {
        Some(element) => element,
        None => return Err(Error::InvalidResponse),
    }.inner_html().trim().parse::<f32>() {
        Ok(aqi) => aqi,
        Err(_) => return Err(Error::InvalidResponse),
    } as u32;
    if arguments.raw {
        println!("{}", aqi);
        return Ok(());
    }
    println!("{} {}",
        match aqi {
            250.. => "Dangerous".purple(),
            150.. => "Very Unhealthy".purple(),
            100.. => "Unhealthy".magenta(),
            50.. => "Poor".red(),
            20.. => "Fair".yellow(),
            0.. => "Excellent".green(),
        }.bold(),
        match aqi {
            // 250.. => (no appropriate terminal color) // Dangerous 250+
            150.. => aqi.to_string().purple(), // Very Unhealthy 150-249
            100.. => aqi.to_string().magenta(), // Unhealthy 100-149
            50.. => aqi.to_string().red(), // Poor 50-99
            20.. => aqi.to_string().yellow(), // Fair 20-49
            0.. => aqi.to_string().green(), // Excellent 0-19
        }.bold()
    );
    if arguments.description {
        println!("{}", match aqi {
            250.. => "Any exposure to the air, even for a few minutes, can lead to serious health effects on everybody. Avoid outdoor activities.",
            150.. => "Health effects will be immediately felt by sensitive groups and should avoid outdoor activity. Healthy individuals are likely to experience difficulty breathing and throat irritation; consider staying indoors and rescheduling outdoor activities.",
            100.. => "Health effects can be immediately felt by sensitive groups. Healthy individuals may experience difficulty breathing and throat irritation with prolonged exposure. Limit outdoor activity.",
            50.. => "The air has reached a high level of pollution and is unhealthy for sensitive groups. Reduce time spent outside if you are feeling symptoms such as difficulty breathing or throat irritation.",
            20.. => "The air quality is generally acceptable for most individuals. However, sensitive groups may experience minor to moderate symptoms from long-term exposure.",
            0.. => "The air quality is ideal for most individuals; enjoy your normal outdoor activities.",
        });
    }
    return Ok(());
}