use scraper::{Html, Selector};

pub async fn fetch_input(auth: String, day: u8) -> String {
    let input = reqwest::Client::new()
        .get(format!("https://adventofcode.com/2023/day/{day}/input"))
        .header("Cookie", format!("session={auth}"))
        .send()
        .await
        .expect("Unable to make input request")
        .text()
        .await
        .expect("Unable to parse string from input response")
        .trim_end()
        .to_owned();
    if input != "Puzzle inputs differ by user.  Please log in to get your puzzle input." {
        input
    } else {
        panic!("Invalid auth")
    }
}

pub async fn fetch_large(day: u8, part: u8) -> (String, Option<String>) {
    (
        reqwest::Client::new()
            .get(format!("https://github.com/Vap0r1ze/aoc-large-inputs/raw/main/dist/{day:02}/input_large.txt"))
            .send()
            .await
            .expect("Unable to make input request")
            .error_for_status()
            .expect("Unable to fetch large response for day, does it exist?")
            .text()
            .await
            .expect("Unable to parse string from input response")
            .trim_end()
            .to_owned(),
        match reqwest::Client::new()
            .get(format!("https://github.com/Vap0r1ze/aoc-large-inputs/raw/main/dist/{day:02}/output_large.txt"))
            .send()
            .await
            .expect("Unable to make input request")
            .error_for_status()
            .ok() {
                Some(r) => Some(
                    r.text()
                        .await
                        .expect("Unable to parse string from input response")
                        .trim_end()
                        .to_owned()
                        .lines()
                        .nth((part - 1) as usize)
                        .expect("Can't get part-th line of large output")
                        .to_string()
                ),
                _ => None
            }
    )
}

pub async fn fetch_example(auth: String, day: u8, part: u8) -> (String, Option<String>) {
    let html = reqwest::Client::new()
        .get(format!("https://adventofcode.com/2023/day/{day}"))
        .header("Cookie", format!("session={auth}"))
        .send()
        .await
        .expect("Unable to make input request")
        .text()
        .await
        .expect("Unable to parse string from input response");

    let dom = Html::parse_document(&html);
    let input_selector = Selector::parse("pre > code").unwrap();
    let solution_selector = Selector::parse(match part {
        1 => "article:nth-child(1) code > em",
        2 => "article:nth-child(3) code > em",
        _ => panic!(),
    })
    .unwrap();

    let input = dom
        .select(&input_selector)
        .next()
        .unwrap()
        .inner_html()
        .trim_end()
        .to_string();
    let solution = dom
        .select(&solution_selector)
        .last()
        .map(|s| s.inner_html().trim_end().to_string());

    (input, solution)
}

#[cfg(test)]
mod tests {
    use crate::fetcher;

    #[tokio::test]
    async fn fetches_large_data() {
        fetcher::fetch_large(6, 1).await;
    }
}