mod structs;

use pulldown_cmark::{Options, Parser};
use quick_xml::events::{BytesEnd, BytesStart, BytesText, Event};
use quick_xml::Writer;
use reqwest::{
    header::{HeaderMap, HeaderValue},
    ClientBuilder,
};
use std::env;
use std::io::Cursor;
use std::iter::Skip;
extern crate serde_json;

pub async fn run(mut args: Skip<env::Args>) {
    let repo = args.next().expect("Missing repo");
    let issue_number = args.next().expect("Missing issue number");
    let mut header_map = HeaderMap::new();
    header_map.insert(
        "accept",
        HeaderValue::from_static("application/vnd.github.v3+json"),
    );
    let client = ClientBuilder::new()
        .default_headers(header_map)
        .user_agent(&format!(
            "{}/{}",
            env!("CARGO_PKG_NAME"),
            env!("CARGO_PKG_VERSION")
        ))
        .build()
        .unwrap();
    let text = client
        .get(&format!(
            "https://api.github.com/repos/{}/issues/{}",
            repo, issue_number
        ))
        .send()
        .await
        .unwrap()
        .text()
        .await
        .unwrap();
    let issue: structs::Issue = serde_json::from_str(&text).unwrap();
    let text = client
        .get(&issue.events_url)
        .send()
        .await
        .unwrap()
        .text()
        .await
        .unwrap();
    let mut events: Vec<structs::EventType> = serde_json::from_str(&text).unwrap();
    let text = client
        .get(&issue.comments_url)
        .send()
        .await
        .unwrap()
        .text()
        .await
        .unwrap();
    let comments: Vec<structs::EventType> = serde_json::from_str(&text).unwrap();
    events.extend(comments);
    events.sort_by(|i, j| {
        let i = match i {
            structs::EventType::Comment(comment) => comment.created_at,
            structs::EventType::Event(event) => event.created_at,
        };
        let j = match j {
            structs::EventType::Comment(comment) => comment.created_at,
            structs::EventType::Event(event) => event.created_at,
        };
        i.partial_cmp(&j).unwrap()
    });

    let mut writer = Writer::new(Cursor::new(Vec::new()));
    {
        let mut elem = BytesStart::owned(b"rss".to_vec(), 3);
        elem.push_attribute(("version", "2.0"));
        writer.write_event(Event::Start(elem)).unwrap();

        let elem = BytesStart::owned(b"channel".to_vec(), 7);
        writer.write_event(Event::Start(elem)).unwrap();

        let elem = BytesStart::owned(b"title".to_vec(), 5);
        writer.write_event(Event::Start(elem)).unwrap();

        let elem = BytesText::from_plain_str(&issue.title).into_owned();
        writer.write_event(Event::Text(elem)).unwrap();

        let elem = BytesEnd::owned(b"title".to_vec());
        writer.write_event(Event::End(elem)).unwrap();

        let elem = BytesStart::owned(b"link".to_vec(), 4);
        writer.write_event(Event::Start(elem)).unwrap();

        let elem = BytesText::from_plain_str(&issue.html_url).into_owned();
        writer.write_event(Event::Text(elem)).unwrap();

        let elem = BytesEnd::owned(b"link".to_vec());
        writer.write_event(Event::End(elem)).unwrap();

        let elem = BytesStart::owned(b"description".to_vec(), 11);
        writer.write_event(Event::Start(elem)).unwrap();

        let elem = BytesText::from_plain_str(&format!("Comments and events from {}", &issue.title))
            .into_owned();
        writer.write_event(Event::Text(elem)).unwrap();

        let elem = BytesEnd::owned(b"description".to_vec());
        writer.write_event(Event::End(elem)).unwrap();

        let elem = BytesStart::owned(b"item".to_vec(), 4);
        writer.write_event(Event::Start(elem)).unwrap();

        let elem = BytesStart::owned(b"title".to_vec(), 5);
        writer.write_event(Event::Start(elem)).unwrap();

        let elem = BytesText::from_plain_str(&issue.title).into_owned();
        writer.write_event(Event::Text(elem)).unwrap();

        let elem = BytesEnd::owned(b"title".to_vec());
        writer.write_event(Event::End(elem)).unwrap();

        let elem = BytesStart::owned(b"link".to_vec(), 4);
        writer.write_event(Event::Start(elem)).unwrap();

        let elem = BytesText::from_plain_str(&issue.html_url).into_owned();
        writer.write_event(Event::Text(elem)).unwrap();

        let elem = BytesEnd::owned(b"link".to_vec());
        writer.write_event(Event::End(elem)).unwrap();

        let mut elem = BytesStart::owned(b"guid".to_vec(), 4);
        elem.push_attribute(("isPermaLink", "false"));
        writer.write_event(Event::Start(elem)).unwrap();

        let elem = BytesText::from_plain_str(&issue.node_id).into_owned();
        writer.write_event(Event::Text(elem)).unwrap();

        let elem = BytesEnd::owned(b"guid".to_vec());
        writer.write_event(Event::End(elem)).unwrap();

        let elem = BytesStart::owned(b"author".to_vec(), 6);
        writer.write_event(Event::Start(elem)).unwrap();

        let elem = BytesText::from_plain_str(&issue.user.login).into_owned();
        writer.write_event(Event::Text(elem)).unwrap();

        let elem = BytesEnd::owned(b"author".to_vec());
        writer.write_event(Event::End(elem)).unwrap();

        let elem = BytesStart::owned(b"pubDate".to_vec(), 7);
        writer.write_event(Event::Start(elem)).unwrap();

        let elem = BytesText::from_plain_str(&issue.created_at.to_rfc2822()).into_owned();
        writer.write_event(Event::Text(elem)).unwrap();

        let elem = BytesEnd::owned(b"pubDate".to_vec());
        writer.write_event(Event::End(elem)).unwrap();

        if !issue.body.is_empty() {
            let elem = BytesStart::owned(b"description".to_vec(), 11);
            writer.write_event(Event::Start(elem)).unwrap();

            let parser = Parser::new_ext(&issue.body, Options::all());
            let mut html_buf = String::with_capacity(issue.body.len());
            pulldown_cmark::html::push_html(&mut html_buf, parser);
            let elem = BytesText::from_plain_str(html_buf.trim()).into_owned();
            writer.write_event(Event::Text(elem)).unwrap();

            let elem = BytesEnd::owned(b"description".to_vec());
            writer.write_event(Event::End(elem)).unwrap();
        }

        let elem = BytesEnd::owned(b"item".to_vec());
        writer.write_event(Event::End(elem)).unwrap();
    }

    for event in events {
        let (title, link, description, author, guid, pub_date) = match event {
            structs::EventType::Comment(comment) => {
                let parser = Parser::new_ext(&comment.body, Options::all());
                let mut html_buf = String::with_capacity(comment.body.len());
                pulldown_cmark::html::push_html(&mut html_buf, parser);
                let mut title = comment.body.splitn(2, '\n').next().unwrap().to_string();
                if title.len() > 80 {
                    title = format!("{}...", title.split_at(80).0);
                }
                (
                    title,
                    Some(comment.html_url),
                    html_buf.trim().to_string(),
                    comment.user.login,
                    comment.node_id,
                    comment.created_at.to_rfc2822(),
                )
            }
            structs::EventType::Event(event) => {
                let mut text = "Extra fields:\n<pre><code>".to_string();
                pulldown_cmark::escape::escape_html(
                    &mut text,
                    &serde_json::to_string_pretty(&event.extra)
                        .unwrap_or_else(|_| format!("{:?}", &event.extra)),
                )
                .unwrap();
                text.push_str("</code></pre>");
                (
                    format!("New event: {}", &event.event),
                    None,
                    text,
                    event.actor.login,
                    event.node_id,
                    event.created_at.to_rfc2822(),
                )
            }
        };

        let elem = BytesStart::owned(b"item".to_vec(), 4);
        writer.write_event(Event::Start(elem)).unwrap();

        let elem = BytesStart::owned(b"title".to_vec(), 5);
        writer.write_event(Event::Start(elem)).unwrap();

        let elem = BytesText::from_plain_str(&title).into_owned();
        writer.write_event(Event::Text(elem)).unwrap();

        let elem = BytesEnd::owned(b"title".to_vec());
        writer.write_event(Event::End(elem)).unwrap();

        if let Some(link) = link {
            let elem = BytesStart::owned(b"link".to_vec(), 4);
            writer.write_event(Event::Start(elem)).unwrap();

            let elem = BytesText::from_plain_str(&link).into_owned();
            writer.write_event(Event::Text(elem)).unwrap();

            let elem = BytesEnd::owned(b"link".to_vec());
            writer.write_event(Event::End(elem)).unwrap();
        }

        let mut elem = BytesStart::owned(b"guid".to_vec(), 4);
        elem.push_attribute(("isPermaLink", "false"));
        writer.write_event(Event::Start(elem)).unwrap();

        let elem = BytesText::from_plain_str(&guid).into_owned();
        writer.write_event(Event::Text(elem)).unwrap();

        let elem = BytesEnd::owned(b"guid".to_vec());
        writer.write_event(Event::End(elem)).unwrap();

        let elem = BytesStart::owned(b"author".to_vec(), 6);
        writer.write_event(Event::Start(elem)).unwrap();

        let elem = BytesText::from_plain_str(&author).into_owned();
        writer.write_event(Event::Text(elem)).unwrap();

        let elem = BytesEnd::owned(b"author".to_vec());
        writer.write_event(Event::End(elem)).unwrap();

        let elem = BytesStart::owned(b"pubDate".to_vec(), 7);
        writer.write_event(Event::Start(elem)).unwrap();

        let elem = BytesText::from_plain_str(&pub_date).into_owned();
        writer.write_event(Event::Text(elem)).unwrap();

        let elem = BytesEnd::owned(b"pubDate".to_vec());
        writer.write_event(Event::End(elem)).unwrap();

        let elem = BytesStart::owned(b"description".to_vec(), 11);
        writer.write_event(Event::Start(elem)).unwrap();

        let elem = BytesText::from_plain_str(&description).into_owned();
        writer.write_event(Event::Text(elem)).unwrap();

        let elem = BytesEnd::owned(b"description".to_vec());
        writer.write_event(Event::End(elem)).unwrap();

        let elem = BytesEnd::owned(b"item".to_vec());
        writer.write_event(Event::End(elem)).unwrap();
    }

    let elem = BytesEnd::owned(b"channel".to_vec());
    writer.write_event(Event::End(elem)).unwrap();

    let elem = BytesEnd::owned(b"rss".to_vec());
    writer.write_event(Event::End(elem)).unwrap();

    println!(
        "{}",
        String::from_utf8(writer.into_inner().into_inner()).unwrap()
    );
}