use std::fmt::{Display, format, Formatter};
use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
use actix_web::{web, App, HttpResponse, HttpServer, get, Responder, HttpRequest};
use actix_web::web::Redirect;

#[derive(Clone)]
enum Protocol {
    HTTP,
    HTTPS
}

impl Display for Protocol {
    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
        match self {
            Protocol::HTTP => write!(f, "http://"),
            Protocol::HTTPS => write!(f, "https://")
        }
    }
}

#[derive(Clone)]
struct DomainLinkConfig {
    domain: String,
    protocol: Protocol,
    target: String,
}

#[derive(Clone)]
struct Config {
    redirects: Vec<DomainLinkConfig>,
    ports: Vec<u16>,
    addresses: Vec<IpAddr>,
}

#[actix_web::main]
async fn main() -> std::io::Result<()> {
    let config = Config {
        redirects: vec![
            DomainLinkConfig {
                domain: "neshura.me".to_owned(),
                protocol: Protocol::HTTPS,
                target: "neshweb.net".to_owned(),
            },
            DomainLinkConfig {
                domain: "lemmy.neshura.me".to_owned(),
                protocol: Protocol::HTTPS,
                target: "bookwormstory.social/u/neshura".to_owned()
            },
            DomainLinkConfig {
                domain: "test2.neshura.me".to_owned(),
                protocol: Protocol::HTTPS,
                target: "neshweb.net".to_owned()
            }
        ],
        ports: vec![8080, 8090],
        addresses: vec![
            IpAddr::V6(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1)),
            IpAddr::V4(Ipv4Addr::new(192, 168, 178, 11))
        ],
    };
    let mut server = HttpServer::new(move || {
        App::new()
            .app_data(web::Data::new(config.redirects.clone()))
            .service(handle)
            .service(dry_handle)
    });
    
    for address in &config.addresses {
        for port in &config.ports {
            server = server.bind((address.clone(), port.clone()))?
        }
    }
    server.run().await
}

#[get("/")]
async fn handle(redirects: web::Data<Vec<DomainLinkConfig>>, request: HttpRequest) -> impl Responder {
    if let Some(host_raw) = request.headers().get("host") {
        let host = host_raw.to_str().expect("host conversion to string should never fail");
        println!("{host}");
        for redirect in redirects.iter() {
            if redirect.domain == host {
                return HttpResponse::PermanentRedirect().insert_header(("location", format!("{}{}", redirect.protocol, redirect.target).as_str())).finish();
            }
        }
        let fail_msg = format!("No Redirect for {host} found");
        return HttpResponse::NotFound().body(fail_msg)
    }
    HttpResponse::NotFound().body("Host not specified")
}

#[get("/dry")]
async fn dry_handle(redirects: web::Data<Vec<DomainLinkConfig>>, request: HttpRequest) -> impl Responder {
    if let Some(host_raw) = request.headers().get("host") {
        let host = host_raw.to_str().expect("host conversion to string should never fail");
        println!("{host}");
        for redirect in redirects.iter() {
            if redirect.domain == host {
                let body = format!("Redirecting: {} -> {}{}", host, redirect.protocol, redirect.target);
                return HttpResponse::Ok().body(body);
            }
        }
        let fail_msg = format!("No Redirect for {host} found");
        return HttpResponse::NotFound().body(fail_msg)
    }
    HttpResponse::NotFound().body("Host not specified")
}