use axum::http::{HeaderMap, Response, StatusCode};
use axum_extra::extract::Query;
use serde::Deserialize;
use acrate_core::diesel_async::{AsyncConnection, AsyncPgConnection};
use acrate_hostmeta::jrd::ResourceDescriptorLinkJRD;
use acrate_hostmeta::xrd::{ResourceDescriptorLinkXRD, ResourceDescriptorPropertyXRD};
use crate::config;

#[derive(Debug, Clone, Deserialize)]
pub struct WebfingerQuery {
	pub resource: Option<String>,
	
	#[serde(default)]
	pub rel: Vec<String>,
}

const WEBFINGER_DOC: &str = "/.well-known/webfinger";

#[axum::debug_handler]
pub async fn webfinger_handler(
	Query(WebfingerQuery {resource, rel}): Query<WebfingerQuery>,
	headers: HeaderMap,
) -> Result<Response<String>, StatusCode> {
	log::info!("Handling a WebFinger request!");
	
	let resource = resource.unwrap_or_else(|| "".to_string());
	log::debug!("Resource is: {resource:#?}");
	
	log::debug!("Rel is: {rel:#?}");
	
	let accept = headers.get("Accept")
		.map(|v| v.to_str())
		.filter(Result::is_ok)
		.map(|v| v.unwrap())
		.unwrap_or("application/json")
		.to_string();
	log::debug!("Accept is: {accept:#?}");
	
	let mut response = Response::new("".to_string());
	
	let mut conn = AsyncPgConnection::establish(config::ACRATE_WEBFINGER_DATABASE_URL())
		.await
		.map_err(|_| StatusCode::BAD_GATEWAY)?;
	
	let aliases = acrate_core::meta::MetaAlias::query_matching(&mut conn, WEBFINGER_DOC, &resource)
		.await
		.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
	
	let properties = acrate_core::meta::MetaProperty::query_matching(&mut conn, WEBFINGER_DOC, &resource)
		.await
		.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
	
	let links = acrate_core::meta::MetaLink::query_matching(&mut conn, WEBFINGER_DOC, &resource)
		.await
		.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
	
	for mime in accept.split(",") {
		{
			let headers = response.headers_mut();
			headers.insert("Content-Type", mime.parse().unwrap());
		}

		let (mime, _params) = match mime.trim().split_once(";") {
			Some((mime, params)) => (mime, Some(params)),
			None => (mime, None),
		};

		match mime {
			"*/*" | "application/json" | "application/jrd+json" => {
				let subject = Some(resource);
				
				let aliases = aliases
					.into_iter()
					.map(|alias| alias.alias)
					.collect();
				
				let properties = properties
					.into_iter()
					.map(|prop| (prop.rel, prop.value))
					.collect();
				
				let links = links
					.into_iter()
					.map(|link| ResourceDescriptorLinkJRD {
						rel: link.rel,
						r#type: link.type_,
						href: link.href,
						titles: Default::default(), // TODO: Titles
						properties: Default::default(), // TODO: Link properties
						template: None, // TODO: Template
					})
					.collect::<Vec<ResourceDescriptorLinkJRD>>();
				
				let rd = acrate_hostmeta::jrd::ResourceDescriptorJRD {
					subject,
					aliases,
					properties,
					links,
				};
				
				let json = serde_json::to_string_pretty(&rd)
					.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
				
				{
					let body = response.body_mut();
					body.push_str(&json);
				}
				
				return Ok(response)
			},
			"application/xml" | "application/xrd+xml" => {
				let subject = Some(resource);
				
				let aliases = aliases
					.into_iter()
					.map(|alias| alias.alias)
					.collect();
				
				let properties = properties
					.into_iter()
					.map(|prop| ResourceDescriptorPropertyXRD {
						r#type: prop.rel,  // TODO: Ah si chiama type?
						value: prop.value,
					})
					.collect();
				
				let links = links
					.into_iter()
					.map(|link| ResourceDescriptorLinkXRD {
						rel: link.rel,
						r#type: link.type_,
						href: link.href,
						titles: Default::default(), // TODO: Titles
						properties: Default::default(), // TODO: Link properties
						template: None, // TODO: Template
					})
					.collect::<Vec<ResourceDescriptorLinkXRD>>();
				
				let rd = acrate_hostmeta::xrd::ResourceDescriptorXRD {
					subject,
					aliases,
					properties,
					links,
				};
				
				let xml = quick_xml::se::to_string(&rd)
					.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
				
				{
					let body = response.body_mut();
					body.push_str("<?xml version='1.0' encoding='UTF-8'?>");
					body.push_str(&xml);
				}
				
				return Ok(response)
			},
			_ => {
				continue;
			}
		}
	}
	
	Err(StatusCode::NOT_ACCEPTABLE)
}