pub mod ogp_images;
pub mod contrast;
pub mod statics;
pub mod configuration;

use configuration::ConfigError;

use std::process::exit;
use std::collections::HashMap;
use std::fmt::{self, Display};

use actix_web::dev::HttpResponseBuilder;
use actix_web::http::{header, StatusCode};
use actix_web::middleware::normalize::TrailingSlash;
use actix_web::middleware::{self, Logger};
use actix_web::web::resource;
use actix_web::{App, HttpRequest, HttpResponse, HttpServer, Responder, ResponseError, Result, post, web};
use argh;
use askama::Template;
use pronouns_today::user_preferences::Preference;
use pronouns_today::{InstanceSettings, Pronoun};

#[cfg(feature = "ogp_images")]
use image::{DynamicImage, ImageOutputFormat};
#[cfg(feature = "ogp_images")]
use ogp_images::render_today;

// TODO:  Make this configurable
const HOSTNAME: &str = "pronouns.today";

#[derive(Template)]
#[template(path = "index.html")]
struct IndexTemplate<'a> {
    name: Option<String>,
	pronoun: &'a Pronoun,
    pronouns: Vec<(usize, &'a Pronoun)>,
    url: String,
}

fn render_page(pronoun: &Pronoun, settings: &InstanceSettings, name: Option<String>, url: String) -> String {
    IndexTemplate {
        name,
		pronoun,
        pronouns: settings.pronoun_list.iter().enumerate().collect(),
        url,
    }
    .render()
    .unwrap()
}

#[post("/")]
async fn create_link(
    settings: web::Data<InstanceSettings>,
    form: web::Form<HashMap<String, String>>,
) -> Result<impl Responder> {
    let mut weights = vec![0; settings.pronoun_list.len()];
    for (k, v) in form.iter() {
        if let Ok(i) = k.parse::<usize>() {
            let w = v.parse::<u8>().map_err(|_| Error::InvlaidPrefString)?;
            if i < weights.len() - 1 {
                weights[i] = w;
            }
        }
    }
    let prefs = InstanceSettings::create_preferences(&weights);
    let pref_string = prefs.as_prefstring();
    let url = match form.get("name") {
        Some(name) if !name.is_empty() => format!("/{}/{}", name, pref_string),
        _ => format!("/{}", pref_string),
    };
    Ok(HttpResponse::SeeOther()
        .header(header::LOCATION, url)
        .finish())
}

fn form_full_url(host: &str, name: Option<&str>, prefstr: Option<&str>) -> String {
    ["https:/", host].into_iter()
        .chain(name)
        .chain(prefstr)
        .collect::<Vec<&str>>()
        .join("/")
}

/// Determine some basic information about a request
///
/// Determines the name and prefstring properties, if available, and also computes the pronoun that
/// should be responded using.  This method is designed to facilitate creating the basic response
/// pages.
///
/// Both arguments should be passed directly from the caller, and the return values are, in order,
/// the prefstring, if available, the user's name, if available, and the computed pronouns.
fn get_request_info<'s, 'r>(
    settings: &'s web::Data<InstanceSettings>,
    req: &'r HttpRequest,
) -> (Option<&'r str>, Option<&'r str>, Result<&'s Pronoun, Error>) {
    let prefs = req.match_info().get("prefs");
    let name  = req.match_info().get("name");
    let pronoun = settings
        .select_pronouns(name, prefs)
        .map_err(|_| Error::InvlaidPrefString);
    (prefs, name, pronoun)
}

async fn handle_basic_request(
    settings: web::Data<InstanceSettings>,
    req: HttpRequest,
) -> Result<impl Responder> {

    let (prefstr, name, pronoun) = get_request_info(&settings, &req);

    Ok(HttpResponse::Ok()
        .content_type("text/html; charset=utf-8")
        .body(render_page(
            pronoun?,
            &settings,
            name.map(str::to_owned),
            form_full_url(HOSTNAME, name, prefstr)
        )))
}

#[cfg(feature = "ogp_images")]
async fn handle_thumbnail_request(
    settings: web::Data<InstanceSettings>,
    req: HttpRequest,
) -> Result<impl Responder> {

    let (_, name, pronoun) = get_request_info(&settings, &req);

    let mut data: Vec<u8> = Vec::with_capacity(15_000);
    let image = DynamicImage::ImageRgb8(render_today(pronoun?, name.unwrap_or("")));
    image.write_to(&mut data, ImageOutputFormat::Png)
        .expect("Error encoding thumbnail to PNG");

    Ok(HttpResponse::Ok()
        .content_type("image/png")
        .body(data))
}

async fn not_found() -> impl Responder {
    HttpResponse::NotFound()
        .content_type("text/html; charset=utf-8")
        .body(include_str!("../templates/404.html"))
}

#[actix_web::main]
async fn main() -> std::io::Result<()> {

    env_logger::init();
	let args: configuration::PronounsTodayArgs = argh::from_env();

	match args.command {
		configuration::SubCommand::DumpStatics(_subargs) => {
			println!("Support for dumping statics not yet implemented");
			Ok(())
		}
		configuration::SubCommand::Run(subargs) => {
			let config = match subargs.load_config() {
				Ok(config) => config,
				Err(ConfigError::IoError(e)) => {
					return Err(e);
				}
				Err(ConfigError::MalformedConfig(e)) => {
					eprintln!("Error parsing config file:\n{}", e);
					exit(1001);
				}
				Err(ConfigError::ConfigCreated(path)) => {
					println!("A config file has been generated at {}!  Please check it out
							 and modify it to your liking, and then run this command
							 again", path.display());
					exit(1002);
				}
			};
			log::info!("Starting with configuration {:?}", config);
			start_server(config).await
		}
	}
}

async fn start_server(config: configuration::Conf) -> std::io::Result<()> {
    // Where we binding bois
    let bind = format!("0.0.0.0:{}", config.port);

	println!("Starting pronouns-today-web on {}", &bind);
    HttpServer::new(move|| {
        let logger = Logger::default();
        let app = App::new()
            .data(config.instance_settings.clone())
            .wrap(logger)
            .wrap(middleware::NormalizePath::new(TrailingSlash::Trim))
            .service(create_link);

		let app = statics::STATIC_ASSETS.iter()
			.fold(app, |app, asset| app.service(asset.generate_resource()));

        #[cfg(feature = "ogp_images")]
        let app = app
            .service(resource("/thumb.png")               .to(handle_thumbnail_request))
            .service(resource("/{prefs}/thumb.png")       .to(handle_thumbnail_request))
            .service(resource("/{name}/{prefs}/thumb.png").to(handle_thumbnail_request));

        app
            .service(resource("/")              .to(handle_basic_request))
            .service(resource("/{prefs}")       .to(handle_basic_request))
            .service(resource("/{name}/{prefs}").to(handle_basic_request))
            .default_service(web::to(not_found))
    })
    .bind(&bind)?
    .run()
    .await
}

#[derive(Template)]
#[template(path = "error.html")]
struct ErrorPage {
    msg: String,
}

#[derive(Debug)]
enum Error {
    InvlaidPrefString,
}

impl Display for Error {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        let msg = match self {
            &Error::InvlaidPrefString => "This URL contains an invalid pronoun preference string",
        };
        write!(f, "{}", msg)
    }
}

impl ResponseError for Error {
    fn status_code(&self) -> actix_web::http::StatusCode {
        match self {
            &Error::InvlaidPrefString => StatusCode::BAD_REQUEST,
        }
    }

    fn error_response(&self) -> HttpResponse {
        HttpResponseBuilder::new(self.status_code())
            .set_header(header::CONTENT_TYPE, "text/html; charset=utf-8")
            .body(
                ErrorPage {
                    msg: self.to_string(),
                }
                .render()
                .unwrap(),
            )
    }
}