use serde::{Deserialize, Serialize};
use std::collections::HashMap;
use std::error::Error;
use std::sync;
use warp::Filter;

use crate::domain;

pub mod http_tpl;
mod util;

type Handlebars<'a> = sync::Arc<handlebars::Handlebars<'a>>;

struct Renderer<'a, DM>
where
    DM: domain::manager::Manager,
{
    domain_manager: sync::Arc<DM>,
    target_cname: sync::Arc<domain::Name>,
    passphrase: sync::Arc<String>,

    handlebars: Handlebars<'a>,
    query_args: HashMap<String, String>,
}

#[derive(Serialize)]
struct BasePresenter<'a, T> {
    page_name: &'a str,
    query_args: &'a HashMap<String, String>,
    data: &'a T,
}

impl<'a, DM> Renderer<'a, DM>
where
    DM: domain::manager::Manager,
{
    // TODO make this use an io::Write, rather than warp::Reply
    fn render<T>(&self, name: &'_ str, value: &'_ T) -> Box<dyn warp::Reply>
    where
        T: Serialize,
    {
        let rendered = match self.handlebars.render(name, value) {
            Ok(res) => res,
            Err(handlebars::RenderError {
                template_name: None,
                ..
            }) => return self.render_error_page(404, "Static asset not found"),
            Err(err) => {
                return self.render_error_page(500, format!("template error: {err}").as_str())
            }
        };

        let content_type = mime_guess::from_path(name)
            .first_or_octet_stream()
            .to_string();

        let reply = warp::reply::html(rendered);

        Box::from(warp::reply::with_header(
            reply,
            "Content-Type",
            content_type,
        ))
    }

    fn render_error_page(&self, status_code: u16, e: &'_ str) -> Box<dyn warp::Reply> {
        #[derive(Serialize)]
        struct Response<'a> {
            error_msg: &'a str,
        }

        Box::from(warp::reply::with_status(
            self.render(
                "/base.html",
                &BasePresenter {
                    page_name: "/error.html",
                    query_args: &HashMap::default(),
                    data: &Response { error_msg: e },
                },
            ),
            status_code.try_into().unwrap(),
        ))
    }

    fn render_page<T>(&self, name: &'_ str, data: &'_ T) -> Box<dyn warp::Reply>
    where
        T: Serialize,
    {
        self.render(
            "/base.html",
            &BasePresenter {
                page_name: name,
                query_args: &self.query_args,
                data,
            },
        )
    }
}

pub fn new<DM>(
    manager: DM,
    target_cname: domain::Name,
    passphrase: String,
) -> Result<
    impl warp::Filter<Extract = impl warp::Reply, Error = warp::Rejection> + Clone + 'static,
    Box<dyn Error>,
>
where
    DM: domain::manager::Manager + 'static,
{
    let manager = sync::Arc::new(manager);
    let target_cname = sync::Arc::new(target_cname);
    let passphrase = sync::Arc::new(passphrase);

    let hbs = sync::Arc::new(self::http_tpl::get()?);
    let with_renderer = warp::any()
        .and(warp::query::<HashMap<String, String>>())
        .map(move |query_args: HashMap<String, String>| Renderer {
            domain_manager: manager.clone(),
            target_cname: target_cname.clone(),
            passphrase: passphrase.clone(),
            handlebars: hbs.clone(),
            query_args,
        });

    let static_dir = warp::get()
        .and(with_renderer.clone())
        .and(warp::path("static"))
        .and(warp::path::full())
        .map(|renderer: Renderer<'_, DM>, full: warp::path::FullPath| {
            renderer.render(full.as_str(), &())
        });

    let index = warp::get()
        .and(with_renderer.clone())
        .and(warp::path::end())
        .map(|renderer: Renderer<'_, DM>| renderer.render_page("/index.html", &()));

    #[derive(Deserialize)]
    struct DomainGetNewRequest {
        domain: domain::Name,
    }

    #[derive(Serialize)]
    struct DomainGetNewResponse {
        domain: domain::Name,
        config: Option<domain::config::Config>,
    }

    let domain_get = warp::get()
        .and(with_renderer.clone())
        .and(warp::path!("domain.html"))
        .and(warp::query::<DomainGetNewRequest>())
        .and(warp::query::<util::ConfigFromURL>())
        .map(
            |renderer: Renderer<'_, DM>,
             req: DomainGetNewRequest,
             domain_config: util::ConfigFromURL| {
                match renderer.domain_manager.get_config(&req.domain) {
                    Ok(_config) => renderer.render_error_page(500, "TODO not yet implemented"),
                    Err(domain::manager::GetConfigError::NotFound) => {
                        let domain_config = match domain_config.try_into() {
                            Ok(domain_config) => domain_config,
                            Err(e) => {
                                return renderer.render_error_page(
                                    400,
                                    format!("parsing domain configuration: {}", e).as_str(),
                                )
                            }
                        };

                        renderer.render_page(
                            "/domain_get_new.html",
                            &DomainGetNewResponse {
                                domain: req.domain,
                                config: domain_config,
                            },
                        )
                    }
                    Err(domain::manager::GetConfigError::Unexpected(e)) => renderer
                        .render_error_page(
                            500,
                            format!("retrieving configuration: {}", e).as_str(),
                        ),
                }
            },
        );

    #[derive(Deserialize)]
    struct DomainPostRequest {
        _init: bool,
        domain: domain::Name,
        passphrase: String,
    }

    let domain_post = warp::post()
        .and(with_renderer.clone())
        .and(warp::path!("domain.html"))
        .and(warp::query::<DomainPostRequest>())
        .and(warp::query::<util::ConfigFromURL>())
        .map(
            |renderer: Renderer<'_, DM>,
             req: DomainPostRequest,
             domain_config: util::ConfigFromURL| {
                if req.passphrase != renderer.passphrase.as_str() {
                    return renderer.render_error_page(401, "Incorrect passphrase");
                }

                //if req.init {
                #[derive(Serialize)]
                struct Response {
                    domain: domain::Name,
                    config: domain::config::Config,
                    target_cname: domain::Name,
                    challenge_token: String,
                }

                let config: domain::config::Config = match domain_config.try_into() {
                    Ok(Some(config)) => config,
                    Ok(None) => {
                        return renderer.render_error_page(400, "domain config is required")
                    }
                    Err(e) => {
                        return renderer
                            .render_error_page(400, format!("invalid domain config: {e}").as_str())
                    }
                };

                let config_hash = match config.hash() {
                    Ok(hash) => hash,
                    Err(e) => {
                        return renderer.render_error_page(
                            500,
                            format!("failed to hash domain config: {e}").as_str(),
                        )
                    }
                };

                let target_cname = (*renderer.target_cname).clone();

                return renderer.render_page(
                    "/domain_post_init.html",
                    &Response {
                        domain: req.domain,
                        config: config,
                        target_cname: target_cname,
                        challenge_token: config_hash,
                    },
                );
                //}
            },
        );

    let not_found = warp::any()
        .and(with_renderer.clone())
        .map(|renderer: Renderer<'_, DM>| renderer.render_error_page(404, "Page not found"));

    Ok(static_dir
        .or(index)
        .or(domain_get)
        .or(domain_post)
        .or(not_found))
}