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;

/*
 * POST /domain/config (domain, config, secret, init?) -> token?
 * GET /domain/config (domain) -> config
 * GET /domains
 */

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

struct RenderContext<'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>,
}

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

    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,
    ))
}

#[derive(Serialize)]
struct BasePresenter<T> {
    page_name: String,
    query_args: HashMap<String, String>,
    data: T,
}

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

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

fn render_page<'a, T, DM>(
    render_ctx: RenderContext<'a, DM>,
    name: String,
    data: T,
) -> Box<dyn warp::Reply>
where
    T: Serialize,
    DM: domain::manager::Manager,
{
    let presenter = BasePresenter {
        page_name: name,
        query_args: render_ctx.query_args,
        data,
    };

    render(render_ctx.handlebars, "/base.html", presenter)
}

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_render_ctx = warp::any()
        .and(warp::query::<HashMap<String, String>>())
        .map(move |query_args: HashMap<String, String>| RenderContext {
            domain_manager: manager.clone(),
            target_cname: target_cname.clone(),
            passphrase: passphrase.clone(),
            handlebars: hbs.clone(),
            query_args,
        });

    let static_dir = warp::get()
        .and(with_render_ctx.clone())
        .and(warp::path("static"))
        .and(warp::path::full())
        .map(
            |render_ctx: RenderContext<'_, DM>, full: warp::path::FullPath| {
                render(render_ctx.handlebars, full.as_str(), ())
            },
        );

    let index = warp::get()
        .and(with_render_ctx.clone())
        .and(warp::path::end())
        .map(|render_ctx: RenderContext<'_, DM>| {
            render_page(render_ctx, String::from("/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_render_ctx.clone())
        .and(warp::path!("domain.html"))
        .and(warp::query::<DomainGetNewRequest>())
        .and(warp::query::<util::ConfigFromURL>())
        .map(
            |render_ctx: RenderContext<'_, DM>,
             req: DomainGetNewRequest,
             domain_config: util::ConfigFromURL| {
                match render_ctx.domain_manager.get_config(&req.domain) {
                    Ok(_config) => render_error_page(
                        render_ctx.handlebars,
                        500,
                        "TODO not yet implemented".to_string(),
                    ),
                    Err(domain::manager::GetConfigError::NotFound) => {
                        let domain_config = match domain_config.try_into() {
                            Ok(domain_config) => domain_config,
                            Err(e) => {
                                return render_error_page(
                                    render_ctx.handlebars,
                                    400,
                                    format!("parsing domain configuration: {}", e),
                                )
                            }
                        };

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

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

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

                //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 render_error_page(
                            render_ctx.handlebars,
                            400,
                            "domain config is required".to_string(),
                        )
                    }
                    Err(e) => {
                        return render_error_page(
                            render_ctx.handlebars,
                            400,
                            format!("invalid domain config: {e}"),
                        )
                    }
                };

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

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

                return render_page(
                    render_ctx,
                    String::from("/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_render_ctx.clone())
            .map(|render_ctx: RenderContext<'_, DM>| {
                render_error_page(render_ctx.handlebars, 404, "Page not found".to_string())
            });

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