use std::{env, path::PathBuf};

use actix_files;
use actix_web::{
    dev::ServiceResponse,
    http::{header::ContentType, StatusCode},
    middleware::{ErrorHandlerResponse, ErrorHandlers, Logger},
    web, App, FromRequest, HttpResponse, HttpServer, Responder, Result, Scope,
};

use crate::event_processor::process_event;
use async_channel;
use futures::{pin_mut, select, FutureExt};
use minijinja;
use minijinja_autoreload::AutoReloader;
use rusqlite::Connection;
use uuid::Uuid;

use crate::events::Event;
use crate::util::{CustomResult, Error, SQLiteConnectionFactory};
use crate::webui::services::{creat_db_pool, ServicesFactory};
use crate::webui::templates::MiniJinjaRenderer;
use crate::webui::worker::{event_processor_loop, EventProcessor};

mod index_views;
mod services;
mod templates;
mod views;
mod worker;
mod minininja_utils;
mod data_views;

struct ProductionEventProcessor;

impl EventProcessor for ProductionEventProcessor {
    fn process_event(&self, conn: &mut Connection, event: Event) -> CustomResult<()> {
        process_event(conn, event)
    }
}

fn create_auto_reloader(enable_template_autoreload: bool) -> AutoReloader {
    AutoReloader::new(move |notifier| {
        let mut env: minijinja::Environment<'static> = minijinja::Environment::new();

        let tmpl_path = PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("resources/templates");
        log::info!("Using template dir {:?}", tmpl_path);

        // if watch_path is never called, no fs watcher is created
        if enable_template_autoreload {
            notifier.watch_path(&tmpl_path, true);
        }
        env.set_source(minijinja::Source::from_path(tmpl_path));
        env.add_filter("thousand_separator", minininja_utils::add_thousand_separators);
        env.add_filter("utc_date", minininja_utils::utc_date);
        env.add_filter("micro_id", minininja_utils::micro_id);
        Ok(env)
    })
}

fn create_static_scope() -> Scope {
    web::scope("/static").service(actix_files::Files::new("/", "./resources/static/"))
}

fn create_api_scope() -> Scope {
    web::scope("/v1").service(views::push_event)
}

fn create_views_scope() -> Scope {
    web::scope("")
        .service(index_views::index)
        .service(index_views::login)
        .service(index_views::logout)
        .service(views::actions)
        .service(views::get_accounts)
        .service(views::get_account)
        .service(views::securities)
        .service(views::security)
        .service(views::users)
        .service(views::overview_submit_button)
        .service(views::actions_partials)
        .service(views::get_accounts_by_security_selectors)
        .service(data_views::get_account_amount_history)
}

#[tokio::main]
pub async fn web_ui_main(
    conn_fact: SQLiteConnectionFactory,
    port: u16,
    enable_template_autoreload: bool,
) -> CustomResult<()> {
    let (event_sender, event_receiver) = async_channel::unbounded::<(Uuid, Event)>();
    let pool = creat_db_pool(&conn_fact.path().unwrap());
    let services = ServicesFactory::new(pool);

    let server = HttpServer::new(move || {
        let template_reloader = create_auto_reloader(enable_template_autoreload);
        App::new()
            .wrap(Logger::default())
            .app_data(web::Data::new(services.clone()))
            .app_data(web::Data::new(template_reloader))
            .app_data(web::Data::new(event_sender.clone()))
            .service(create_static_scope())
            .service(create_api_scope())
            .service(create_views_scope())
            .wrap(ErrorHandlers::new().handler(StatusCode::NOT_FOUND, not_found))
    })
    .workers(2)
    .bind(("0.0.0.0", port))
    .unwrap();

    let t1 = server.run().fuse();

    let mut conn = conn_fact.connection().unwrap();
    let t2 = event_processor_loop(&mut conn, &ProductionEventProcessor {}, event_receiver).fuse();
    pin_mut!(t1, t2);

    select! {
        x = t1 => x.map_err(Error::IOError),
        y = t2 => y,
    }
}

/// Error handler for a 404 Page not found error.
fn not_found<B>(svc_res: ServiceResponse<B>) -> Result<ErrorHandlerResponse<B>> {
    let res = get_error_response(&svc_res, "Page not found");

    Ok(ErrorHandlerResponse::Response(ServiceResponse::new(
        svc_res.into_parts().0,
        res.map_into_right_body(),
    )))
}

/// Generic error handler.
fn get_error_response<B>(res: &ServiceResponse<B>, error: &str) -> HttpResponse {
    let req = res.request();

    let tmpl_env = MiniJinjaRenderer::extract(req).into_inner().unwrap();

    // Provide a fallback to a simple plain text response in case an error occurs during the
    // rendering of the error page.
    let fallback = |err: &str| {
        HttpResponse::build(res.status())
            .content_type(ContentType::plaintext())
            .body(err.to_string())
    };

    let ctx = minijinja::context! {
        error => error,
        status_code => res.status().as_str(),
    };

    match tmpl_env.render("error.html", ctx) {
        Ok(body) => body
            .customize()
            .with_status(res.status())
            .respond_to(req)
            .map_into_boxed_body(),

        Err(_) => fallback(error),
    }
}