sgammon/GUST

/*
 * Copyright © 2020, The Gust Framework Authors. All rights reserved.
 *
 * The Gust/Elide framework and tools, and all associated source or object computer code, except where otherwise noted,
 * are licensed under the Zero Prosperity license, which is enclosed in this repository, in the file LICENSE.txt. Use of
 * this code in object or source form requires and implies consent and agreement to that license in principle and
 * practice. Source or object code not listing this header, or unless specified otherwise, remain the property of
 * Elide LLC and its suppliers, if any. The intellectual and technical concepts contained herein are proprietary to
 * Elide LLC and its suppliers and may be covered by U.S. and Foreign Patents, or patents in process, and are protected
 * by trade secret and copyright law. Dissemination of this information, or reproduction of this material, in any form,
 * is strictly forbidden except in adherence with assigned license requirements.
 */
package server

import gust.backend.AppController
import gust.backend.PageContextManager
import gust.backend.PageRender
import io.micronaut.http.HttpResponse
import io.micronaut.http.annotation.Controller
import io.micronaut.http.annotation.Get
import io.micronaut.http.annotation.QueryValue
import io.micronaut.security.annotation.Secured
import io.micronaut.views.View
import org.slf4j.LoggerFactory
import javax.inject.Inject


/**
 * Todolist homepage controller - responsible for serving the homepage, with a little preview of the app, with the
 * ability to use it (anonymously / ephemerally). It also offers the ability to sign in and persist one's tasks. The
 * homepage UI is defined in Soy, and styled in SASS.
 */
@Controller
@Secured("isAnonymous()")
class HomeController @Inject constructor(ctx: PageContextManager): AppController(ctx) {
  companion object {
    // Logging pipe.
    @JvmStatic private val logging = LoggerFactory.getLogger(HomeController::class.java)

    // Default name to show.
    private const val defaultName = "World"
  }

  /**
   * `/` (`HTTP GET`): Handler for the root homepage for Todolist - i.e. `/`. Serves the preview page if the user isn't
   * logged in, or the regular app page & container if they are.
   *
   * The content for this page depends conditionally on the user's login status. If they aren't logged in, we render a
   * page with a sign-in button and a little toy copy of Todolist. The toy copy is identical to the real one, but it
   * offers no persistence of tasks beyond the current browser session.
   *
   * If the user opts to make use of the anonymous/toy version, and then later chooses to sign in, their previous tasks
   * are preserved, along with their user ID (using anonymous user upgrade via Firebase). This flow happens via the
   * client-side app, so we don't need to worry about it here. Similarly, if the user hits the homepage without being
   * logged in, and then logs in, that flow is also handled by the re-hydrated CSR frontend.
   */
  @View("todolist.home.page")
  @Get("/", produces = ["text/html;charset=UTF-8"])
  fun home(@QueryValue("name", defaultValue = defaultName) name: String): HttpResponse<PageRender> {
    if (name != defaultName)
      logging.info("Greeting user with name '$name'...")
    if (logging.isDebugEnabled)
      logging.debug("Serving home page...")
    return this.serve(
      this.context
        .title("Todolist - Homepage - Manage personal todo-lists across devices")
        .put("name", name)
        .stylesheet("todolist.mdl")
        .stylesheet("todolist.styles")
        .script("todolist.main"))
  }
}