import Elementary
import ElementaryHTMX
import SharedModels

struct MainPage<Inner: HTML>: SendableHTMLDocument where Inner: Sendable {

  var title: String { "Purchase Orders" }
  var lang: String { "en" }

  let inner: Inner
  let displayNav: Bool
  let routeHeader: RouteHeaderView

  init(
    displayNav: Bool = false,
    route: RouteHeaderView.ViewRoute,
    _ inner: () -> Inner
  ) {
    self.displayNav = displayNav
    self.routeHeader = .init(route: route)
    self.inner = inner()
  }

  var head: some HTML {
    meta(.charset(.utf8))
    script(.src("https://unpkg.com/htmx.org@2.0.4")) {}
    script(.src("/js/main.js")) {}
    link(.rel(.stylesheet), .href("/css/main.css"))
    link(.rel(.icon), .href("/images/favicon.ico"), .custom(name: "type", value: "image/x-icon"))
  }

  var body: some HTML {
    header(.class("header")) {
      Logo()
      if displayNav {
        Navbar()
      }
    }
    routeHeader
    inner
  }
}

extension MainPage where Inner == LoggedIn {
  static func loggedIn(next: String?) -> Self {
    MainPage(displayNav: true, route: .purchaseOrders) {
      LoggedIn(next: next)
    }
  }
}

struct LoggedIn: HTML, Sendable {
  let next: String?
  var content: some HTML {
    div(
      .hx.get(nextRoute ?? ViewRoute.router.path(for: .purchaseOrder(.index))),
      .hx.pushURL(true),
      .hx.target(.body),
      .hx.trigger(.event(.revealed)),
      .hx.indicator(".hx-indicator")
    ) {
      Img.spinner().attributes(.class("hx-indicator"))
    }
  }

  // HACK: to get search route to work after login.
  var nextRoute: String? {
    if let next, next.contains("search") {
      return ViewRoute.router.path(for: .purchaseOrder(.search(.index(context: .employee, table: true))))
    }
    return next
  }
}

struct RouteHeaderView: HTML, Sendable {

  let title: String
  let description: String

  init(title: String, description: String) {
    self.title = title
    self.description = description
  }

  init(route: ViewRoute) {
    self.init(title: route.title, description: route.description)
  }

  var content: some HTML {
    div(.class("container"), .style("padding: 20px 20px;")) {
      h1 { title }
      br()
      p(.class("secondary")) { i { description } }
      br()
    }
  }

  enum ViewRoute: String, Sendable {

    case employees
    case login
    case purchaseOrders
    case users
    case vendors

    var title: String {
      switch self {
      case .purchaseOrders:
        return "Purchase Orders"
      default:
        return rawValue.capitalized
      }
    }

    var description: String {
      switch self {
      case .employees:
        return "Employees are who purchase orders can be issued to."
      case .purchaseOrders, .login:
        return ""
      case .users:
        return "Users are who can login and issue purchase orders for employees."
      case .vendors:
        return "Vendors are where purchase orders can be issued to."
      }
    }

  }
}

struct Logo: HTML, Sendable {

  var content: some HTML {
    div(.id("logo")) {
      "HHE - Purchase Orders"
    }
  }
}

protocol SendableHTMLDocument: HTMLDocument, Sendable {}