Implemented phase 6 for the POC prototype in the Website service.

Services/Website/Sources/Library/Internal/Pages/SellerDashboardPage.swift

@@ -12,6 +12,9 @@ struct SellerDashboardPage {
     let assetVersion: String?
     let locale: Locale
 
+    /// The upcoming events, each with whether the shop trades there.
+    let events: [(event: Event, isTrading: Bool)]
+
     /// The shop's listings still for sale, newest first.
     let listings: [Listing]
 
@@ -38,6 +41,7 @@ struct SellerDashboardPage {
     ///   - offers: the offers waiting for the seller's answer, the soonest to expire first.
     ///   - sales: the shop's sales, the latest agreed first.
     ///   - listings: the shop's listings still for sale, newest first.
+    ///   - events: the upcoming events; none by default.
     ///   - viewer: the signed-in viewer.
     ///   - now: the moment stamps are read relative to; the present by default.
     ///   - assetVersion: the version token appended to the page's asset URLs, or `nil` (the default) to leave them unversioned.
@@ -47,6 +51,7 @@ struct SellerDashboardPage {
         offers: [Offer],
         sales: [Sale],
         listings: [Listing],
+        events: [Event] = [],
         viewer: Viewer? = nil,
         now: Date = .init(),
         assetVersion: String? = nil,
@@ -54,6 +59,7 @@ struct SellerDashboardPage {
     ) {
         self.analytics = analytics
         self.assetVersion = assetVersion
+        self.events = events.map { event in (event, event.shops.contains { $0.slug == shop.slug }) }
         self.listings = listings
         self.locale = .init(identifier: "en")
         self.now = now
@@ -231,6 +237,43 @@ extension SellerDashboardPage: Page {
                         }
                     }
                 }
+                if !events.isEmpty {
+                    form(
+                        .class("card sell__panel"),
+                        .action("\(String.Route.sellerDashboard)/events"),
+                        .method(.post)
+                    ) {
+                        div(.class("section-head")) {
+                            h2(.class("type-panel")) {
+                                "Events you'll trade at"
+                            }
+                            span(.class("type-small")) {
+                                "Buyers can agree online and collect at the con"
+                            }
+                        }
+                        div(.class("listing-form__checks")) {
+                            ForEach(events) { entry in
+                                label(.class("check")) {
+                                    input(
+                                        .type(.checkbox),
+                                        .name("events"),
+                                        .value(entry.event.slug)
+                                    )
+                                    .attributes(.checked, when: entry.isTrading)
+                                    "\(entry.event.name) · \(Date.span(from: entry.event.startsOn, to: entry.event.endsOn))"
+                                }
+                            }
+                        }
+                        div(.class("listing-form__submit")) {
+                            button(
+                                .class("button button--dark button--sm"),
+                                .type(.submit)
+                            ) {
+                                "Save events"
+                            }
+                        }
+                    }
+                }
             }
         }
     }