added sharing and subscriptions

frontend/src/lib/lists.svelte.ts

@@ -7,11 +7,31 @@ export type List = {
   name: string;
   emoji: string | null;
   description: string | null;
+  share_token: string | null;
   position: number;
   created_at: string;
   updated_at: string;
 };
 
+export type SharedView = { list: List; items: Item[] };
+
+export type Subscription = {
+  id: string;
+  kind: "list" | "item";
+  created_at: string;
+  list_id: string | null;
+  item_id: string | null;
+  title: string;
+  emoji: string | null;
+  share_token: string | null;
+  url: string | null;
+  image_url: string | null;
+  current_price: number | null;
+  currency: string | null;
+  in_stock: boolean | null;
+  target_price: number | null;
+};
+
 export type Item = {
   id: string;
   list_id: string;
@@ -64,6 +84,9 @@ export const listsApi = {
   update: (id: string, b: Partial<NewList> & { position?: number }) =>
     api.patch<List>(`/lists/${id}`, b),
   remove: (id: string) => api.del<{ deleted: string }>(`/lists/${id}`),
+  share: (id: string) => api.post<List>(`/lists/${id}/share`, {}),
+  unshare: (id: string) => api.del<List>(`/lists/${id}/share`),
+  shared: (token: string) => api.get<SharedView>(`/shared/${token}`),
 
   items: (listId: string) => api.get<Item[]>(`/lists/${listId}/items`),
   addItem: (listId: string, b: NewItem) =>
@@ -75,6 +98,11 @@ export const listsApi = {
   removeItem: (id: string) => api.del<{ deleted: string }>(`/items/${id}`),
   refetch: (id: string) => api.post<Item>(`/items/${id}/refetch`, {}),
   history: (id: string) => api.get<PricePoint[]>(`/items/${id}/history`),
+
+  subscriptions: () => api.get<Subscription[]>("/subscriptions"),
+  subscribe: (b: { list_id?: string; item_id?: string }) =>
+    api.post<{ id: string }>("/subscriptions", b),
+  unsubscribe: (id: string) => api.del<{ deleted: string }>(`/subscriptions/${id}`),
 };
 
 /** Reactive store for the user's lists. */
@@ -97,6 +125,52 @@ class ListsStore {
     await listsApi.remove(id);
     this.items = this.items.filter((l) => l.id !== id);
   }
+
+  /** Swap in an updated list (e.g. after share/unshare). */
+  replace(list: List) {
+    const i = this.items.findIndex((l) => l.id === list.id);
+    if (i >= 0) this.items[i] = list;
+  }
 }
 
 export const lists = new ListsStore();
+
+/** The current user's subscriptions, with helpers to toggle by list/item. */
+class SubsStore {
+  items = $state<Subscription[]>([]);
+  loaded = $state(false);
+
+  async load() {
+    this.items = await listsApi.subscriptions();
+    this.loaded = true;
+  }
+
+  /** Existing subscription id for a list, or null. */
+  forList(listId: string): string | null {
+    return this.items.find((s) => s.list_id === listId)?.id ?? null;
+  }
+
+  /** Existing subscription id for an item, or null. */
+  forItem(itemId: string): string | null {
+    return this.items.find((s) => s.item_id === itemId)?.id ?? null;
+  }
+
+  async subscribeList(listId: string) {
+    if (this.forList(listId)) return;
+    await listsApi.subscribe({ list_id: listId });
+    await this.load();
+  }
+
+  async subscribeItem(itemId: string) {
+    if (this.forItem(itemId)) return;
+    await listsApi.subscribe({ item_id: itemId });
+    await this.load();
+  }
+
+  async unsubscribe(id: string) {
+    await listsApi.unsubscribe(id);
+    this.items = this.items.filter((s) => s.id !== id);
+  }
+}
+
+export const subs = new SubsStore();