initial commit

src/masto/timelines.ts

@@ -0,0 +1,75 @@
+import { type mastodon } from "masto";
+import { Accessor, createResource, createSignal } from "solid-js";
+
+type TimelineFetchTips = {
+  direction?: "new" | "old";
+};
+
+type Timeline = {
+  list(params: {
+    maxId?: string;
+    minId?: string;
+  }): mastodon.Paginator<mastodon.v1.Status[], unknown>;
+};
+
+export function useTimeline(
+  timeline: Accessor<Timeline>,
+) {
+  let minId: string | undefined;
+  let maxId: string | undefined;
+  let otl: Timeline | undefined;
+  const idSet = new Set<string>();
+  return createResource<
+    mastodon.v1.Status[],
+    [Timeline],
+    TimelineFetchTips | undefined
+  >(
+    () => [timeline()] as const,
+    async ([tl], info) => {
+      if (otl !== tl) {
+        minId = undefined;
+        maxId = undefined;
+        idSet.clear();
+        info.value = [];
+        otl = tl;
+      }
+      const direction =
+        typeof info.refetching !== "boolean"
+          ? info.refetching?.direction
+          : "old";
+      const pager = await tl.list(
+        direction === "old"
+          ? {
+              maxId: minId,
+            }
+          : {
+              minId: maxId,
+            },
+      );
+      const old = info.value || [];
+      const diff = pager.filter((x) => !idSet.has(x.id));
+      for (const v of diff.map((x) => x.id)) {
+        idSet.add(v);
+      }
+      if (direction === "old") {
+        minId = pager[pager.length - 1]?.id;
+        if (!maxId && pager.length > 0) {
+          maxId = pager[0].id;
+        }
+        return [...old, ...diff];
+      } else {
+        maxId = pager.length > 0 ? pager[0].id : undefined;
+        if (!minId && pager.length > 0) {
+          minId = pager[pager.length - 1]?.id;
+        }
+        return [...diff, ...old];
+      }
+    },
+    {
+      initialValue: [],
+      storage(init) {
+        return createSignal(init, { equals: false });
+      },
+    },
+  );
+}