From c52e7d93c31e7bdacdd143ba6df4524918d732b3 Mon Sep 17 00:00:00 2001
From: takker99 <37929109+takker99@users.noreply.github.com>
Date: Wed, 20 Jul 2022 08:40:12 +0900
Subject: [PATCH] :sparkles: Implement wrappers for /api/page-snapshots/

---
 deps/scrapbox-rest.ts |   2 +
 rest/getSnapshots.ts  | 150 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 152 insertions(+)
 create mode 100644 rest/getSnapshots.ts

diff --git a/deps/scrapbox-rest.ts b/deps/scrapbox-rest.ts
index af75dbe..d9a62f9 100644
--- a/deps/scrapbox-rest.ts
+++ b/deps/scrapbox-rest.ts
@@ -16,11 +16,13 @@ export type {
   NotPrivilegeError,
   Page,
   PageList,
+  PageSnapshot,
   ProjectId,
   ProjectResponse,
   ProjectSearchResult,
   SearchedTitle,
   SearchResult,
   SessionError,
+  Snapshot,
   TweetInfo,
 } from "https://raw.githubusercontent.com/scrapbox-jp/types/0.3.5/rest.ts";
diff --git a/rest/getSnapshots.ts b/rest/getSnapshots.ts
new file mode 100644
index 0000000..9d3e071
--- /dev/null
+++ b/rest/getSnapshots.ts
@@ -0,0 +1,150 @@
+import type {
+  ErrorLike,
+  NotFoundError,
+  NotLoggedInError,
+  NotMemberError,
+  PageSnapshot,
+  Snapshot,
+} from "../deps/scrapbox-rest.ts";
+import { tryToErrorLike } from "../is.ts";
+import { cookie } from "./auth.ts";
+import { BaseOptions, Result, setDefaults } from "./util.ts";
+import { UnexpectedResponseError } from "./error.ts";
+
+/** 不正なfollowingIdを渡されたときに発生するエラー */
+export interface InvalidPageSnapshotIdError extends ErrorLike {
+  name: "InvalidPageSnapshotIdError";
+}
+
+export interface GetSnapshotsOptions extends BaseOptions {
+  /** 次のsnapshots listを示すID */
+  followingId?: string;
+}
+
+/** get page snapshots
+ *
+ * @param options connect.sid etc.
+ */
+export const getSnapshots = async (
+  project: string,
+  pageId: string,
+  options?: GetSnapshotsOptions,
+): Promise<
+  Result<
+    (PageSnapshot & { followingId: string }),
+    | NotFoundError
+    | NotLoggedInError
+    | NotMemberError
+    | InvalidPageSnapshotIdError
+  >
+> => {
+  const { sid, hostName, fetch, followingId } = setDefaults(options ?? {});
+  const path = `https://${hostName}/api/page-snapshots/${project}/${pageId}/${
+    followingId ? `?followingId=${followingId}` : ""
+  }`;
+
+  const res = await fetch(
+    path,
+    sid ? { headers: { Cookie: cookie(sid) } } : undefined,
+  );
+
+  if (!res.ok) {
+    if (res.status === 422) {
+      return {
+        ok: false,
+        value: {
+          name: "InvalidPageSnapshotIdError",
+          message: await res.text(),
+        },
+      };
+    }
+    const text = await res.text();
+    const value = tryToErrorLike(text);
+    if (!value) {
+      throw new UnexpectedResponseError({
+        path: new URL(path),
+        ...res,
+        body: text,
+      });
+    }
+    return {
+      ok: false,
+      value: value as (NotFoundError | NotLoggedInError | NotMemberError),
+    };
+  }
+
+  const data = (await res.json()) as PageSnapshot;
+  return {
+    ok: true,
+    value: { ...data, followingId: res.headers.get("X-following-id") ?? "" },
+  };
+};
+
+/** 指定したページのsnapshotsを、responseに入っている塊ごとに全て返す
+ *
+ * @param project ページのproject name
+ * @param pageId page id
+ * @return 認証が通らなかったらエラーを、通ったらasync generatorを返す
+ */
+export const readSnapshotsBulk = async (
+  project: string,
+  pageId: string,
+  options?: BaseOptions,
+): Promise<
+  | NotFoundError
+  | NotLoggedInError
+  | NotMemberError
+  | InvalidPageSnapshotIdError
+  | AsyncGenerator<Snapshot[], void, unknown>
+> => {
+  const first = await getSnapshots(project, pageId, options);
+  if (!first.ok) return first.value;
+
+  return async function* () {
+    yield first.value.snapshots;
+    let followingId = first.value.followingId;
+
+    while (followingId) {
+      const result = await getSnapshots(project, pageId, {
+        followingId,
+        ...options,
+      });
+
+      // すでに認証は通っているので、ここでエラーになるはずがない
+      if (!result.ok) {
+        throw new Error("The authorization cannot be unavailable");
+      }
+      yield result.value.snapshots;
+      followingId = result.value.followingId;
+    }
+  }();
+};
+
+/** 指定したページの全てのsnapshotsを取得し、一つづつ返す
+ *
+ * @param project ページのproject name
+ * @param pageId page id
+ * @return 認証が通らなかったらエラーを、通ったらasync generatorを返す
+ */
+export const readSnapshots = async (
+  project: string,
+  pageId: string,
+  options?: BaseOptions,
+): Promise<
+  | NotFoundError
+  | NotLoggedInError
+  | NotMemberError
+  | InvalidPageSnapshotIdError
+  | AsyncGenerator<Snapshot, void, unknown>
+> => {
+  const reader = await readSnapshotsBulk(project, pageId, options);
+  if ("name" in reader) return reader;
+
+  return async function* () {
+    for await (const titles of reader) {
+      for (const title of titles) {
+        yield title;
+      }
+    }
+  }();
+};