feat(federation): ✨ Implement Share federation support

api/shares/[uuid]/index.ts

@@ -0,0 +1,79 @@
+import { Status as StatusSchema } from "@versia/client/schemas";
+import { Note } from "@versia/kit/db";
+import { Notes } from "@versia/kit/tables";
+import { and, eq, inArray } from "drizzle-orm";
+import { describeRoute } from "hono-openapi";
+import { resolver, validator } from "hono-openapi/zod";
+import { z } from "zod";
+import { apiRoute, handleZodError } from "@/api";
+import { ApiError } from "~/classes/errors/api-error";
+import { config } from "~/config.ts";
+import { ShareSchema } from "~/packages/sdk/schemas";
+
+export default apiRoute((app) =>
+    app.get(
+        "/shares/:id",
+        describeRoute({
+            summary: "Retrieve the Versia representation of a share.",
+            tags: ["Federation"],
+            responses: {
+                200: {
+                    description: "Share",
+                    content: {
+                        "application/json": {
+                            schema: resolver(ShareSchema),
+                        },
+                    },
+                },
+                404: {
+                    description:
+                        "Entity not found, is remote, or the requester is not allowed to view it.",
+                    content: {
+                        "application/json": {
+                            schema: resolver(ApiError.zodSchema),
+                        },
+                    },
+                },
+            },
+        }),
+        validator(
+            "param",
+            z.object({
+                id: StatusSchema.shape.id,
+            }),
+            handleZodError,
+        ),
+        async (context) => {
+            const { id } = context.req.valid("param");
+
+            const note = await Note.fromSql(
+                and(
+                    eq(Notes.id, id),
+                    inArray(Notes.visibility, ["public", "unlisted"]),
+                ),
+            );
+
+            if (!(note && (await note.isViewableByUser(null))) || note.remote) {
+                throw ApiError.noteNotFound();
+            }
+
+            // If base_url uses https and request uses http, rewrite request to use https
+            // This fixes reverse proxy errors
+            const reqUrl = new URL(context.req.url);
+            if (
+                config.http.base_url.protocol === "https:" &&
+                reqUrl.protocol === "http:"
+            ) {
+                reqUrl.protocol = "https:";
+            }
+
+            const { headers } = await note.author.sign(
+                note.toVersiaShare(),
+                reqUrl,
+                "GET",
+            );
+
+            return context.json(note.toVersiaShare(), 200, headers.toJSON());
+        },
+    ),
+);