feat: share post to other apps

components/social/share-post-provider.tsx

@@ -0,0 +1,69 @@
+"use client";
+
+/**
+ * SharePostProvider — mounts a single global SharePostSheet that any
+ * component in the tree can summon via `useSharePost().openShareSheet(post)`.
+ *
+ * The sheet itself is a heavy modal/drawer that loads URLs, pre-fetches
+ * images for native share, etc. — we don't want every caller to mount
+ * its own copy. Mounting once at the root and triggering via context
+ * keeps state isolated and makes "Share" a one-liner anywhere downstream:
+ *
+ *   const { openShareSheet } = useSharePost();
+ *   openShareSheet(newlyCreatedPost);
+ *
+ * Used today by compose-post.tsx (toast after a successful post create
+ * offers a "Share" action that opens the sheet for the new post).
+ * Future surfaces like profile cards can call into the same hook.
+ */
+
+import {
+  createContext,
+  useCallback,
+  useContext,
+  useState,
+} from "react";
+import type { Post } from "@/lib/social";
+import { useMediaQuery } from "@/components/selection-toolbar/shared";
+import { SharePostSheet } from "./share-post-sheet";
+
+type SharePostContextValue = {
+  openShareSheet: (post: Post) => void;
+};
+
+const SharePostContext = createContext<SharePostContextValue | null>(null);
+
+export function useSharePost(): SharePostContextValue {
+  const v = useContext(SharePostContext);
+  if (!v) {
+    throw new Error("useSharePost must be used inside <SharePostProvider>");
+  }
+  return v;
+}
+
+export function SharePostProvider({
+  children,
+}: {
+  children: React.ReactNode;
+}) {
+  const [activePost, setActivePost] = useState<Post | null>(null);
+  const isMobile = useMediaQuery("(max-width: 767px)");
+
+  const openShareSheet = useCallback((post: Post) => {
+    setActivePost(post);
+  }, []);
+
+  return (
+    <SharePostContext.Provider value={{ openShareSheet }}>
+      {children}
+      {activePost ? (
+        <SharePostSheet
+          open={true}
+          onClose={() => setActivePost(null)}
+          post={activePost}
+          isMobile={isMobile}
+        />
+      ) : null}
+    </SharePostContext.Provider>
+  );
+}