chore: implement reaction frontend

web/src/components/MemoReactionistView.tsx

+import { uniq } from "lodash-es";
+import { memo, useEffect, useState } from "react";
+import { extractUsernameFromName, useUserStore } from "@/store/v1";
+import { Memo } from "@/types/proto/api/v2/memo_service";
+import { Reaction, Reaction_Type } from "@/types/proto/api/v2/reaction_service";
+import { User } from "@/types/proto/api/v2/user_service";
+import ReactionSelector from "./ReactionSelector";
+import ReactionView from "./ReactionView";
+
+interface Props {
+  memo: Memo;
+  reactions: Reaction[];
+}
+
+const MemoReactionListView = (props: Props) => {
+  const { memo, reactions } = props;
+  const userStore = useUserStore();
+  const [reactionGroup, setReactionGroup] = useState<Map<Reaction_Type, User[]>>(new Map());
+
+  useEffect(() => {
+    (async () => {
+      const reactionGroup = new Map<Reaction_Type, User[]>();
+      for (const reaction of reactions) {
+        const user = await userStore.getOrFetchUserByUsername(extractUsernameFromName(reaction.creator));
+        const users = reactionGroup.get(reaction.reactionType) || [];
+        users.push(user);
+        reactionGroup.set(reaction.reactionType, uniq(users));
+      }
+      setReactionGroup(reactionGroup);
+    })();
+  }, [reactions]);
+
+  return (
+    <div className="w-full mt-2 flex flex-row justify-start items-start flex-wrap gap-1">
+      <ReactionSelector memo={memo} />
+      {Array.from(reactionGroup).map(([reactionType, users]) => {
+        return <ReactionView key={`${reactionType.toString()} ${users.length}`} memo={memo} reactionType={reactionType} users={users} />;
+      })}
+    </div>
+  );
+};
+
+export default memo(MemoReactionListView);

web/src/components/MemoRelationListView.tsx

@@ -8,11 +8,11 @@ import Icon from "./Icon";
 
 interface Props {
   memo: Memo;
-  relationList: MemoRelation[];
+  relations: MemoRelation[];
 }
 
 const MemoRelationListView = (props: Props) => {
-  const { memo, relationList } = props;
+  const { memo, relations: relationList } = props;
   const memoStore = useMemoStore();
   const [referencingMemoList, setReferencingMemoList] = useState<Memo[]>([]);
   const [referencedMemoList, setReferencedMemoList] = useState<Memo[]>([]);

web/src/components/MemoView.tsx

@@ -20,6 +20,7 @@ import { showCommonDialog } from "./Dialog/CommonDialog";
 import Icon from "./Icon";
 import MemoContent from "./MemoContent";
 import showMemoEditorDialog from "./MemoEditor/MemoEditorDialog";
+import MemoReactionistView from "./MemoReactionistView";
 import MemoRelationListView from "./MemoRelationListView";
 import MemoResourceListView from "./MemoResourceListView";
 import showPreviewImageDialog from "./PreviewImageDialog";
@@ -265,7 +266,8 @@ const MemoView: React.FC<Props> = (props: Props) => {
         onClick={handleMemoContentClick}
       />
       <MemoResourceListView resources={memo.resources} />
-      <MemoRelationListView memo={memo} relationList={referenceRelations} />
+      <MemoRelationListView memo={memo} relations={referenceRelations} />
+      <MemoReactionistView memo={memo} reactions={memo.reactions} />
     </div>
   );
 };

web/src/components/ReactionSelector.tsx

+import { Dropdown, Menu, MenuButton } from "@mui/joy";
+import { useRef, useState } from "react";
+import useClickAway from "react-use/lib/useClickAway";
+import Icon from "@/components/Icon";
+import { memoServiceClient } from "@/grpcweb";
+import { MemoNamePrefix, useMemoStore } from "@/store/v1";
+import { Memo } from "@/types/proto/api/v2/memo_service";
+import { Reaction_Type } from "@/types/proto/api/v2/reaction_service";
+import { stringifyReactionType } from "./ReactionView";
+
+interface Props {
+  memo: Memo;
+}
+
+const REACTION_TYPES = [
+  Reaction_Type.THUMBS_UP,
+  Reaction_Type.HEART,
+  Reaction_Type.ROCKET,
+  Reaction_Type.LAUGH,
+  Reaction_Type.EYES,
+  Reaction_Type.THUMBS_DOWN,
+];
+
+const ReactionSelector = (props: Props) => {
+  const { memo } = props;
+  const memoStore = useMemoStore();
+  const [open, setOpen] = useState(false);
+  const containerRef = useRef<HTMLDivElement>(null);
+
+  useClickAway(containerRef, () => {
+    setOpen(false);
+  });
+
+  const handleReactionClick = async (reaction: Reaction_Type) => {
+    try {
+      await memoServiceClient.upsertMemoReaction({
+        id: memo.id,
+        reaction: {
+          contentId: `${MemoNamePrefix}${memo.id}`,
+          reactionType: reaction,
+        },
+      });
+      await memoStore.getOrFetchMemoById(memo.id, {
+        skipCache: true,
+      });
+    } catch (error) {
+      // skip error.
+    }
+  };
+
+  return (
+    <Dropdown open={open} onOpenChange={(_, isOpen) => setOpen(isOpen)}>
+      <MenuButton slots={{ root: "div" }} slotProps={{}}>
+        <span className="h-7 w-7 flex justify-center items-center rounded-full border dark:border-zinc-700 hover:opacity-80">
+          <Icon.Smile className="w-4 h-4 mx-auto dark:text-gray-400" />
+        </span>
+      </MenuButton>
+      <Menu className="relative text-sm" component="div" size="sm" placement="bottom-start">
+        <div ref={containerRef}>
+          <div className="flex-row justify-start items-start py-0.5 px-2 h-auto font-mono space-x-1">
+            {REACTION_TYPES.map((reactionType) => {
+              return (
+                <div
+                  key={reactionType}
+                  className="inline-flex w-auto cursor-pointer rounded text-lg px-1 text-gray-500 dark:text-gray-400 hover:bg-zinc-100 dark:hover:bg-zinc-800"
+                  onClick={() => handleReactionClick(reactionType)}
+                >
+                  {stringifyReactionType(reactionType)}
+                </div>
+              );
+            })}
+          </div>
+        </div>
+      </Menu>
+    </Dropdown>
+  );
+};
+
+export default ReactionSelector;

web/src/components/ReactionView.tsx

+import { Tooltip } from "@mui/joy";
+import classNames from "classnames";
+import { memoServiceClient } from "@/grpcweb";
+import useCurrentUser from "@/hooks/useCurrentUser";
+import { MemoNamePrefix, useMemoStore } from "@/store/v1";
+import { Memo } from "@/types/proto/api/v2/memo_service";
+import { Reaction_Type } from "@/types/proto/api/v2/reaction_service";
+import { User } from "@/types/proto/api/v2/user_service";
+
+interface Props {
+  memo: Memo;
+  reactionType: Reaction_Type;
+  users: User[];
+}
+
+export const stringifyReactionType = (reactionType: Reaction_Type): string => {
+  switch (reactionType) {
+    case Reaction_Type.EYES:
+      return "👀";
+    case Reaction_Type.HEART:
+      return "💗";
+    case Reaction_Type.LAUGH:
+      return "😂";
+    case Reaction_Type.ROCKET:
+      return "🚀";
+    case Reaction_Type.THUMBS_DOWN:
+      return "👎";
+    case Reaction_Type.THUMBS_UP:
+      return "👍";
+    default:
+      return "";
+  }
+};
+
+const stringifyUsers = (users: User[]): string => {
+  if (users.length === 0) {
+    return "";
+  }
+  if (users.length < 5) {
+    return users.map((user) => user.nickname || user.username).join(", ");
+  }
+  return `${users
+    .slice(0, 5)
+    .map((user) => user.nickname || user.username)
+    .join(", ")} and ${users.length - 5} others`;
+};
+
+const ReactionView = (props: Props) => {
+  const { memo, reactionType, users } = props;
+  const currenUser = useCurrentUser();
+  const memoStore = useMemoStore();
+  const hasReaction = users.some((user) => currenUser && user.username === currenUser.username);
+
+  const handleReactionClick = async () => {
+    if (!currenUser) {
+      return;
+    }
+
+    const index = users.findIndex((user) => user.username === currenUser.username);
+    try {
+      if (index === -1) {
+        await memoServiceClient.upsertMemoReaction({
+          id: memo.id,
+          reaction: {
+            contentId: `${MemoNamePrefix}${memo.id}`,
+            reactionType,
+          },
+        });
+      } else {
+        const reactions = memo.reactions.filter(
+          (reaction) => reaction.reactionType === reactionType && reaction.creator === currenUser.name,
+        );
+        for (const reaction of reactions) {
+          await memoServiceClient.deleteMemoReaction({ id: reaction.id });
+        }
+      }
+    } catch (error) {
+      // Skip error.
+    }
+    await memoStore.getOrFetchMemoById(memo.id, { skipCache: true });
+  };
+
+  return (
+    <Tooltip title={stringifyUsers(users)} placement="top">
+      <div
+        className={classNames(
+          "h-7 border px-2 py-0.5 rounded-full font-memo flex flex-row justify-center items-center gap-1 dark:border-zinc-700",
+          currenUser && "cursor-pointer",
+          hasReaction && "bg-blue-50 border-blue-100 dark:bg-zinc-900",
+        )}
+        onClick={handleReactionClick}
+      >
+        <span>{stringifyReactionType(reactionType)}</span>
+        <span className="text-sm text-gray-500 dark:text-gray-400">{users.length}</span>
+      </div>
+    </Tooltip>
+  );
+};
+
+export default ReactionView;

web/src/pages/MemoDetail.tsx

@@ -139,7 +139,7 @@ const MemoDetail = () => {
           )}
           <MemoContent key={`${memo.id}-${memo.updateTime}`} memoId={memo.id} content={memo.content} readonly={readonly} />
           <MemoResourceListView resources={memo.resources} />
-          <MemoRelationListView memo={memo} relationList={referenceRelations} />
+          <MemoRelationListView memo={memo} relations={referenceRelations} />
           <div className="w-full mt-3 flex flex-row justify-between items-center gap-2">
             <div className="flex flex-row justify-start items-center">
               {!readonly && (

web/src/store/v1/resourceName.ts

 export const UserNamePrefix = "users/";
+export const MemoNamePrefix = "memos/";
 
 export const extractUsernameFromName = (name: string = "") => {
   return name.slice(UserNamePrefix.length);