Support for rating system (#10124)

Signed-off-by: Andrey Sobolev <haiodo@gmail.com>

server-plugins/rating/src/index.ts

@@ -0,0 +1,139 @@
+//
+// Copyright © 2020, 2021 Anticrm Platform Contributors.
+// Copyright © 2021, 2022 Hardcore Engineering Inc.
+//
+// Licensed under the Eclipse Public License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License. You may
+// obtain a copy of the License at https://www.eclipse.org/legal/epl-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import core, {
+  TxProcessor,
+  type Doc,
+  type MeasureContext,
+  type Tx,
+  type TxCreateDoc,
+  type TxCUD,
+  type TxRemoveDoc,
+  type TxUpdateDoc
+} from '@hcengineering/core'
+import type { Plugin } from '@hcengineering/platform'
+import { plugin } from '@hcengineering/platform'
+import rating, { ReactionKind, type DocReaction } from '@hcengineering/rating'
+import {
+  BaseMiddleware,
+  type Middleware,
+  type PipelineContext,
+  type TxMiddlewareResult
+} from '@hcengineering/server-core'
+
+/**
+ * @public
+ */
+export const serverRatingId = 'server-rating' as Plugin
+
+export class RatingMiddleware extends BaseMiddleware {
+  static async create (ctx: MeasureContext, context: PipelineContext, next?: Middleware): Promise<Middleware> {
+    return new RatingMiddleware(context, next)
+  }
+
+  async tx (ctx: MeasureContext, tx: Tx[]): Promise<TxMiddlewareResult> {
+    for (const t of tx) {
+      if (TxProcessor.isExtendsCUD(t._class)) {
+        const cud = t as TxCUD<Doc>
+
+        if (cud.objectClass === rating.class.DocRating || cud.objectClass === rating.class.PersonRating) {
+          throw new Error('Direct modifications of ratings are not allowed.')
+        }
+        const c = rating.class.DocReaction
+        if (cud.objectClass === c) {
+          // Star/Like,Rate values could only be used one per user.
+          switch (cud._class) {
+            case core.class.TxCreateDoc:
+              // Check for duplicate of like, rate value, Emojii
+              await this.validateNewReaction(ctx, cud as TxCreateDoc<DocReaction>)
+              break
+            case core.class.TxUpdateDoc:
+              // Disallow update for Emojii, Star, Like, Usefull
+              // Allow only for RateValue
+              await this.validateReactionUpdate(ctx, cud as TxUpdateDoc<DocReaction>)
+              break
+            case core.class.TxRemoveDoc:
+              await this.validateReactionRemove(ctx, cud as TxRemoveDoc<DocReaction>)
+              break
+          }
+        }
+      }
+    }
+    return await this.provideTx(ctx, tx)
+  }
+
+  private async validateNewReaction (ctx: MeasureContext, create: TxCreateDoc<DocReaction>): Promise<void> {
+    if (create.attributes.reactionType !== ReactionKind.Star) {
+      // Should allow only one reaction per document per user for Emoji, Like, Usefull
+      const current = await this.provideFindAll(ctx, rating.class.DocReaction, {
+        attachedTo: create.attachedTo,
+        attachedToClass: create.objectClass
+      })
+      if (
+        current.some(
+          (it) =>
+            it.reactionType === create.attributes.reactionType &&
+            (it.value === create.attributes.value ||
+              (create.attributes.reactionType === ReactionKind.Emoji && it.emoji === create.attributes.emoji))
+        )
+      ) {
+        throw new Error('Duplicate emoji reaction is not allowed.')
+      }
+    } else {
+      // For stars, we probable need to merge them into one value.
+    }
+  }
+
+  private async validateReactionUpdate (ctx: MeasureContext, upd: TxUpdateDoc<DocReaction>): Promise<void> {
+    if (upd.operations.reactionType !== undefined) {
+      throw new Error('Modifications of reaction type are not allowed.')
+    }
+    // Find current reaction tried to be modified
+    const current = (
+      await this.provideFindAll(ctx, rating.class.DocReaction, {
+        _id: upd.objectId,
+        _class: upd.objectClass
+      })
+    ).shift()
+    if (current === undefined) {
+      throw new Error('Reaction not found.')
+    }
+    if (upd.operations.value === undefined || upd.operations.value < 0 || upd.operations.value > 10) {
+      throw new Error('Reaction value modification is required.')
+    }
+  }
+
+  private async validateReactionRemove (ctx: MeasureContext, upd: TxRemoveDoc<DocReaction>): Promise<void> {
+    // Find current reaction tried to be modified
+    // const current = (
+    //   await this.provideFindAll(ctx, rating.class.DocReaction, {
+    //     _id: upd.objectId,
+    //     _class: upd.objectClass
+    //   })
+    // ).shift()
+    // if (current === undefined) {
+    // No error, already removed
+    // }
+    // if (current.reactionType === ReactionKind.Star) {
+    //   throw new Error('Star reactions could not be removed.')
+    // }
+  }
+}
+
+/**
+ * @public
+ */
+export default plugin(serverRatingId, {})