Работа над приложением

server/core/DbSearcher.js

@@ -1,27 +1,82 @@
+//const _ = require('lodash');
+
+const utils = require('./utils');
+
 class DbSearcher {
     constructor(db) {
         this.db = db;
     }
 
-    async search(query) {
+    async selectAuthorIds(query) {
         const db = this.db;
 
-        let result = [];
-
+        let authorRows;
+        //сначала выберем все id авторов по фильтру
+        //порядок id соответсвует ASC-сортировке по author
         if (query.author) {
             //
         } else {
-            result = await db.select({
+            authorRows = await db.select({
                 table: 'author',
-                map: `(r) => ({id: r.id, author: r.author})`
+                map: `(r) => ({id: r.id})`,
             });
         }
 
-        if (query.limit) {
-            result = result.slice(0, query.limit);
-        }
+        let authorIds = new Set();
+        for (const row of authorRows)
+            authorIds.add(row.id);
 
-        return result;
+        const idsArr = [];
+        idsArr.push(authorIds);
+
+        //серии
+        //названия
+        //жанры
+        //языки
+
+        if (idsArr.length > 1)
+            authorIds = utils.intersectSet(idsArr);
+
+        //сортировка
+        authorIds = Array.from(authorIds);
+        authorIds.sort();
+
+        return authorIds;
+    }
+
+    async getAuthorIds(query) {
+        const db = this.db;
+
+        if (!db.searchCache)
+            db.searchCache = {};
+
+        /*const q = query;
+        const key = JSON.stringify([q.author, ]);
+        query);
+        delete q.limit;
+
+        q = */
+        return await this.selectAuthorIds(query);
+    }
+
+    async search(query) {
+        const db = this.db;
+
+        const authorIds = await this.getAuthorIds(query);
+
+        const totalFound = authorIds.length;
+        const limit = (query.limit ? query.limit : 1000);
+
+        //выборка найденных авторов
+        let result = await db.select({
+            table: 'author',
+            map: `(r) => ({id: r.id, author: r.author})`,
+            where: `@@id(${db.esc(authorIds)})`
+        });
+
+        result = result.slice(0, limit);
+
+        return {result, totalFound};
     }
 }