feat: Post search (#70)

* feat: add post search 

Co-authored-by: zheyanyu <zheyanyu@amazon.com>
Co-authored-by: Nestor Carvantes <carvantes@gmail.com>

src/router/routes/genericResourceRoute.ts

@@ -6,6 +6,7 @@
 import express, { Router } from 'express';
 import { Authorization, TypeOperation } from 'fhir-works-on-aws-interface';
 import createError from 'http-errors';
+import { isEmpty, mergeWith } from 'lodash';
 import CrudHandlerInterface from '../handlers/CrudHandlerInterface';
 import RouteHelper from './routeHelper';
 
@@ -127,31 +128,59 @@ export default class GenericResourceRoute {
         }
 
         if (this.operations.includes('search-type')) {
+            const handleSearch = async (res: express.Response, resourceType: string, searchParamQuery: any) => {
+                const allowedResourceTypes = await this.authService.getAllowedResourceTypesForOperation({
+                    operation: 'search-type',
+                    userIdentity: res.locals.userIdentity,
+                });
+
+                const response = await this.handler.typeSearch(
+                    resourceType,
+                    searchParamQuery,
+                    allowedResourceTypes,
+                    res.locals.userIdentity,
+                );
+                const updatedSearchResponse = await this.authService.authorizeAndFilterReadResponse({
+                    operation: 'search-type',
+                    userIdentity: res.locals.userIdentity,
+                    readResponse: response,
+                });
+                return updatedSearchResponse;
+            };
             // SEARCH
             this.router.get(
                 '/',
                 RouteHelper.wrapAsync(async (req: express.Request, res: express.Response) => {
                     // Get the ResourceType looks like '/Patient'
                     const resourceType = req.baseUrl.substr(1);
                     const searchParamQuery = req.query;
+                    const updatedSearchResponse = await handleSearch(res, resourceType, searchParamQuery);
+                    res.send(updatedSearchResponse);
+                }),
+            );
+            this.router.post(
+                '/_search',
+                RouteHelper.wrapAsync(async (req: express.Request, res: express.Response) => {
+                    // Get the ResourceType looks like '/Patient'
+                    const resourceType = req.baseUrl.substr(1);
+                    const searchParamQuery = req.query;
+                    const { body } = req;
 
-                    const allowedResourceTypes = await this.authService.getAllowedResourceTypesForOperation({
-                        operation: 'search-type',
-                        userIdentity: res.locals.userIdentity,
-                    });
+                    if (!isEmpty(body)) {
+                        mergeWith(searchParamQuery, body, (valueOne, valueTwo) => {
+                            if (
+                                !isEmpty(valueOne) &&
+                                !isEmpty(valueTwo) &&
+                                (Array.isArray(valueOne) || Array.isArray(valueTwo) || valueOne !== valueTwo)
+                            ) {
+                                return [...new Set([].concat(valueOne, valueTwo))];
+                            }
+                            return undefined; // Merging is handled by lodash mergeWith if undefined is returned
+                        });
+                    }
 
-                    const response = await this.handler.typeSearch(
-                        resourceType,
-                        searchParamQuery,
-                        allowedResourceTypes,
-                        res.locals.userIdentity,
-                    );
-                    const updatedReadResponse = await this.authService.authorizeAndFilterReadResponse({
-                        operation: 'search-type',
-                        userIdentity: res.locals.userIdentity,
-                        readResponse: response,
-                    });
-                    res.send(updatedReadResponse);
+                    const updatedSearchResponse = await handleSearch(res, resourceType, searchParamQuery);
+                    res.send(updatedSearchResponse);
                 }),
             );
         }