From 52a59d3865444d37a2c605d2799346172fec2904 Mon Sep 17 00:00:00 2001
From: Akshay Patel <akshay.ap95@gmail.com>
Date: Sun, 3 May 2020 14:36:07 +0530
Subject: [PATCH] feat(viewpatients): enables to navigation to previous page

Add a field in PageRequest to store refrence that will enable getting previous page.

feat #1969
---
 .../patients/list/ViewPatients.test.tsx         |  8 +++++++-
 src/clients/db/PageRequest.ts                   |  3 +++
 src/clients/db/Repository.ts                    | 17 ++++++++++-------
 src/patients/list/ViewPatients.tsx              |  5 ++++-
 4 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/src/__tests__/patients/list/ViewPatients.test.tsx b/src/__tests__/patients/list/ViewPatients.test.tsx
index 298ad87cf7..ccf1d574fa 100644
--- a/src/__tests__/patients/list/ViewPatients.test.tsx
+++ b/src/__tests__/patients/list/ViewPatients.test.tsx
@@ -174,7 +174,13 @@ describe('Patients', () => {
         {
           sorts: [{ field: 'index', direction: 'asc' }],
         },
-        { number: 1, size: 1, nextPageInfo: { index: null }, direction: 'next' },
+        {
+          number: 1,
+          size: 1,
+          nextPageInfo: { index: null },
+          direction: 'next',
+          previousPageInfo: { index: null },
+        },
       )
     })
   })
diff --git a/src/clients/db/PageRequest.ts b/src/clients/db/PageRequest.ts
index 065f80f66b..2ad698b0a0 100644
--- a/src/clients/db/PageRequest.ts
+++ b/src/clients/db/PageRequest.ts
@@ -2,6 +2,8 @@ export default interface PageRequest {
   number: number | undefined
   size: number | undefined
   nextPageInfo: { [key: string]: string | null } | undefined
+  previousPageInfo: { [key: string]: string | null } | undefined
+
   direction: 'previous' | 'next' | null
 }
 export const UnpagedRequest: PageRequest = {
@@ -9,4 +11,5 @@ export const UnpagedRequest: PageRequest = {
   size: undefined,
   nextPageInfo: undefined,
   direction: null,
+  previousPageInfo: undefined,
 }
diff --git a/src/clients/db/Repository.ts b/src/clients/db/Repository.ts
index 3cdcf75191..db5924cbbc 100644
--- a/src/clients/db/Repository.ts
+++ b/src/clients/db/Repository.ts
@@ -61,8 +61,8 @@ export default class Repository<T extends AbstractDBModel> {
         s.direction = s.direction === 'asc' ? 'desc' : 'asc'
         selector[s.field] = {
           $lte:
-            pageRequest.nextPageInfo && pageRequest.nextPageInfo[s.field]
-              ? pageRequest.nextPageInfo[s.field]
+            pageRequest.previousPageInfo && pageRequest.previousPageInfo[s.field]
+              ? pageRequest.previousPageInfo[s.field]
               : null,
         }
       })
@@ -72,33 +72,36 @@ export default class Repository<T extends AbstractDBModel> {
       selector,
       sort: sort.sorts.length > 0 ? sort.sorts.map((s) => ({ [s.field]: s.direction })) : undefined,
       limit: pageRequest.size ? pageRequest.size + 1 : undefined,
-      skip: pageRequest.direction === 'previous' ? pageRequest.size : undefined,
     })
     const mappedResult = result.docs.map(mapDocument)
-
     if (pageRequest.direction === 'previous') {
       mappedResult.reverse()
     }
-    const nextPageInfo: { [key: string]: string } = {}
 
+    const nextPageInfo: { [key: string]: string } = {}
     if (mappedResult.length > 0) {
       sort.sorts.forEach((s) => {
         nextPageInfo[s.field] = mappedResult[mappedResult.length - 1][s.field]
       })
     }
 
+    const previousPageInfo: { [key: string]: string } = {}
+    sort.sorts.forEach((s) => {
+      previousPageInfo[s.field] = mappedResult[0][s.field]
+    })
+
     const pagedResult: Page<T> = {
       content:
         pageRequest.size !== undefined && mappedResult.length === pageRequest.size + 1
           ? mappedResult.slice(0, mappedResult.length - 1)
           : mappedResult,
       hasNext: pageRequest.size !== undefined && mappedResult.length === pageRequest.size + 1,
-      // hasPrevious: pageRequest.number !== undefined && pageRequest.number > 1,
-      hasPrevious: false,
+      hasPrevious: pageRequest.number !== undefined && pageRequest.number > 1,
       pageRequest: {
         size: pageRequest.size,
         number: pageRequest.number,
         nextPageInfo,
+        previousPageInfo,
         direction: null,
       },
     }
diff --git a/src/patients/list/ViewPatients.tsx b/src/patients/list/ViewPatients.tsx
index fdced50eb7..a9b6d519b6 100644
--- a/src/patients/list/ViewPatients.tsx
+++ b/src/patients/list/ViewPatients.tsx
@@ -29,6 +29,7 @@ const ViewPatients = () => {
     size: 1,
     number: 1,
     nextPageInfo: { index: null },
+    previousPageInfo: { index: null },
     direction: 'next',
   })
 
@@ -39,6 +40,7 @@ const ViewPatients = () => {
           number: p.number + 1,
           size: p.size,
           nextPageInfo: patients.pageRequest?.nextPageInfo,
+          previousPageInfo: undefined,
           direction: 'next',
         }
         return newPageRequest
@@ -53,7 +55,8 @@ const ViewPatients = () => {
         return {
           number: p.number - 1,
           size: p.size,
-          nextPageInfo: patients.pageRequest?.nextPageInfo,
+          nextPageInfo: undefined,
+          previousPageInfo: patients.pageRequest?.previousPageInfo,
           direction: 'previous',
         }
       }