From ee04d66fa9e1565626d098049c091d11553d479c Mon Sep 17 00:00:00 2001
From: Jacek Kutzmann <j.kutzmann@kainos.com>
Date: Mon, 14 Nov 2016 11:23:04 +0100
Subject: [PATCH] VEL-1521 fixed pagination links

---
 src/fhir/search_helpers.coffee          | 10 +---
 test/fhir/search/pagination_search.yaml | 73 ++++++++++++++++++++++++-
 2 files changed, 74 insertions(+), 9 deletions(-)

diff --git a/src/fhir/search_helpers.coffee b/src/fhir/search_helpers.coffee
index b213282..b376c63 100644
--- a/src/fhir/search_helpers.coffee
+++ b/src/fhir/search_helpers.coffee
@@ -14,11 +14,11 @@ exports.search_links = (query, expr, total)->
     base_url = base_url + "&_page=0"
 
   requested_count = expr.count
-  requested_page = expr.page
+  requested_page = expr.page ? 0
 
   res.push({relation: 'self', url: base_url})
 
-  if requested_count && requested_count < total
+  if requested_count && requested_count * (requested_page + 1) < total
     next_url = base_url.replace /_page=\d+/, -> "_page=#{requested_page + 1}"
     res.push({relation: 'next', url: next_url})
 
@@ -27,11 +27,7 @@ exports.search_links = (query, expr, total)->
     res.push({relation: 'previous', url: next_url})
 
   if requested_count
-    last_page = if requested_count < total
-        Math.floor(total / requested_count)
-      else
-        requested_page
-
+    last_page = Math.max(0, Math.ceil(total / requested_count) - 1)
     last_url = base_url.replace /_page=\d+/, -> "_page=#{last_page}"
     res.push({relation: 'last', url: last_url})
 
diff --git a/test/fhir/search/pagination_search.yaml b/test/fhir/search/pagination_search.yaml
index ae5390a..d7e570b 100644
--- a/test/fhir/search/pagination_search.yaml
+++ b/test/fhir/search/pagination_search.yaml
@@ -62,7 +62,7 @@ queries:
       - path: ['link', 2, 'url']
         result: "/Encounter?patient=Patient/nicola&_sort=patient&_page=0&_count=1"
       - path: ['link', 3, 'url']
-        result: "/Encounter?patient=Patient/nicola&_sort=patient&_page=3&_count=1"
+        result: "/Encounter?patient=Patient/nicola&_sort=patient&_page=2&_count=1"
 
   - query: {resourceType: 'Encounter', queryString: 'patient=Patient/nicola&_sort=patient&_page=1&_count=1&_totalMethod=exact'}
     total: 3
@@ -76,10 +76,79 @@ queries:
       - path: ['link', 2, 'url']
         result: "/Encounter?patient=Patient/nicola&_sort=patient&_page=0&_count=1&_totalMethod=exact"
       - path: ['link', 3, 'url']
-        result: "/Encounter?patient=Patient/nicola&_sort=patient&_page=3&_count=1&_totalMethod=exact"
+        result: "/Encounter?patient=Patient/nicola&_sort=patient&_page=2&_count=1&_totalMethod=exact"
 
   - query: {resourceType: 'Encounter', queryString: 'patient=Patient/nicola&_sort=patient&_page=1&_count=1&_totalMethod=no'}
     total: _undefined
     probes:
       - path: ['link']
         result: '_undefined'
+
+  - query: {resourceType: 'Encounter', queryString: 'patient=Patient/nicola&_sort=patient&_count=3'}
+    total: 3
+    probes:
+      - path: ['entry', 'length']
+        result: 3
+      - path: ['link', 0, 'url']
+        result: "/Encounter?patient=Patient/nicola&_sort=patient&_count=3&_page=0"
+      - path: ['link', 1, 'url']
+        result: "/Encounter?patient=Patient/nicola&_sort=patient&_count=3&_page=0"
+      - path: ['link', 2, 'url']
+
+  - query: {resourceType: 'Encounter', queryString: 'patient=Patient/nicola&_sort=patient&_page=0&_count=3'}
+    total: 3
+    probes:
+      - path: ['entry', 'length']
+        result: 3
+      - path: ['link', 0, 'url']
+        result: "/Encounter?patient=Patient/nicola&_sort=patient&_page=0&_count=3"
+      - path: ['link', 1, 'url']
+        result: "/Encounter?patient=Patient/nicola&_sort=patient&_page=0&_count=3"
+      - path: ['link', 2, 'url']
+
+  - query: {resourceType: 'Encounter', queryString: 'patient=Patient/nicola&_sort=patient&_page=2&_count=3'}
+    total: 3
+    probes:
+      - path: ['entry', 'length']
+        result: 0
+      - path: ['link', 0, 'url']
+        result: "/Encounter?patient=Patient/nicola&_sort=patient&_page=2&_count=3"
+      - path: ['link', 1, 'url']
+        result: "/Encounter?patient=Patient/nicola&_sort=patient&_page=1&_count=3"
+      - path: ['link', 2, 'url']
+        result: "/Encounter?patient=Patient/nicola&_sort=patient&_page=0&_count=3"
+      - path: ['link', 3, 'url']
+
+  - query: {resourceType: 'Encounter', queryString: 'patient=Patient/nicola&_sort=patient&_page=1&_count=2'}
+    total: 3
+    probes:
+      - path: ['entry', 'length']
+        result: 1
+      - path: ['link', 0, 'relation']
+        result: "self"
+      - path: ['link', 0, 'url']
+        result: "/Encounter?patient=Patient/nicola&_sort=patient&_page=1&_count=2"
+      - path: ['link', 1, 'relation']
+        result: "previous"
+      - path: ['link', 1, 'url']
+        result: "/Encounter?patient=Patient/nicola&_sort=patient&_page=0&_count=2"
+      - path: ['link', 2, 'relation']
+        result: "last"
+      - path: ['link', 2, 'url']
+        result: "/Encounter?patient=Patient/nicola&_sort=patient&_page=1&_count=2"
+      - path: ['link', 3, 'url']
+
+  - query: {resourceType: 'Encounter', queryString: 'patient=Patient/nonexistent&_sort=patient&_page=0&_count=3'}
+    total: 0
+    probes:
+      - path: ['entry', 'length']
+        result: 0
+      - path: ['link', 0, 'relation']
+        result: "self"
+      - path: ['link', 0, 'url']
+        result: "/Encounter?patient=Patient/nonexistent&_sort=patient&_page=0&_count=3"
+      - path: ['link', 1, 'relation']
+        result: "last"
+      - path: ['link', 1, 'url']
+        result: "/Encounter?patient=Patient/nonexistent&_sort=patient&_page=0&_count=3"
+      - path: ['link', 2, 'url']