From 790ca38644b8c37c9feb7c433143a6b49b4f137e Mon Sep 17 00:00:00 2001
From: navanchauhan <navanchauhan@gmail.com>
Date: Wed, 18 Jan 2023 02:41:10 -0700
Subject: added pagination and results per page

---
 definitions.go                |  7 +++-
 handlerFuncs.go               | 74 +++++++++++++++++++++++++++++++------------
 main.go                       |  5 ---
 templates/results.gtpl        |  6 ++--
 templates/search.gtpl         |  4 +--
 templates/search_results.html | 14 +++++---
 6 files changed, 74 insertions(+), 36 deletions(-)

diff --git a/definitions.go b/definitions.go
index 2289865..6a7b9d1 100644
--- a/definitions.go
+++ b/definitions.go
@@ -3,7 +3,7 @@ package main
 type SearchQuery struct {
 	Query      string
 	MaxResults int64
-	Offset     int64
+	Page       int64
 }
 
 type BaseResponse struct {
@@ -21,6 +21,11 @@ type SearchResponse struct {
 	Offset        int64
 	LastOffset    int64
 	NumPages      int
+	MaxResults    int64
+	CurPage       int64
+	ShowPrev      bool
+	PrevPage      int64
+	NextPage      int64
 }
 
 type DocumentResponse struct {
diff --git a/handlerFuncs.go b/handlerFuncs.go
index d6542e0..01488c2 100644
--- a/handlerFuncs.go
+++ b/handlerFuncs.go
@@ -14,26 +14,41 @@ func searchHandler(w http.ResponseWriter, r *http.Request, index *meilisearch.In
 	fmt.Println(r.Form)
 	if r.Form["query"] != nil || r.FormValue("query") != "" {
 		//fmt.Println("query:", r.Form["query"])
-		var myOffset int64
-		if r.Form["offset"] != nil {
-			offset, _ := strconv.ParseInt(r.FormValue("offset"), 10, 64)
-			myOffset = offset
-			if offset < 0 {
-				myOffset = 0
+		var pageNo int64
+		var maxHits int64
+		if r.Form["page"] != nil {
+			convertedInt, _ := strconv.ParseInt(r.FormValue("page"), 10, 64)
+			if convertedInt > 0 {
+				pageNo = convertedInt
+			} else {
+				pageNo = 1
 			}
 		} else {
-			offset := int64(0)
-			myOffset = offset
+			pageNo = 1
+		}
+		if r.Form["maxHits"] != nil {
+			convertedInt, _ := strconv.ParseInt(r.FormValue("maxHits"), 10, 64)
+			if convertedInt > 0 {
+				maxHits = convertedInt
+			} else {
+				maxHits = 20
+			}
+		} else {
+			maxHits = 20
+		}
+
+		if maxHits > 100 {
+			maxHits = 100
 		}
 		query := SearchQuery{
 			Query:      r.FormValue("query"),
-			MaxResults: 100,
-			Offset:     myOffset,
+			MaxResults: maxHits,
+			Page:       pageNo,
 		}
 
 		res, err := index.Search(query.Query, &meilisearch.SearchRequest{
-			Limit:  query.MaxResults,
-			Offset: query.Offset,
+			HitsPerPage: query.MaxResults,
+			Page:        query.Page,
 			AttributesToRetrieve: []string{
 				"title",
 				"applicant",
@@ -52,22 +67,39 @@ func searchHandler(w http.ResponseWriter, r *http.Request, index *meilisearch.In
 			return
 		}
 
-		numPages := pageCount(int(res.EstimatedTotalHits), int(query.MaxResults))
-
 		searchTemplate.Execute(w, SearchResponse{
 			GlobalVars:    globalVariables,
 			Success:       true,
 			SearchResults: res.Hits,
-			NumResults:    len(res.Hits) + int(query.Offset),
-			TotalResults:  res.EstimatedTotalHits,
-			MoreResults:   res.EstimatedTotalHits > query.MaxResults,
+			NumResults:    int(res.TotalHits) - (int(res.TotalPages)-int(res.Page))*int(res.HitsPerPage),
+			TotalResults:  res.TotalHits,
+			MoreResults:   res.Page < res.TotalPages,
 			OriginalQuery: query,
-			Offset:        query.Offset + query.MaxResults,
-			LastOffset:    query.Offset - query.MaxResults,
-			NumPages:      numPages,
+			NumPages:      int(res.TotalPages),
+			MaxResults:    maxHits,
+			CurPage:       res.Page,
+			ShowPrev:      res.Page > 1,
+			PrevPage:      res.Page - 1,
+			NextPage:      res.Page + 1,
 		})
+
 	} else {
-		fmt.Println("query is empty")
+		// Return empty search results
+		searchTemplate.Execute(w, SearchResponse{
+			GlobalVars:    globalVariables,
+			Success:       true,
+			SearchResults: []interface{}{},
+			NumResults:    0,
+			TotalResults:  0,
+			MoreResults:   false,
+			OriginalQuery: SearchQuery{},
+			NumPages:      0,
+			MaxResults:    0,
+			CurPage:       0,
+			ShowPrev:      false,
+			PrevPage:      0,
+			NextPage:      0,
+		})
 	}
 }
 
diff --git a/main.go b/main.go
index 0cf7e35..9394aa6 100644
--- a/main.go
+++ b/main.go
@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"html/template"
 	"io/fs"
-	"math"
 	"net/http"
 	"os"
 	"strconv"
@@ -31,10 +30,6 @@ func create_pdf_url(year string, knumber string) string {
 	}
 }
 
-func pageCount(total int, perPage int) int {
-	return int(math.Ceil(float64(total) / float64(perPage)))
-}
-
 func main() {
 	err := godotenv.Load(".env")
 	if err != nil {
diff --git a/templates/results.gtpl b/templates/results.gtpl
index 151a7d3..ce2b99d 100644
--- a/templates/results.gtpl
+++ b/templates/results.gtpl
@@ -28,9 +28,11 @@
     </tr>
     {{ end }}
     </table>
+    {{if .ShowPrev }}
+    <a href="/classic/search?query={{.OriginalQuery.Query}}&page={{.PrevPage}}&maxHits={{.MaxResults}}"> <p>Previous Page</p></a>
+    {{ end }}
     {{ if .MoreResults }}
-    <a href="/classic/search?query={{.OriginalQuery.Query}}&offset={{.LastOffset}}"> <p>Previous Page</p></a>
-    <a href="/classic/search?query={{.OriginalQuery.Query}}&offset={{.Offset}}"> <p>Next Page</p></a>
+    <a href="/classic/search?query={{.OriginalQuery.Query}}&page={{.PrevPage}}&maxHits={{.MaxResults}}"> <p>Next Page</p></a>
     {{ end }}
 </body>
 </html>
\ No newline at end of file
diff --git a/templates/search.gtpl b/templates/search.gtpl
index b892f19..841b068 100644
--- a/templates/search.gtpl
+++ b/templates/search.gtpl
@@ -1,9 +1,9 @@
 <!DOCTYPE html>
 <html>
 <body>
-    <h1>{{.GlobalVars.Name}}</h1>
+    <h1>{{.GlobalVars.Name}} - Classic Mode</h1>
     <form action="/classic/search" method="GET">
-        <input type="text" name="query" value="{{.OriginalQuery.Query}}" placeholder="Search Query" spellcheck="false">
+        <input type="text" name="query" placeholder="Search Query" spellcheck="false">
         <input type="submit">
     </form>
 </body>
diff --git a/templates/search_results.html b/templates/search_results.html
index 4c053ab..4e9b9a4 100644
--- a/templates/search_results.html
+++ b/templates/search_results.html
@@ -73,25 +73,28 @@
         {{ end }}
     
 </section>
-    {{ if .MoreResults }}
+    
     <section class="section">
         <div class="container">
             <div class="columns">
+              {{if .ShowPrev }}
                 <div class="column">
                     <div class="field has-addons">
                         
-            <button class="button is-primary is-light is-medium is-fullwidth" href="/search?query={{.OriginalQuery.Query}}&offset={{.LastOffset}}" title="Previous Page">
+            <a class="button is-primary is-light is-medium is-fullwidth" href="/search?query={{.OriginalQuery.Query}}&page={{.PrevPage}}&maxHits={{.MaxResults}}" title="Previous Page">
                 
                 <span class="icon is-small">
                     <i class="fa-solid fa-left-long"></i>
                   </span>
                 <span>Previous Page</span>
-                </button>
+                </a>
                     </div>
             </div>
+            {{ end }}
+            {{ if .MoreResults }}
               <div class="column">
                 <div class="field has-addons">
-            <a class="button is-primary is-medium is-fullwidth" href="/search?query={{.OriginalQuery.Query}}&offset={{.Offset}}" title="Next Page">
+            <a class="button is-primary is-medium is-fullwidth" href="/search?query={{.OriginalQuery.Query}}&page={{.NextPage}}&maxHits={{.MaxResults}}" title="Next Page">
                 <span>
                   Next Page
                 </span>
@@ -100,10 +103,11 @@
                   </span>
               </a></div>
             </div>
+            {{ end }}
         </div></div>
         </section>
     
-    {{ end }}
+    
     <script>
       if (typeof navigator.serviceWorker !== 'undefined') {
         navigator.serviceWorker.register('/static/pwabuilder-sw.js')
-- 
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