From 269be4a9784f07a824169f87e8bc787e59893b56 Mon Sep 17 00:00:00 2001
From: Shawn Smith <shawnpsmith@gmail.com>
Date: Sun, 28 Feb 2016 15:03:54 +0900
Subject: [PATCH] start recent list

---
 handlers/check.go       | 47 +++++++++++++++++++++++++++++++++++++++++
 handlers/home.go        | 44 +++++++++++++++++++++++++++++++++++++-
 handlers/recent_heap.go | 25 ++++++++++++++++++++++
 templates/home.html     | 14 ++++++++++++
 4 files changed, 129 insertions(+), 1 deletion(-)
 create mode 100644 handlers/recent_heap.go

diff --git a/handlers/check.go b/handlers/check.go
index 549e45d..a3a8d07 100644
--- a/handlers/check.go
+++ b/handlers/check.go
@@ -123,8 +123,19 @@ func CheckHandler(w http.ResponseWriter, r *http.Request) {
 		if err != nil {
 			log.Println("Bolt writing error:", err)
 		}
+
 	}
 
+	err = db.Update(func(tx *bolt.Tx) error {
+		// fetch meta-bucket
+		mb := tx.Bucket([]byte(MetaBucket))
+		if mb == nil {
+			return fmt.Errorf("high score bucket not found")
+		}
+
+		return updateRecentlyViewed(mb, repo)
+	})
+
 	b, err := json.Marshal(map[string]string{"redirect": "/report/" + repo})
 	if err != nil {
 		log.Println("JSON marshal error:", err)
@@ -203,3 +214,39 @@ func updateReposCount(mb *bolt.Bucket, resp checksResp, repo string) (err error)
 	log.Println("Repo count is now", totalInt)
 	return nil
 }
+
+func updateRecentlyViewed(mb *bolt.Bucket, repo string) error {
+	b := mb.Get([]byte("recent"))
+	if b == nil {
+		b, _ = json.Marshal([]recentHeap{})
+	}
+	recent := &recentHeap{}
+	json.Unmarshal(b, recent)
+
+	heap.Init(recent)
+	// if this repo is already in the list, remove the original entry:
+	for i := range *recent {
+		if (*recent)[i].Repo == repo {
+			heap.Remove(recent, i)
+			break
+		}
+	}
+	// now we can safely push it onto the heap
+	heap.Push(recent, recentItem{
+		Repo: repo,
+	})
+	if len(*recent) > 5 {
+		// trim heap if it's grown to over 5
+		*recent = (*recent)[1:6]
+	}
+	b, err := json.Marshal(&recent)
+	if err != nil {
+		return err
+	}
+	err = mb.Put([]byte("recent"), b)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
diff --git a/handlers/home.go b/handlers/home.go
index ac33b56..84feac2 100644
--- a/handlers/home.go
+++ b/handlers/home.go
@@ -1,8 +1,15 @@
 package handlers
 
 import (
+	"container/heap"
+	"encoding/json"
+	"fmt"
+	"html/template"
 	"log"
 	"net/http"
+	"time"
+
+	"github.com/boltdb/bolt"
 )
 
 // HomeHandler handles the homepage
@@ -10,7 +17,42 @@ func HomeHandler(w http.ResponseWriter, r *http.Request) {
 	log.Println("Serving home page")
 
 	if r.URL.Path[1:] == "" {
-		http.ServeFile(w, r, "templates/home.html")
+		db, err := bolt.Open(DBPath, 0755, &bolt.Options{Timeout: 1 * time.Second})
+		if err != nil {
+			log.Println("Failed to open bolt database: ", err)
+			return
+		}
+		defer db.Close()
+
+		recent := &recentHeap{}
+		err = db.View(func(tx *bolt.Tx) error {
+			rb := tx.Bucket([]byte(MetaBucket))
+			if rb == nil {
+				return fmt.Errorf("meta bucket not found")
+			}
+			b := rb.Get([]byte("recent"))
+			if b == nil {
+				b, err = json.Marshal([]recentHeap{})
+				if err != nil {
+					return err
+				}
+			}
+			json.Unmarshal(b, recent)
+
+			heap.Init(recent)
+
+			return nil
+		})
+
+		var recentRepos []string
+		for _, r := range *recent {
+			recentRepos = append(recentRepos, r.Repo)
+		}
+
+		t := template.Must(template.New("home.html").Delims("[[", "]]").ParseFiles("templates/home.html"))
+		t.Execute(w, map[string]interface{}{"Recent": recentRepos})
+
+		return
 	} else {
 		http.NotFound(w, r)
 	}
diff --git a/handlers/recent_heap.go b/handlers/recent_heap.go
new file mode 100644
index 0000000..2ee086e
--- /dev/null
+++ b/handlers/recent_heap.go
@@ -0,0 +1,25 @@
+package handlers
+
+type recentItem struct {
+	Repo string `json:"repo"`
+}
+
+type recentHeap []recentItem
+
+func (h recentHeap) Len() int           { return len(h) }
+func (h recentHeap) Less(i, j int) bool { return true }
+func (h recentHeap) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }
+
+func (h *recentHeap) Push(x interface{}) {
+	// Push and Pop use pointer receivers because they modify the slice's length,
+	// not just its contents.
+	*h = append(*h, x.(recentItem))
+}
+
+func (h *recentHeap) Pop() interface{} {
+	old := *h
+	n := len(old)
+	x := old[n-1]
+	*h = old[0 : n-1]
+	return x
+}
diff --git a/templates/home.html b/templates/home.html
index 38e7921..bd018ba 100644
--- a/templates/home.html
+++ b/templates/home.html
@@ -100,6 +100,20 @@
                         </tr>
                     </tbody>
                   </table>
+                  <table class="table">
+                    <thead>
+                      <tr>
+                        <th>Recently Viewed</th>
+                      </tr>
+                    </thead>
+                    <tbody>
+                        [[ range .Recent ]]
+                        <tr>
+                            <td class="table-link"><a href="/report/[[ . ]]">[[ . ]]</td>
+                        </tr>
+                        [[ end ]]
+                    </tbody>
+                  </table>
               </div>
               <div class="column is-quarter">
               </div>