1 files changed, 56 insertions, 2 deletions

diff --git a/main.go b/main.go
index 8440286..2824041 100644
--- a/main.go
+++ b/main.go
@@ -5,10 +5,12 @@ import (
         "fmt"
         "html/template"
         "log"
+        "math/rand"
         "net/http"
         "os"
         "path"
         "path/filepath"
+        "reflect"
         "sort"
         "strings"
         "time"
@@ -87,6 +89,50 @@ var EmbedTemplatePost string
 //go:embed "files/index.xml"
 var EmbedTemplateFeed string
 
+// firstN returns the first n items of a slice.
+func firstN(n int, items interface{}) interface{} {
+        v := reflect.ValueOf(items)
+        if v.Kind() != reflect.Slice {
+                panic("firstN: not a slice")
+        }
+        if v.Len() < n {
+                return items
+        }
+        return v.Slice(0, n).Interface()
+}
+
+// lastN returns the last n items of any slice.
+func lastN(n int, items interface{}) interface{} {
+        v := reflect.ValueOf(items)
+        if v.Kind() != reflect.Slice {
+                panic("lastN: not a slice")
+        }
+        l := v.Len()
+        if l < n {
+                return items
+        }
+        return v.Slice(l-n, l).Interface()
+}
+
+// randomN returns n random items of any slice.
+func randomN(n int, items interface{}) interface{} {
+        v := reflect.ValueOf(items)
+        if v.Kind() != reflect.Slice {
+                panic("randomN: not a slice")
+        }
+        l := v.Len()
+        if l < n {
+                return items
+        }
+        rand.Seed(time.Now().UnixNano())
+        indices := rand.Perm(l)[:n]
+        result := reflect.MakeSlice(v.Type(), n, n)
+        for i, idx := range indices {
+                result.Index(i).Set(v.Index(idx))
+        }
+        return result.Interface()
+}
+
 // Function to clean HTML tags using bluemonday.
 func cleanHTMLTags(htmlString string) string {
         p := bluemonday.StrictPolicy()
@@ -284,7 +330,11 @@ func buildProject(projectRoot string) {
                         templates = append([]string{templatePathname}, templates...)
                         templates = append([]string{baseTemplatePathname}, templates...)
 
-                        t, err := template.ParseFiles(templates...)
+                        t, err := template.New("base.html").Funcs(template.FuncMap{
+                                "first":  firstN,
+                                "last":   lastN,
+                                "random": randomN,
+                        }).ParseFiles(templates...)
                         if err != nil {
                                 panic(err)
                         }
@@ -335,7 +385,11 @@ func buildProject(projectRoot string) {
                 templates = append([]string{templatePathname}, templates...)
                 templates = append([]string{baseTemplatePathname}, templates...)
 
-                t, err := template.ParseFiles(templates...)
+                t, err := template.New("base.html").Funcs(template.FuncMap{
+                        "first":  firstN,
+                        "last":   lastN,
+                        "random": randomN,
+                }).ParseFiles(templates...)
                 if err != nil {
                         panic(err)
                 }