From 0eb6c1055058b288bdce66e0797db07e96a7fbf2 Mon Sep 17 00:00:00 2001
From: Mike Bloy <mike@bloy.org>
Date: Sun, 8 May 2022 21:43:33 -0500
Subject: [PATCH] webserver with random image serving

---
 cmd/root.go     |  1 -
 web/handlers.go | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 web/server.go   | 12 ++++++++----
 3 files changed, 55 insertions(+), 5 deletions(-)
 create mode 100644 web/handlers.go

diff --git a/cmd/root.go b/cmd/root.go
index fbdbaf7..b3c9369 100644
--- a/cmd/root.go
+++ b/cmd/root.go
@@ -62,5 +62,4 @@ func initConfig() {
 			os.Exit(1)
 		}
 	}
-	fmt.Println(viper.AllSettings())
 }
diff --git a/web/handlers.go b/web/handlers.go
new file mode 100644
index 0000000..8077d16
--- /dev/null
+++ b/web/handlers.go
@@ -0,0 +1,47 @@
+package web
+
+import (
+	"fmt"
+	"io/fs"
+	"math/rand"
+	"net/http"
+	"os"
+)
+
+func imageHandler() http.Handler {
+	fs := http.FS(os.DirFS(config.imageDir))
+	hfs := http.FileServer(fs)
+	return hfs
+}
+
+func chooseRandomFile(imageDir string) (filepath string, err error) {
+	validEntries := make([]string, 0)
+	log := config.logger.Sugar()
+	err = fs.WalkDir(os.DirFS(imageDir), ".", func(path string, d fs.DirEntry, err error) error {
+		if err != nil {
+			log.Errorw("Error walking directory", "imageDir", imageDir, "error", err)
+			return err
+		}
+		if d.Type().IsRegular() {
+			validEntries = append(validEntries, fmt.Sprintf("%s/%s", imageDir, d.Name()))
+		}
+		return nil
+	})
+
+	chosen := rand.Intn(len(validEntries))
+	filepath = validEntries[chosen]
+	return
+}
+
+func randomImageFunc(w http.ResponseWriter, r *http.Request) {
+	log := config.logger.Sugar()
+	path, err := chooseRandomFile(config.imageDir)
+	if err != nil {
+		log.Errorw("Couldn't choose a random file", "error", err)
+		w.WriteHeader(http.StatusInternalServerError)
+		fmt.Fprint(w, "Error selecting a file.")
+		return
+	}
+	log.Infow("serving image file", "path", path)
+	http.ServeFile(w, r, path)
+}
diff --git a/web/server.go b/web/server.go
index a066b6d..1c419f6 100644
--- a/web/server.go
+++ b/web/server.go
@@ -3,7 +3,6 @@ package web
 import (
 	"fmt"
 	"net/http"
-	"os"
 
 	"github.com/spf13/viper"
 	"go.uber.org/zap"
@@ -23,11 +22,16 @@ func Run(rootLogger *zap.Logger, exitch chan bool) {
 	config.logger = rootLogger.Named("web")
 	config.port = viper.GetInt("webserver_port")
 	config.imageDir = viper.GetString("image_dir")
-	addr := fmt.Sprintf(":%d", config.port)
-	http.Handle("/", http.FileServer(http.FS(os.DirFS("."))))
+
+	http.Handle("/img/", http.StripPrefix("/img", imageHandler()))
+	http.HandleFunc("/randimg/", randomImageFunc)
 	var logger = config.logger.Sugar()
 
-	logger.Infow("Webserver startup", "port", config.port)
+	logger.Infow("Webserver startup",
+		"port", config.port,
+		"imageDir", config.imageDir)
+
+	addr := fmt.Sprintf(":%d", config.port)
 
 	if err := http.ListenAndServe(addr, nil); err != nil {
 		logger.Errorf("Webserver fatal error: %s", err)