From 0d5994a1d673b5c18a6b71722c6d637b16a4dc49 Mon Sep 17 00:00:00 2001
From: Tomas Vik <me@viktomas.com>
Date: Wed, 16 Aug 2023 14:59:26 +0200
Subject: [PATCH] feat: handle taken port

---
 .air.toml |  2 +-
 main.go   | 24 ++++++++++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/.air.toml b/.air.toml
index 16e413a..db5e35e 100644
--- a/.air.toml
+++ b/.air.toml
@@ -15,7 +15,7 @@ tmp_dir = "tmp"
   full_bin = ""
   include_dir = []
   include_ext = ["go", "tpl", "tmpl", "html", "css"]
-  include_file = []
+  include_file = ["gpic"]
   kill_delay = "0s"
   log = "build-errors.log"
   poll = false
diff --git a/main.go b/main.go
index 6c3afd6..989cc55 100644
--- a/main.go
+++ b/main.go
@@ -7,6 +7,7 @@ import (
 	"html/template"
 	"io"
 	"log"
+	"net"
 	"net/http"
 	"os"
 	"os/exec"
@@ -153,6 +154,18 @@ func main() {
 	go func() {
 		defer wg.Done()
 		err = http.ListenAndServe(addr, nil)
+		if err != nil {
+			fmt.Printf("Warning: %s\n", err)
+			err = nil
+			port, err := findAvailablePort()
+			if err != nil {
+				fmt.Printf("Error: %s\n", err)
+				return
+			}
+			addr = fmt.Sprintf("localhost:%d", port)
+			url = fmt.Sprintf("http://%s", addr)
+			err = http.ListenAndServe(addr, nil)
+		}
 		if err != nil {
 			fmt.Printf("Error: %s\n", err)
 		}
@@ -200,3 +213,14 @@ func isImageFile(filename string) bool {
 	ext := filepath.Ext(filename)
 	return ext == ".jpg" || ext == ".jpeg" || ext == ".png" || ext == ".gif"
 }
+
+func findAvailablePort() (int, error) {
+	listener, err := net.Listen("tcp", "localhost:0") // 0 indicates a random available port
+	if err != nil {
+		return 0, err
+	}
+	defer listener.Close()
+
+	addr := listener.Addr().(*net.TCPAddr)
+	return addr.Port, nil
+}