Initial structure

error.go

@@ -0,0 +1,15 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+)
+
+type Error struct {
+	Message string `json:"message"`
+}
+
+func sendError(w http.ResponseWriter, code int, msg string, args ...any) {
+	w.WriteHeader(code)
+	sendJSON(w, Error{Message: fmt.Sprintf(msg, args...)})
+}

json.go

@@ -0,0 +1,14 @@
+package main
+
+import (
+	"encoding/json"
+	"net/http"
+)
+
+func sendJSON(w http.ResponseWriter, v any) {
+	w.Header().Set("Content-Type", "application/json")
+
+	enc := json.NewEncoder(w)
+	enc.SetEscapeHTML(false)
+	_ = enc.Encode(v)
+}

main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"database/sql"
 	"fmt"
+	"html/template"
 	"log"
 	"net/http"
 	"os"
@@ -10,6 +11,43 @@ import (
 	_ "github.com/lib/pq"
 )
 
+type ShortLinks struct {
+	tmpl *template.Template
+	mux  *http.ServeMux
+}
+
+func NewShortLinks() (*ShortLinks, error) {
+	tmpl := template.New("index.html")
+
+	tmpl, err := tmpl.ParseFiles("static/index.html")
+	if err != nil {
+		return nil, fmt.Errorf("static/index.html: %w", err)
+	}
+
+	sl := &ShortLinks{
+		tmpl: tmpl,
+		mux:  http.NewServeMux(),
+	}
+
+	sl.mux.HandleFunc("/", sl.serveRoot)
+
+	return sl, nil
+}
+
+func (sl *ShortLinks) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	sl.mux.ServeHTTP(w, r)
+}
+
+func (sl *ShortLinks) serveRoot(w http.ResponseWriter, r *http.Request) {
+	log.Printf("%s %s", r.RemoteAddr, r.URL.Path)
+
+	err := sl.tmpl.Execute(w, nil)
+	if err != nil {
+		sendError(w, http.StatusInternalServerError, "error executing template: %s", err)
+		return
+	}
+}
+
 func main() {
 	port := os.Getenv("PORT")
 	if port == "" {
@@ -26,7 +64,6 @@ func main() {
 		log.Fatal(err)
 	}
 
-	// Execute the SQL statement
 	_, err = db.Exec(`
 CREATE TABLE IF NOT EXISTS links (
     short VARCHAR(100) PRIMARY KEY,
@@ -36,6 +73,13 @@ CREATE TABLE IF NOT EXISTS links (
 		log.Fatalf("Failed to create table: %v", err)
 	}
 
+	sl, err := NewShortLinks()
+	if err != nil {
+		log.Fatalf("Failed to create shortlinks: %v", err)
+	}
+
+	http.Handle("/", sl)
+
 	bind := fmt.Sprintf(":%s", port)
 	log.Printf("listening on %s", bind)