From 795c7eccb8d34ce4150b7dc7a7f4822a3ba1db0b Mon Sep 17 00:00:00 2001
From: Tilo K <tiloklarenbeek@gmail.com>
Date: Sun, 15 Feb 2026 15:22:10 +0100
Subject: [PATCH] Inital commit

---
 go.mod                             |  3 ++
 main.go                            | 43 ++++++++++++++++++
 readheaders.go                     | 71 ++++++++++++++++++++++++++++++
 response_helper/response_helper.go | 14 ++++++
 4 files changed, 131 insertions(+)
 create mode 100644 go.mod
 create mode 100644 main.go
 create mode 100644 readheaders.go
 create mode 100644 response_helper/response_helper.go

diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..4c302fa
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module tilok.dev/go-http-server
+
+go 1.25.0
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..5c10d62
--- /dev/null
+++ b/main.go
@@ -0,0 +1,43 @@
+package main
+
+import (
+	"bufio"
+	"log/slog"
+	"net"
+
+	rh "tilok.dev/go-http-server/response_helper"
+)
+
+func main() {
+	//TODO: Make interface configurable
+	interf := "127.0.0.1:8080"
+	listener, err := net.Listen("tcp", interf)
+	if err != nil {
+		slog.Error("Could not create listener", "err", err.Error())
+	}
+
+	defer listener.Close()
+
+	for {
+		conn, err := listener.Accept()
+		if err != nil {
+			slog.Error("Could not accept connection", "err", err.Error())
+			continue
+		}
+
+		go handleConnection(conn)
+	}
+}
+
+func handleConnection(conn net.Conn) {
+	defer conn.Close()
+	reader := bufio.NewReader(conn)
+	headers := readHeaders(reader)
+	if headers == nil {
+		rh.RespondWithStatusCode(400, conn)
+		return
+	}
+
+	slog.Info("Received request", "method", headers.Method, "uri", headers.Uri, "proto", headers.Proto, "client", conn.RemoteAddr().String())
+	headers.debugPrintHeaders()
+}
diff --git a/readheaders.go b/readheaders.go
new file mode 100644
index 0000000..e518e61
--- /dev/null
+++ b/readheaders.go
@@ -0,0 +1,71 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"log/slog"
+	"strings"
+)
+
+type Headers struct {
+	Method string
+	Uri    string
+	Proto  string
+
+	KV map[string]string
+}
+
+func readHeaders(reader *bufio.Reader) *Headers {
+	headers := Headers{}
+	kvHeaders := make(map[string]string)
+	versionLine, err := reader.ReadString('\n')
+	if err != nil {
+		slog.Error("Could not read version line", "err", err.Error())
+		return nil
+	}
+
+	method, uri, proto := parseRequestLine(versionLine)
+	if method == "" || uri == "" || proto == "" {
+		slog.Error("Invalid request line", "line", versionLine)
+		return nil
+	}
+
+	headers.Method = method
+	headers.Uri = uri
+	headers.Proto = proto
+
+	headerStr, err := reader.ReadString('\n')
+	if err != nil {
+		slog.Error("Could not read headers", "err", err.Error())
+		return nil
+	}
+
+	for strings.TrimSpace(headerStr) != "" {
+		header := strings.SplitN(headerStr, ":", 2)
+		if len(header) == 2 {
+			kvHeaders[strings.TrimSpace(header[0])] = strings.TrimSpace(header[1])
+		}
+		headerStr, err = reader.ReadString('\n')
+		if err != nil {
+			slog.Error("Could not read headers", "err", err.Error())
+			return nil
+		}
+	}
+	headers.KV = kvHeaders
+	return &headers
+}
+
+func (m *Headers) debugPrintHeaders() {
+	for key, value := range m.KV {
+		fmt.Printf("%s: %s\n", key, value)
+	}
+}
+
+func parseRequestLine(versionLine string) (string, string, string) {
+	cleanLine := strings.TrimSpace(versionLine)
+	parts := strings.Split(cleanLine, " ")
+	if len(parts) != 3 {
+		return "", "", ""
+	}
+	return parts[0], parts[1], parts[2]
+}
diff --git a/response_helper/response_helper.go b/response_helper/response_helper.go
new file mode 100644
index 0000000..14c97e7
--- /dev/null
+++ b/response_helper/response_helper.go
@@ -0,0 +1,14 @@
+package response_helper
+
+import (
+	"fmt"
+	"net"
+	"net/http"
+)
+
+func RespondWithStatusCode(statusCode int, conn net.Conn) {
+	conn.Write([]byte(fmt.Sprintf("HTTP/1.1 %d %s\r\n", statusCode, http.StatusText(statusCode))))
+	conn.Write([]byte("Content-Type: text/plain\r\n"))
+	conn.Write([]byte("Content-Length: 0\r\n"))
+	conn.Write([]byte("\r\n"))
+}