package main

import (

"flag"

"fmt"

"io"

"log"

"log/slog"

"net/http"

"os"

"strings"

"unicode/utf8"

"within.website/x/internal"

)

var (

bind = flag.String("bind", ":3000", "TCP port to bind to")

silent = flag.Bool("silent", false, "if set, don't log http headers")

maxHeaderSize = 64 * 1024 // 64KB limit for headers

)

func main() {

internal.HandleStartup()

slog.Info("listening", "url", "http://localhost"+*bind)

log.Fatal(http.ListenAndServe(*bind, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {

if r.URL.Path == "/.within/health" {

w.Header().Set("Content-Type", "text/plain")

fmt.Fprintln(w, "OK")

return

}

// Validate and sanitize RequestURI

sanitizedURI := r.RequestURI

if !utf8.ValidString(sanitizedURI) {

sanitizedURI = "[invalid UTF-8]"

}

if len(sanitizedURI) > 1024 {

sanitizedURI = sanitizedURI[:1024] + "...[truncated]"

}

contains := strings.Contains(r.Header.Get("Accept"), "text/html")

slog.InfoContext(r.Context(), "got request", "method", r.Method, "path", sanitizedURI)

// Set Content-Type based on response format

if contains {

w.Header().Set("Content-Type", "text/html; charset=utf-8")

fmt.Fprint(w, "<pre id=\"main\"><code>")

} else {

w.Header().Set("Content-Type", "text/plain; charset=utf-8")

}

var out io.Writer

switch *silent {

case true:

out = w

case false:

out = io.MultiWriter(w, os.Stdout)

}

// Write request line

fmt.Fprintln(out, r.Method, sanitizedURI)

// Write headers with basic size limit and error handling

headerSize := 0

for key, values := range r.Header {

headerLine := key + ": " + strings.Join(values, ", ") + "\r\n"

headerSize += len(headerLine)

if headerSize > maxHeaderSize {

fmt.Fprintln(out, "[... headers truncated due to size limit ...]")

break

}

fmt.Fprint(out, headerLine)

}

// Add blank line to separate headers from body

fmt.Fprintln(out)

if contains {

fmt.Fprintln(w, "</code></pre>")

}

})))

}