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package main
import (
"database/sql"
"flag"
"fmt"
"log/slog"
"net/http"
"os"
"strings"
"time"
)
func newMux(db *sql.DB) http.Handler {
mux := http.NewServeMux()
mux.HandleFunc("/robots.txt", func(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "text/plain")
fmt.Fprint(w, "User-agent: *\nDisallow: /\n")
})
mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
path := strings.TrimPrefix(r.URL.Path, "/")
if path == "" {
http.Error(w, "not found", http.StatusNotFound)
return
}
if strings.Contains(path, "/") {
http.Error(w, "not found", http.StatusNotFound)
return
}
id, err := decodeID(path)
if err != nil {
http.Error(w, "not found", http.StatusNotFound)
return
}
url, err := getURL(db, id)
if err != nil {
http.Error(w, "not found", http.StatusNotFound)
return
}
http.Redirect(w, r, url, http.StatusMovedPermanently)
})
return withLogging(mux)
}
type responseWriter struct {
http.ResponseWriter
status int
}
func (w *responseWriter) WriteHeader(code int) {
w.status = code
w.ResponseWriter.WriteHeader(code)
}
func withLogging(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
start := time.Now()
rw := &responseWriter{ResponseWriter: w, status: http.StatusOK}
next.ServeHTTP(rw, r)
slog.Info("request",
"method", r.Method,
"path", r.URL.Path,
"status", rw.status,
"duration", time.Since(start),
"remote", r.RemoteAddr,
)
})
}
func cmdServe(args []string) {
fs := flag.NewFlagSet("serve", flag.ExitOnError)
addr := fs.String("addr", ":8080", "listen address")
dbPath := fs.String("db", "data/nilink.db", "database path")
fs.Parse(args)
db, err := openDB(*dbPath)
if err != nil {
fmt.Fprintf(os.Stderr, "error: %v\n", err)
os.Exit(1)
}
defer db.Close()
slog.Info("listening", "addr", *addr)
if err := http.ListenAndServe(*addr, newMux(db)); err != nil {
fmt.Fprintf(os.Stderr, "error: %v\n", err)
os.Exit(1)
}
}
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