package main

import (
    "fmt"
    "net/http"
    "log"
)

var(
    metrics_num_passwords int
)

func main() {
    log.Println("Starting HTTP listener")

    http.HandleFunc("/", httpHandler)
    http.HandleFunc("/metrics", metricsHandler)
    listenErr := http.ListenAndServe(":80", nil) // set listen port
    if listenErr != nil {
        log.Fatalln(listenErr.Error())
    }
}

// Handling incoming HTTP connections
func httpHandler(w http.ResponseWriter, r *http.Request) {
    // Get user/pass combo
    user, pass, ok := r.BasicAuth()

    if ok {
    	// This also includes empty user/pass combos (if they are correctly encoded)
    	// To avoid them, use `len(user) > 0 && len(pass) > 0`
    	log.Printf("%s: %s %s:%s@%s%s", r.RemoteAddr, r.Method, user, pass, r.Host, r.URL.Path)
    	
    	// Raise stats
	    metrics_num_passwords++
    } else {
    	log.Printf("%s: %s %s%s", r.RemoteAddr, r.Method, r.Host, r.URL.Path)
    }

    // Decline that try
    w.Header().Set("WWW-Authenticate", `Basic realm="Protected Area"`)
    w.WriteHeader(http.StatusUnauthorized)
}

// Handle HTTP /metrics requests
func metricsHandler(w http.ResponseWriter, req *http.Request) {
    fmt.Fprintf(w, "num_passwords %d\n", metrics_num_passwords)
}