package main

import (
	"bytes"
	"log"
	"strconv"
	"time"

	"html/template"
	"net/http"

	"github.com/prometheus/client_golang/prometheus/promhttp"
)

func httpAccessLog(req *http.Request) {
	log.Printf("[TRACE] %s - %s - %s\n", req.Method, req.RemoteAddr, req.RequestURI)
}

func crossSiteOrigin(w http.ResponseWriter) {
	w.Header().Add("Access-Control-Allow-Origin", "*")
	w.Header().Add("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE")
	w.Header().Add("Access-Control-Allow-Headers", "Accept, Content-Type, Content-Length, Accept-Encoding, Authorization, X-API-Token")
}

func httpServer(host string, port int) {
	path := http.NewServeMux()

	connection := &http.Server{
		Addr:         host + ":" + strconv.FormatInt(int64(port), 10),
		Handler:      path,
		ReadTimeout:  time.Duration(config.WebSrvReadTimeout) * time.Second,
		WriteTimeout: time.Duration(config.WebSrvWriteTimeout) * time.Second,
		IdleTimeout:  time.Duration(config.WebSrvIdleTimeout) * time.Second,
	}

	path.HandleFunc("/", webRoot)
	path.HandleFunc("/metrics", func(w http.ResponseWriter, r *http.Request) {
		httpAccessLog(r)
		crossSiteOrigin(w)
		promhttp.Handler().ServeHTTP(w, r)
	})

	if err := connection.ListenAndServe(); err != nil {
		log.Fatalf("[ERROR] %s\n", err)
	}
}

func webRoot(w http.ResponseWriter, r *http.Request) {
	outputData := struct {
		Title     string
		ErrorCode int
	}{
		Title:     "forbidden",
		ErrorCode: http.StatusForbidden,
	}

	tmplt, err := template.New("webRoot").Parse(webErrorTmplt())
	if err != nil {
		log.Fatalf("[FATAL] Unable to parse webRoot template: %v\n", err)
	}

	var output bytes.Buffer
	if err := tmplt.Execute(&output, outputData); err != nil {
		log.Fatalf("[FATAL] Unable to process webRoot template: %v\n", err)
	}

	w.Write(output.Bytes())
}