package main

import (
	"fmt"
	"log"
	"strings"
	"time"

	"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")
}

func (config *config) httpServer() {
	path := http.NewServeMux()

	connection := &http.Server{
		Addr:         fmt.Sprintf("%s:%d", config.WebSrvIP, config.WebSrvPort),
		Handler:      path,
		ReadTimeout:  time.Duration(config.WebSrvReadTimeout) * time.Second,
		WriteTimeout: time.Duration(config.WebSrvWriteTimeout) * time.Second,
		IdleTimeout:  time.Duration(config.WebSrvIdleTimeout) * time.Second,
	}

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

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

func webRoot(w http.ResponseWriter, r *http.Request) {
	httpAccessLog(r)
	crossSiteOrigin(w)

	if strings.ToLower(r.Method) == "get" {
		tmpltWebRoot(w)
	} else {
		log.Printf("[DEBUG] Request to '/' was made using the wrong method: expected %s, got %s\n", "GET", strings.ToUpper(r.Method))
		tmpltError(w, http.StatusBadRequest, "Invalid http method.")
	}
}

func webHealthCheck(w http.ResponseWriter, r *http.Request) {
	httpAccessLog(r)
	crossSiteOrigin(w)

	if strings.ToLower(r.Method) == "get" {
		tmpltHealthCheck(w)
	} else {
		log.Printf("[DEBUG] Request to '/healthcheck' was made using the wrong method: expected %s, got %s\n", "GET", strings.ToUpper(r.Method))
		tmpltError(w, http.StatusBadRequest, "Invalid http method.")
	}
}