webserver.go

package main

import (
	"context"
	"encoding/json"
	"fmt"
	"html/template"
	"log"
	"net"
	"net/http"
	"os"
	"path/filepath"
	"strings"
)

type timerValue struct {
	HMS          string `json:"hms"`
	HMSIndicator string `json:"hms_indicator"`
	Seconds      int    `json:"seconds"`
	Over         bool   `json:"over,omitempty"`
	Type         int    `json:"type"`
	Running      bool   `json:"running"`
	Name         string `json:"name"`
}

var dm bool
var productionName string

func runWebServer(bindAddr string, bindPort int, darkmode bool, production string, ctx context.Context) {
	dm = darkmode
	productionName = production
	staticServer := http.FileServer(http.Dir("./static"))
	http.Handle("/static/", http.StripPrefix("/static/", staticServer))
	http.HandleFunc("/timer/", timerValueHandler)
	http.HandleFunc("/messages", messageListHandler)
	http.HandleFunc("/", webHandler)
	if bindAddr == "" {
		// binding to all addresses
		/*
			ips, err := findMyIPs()
			if err != nil {
				log.Fatalf("Unable to get my IP addresses: %s", err)
			}
		*/
		for _, ip := range IPAddrs {
			log.Printf("Webserver listening on %s:%d", ip, bindPort)
		}
	} else {
		log.Printf("Webserver listening on %s:%d", bindAddr, bindPort)
	}

	go func() {
		log.Fatal(http.ListenAndServe(fmt.Sprintf("%s:%d", bindAddr, bindPort), nil))
	}()
}

func webHandler(w http.ResponseWriter, r *http.Request) {
	files := []string{filepath.Join("templates", "base.html")}
	if dm {
		files = append(files, filepath.Join("templates", "darkmode.html"))
	}
	t, err := template.ParseFiles(files...)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	ip, _, err := net.SplitHostPort(r.RemoteAddr)
	if err != nil {
		ip = "UNKNOWN"
	}

	hostname, err := os.Hostname()
	if err != nil {
		hostname = "UNKNOWN"
	}
	data := struct {
		Timers     []*Timer
		IPAddr     string
		Hostname   string
		Production string
		Messages   [len(Messages)]string
	}{
		Timers:     TimersAsSlice(Timers),
		IPAddr:     ip,
		Hostname:   hostname,
		Production: productionName,
		Messages:   Messages,
	}

	err = t.Execute(w, data)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
	}
}

func timerValueHandler(w http.ResponseWriter, r *http.Request) {
	//query := r.URL.Query()
	//log.Println(r.URL.Path)
	w.Header().Set("Content-Type", "application/json")
	out := json.NewEncoder(w)
	path := strings.SplitN(r.URL.Path[1:], "/", -1)
	//log.Println(path)

	if len(path) != 2 {
		log.Println("invalid path in timerValueHandler")
		http.Error(w, "invalid parameters; name not specified", http.StatusBadRequest)
		return
	}
	var timersToOutput []*Timer
	if path[1] == "all" {
		// return just a list of timer names
		timersToOutput = TimersAsSlice(Timers)
		//timerNames := make([]string, len(timersOrdered))
		//for i, t := range timersOrdered {
		//	timerNames[i] = t.Name
		//}
	} else {
		t, ok := Timers[path[1]]
		if !ok {
			log.Printf("timer name '%s' not found", path[1])
			http.Error(w, "timer name not found", http.StatusNotFound)
			return
		}
		timersToOutput = append(timersToOutput, t)
	}

	// only send updates on full second increments
	delayUntilNextSecond()
	var tList = make([]timerValue, len(timersToOutput))
	var tv timerValue
	for i, t := range timersToOutput {
		tv.HMS = t.HMS()
		tv.HMSIndicator = t.HMSIndicator()
		tv.Seconds = t.Seconds()
		tv.Over = t.Over()
		tv.Type = t.Type()
		tv.Running = t.Running()
		tv.Name = t.Name
		tList[i] = tv
	}

	err := out.Encode(tList)
	if err != nil {
		log.Fatalf("Unable to encode response: %s", err)
		http.Error(w, "Unable to encode response", http.StatusInternalServerError)
	}
}

func messageListHandler(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	out := json.NewEncoder(w)
	//path := strings.SplitN(r.URL.Path[1:], "/", -1)
	//log.Println(path)

	//if len(path) != 1 {
	//	log.Println("invalid path in messageListHandler")
	//	return
	//}
	err := out.Encode(Messages)
	if err != nil {
		log.Fatalf("Unable to encode response: %s", err)
		http.Error(w, "Unable to encode response", http.StatusInternalServerError)
	}
}