Initial version of the timetable/countdown

Signed-off-by: Alban Bedel <albeu@free.fr>
2024-08-17 19:15:08 +02:00
commit 6fbfa94bbc
9 changed files with 513 additions and 0 deletions
--- a/.gitignore
+++ b/.gitignore
@@ -0,0 +1 @@
+timetable
--- a/18
+++ b/18
@@ -0,0 +1,18 @@
+FROM golang:1.22-alpine as builder
+ARG CGO_ENABLED=0
+WORKDIR /app
+
+COPY go.mod go.sum ./
+RUN go mod download
+COPY *.go .
+
+RUN go build
+
+FROM gcr.io/distroless/static:nonroot
+WORKDIR /app
+COPY --from=builder /app/timetable /usr/bin/timetable
+COPY timetables.yaml .
+COPY static/*.html static/*.css static/*.js static/
+
+USER nonroot
+ENTRYPOINT ["timetable"]
--- a/go.mod
+++ b/go.mod
@@ -0,0 +1,5 @@
+module git.gaengeviertel.de/IT/timetable
+
+go 1.22
+
+require gopkg.in/yaml.v3 v3.0.1
--- a/go.sum
+++ b/go.sum
@@ -0,0 +1,4 @@
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
--- a/static/countdown.css
+++ b/static/countdown.css
@@ -0,0 +1,18 @@
+body {
+    font-size: 8vw;
+    background: black;
+    color: white;
+}
+
+.flash {
+    background: red;
+}
+
+#view {
+    position: fixed;
+    inset: 0;
+    width: fit-content;
+    height: fit-content;
+    margin: auto;
+    text-align: center;
+}
--- a/static/countdown.html
+++ b/static/countdown.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>Countdown</title>
+    <link rel="stylesheet" href="/static/countdown.css"/>
+  </head>
+  <script src="/static/countdown.js"></script>
+  </script>
+  <body>
+    <div id="view">
+      <div id="artist"></div>
+      <div id="counter">
+	<span id="counter-value"></span>
+	<span id="counter-unit"></span>
+      </div>
+    </div>
+  </body>
+</html>
--- a/static/countdown.js
+++ b/static/countdown.js
@@ -0,0 +1,153 @@
+var urlParams = new URLSearchParams(window.location.search);
+var path = window.location.pathname.split("/");
+var loc = path[path.length - 1];
+var url = "/timetable/" + loc;
+var timetable = {};
+var timeOffset = Number.parseInt(urlParams.get("timeOffset"));
+var flashDelay = urlParams.has("flashDelay") ? Number.parseInt(urlParams.get("flashDelay")) : 500;
+var flashStart = urlParams.has("flashStart") ? Number.parseInt(urlParams.get("flashStart")) : 5*60;
+var flashElement = "counter";
+var lastFlash = null;
+var locale =  "de-DE";
+
+var shortTime = new Intl.DateTimeFormat(locale, { timeStyle: "short" })
+
+function setTimetable(tt) {
+    timetable = tt;
+    updateCounter();
+}
+
+function getShow(tt, when) {
+    if (tt.shows == null) {
+	return null;
+    }
+
+    for (let i = 0; i < timetable.shows.length; i++) {
+	let show = tt.shows[i];
+	let start = new Date(show.start);
+
+	// Show has not yet started
+	if (when < start.getTime())
+	    return null;
+
+	// No end
+	if (show.end == null) {
+	    return show;
+	}
+
+	// Has it ended?
+	let end = new Date(show.end);
+	if (when < end.getTime())
+	    return show;
+    }
+
+    return null;
+}
+
+function getNextShow(tt, when) {
+    if (tt.shows == null) {
+	return null;
+    }
+
+    for (let i = 0; i < timetable.shows.length; i++) {
+	let show = tt.shows[i];
+	let start = new Date(show.start);
+
+	// Return the first show that has not yet started
+	if (when < start.getTime())
+	    return show;
+    }
+
+    return null;
+}
+
+function stopFlash() {
+    let elem = document.getElementById(flashElement);
+    if (elem === null)
+	return;
+
+    elem.classList.remove("flash");
+    lastFlash = null;
+}
+
+function doFlash(now) {
+    let elem = document.getElementById(flashElement);
+    if (elem === null)
+	return;
+
+    if (lastFlash === null) {
+	lastFlash = now;
+    }
+
+    if (now - lastFlash >= flashDelay) {
+	elem.classList.toggle("flash");
+	lastFlash = now;
+    }
+}
+
+function updateCounter() {
+    let artistSpan = document.getElementById("artist");
+    let valueSpan = document.getElementById("counter-value");
+    let unitSpan = document.getElementById("counter-unit");
+
+    if (artistSpan === null || valueSpan === null || unitSpan === null)
+	return;
+
+    let now = new Date();
+    if (timeOffset > 0) {
+	now = new Date(now.getTime() + timeOffset*60000);
+    }
+
+    let show = getShow(timetable, now.getTime());
+    if (show == null) {
+	show = getNextShow(timetable, now.getTime());
+	if (show != null) {
+	    let start = new Date(show.start);
+
+	    artistSpan.textContent = "Next: " + show.name;
+	    valueSpan.textContent = shortTime.format(start);
+	} else {
+	    artistSpan.textContent = "";
+	}
+	unitSpan.textContent = "";
+	stopFlash();
+	return;
+    }
+
+    let value = "";
+    let unit = ""
+    if (show.end != null) {
+	let end = new Date(show.end);
+	let sec = Math.round((end - now) / 1000);
+	if (sec >= 60) {
+	    value = Math.ceil(sec / 60).toString();
+	    unit = "m";
+	} else {
+	    value = sec.toString();
+	    unit = "s";
+	}
+
+	if (sec < flashStart)
+	    doFlash(now);
+	else
+	    stopFlash();
+    } else {
+	stopFlash();
+    }
+
+    artistSpan.textContent = show.name;
+    valueSpan.textContent = value;
+    unitSpan.textContent = unit;
+}
+setInterval(updateCounter, 100);
+
+function updateTimetable() {
+    console.log("Updating timetable");
+    fetch(url, { signal: AbortSignal.timeout(5000) })
+	.then(res => res.json())
+	.then(tt => setTimetable(tt))
+	.catch(err => console.log(err));
+}
+setInterval(updateTimetable, 2*60*1000);
+
+updateTimetable();
--- a/timetable.go
+++ b/timetable.go
@@ -0,0 +1,286 @@
+package main
+
+import (
+	"context"
+	"encoding/csv"
+	"encoding/json"
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"path"
+	"regexp"
+	"strconv"
+	"time"
+
+	"gopkg.in/yaml.v3"
+)
+
+type Show struct {
+	Name  string     `json:"name"`
+	Start time.Time  `json:"start"`
+	End   *time.Time `json:"end,omitempty"`
+}
+
+type TimeTable struct {
+	Title     string `json:"title"`
+	Location  string `json:"location"`
+	Shows     []Show `json:"shows"`
+}
+
+func (tt TimeTable) findShowAt(when time.Time) (int) {
+	for i, s := range(tt.Shows) {
+		if when.After(s.Start) && (s.End == nil || when.Before(*s.End)) {
+			return i
+		}
+	}
+	return -1
+}
+
+func (tt TimeTable) ShowAt(when time.Time) (Show, bool) {
+	if idx := tt.findShowAt(when); idx >= 0 {
+		return tt.Shows[idx], true
+	} else {
+		return Show{}, false
+	}
+}
+
+func (tt TimeTable) CurrentShow() (Show, bool) {
+	return tt.ShowAt(time.Now())
+}
+
+func (tt TimeTable) NextShowAt(when time.Time) (Show, bool) {
+	if idx := tt.findShowAt(when); idx >= 0 && (idx+1) < len(tt.Shows) {
+		return tt.Shows[idx], true
+	} else {
+		return Show{}, false
+	}
+}
+
+func (tt TimeTable) NextShow() (Show, bool) {
+	return tt.NextShowAt(time.Now())
+}
+
+type TimeTableSource struct {
+	ID            string `yaml:"id"`
+	URL           string `yaml:"url"`
+	Title         string `yaml:"title,omitempty"`
+	Location      string `yaml:"location,omitempty"`
+	StartDate     string `yaml:"startDate,omitempty"`
+	TimeColumn    int    `yaml:"timeColumn"`
+	NameColumn    int    `yaml:"nameColumn"`
+	CountdownPath string `yaml:"countDownPath"`
+}
+
+type Config struct {
+	Listen    string            `yaml:"listen"`
+	StaticDir string            `yaml:"staticdir"`
+	Sources   []TimeTableSource `yaml:"sources,omitempty"`
+}
+
+func getCSV(src string, ctx context.Context) ([][]string, error) {
+	req, err := http.NewRequestWithContext(ctx, "GET", src, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+
+	if resp.StatusCode > 299 {
+		return nil, fmt.Errorf("HTTP error %d: %s", resp.StatusCode, resp.Status)
+	}
+
+	ct := resp.Header.Get("Content-Type")
+	if ct != "text/csv" && ct != "" {
+		return nil, fmt.Errorf("Content is not CSV: %s", ct)
+	}
+
+	return csv.NewReader(resp.Body).ReadAll()
+}
+
+func timeAtHour(t time.Time, h int) time.Time {
+	return time.Date(t.Year(), t.Month(), t.Day(), h, 0, 0, 0, t.Location())
+}
+
+func (src *TimeTableSource) GetTimetable(ctx context.Context) (TimeTable, error) {
+	records, err := getCSV(src.URL, ctx)
+	if err != nil {
+		return TimeTable{}, err
+	}
+
+	start, err := time.ParseInLocation(time.DateOnly, src.StartDate, time.Local)
+	if err != nil {
+		return TimeTable{}, err
+	}
+
+	tt := TimeTable{
+		Title: src.Title,
+		Location: src.Location,
+	}
+
+	numColumns := src.TimeColumn + 1
+	if src.NameColumn > src.TimeColumn {
+		numColumns = src.NameColumn + 1
+	}
+
+	timeSlotRe := regexp.MustCompile(`([0-9]+)-([0-9]+)?`)
+	for _, row := range(records) {
+		// Check that we have enought columns
+		if (len(row) < numColumns) {
+			continue
+		}
+
+		// Parse the time slot, skip if invalid
+		timeSlot := timeSlotRe.FindStringSubmatch(row[src.TimeColumn])
+		if len(timeSlot) < 2 {
+			continue
+		}
+
+		startHour, err := strconv.Atoi(timeSlot[1])
+		if err != nil {
+			continue
+		}
+
+		start = timeAtHour(start, startHour)
+		end  := start
+
+		if len(timeSlot) > 2 {
+			endHour, err := strconv.Atoi(timeSlot[2])
+			if err != nil {
+				continue
+			}
+			if endHour < startHour {
+				end = end.Add(time.Hour * 24)
+			}
+			end = timeAtHour(end, endHour)
+		}
+
+		show := Show{
+			Name:  row[src.NameColumn],
+			Start: start,
+		}
+
+		if end != start {
+			show.End = &end
+		}
+
+		if show.Name != "" {
+			tt.Shows = append(tt.Shows, show)
+		}
+
+		start = end
+	}
+
+	return tt, nil
+}
+
+func (src TimeTableSource) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	// Early validity check
+	switch when := r.PathValue("when"); when {
+	case "":
+	case "now":
+	case "next":
+	case "first":
+	default:
+		http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
+	}
+
+	ctx, cancel := context.WithTimeout(r.Context(), time.Second*10)
+	defer cancel()
+
+	tt, err := src.GetTimetable(ctx)
+	if err != nil {
+		log.Printf("Failed to get timetable: %s", err)
+		http.Error(w, http.StatusText(http.StatusBadGateway), http.StatusBadGateway)
+		return
+	}
+
+	var data any
+	found := true
+	switch when := r.PathValue("when"); when {
+	case "":
+		data = tt
+	case "now":
+		data, found  = tt.CurrentShow()
+	case "next":
+		data, found = tt.NextShow()
+	case "first":
+		if len(tt.Shows) > 0 {
+			data = tt.Shows[0]
+		} else {
+			found = false
+		}
+	default:
+		http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+
+	// Send an empty object if nothing was found
+	if !found {
+		data = make(map[string]string)
+	}
+	json.NewEncoder(w).Encode(data)
+}
+
+func LoadConfig(path string) (Config, error) {
+	rd, err := os.Open(path)
+	if err != nil {
+		return Config{}, fmt.Errorf("Failed to open config: %w", err)
+	}
+	defer rd.Close()
+
+	var cfg Config
+	err = yaml.NewDecoder(rd).Decode(&cfg)
+	if err != nil {
+		return Config{}, fmt.Errorf("Failed to parse config: %w", err)
+	}
+
+	return cfg, nil
+}
+
+func main() {
+	cfgFile := "timetables.yaml"
+
+	cfg, err := LoadConfig(cfgFile)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	staticDir := cfg.StaticDir
+	if staticDir == "" {
+		staticDir = "static"
+	}
+
+	http.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir(staticDir))))
+
+	for _, src := range(cfg.Sources) {
+		if src.ID == "" || src.URL == "" {
+			log.Printf("Skipping invalid source: %s\n", src)
+			continue
+		}
+		log.Printf("Registering timetable %s\n", src.ID)
+
+		if src.CountdownPath == "" {
+			src.CountdownPath = "countdown.html"
+		}
+
+		http.Handle(fmt.Sprintf("/timetable/%s", src.ID), src)
+		http.Handle(fmt.Sprintf("/timetable/%s/{when}", src.ID), src)
+		http.HandleFunc(fmt.Sprintf("/countdown/%s", src.ID),
+			func (w http.ResponseWriter, req *http.Request) {
+				http.ServeFile(w, req, path.Join(staticDir, src.CountdownPath))
+			})
+	}
+
+	listen := cfg.Listen
+	if listen == "" {
+		listen = ":8080"
+	}
+
+	log.Fatal(http.ListenAndServe(listen, nil))
+}
--- a/timetables.yaml
+++ b/timetables.yaml
@@ -0,0 +1,10 @@
+timeZone: Europe/Berlin
+
+sources:
+  - id: ladoens
+    title: 15 Jahre Gänge 5 Jahre Galerie LADØNS DJ-Marathon
+    location: Galerie LADØNS
+    url: https://docs.google.com/spreadsheets/d/1gxQC-veUu_3PU1QbQDkXAGnELVbDrriLWYk9Zygu_-s/export?format=csv
+    startDate: 2024-08-24
+    timeColumn: 0
+    nameColumn: 1