10 changed files with 188 additions and 691 deletions
--- a/.gitignore
+++ b/.gitignore
@ -1,4 +1,3 @@
 result
 vrnp
-main
 *.swp
--- a/README.md
+++ b/README.md
@ -2,21 +2,12 @@

 ## TODO

-### Server
-
 - [x] Use timeout for fetching departures
 - [x] Add basic auth
 - [x] Create Nix package
 - [x] Create container
+- [x] Write ESP8266 client
+- [ ] Make port configurable
 - [x] Transfer using JSON
 - [x] Correctly implement basic auth
- [ ] Make port configurable
- [ ] Use unidecode to replace non-ascii stuff
- [ ] Add query parameter for selecting EFAClient
- [ ] Return current time for displaying clock
-
-### Client
-
- [x] Write ESP8266 client
- [x] Add code for handling button presses
- [ ] Add clock
+- [ ] Use unidecode to replace non-ascii stuff in the backend
--- a/client/animations/tiny_train.gif
+++ b/client/animations/tiny_train.gif
--- a/client/bitmaps.h
+++ b/client/bitmaps.h
@ -81,17 +81,3 @@ static const uint8_t PROGMEM spinny[][8] = {
    0x00,
  },
 };
-static const uint16_t PROGMEM tiny_train_dims[] = {24, 9, 1};
-static const uint8_t PROGMEM tiny_train[][27] = {
-  {
-    0x00, 0x04, 0x00,
-    0x00, 0x02, 0x00,
-    0x01, 0xff, 0xfe,
-    0x00, 0xa4, 0x94,
-    0x01, 0x24, 0x92,
-    0x01, 0x24, 0x92,
-    0x03, 0xfc, 0xff,
-    0x03, 0xff, 0xff,
-    0x01, 0xb0, 0x36,
-  },
-};
--- a/client/client.ino
+++ b/client/client.ino
@ -1,300 +1,39 @@
 #include <ArduinoJson.h>
-#include <Adafruit_GFX.h>
-#include <Adafruit_ST7735.h>
 #include <ESP8266WiFi.h>
-#include <ESP8266HTTPClient.h>
-#include <memory>
 #include <SPI.h>
+#include <Wire.h>
+#include <Adafruit_GFX.h>
+#include <Adafruit_SSD1306.h>
+#include <ESP8266HTTPClient.h>
 #include <WiFiClientSecureBearSSL.h>

 #include "bitmaps.h"
 #include "wifi_credentials.h"

-#define TFT_CS D8
-#define TFT_DC D4
-#define TFT_RESET D3
+// Screen stuff
+#define SCREEN_WIDTH 128 // OLED display width, in pixels
+#define SCREEN_HEIGHT 64 // OLED display height, in pixels
+#define OLED_RESET    -1 // Reset pin # (or -1 if sharing Arduino reset pin)
+#define SCREEN_ADDRESS 0x3C

 // Button stuff
 #define BUTTON_PIN D6

-// Display stuff
 #define FRAME_DELAY 80
-#define COLOR_BG (rgb(0, 0, 0))
-#define COLOR_DIVIDER (rgb(0xff, 0x60, 0x0d))
-#define COLOR_TOP (rgb(0xa0, 0xa0, 0xa0))
-#define COLOR_TEXT (rgb(0xff, 0x60, 0x0d))
-
-// Layout
-#define WIDTH 160
-#define HEIGHT 128
-
-#define CX 6
-#define CY 8
-
-#define MARGIN_LEFT 5
-#define MARGIN_RIGHT 5
-
-#define TOP_X MARGIN_LEFT
-#define TOP_Y 4
-#define TOP_WIDTH (WIDTH - 2 * MARGIN_LEFT)
-#define TOP_HEIGHT CY
-
-#define MAIN_X MARGIN_LEFT
-#define MAIN_Y 19
-#define MAIN_WIDTH (WIDTH - 2 * MARGIN_LEFT)
-#define MAIN_HEIGHT (8 * CY)
-
-#define CLOCK_X MARGIN_LEFT
-#define CLOCK_Y 113
-#define CLOCK_WIDTH (5 * CX)
-#define CLOCK_HEIGHT CY
-
-#define STATUS_X 83
-#define STATUS_Y CLOCK_Y
-#define STATUS_WIDTH (12 * CX)
-#define STATUS_HEIGHT CY
-
-struct Timetable {
-  const char *label;
-  const char *path;
-};
-
-// Selectable timetables
-Timetable timetables[] = {
-  {"Johanneskirche    Bstg. 1", "/departures?stop_id=de:08311:30104&platform=1"},
-  {"Johanneskirche    Bstg. 2", "/departures?stop_id=de:08311:30104&platform=2"},
-  {"Blumenthalstr     Bstg. A", "/departures?stop_id=de:08221:1225&platform=A"},
-  {"Blumenthalstr     Bstg. B", "/departures?stop_id=de:08221:1225&platform=B"}
-};
-size_t selectedTimetable = 0;
-
-// Function definitions
-void drawLayout();
-void clearTop();
-void clearStatus();
-void clearMain();
-void clearClock();
-uint16_t rgb(uint16_t, uint16_t, uint16_t);
-String fetchDepartures(String);

 // Peripherals

-Adafruit_ST7735 display(TFT_CS, TFT_DC, TFT_RESET);
+Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

-// App state interface
-
-//           init                                                   
-//             │                                                    
-//             │                                                   
-//             │                                                    
-//             │      ┌───┐                                         
-//          ┌──▼──────▼┐  │                                         
-//          │Connecting│  │!connected                               
-//          └──┬───▲──┬┘  │                                         
-//             │   │  └───┘                                         
-//             │   │                                                
-//    connected│   │!connected                                      
-//             │   │                                                
-//             │   │                                                
-//             │   │                             ┌───┐              
-//          ┌──▼───┴─┐   timeout (3s)   ┌────────▼┐  │              
-//          │Fetching◄──────────────────┤Selecting│  │              
-//          └──┬───▲─┘                  └────▲───┬┘  │button pressed
-//             │   │                         │   └───┘              
-// got response│   │timeout (25s)            │                      
-//             │   │                         │                      
-//             │   │                         │                      
-//             │   │                         │button pressed        
-//        ┌────▼───┴─────────┐               │                      
-//        │Showing Departures│───────────────┘                      
-//        └──────────────────┘                                      
-
-class State {
-public:
-  // When the state is entered
-  virtual void enter();
-  // Called in the business loop
-  virtual void tick();
-  // Called when the button is pushed
-  virtual void button();
-  virtual ~State() = default;
-};
-
-class StateConnecting : public State {
-public:
-  void enter() override;
-  void tick() override;
-};
-
-class StateFetching : public State {
-public:
-  void enter() override;
-};
-
-class StateShowingDepartures : public State {
-private:
-  // Todo: discard JsonDocument asap, parse into better format
-  JsonDocument departures;
-  unsigned long entered;
-public:
-  StateShowingDepartures(String&);
-  void enter() override;
-  void tick() override;
-  void button() override;
-};
-
-class StateSelecting : public State {
-private:
-  unsigned long entered;
-public:
-  void enter() override;
-  void tick() override;
-  void button() override;
-};
-
-// Empty default implementations
-
-void State::enter() {}
-void State::tick() {}
-void State::button() {}
-
-// App state implementation
-
-uint64_t currentTick = 0;
-// Initially true so that enter() of the initial state is called.
-bool stateChanged = true;
-std::unique_ptr<State> state = std::make_unique<StateConnecting>();
-
-template <typename StateType, typename... Args>
-void setState(Args&&... args) {
-  state = std::make_unique<StateType>(std::forward<Args>(args)...);
-  stateChanged = true;
-}
-
-void StateConnecting::enter() {
-  Serial.println("Entering StateConnecting");
-
-  display.fillRect(STATUS_X, STATUS_Y, STATUS_WIDTH, STATUS_HEIGHT, COLOR_BG);
-  display.setCursor(STATUS_X, STATUS_Y);
-  display.setTextColor(COLOR_TEXT);
-  display.printf("connecting");
-}
-
-void StateConnecting::tick() {
-  if (WiFi.status() != WL_CONNECTED) {
-    display.fillRect(STATUS_X + 11 * CX, STATUS_Y, CX, CY, COLOR_BG);
-    display.setCursor(STATUS_X + 11 * CX, STATUS_Y);
-    display.setTextColor(COLOR_TEXT);
-    display.print("|/-\\"[currentTick % 4]);
-    delay(125);
-    return;
-  }
-
-  setState<StateFetching>();
-}
-
-// Fetching is a bit of an ugly duckling; it performs all its logic in enter().
-// This is because the request it does is synchronous.
-// Sadly this means no animation is possible right now.
-// At least the fetch call still does yield() under the hood :)
-void StateFetching::enter() {
-  Serial.println("Entering StateFetching");
-
-  if (WiFi.status() != WL_CONNECTED) {
-    setState<StateConnecting>();
-    return;
-  }
-  display.fillRect(STATUS_X, STATUS_Y, STATUS_WIDTH, STATUS_HEIGHT, COLOR_BG);
-  display.setTextColor(COLOR_TEXT);
-  display.setCursor(STATUS_X, STATUS_Y);
-  display.print("    fetching");
-  
-  String departuresRaw = fetchDepartures(timetables[selectedTimetable].path);
-  
-  setState<StateShowingDepartures>(departuresRaw);
-};
-
-StateShowingDepartures::StateShowingDepartures(String &departuresRaw) {
-  deserializeJson(departures, departuresRaw);
-}
-
-void StateShowingDepartures::enter() {
-  Serial.println("Entering StateShowingDepartures");
-  entered = millis();
-
-  clearStatus();
-  clearMain();
-
-  // draw timetable
-  display.setTextColor(COLOR_TEXT);
-  int line = 0;
-  for (JsonVariant departure : departures["departures"].as<JsonArray>()) {
-    if (line > 8) {
-      break;
-    }
-
-    char symbol[3] = {0};
-    char direction[16] = {0};
-
-    utf8ToCP437German(departure["symbol"].as<const char *>(), symbol, std::size(symbol));
-    utf8ToCP437German(departure["direction"].as<const char *>(), direction, std::size(direction));
-
-    display.setCursor(MAIN_X, MAIN_Y + (CY + 3) * line);
-    display.printf("%2s %-15.15s ", symbol, direction);
-    if (departure["leaving"].as<String>().equals("sofort")) {
-      int16_t x = display.getCursorX();
-      int16_t y = display.getCursorY();
-      display.drawBitmap(x + 6 * CX - tiny_train_dims[0], y, tiny_train[0], tiny_train_dims[0], tiny_train_dims[1], COLOR_TEXT);
-    } else {
-      display.printf("%6s", departure["leaving"].as<const char*>());
-    }
-
-    line++;
-  }
-
-  clearClock();
-  display.setCursor(CLOCK_X, CLOCK_Y);
-  display.printf("%5s", departures["serverTime"].as<const char *>());
-}
-
-void StateShowingDepartures::tick() {
-  unsigned long elapsed = millis() - entered;
-  if (elapsed > 25000) {
-    setState<StateFetching>();
-  }
-}
-
-void StateShowingDepartures::button() {
-  setState<StateSelecting>();
-}
-
-void StateSelecting::enter() {
-  Serial.println("Entering StateSelecting");
-  entered = millis();
-  
-  clearMain();
-  clearStatus();
-}
-
-void StateSelecting::tick() {
-  unsigned long elapsed = millis() - entered;
-  if (elapsed > 3000) {
-    setState<StateFetching>();
-  }
-}
-
-void StateSelecting::button() {
-  entered = millis();
-  selectedTimetable = (selectedTimetable + 1) % (sizeof timetables / sizeof timetables[0]);
-  clearTop();
-  display.setCursor(TOP_X, TOP_Y);
-  display.setTextColor(COLOR_TOP);
-  display.print(timetables[selectedTimetable].label);
-}
-
-// button ISR setup
+// App state

+enum {
+  CONNECTING,
+  SHOWING_DEPARTURES
+} state = CONNECTING;
+int frame = 0;
 int buttonPushed = false;
+JsonDocument departures;

 void ICACHE_RAM_ATTR onButtonFalling() {
  buttonPushed = true;
@ -303,83 +42,47 @@ void ICACHE_RAM_ATTR onButtonFalling() {
 void setup() {
  Serial.begin(9600);

-  Serial.println("serial init");
-  display.initR();
-  display.setSPISpeed(40000000);
-  display.cp437(true);
-  display.setRotation(3);
-  Serial.println("display initialized");
-  Serial.printf("display dimensions: %" PRId16 "x%" PRId16 "\n", display.width(), display.height());
-
-  drawLayout();
-  display.setCursor(TOP_X, TOP_Y);
-  display.setTextColor(COLOR_TOP);
-  display.print(timetables[selectedTimetable].label);
+  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
+  if(!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
+    Serial.println("SSD1306 allocation failed");
+    for(;;); // Don't proceed, loop forever
+  }
+  Serial.println("SSD1306 initialized");
+  display.clearDisplay();

  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  attachInterrupt(BUTTON_PIN, onButtonFalling, FALLING);

-  state = std::make_unique<StateConnecting>();
+  display.setTextColor(SSD1306_INVERSE);
+  display.setTextSize(1);
+  display.setCursor(0, 0);
+  display.printf("Connecting to\n%s\n", WIFI_SSID);
+  display.display();
+  /*
+  display.print(" 5 Mannheim    sofort\n"
+                "26 Kirchheim    9 min\n"
+                " 5 Weinheim     20:13");
+  */
 }

-void loop() {
-  if (stateChanged) {
-    stateChanged = false;
-    // Note: enter() may call setState(). In that case we want to end up right back here.
-    state->enter();
-  } else if (buttonPushed) {
-    // "Handle" jitter
-    delay(100);
-    buttonPushed = false;
-    state->button();
-  } else {
-    state->tick();
-    currentTick++;
-  }
-  // Let background system do its thing
-  yield();
-}
-
-uint16_t rgb(uint16_t r, uint16_t g, uint16_t b) {
-  // Color layout: RRRRRGGGGGGBBBBB (5, 6, 5)
-  return ((b >> 3) & 0b11111) << 11 | ((g >> 2) & 0b111111) << 5 | ((r >> 3) & 0b11111);
-}
-
-void clearTop() {
-  display.fillRect(TOP_X, TOP_Y, TOP_WIDTH, TOP_HEIGHT, COLOR_BG);
-}
-
-void clearMain() {
-  display.fillRect(MAIN_X, MAIN_Y, MAIN_WIDTH, MAIN_HEIGHT, COLOR_BG);
-}
-
-void clearStatus() {
-  display.fillRect(STATUS_X, STATUS_Y, STATUS_WIDTH, STATUS_HEIGHT, COLOR_BG);
-}
-
-void clearClock() {
-  display.fillRect(CLOCK_X, CLOCK_Y, CLOCK_WIDTH, CLOCK_HEIGHT, COLOR_BG);
-}
-
-void drawLayout() {
-  display.fillScreen(COLOR_BG);
-  display.drawFastHLine(5, 15, 150, COLOR_DIVIDER);
-  display.drawFastHLine(5, 109, 150, COLOR_DIVIDER);
-  display.drawFastHLine(5, 123, 150, COLOR_DIVIDER);
+void drawSpinner(int frame) {
+  display.fillRect(120, 56, spinny_dims[0], spinny_dims[1], SSD1306_BLACK);
+  display.drawBitmap(120, 56, spinny[frame % spinny_dims[2]], spinny_dims[0], spinny_dims[1], SSD1306_WHITE);
 }

 // TODO: Error handling
-String fetchDepartures(String path) {
+String fetchDepartures() {
  std::unique_ptr<BearSSL::WiFiClientSecure> https(new BearSSL::WiFiClientSecure);
  https->setInsecure();
  
  HTTPClient client;
-  if (!client.begin(*https, "vrnp.beany.club", 443, path)) {
-    display.fillScreen(COLOR_BG);
+  if (!client.begin(*https, "vrnp.beany.club", 443, "/departures?stop_id=de:08221:1225&platform=A")) {
+    display.clearDisplay();
    display.setCursor(0, 0);
    display.print("begin failed");
+    display.display();
    for (;;);
  }

@ -387,78 +90,88 @@ String fetchDepartures(String path) {
  client.addHeader("Accept", "application/json");
  int statusCode = client.GET();
  if (statusCode != 200) {
-    display.fillScreen(COLOR_BG);
+    display.clearDisplay();
    display.setCursor(0, 0);
    display.printf("http non-ok: %d\n", statusCode);
+    display.display();
    for (;;);
  }

  return client.getString();
 }

-char mapUtf8CodepointToCP437German(uint32_t codepoint) {
-  switch (codepoint) {
-    case 0x00e4: return 0x84; // ä
-    case 0x00c4: return 0x8e; // Ä
-    case 0x00f6: return 0x94; // ö
-    case 0x00d6: return 0x99; // Ö
-    case 0x00fc: return 0x81; // ü
-    case 0x00dc: return 0x9a; // Ü
-    case 0x00df: return 0xe1; // ß
-    default: return '?';
+void loop() {
+  switch (state) {
+    case CONNECTING: {
+      if (WiFi.status() != WL_CONNECTED) {
+        drawSpinner(frame++);
+        display.display();
+        delay(FRAME_DELAY);
+        return;
      }
+      
+      display.clearDisplay();
+      display.fillRect(0, 56, 128, 8, SSD1306_INVERSE);
+      display.setCursor(0, 56);
+      display.print("requesting departures");
+      display.display();
+
+      String departuresRaw = fetchDepartures();
+      deserializeJson(departures, departuresRaw);
+      
+      state = SHOWING_DEPARTURES;
+      frame = 0;
+      return;
+    }
+      
+    case SHOWING_DEPARTURES:
+      if (WiFi.status() != WL_CONNECTED) {
+        state = CONNECTING;
+        return;
      }

      /*
-Maps german umlauts and sharp s from utf8 to cp437 encoding.
-Other utf8 characters and malformed utf8 are replaced by '?'.
-The resulting string is truncated to cp437StrSize.
+      if (buttonPushed) {
+        buttonPushed = false;
+        delay(FRAME_DELAY);
+        return;
+      }
      */
-void utf8ToCP437German(const char *utf8Str, char *cp437Str, size_t cp437StrSize) {
-  size_t utf8StrLength = strlen(utf8Str);
-  size_t utf8StrIndex = 0;
-  size_t cp437StrIndex = 0;

-  char c;
+      // Marquee effect for direction strings longer than 11 characters
+      // Neither particularly efficient nor legible
+      // (This could use some love)

-  // One char at the end of the cp437Str is reserved to the terminating null
-  while (utf8StrIndex < utf8StrLength && cp437StrIndex + 1 < cp437StrSize) {
-    uint8_t cu0 = utf8Str[utf8StrIndex];
+      int availableWidth = 11;

-    if (cu0 < 0x80) {
-      // ASCII maps to ASCII
-      c = cu0;
-      utf8StrIndex++;
-    } else if ((cu0 & 0b11100000) == 0b11000000) {
-      // codepoints encoded as two code units may contain german special characters
-      if (utf8StrIndex + 1 >= utf8StrLength) {
-        // if there's no 10xxxxxxx byte after this one, we've reached the end (malformed)
-        c = '?';
-        break;
+      display.clearDisplay();
+      display.setCursor(0, 0);
+      for (JsonVariant departure : departures["departures"].as<JsonArray>()) {
+        const char *directionStr = departure["direction"].as<const char *>();
+
+        char buf[128] = {0};
+        const char *dirStart;
+
+        if (strlen(directionStr) <= availableWidth || (strlen(directionStr) + 3 + availableWidth) > 127) {
+          dirStart = directionStr;
        } else {
-        // otherwise decode the codepoint and map it to cp437
-        uint8_t cu1 = utf8Str[utf8StrIndex + 1];
-        uint32_t cp = (cu0 & 0x1f << 6) | cu1 & 0x3f;
-        c = mapUtf8CodepointToCP437German(cp);
-        utf8StrIndex += 2;
-      }
-    // for 3 and 4-code unit codepoints just put a ? and skip all their code units
-    // here we dont care whether the string is malformed
-    } else if ((cu0 & 0b11110000) == 0b11100000) {
-      c = '?';
-      utf8StrIndex += 3;
-    } else if ((cu0 & 0b11111000) == 0b11110000) {
-      c = '?';
-      utf8StrIndex += 4;
-    } else {
-      // catch all for malformed utf8
-      c = '?';
-      utf8StrIndex++;
+          memcpy(buf, directionStr, strlen(directionStr));
+          memcpy(buf + strlen(directionStr), "   ", 3);
+          memcpy(buf + strlen(directionStr) + 3, directionStr, availableWidth);
+          buf[strlen(directionStr) + 3 + availableWidth] = '\0';
+          dirStart = buf + frame % (strlen(directionStr) + 3);
        }

-    cp437Str[cp437StrIndex] = c;
-    cp437StrIndex++;
+        display.printf("%2s %-11.11s %6s\n",
+          departure["symbol"].as<const char*>(),
+          dirStart,
+          departure["leaving"].as<const char*>()
+        );
      }
+      display.display();
      
-  cp437Str[cp437StrIndex] = '\0';
+      frame++;
+      delay(500);
+      return;
+  }
 }
--- a/client/scripts/extract_bitmaps.py
+++ b/client/scripts/extract_bitmaps.py
@ -43,4 +43,3 @@ def generate_bitmap_from_gif(file: Path, fd):

 if __name__ == "__main__":
    generate_bitmap_from_gif(Path("./animations/spinny.gif"), sys.stdout)
-    generate_bitmap_from_gif(Path("./animations/tiny_train.gif"), sys.stdout)
--- a/efa_client.go
+++ b/efa_client.go
@ -1,143 +0,0 @@
-package main
-
-import "net/http"
-import "net/url"
-import "strings"
-
-type EFAClient interface {
-	GetName() string
-	BuildRequest(string) (*http.Request, error)
-}
-
-var allEfaClients []EFAClient = []EFAClient{
-	BwegtEFAClient{},
-	VRNEFAClient{},
-	KVVEFAClient{},
-	VAGEFAClient{},
-}
-
-type VRNEFAClient struct {
-}
-
-func (c VRNEFAClient) GetName() string {
-	return "VRN"
-}
-
-func (c VRNEFAClient) BuildRequest(stopId string) (*http.Request, error) {
-	// Create request object
-	req, err := http.NewRequest("GET", "https://www.vrn.de/mngvrn/XML_DM_REQUEST", nil)
-	if err != nil {
-		return nil, err
-	}
-
-	// Configure our request
-	query := url.Values{}
-	query.Set("coordOutputFormat", "EPSG:4326")
-	query.Set("depType", "stopEvents")
-	query.Set("includeCompleteStopSeq", "0")
-	query.Set("limit", "10")
-	query.Set("locationServerActive", "0")
-	query.Set("mode", "direct")
-	query.Set("name_dm", stopId)
-	query.Set("outputFormat", "json")
-	query.Set("type_dm", "stop")
-	query.Set("useOnlyStops", "1")
-	query.Set("useRealtime", "1")
-	req.URL.RawQuery = query.Encode()
-
-	return req, nil
-}
-
-type KVVEFAClient struct {
-}
-
-func (c KVVEFAClient) GetName() string {
-	return "KVV"
-}
-
-func (c KVVEFAClient) BuildRequest(stopId string) (*http.Request, error) {
-	form := url.Values{}
-	form.Set("action", "XSLT_DM_REQUEST")
-	form.Set("name_dm", stopId)
-	form.Set("type_dm", "stop")
-	form.Set("useRealtime", "1")
-	form.Set("limit", "10")
-	form.Set("mode", "direct")
-	form.Set("useRealtime", "1")
-	form.Set("outputFormat", "json")
-	body := strings.NewReader(form.Encode())
-
-	req, err := http.NewRequest("POST", "https://www.kvv.de/tunnelEfaDirect.php", body)
-	if err != nil {
-		return nil, err
-	}
-
-	req.Header.Set("User-Agent", "coolio/1.0")
-	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
-
-	return req, nil
-}
-
-type BwegtEFAClient struct {
-}
-
-func (c BwegtEFAClient) GetName() string {
-	return "bwegt"
-}
-
-func (c BwegtEFAClient) BuildRequest(stopId string) (*http.Request, error) {
-	// Create request object
-	req, err := http.NewRequest("GET", "https://www.bwegt.de/bwegt-efa/XML_DM_REQUEST", nil)
-	if err != nil {
-		return nil, err
-	}
-
-	// Configure our request
-	query := url.Values{}
-	query.Set("coordOutputFormat", "EPSG:4326")
-	query.Set("depType", "stopEvents")
-	query.Set("includeCompleteStopSeq", "0")
-	query.Set("limit", "10")
-	query.Set("locationServerActive", "0")
-	query.Set("mode", "direct")
-	query.Set("name_dm", stopId)
-	query.Set("outputFormat", "json")
-	query.Set("type_dm", "stop")
-	query.Set("useOnlyStops", "1")
-	query.Set("useRealtime", "1")
-	req.URL.RawQuery = query.Encode()
-
-	return req, nil
-}
-
-type VAGEFAClient struct {
-}
-
-func (c VAGEFAClient) GetName() string {
-	return "VAG"
-}
-
-func (c VAGEFAClient) BuildRequest(stopId string) (*http.Request, error) {
-	// Create request object
-	req, err := http.NewRequest("GET", "https://efa.vagfr.de/vagfr3/XSLT_DM_REQUEST", nil)
-	if err != nil {
-		return nil, err
-	}
-
-	// Configure our request
-	query := url.Values{}
-	query.Set("coordOutputFormat", "EPSG:4326")
-	query.Set("depType", "stopEvents")
-	query.Set("includeCompleteStopSeq", "0")
-	query.Set("limit", "10")
-	query.Set("locationServerActive", "0")
-	query.Set("mode", "direct")
-	query.Set("name_dm", stopId)
-	query.Set("outputFormat", "json")
-	query.Set("type_dm", "stop")
-	query.Set("useOnlyStops", "1")
-	query.Set("useRealtime", "1")
-	req.URL.RawQuery = query.Encode()
-
-	return req, nil
-}
--- a/flake.lock
+++ b/flake.lock
@ -1,23 +1,5 @@
 {
  "nodes": {
-    "flake-utils": {
-      "inputs": {
-        "systems": "systems"
-      },
-      "locked": {
-        "lastModified": 1731533236,
-        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
-        "type": "github"
-      },
-      "original": {
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "type": "github"
-      }
-    },
    "gitignore": {
      "inputs": {
        "nixpkgs": [
@ -56,25 +38,9 @@
    },
    "root": {
      "inputs": {
-        "flake-utils": "flake-utils",
        "gitignore": "gitignore",
        "nixpkgs": "nixpkgs"
      }
-    },
-    "systems": {
-      "locked": {
-        "lastModified": 1681028828,
-        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
-        "owner": "nix-systems",
-        "repo": "default",
-        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
-        "type": "github"
-      },
-      "original": {
-        "owner": "nix-systems",
-        "repo": "default",
-        "type": "github"
-      }
    }
  },
  "root": "root",
--- a/flake.nix
+++ b/flake.nix
@ -3,20 +3,20 @@

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";
-    flake-utils.url = "github:numtide/flake-utils";
    gitignore = {
      url = "github:hercules-ci/gitignore.nix";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };

-  outputs = { self, nixpkgs, flake-utils, gitignore }: flake-utils.lib.eachDefaultSystem (system:
+  outputs = { self, nixpkgs, gitignore }:
  let
-      pkgs = import nixpkgs { inherit system; };
+    system = "x86_64-linux";
+    pkgs = nixpkgs.legacyPackages.${system};

    vrnp-static = pkgs.buildGoModule {
      pname = "vrnp";
-        version = "0.0.10";
+      version = "0.0.4";
      vendorHash = null;

      # For building the package, we use only the files not ignored by Git as inputs.
@ -31,15 +31,15 @@
      CGO_ENABLED = 0;
    };
  in {
-      devShell = pkgs.mkShell {
+    devShell.${system} = pkgs.mkShellNoCC {
      packages = [
        pkgs.go
        (pkgs.python3.withPackages (ps: with ps; [ pillow ]))
      ];
    };
-      packages = {
+    packages.${system} = {
      default = vrnp-static;
-        image-meta = pkgs.runCommand "image-meta" {} ''
+      image-meta = pkgs.runCommand "vrnp-version" {} ''
        mkdir -p $out
        echo -n ${vrnp-static.version} > $out/version
        echo -n git.pbrinkmeier.de/paul/vrnp:${vrnp-static.version} > $out/name
@ -55,6 +55,5 @@
        config.Cmd = [ "${vrnp-static}/bin/vrnp" ];
      };
    };
-    }
-  );
+  };
 }
--- a/main.go
+++ b/main.go
@ -1,22 +1,19 @@
 package main

-import "cmp"
 import "encoding/json"
 import "errors"
 import "fmt"
 import "log"
 import "net/http"
+import "net/url"
 import "os"
 import "slices"
-import "strings"
 import "strconv"
-import "sync/atomic"
 import "time"

 // JSON unmarshaling types for departure monitor API

 type DMResponse struct {
-	DateTime DMDateTime `json:"dateTime"`
 	DepartureList []DMDeparture `json:"departureList"`
 }

@ -46,12 +43,28 @@ type DMDateTime struct {
 	Minute string `json:"minute"`
 }

-func FetchDepartures(c EFAClient, stopId string) (DMResponse, error) {
-	req, err := c.BuildRequest(stopId)
+func FetchDepartures(stopId string) (DMResponse, error) {
+	// Create request object
+	req, err := http.NewRequest("GET", "https://www.vrn.de/mngvrn/XML_DM_REQUEST", nil)
 	if err != nil {
 		return DMResponse{}, err
 	}

+	// Configure our request
+	query := url.Values{}
+	query.Set("coordOutputFormat", "EPSG:4326")
+	query.Set("depType", "stopEvents")
+	query.Set("includeCompleteStopSeq", "0")
+	query.Set("limit", "10")
+	query.Set("locationServerActive", "0")
+	query.Set("mode", "direct")
+	query.Set("name_dm", stopId)
+	query.Set("outputFormat", "json")
+	query.Set("type_dm", "stop")
+	query.Set("useOnlyStops", "1")
+	query.Set("useRealtime", "1")
+	req.URL.RawQuery = query.Encode()
+
 	// Send the request, wait max 10 seconds
 	client := http.Client{
 		Timeout: 10 * time.Second,
@ -75,7 +88,6 @@ func FetchDepartures(c EFAClient, stopId string) (DMResponse, error) {

 type Departures struct {
 	Departures []Departure `json:"departures"`
-	ServerTime string      `json:"serverTime"`
 }

 type Departure struct {
@ -83,7 +95,6 @@ type Departure struct {
 	Symbol    string `json:"symbol"`
 	Direction string `json:"direction"`
 	Leaving   string `json:"leaving"`
-	Countdown int    `json:"-"`
 }

 func ParseDepartures(response DMResponse, allowedPlatform *string) (Departures, error) {
@ -106,12 +117,6 @@ func ParseDepartures(response DMResponse, allowedPlatform *string) (Departures,
 			return Departures{}, errors.New("could not parse countdown")
 		}

-		matchesPlatform := allowedPlatform == nil || d.Platform == *allowedPlatform
-		isInThePast := countdown < 0
-		if !matchesPlatform || isInThePast {
-			continue
-		}
-
 		if countdown == 0 {
 			leaving = "sofort"
 		}
@ -123,42 +128,25 @@ func ParseDepartures(response DMResponse, allowedPlatform *string) (Departures,
 			leaving = fmt.Sprintf("%02s:%02s", dt.Hour, dt.Minute)
 		}

+		if allowedPlatform != nil && d.Platform != *allowedPlatform {
+			continue
+		}
+
 		ds = append(ds, Departure{
 			d.Platform,
 			d.ServingLine.Symbol,
 			direction,
 			leaving,
-			countdown,
 		})
 	}

-	slices.SortFunc(ds, func(a Departure, b Departure) int {
-		return cmp.Compare(a.Countdown, b.Countdown)
-	})
-
-	dt := response.DateTime
-
-	return Departures{
-		ds,
-		fmt.Sprintf("%02s:%02s", dt.Hour, dt.Minute),
-	}, nil
+	return Departures{ds}, nil
 }

 func main() {
 	password := os.Getenv("VRNP_PASSWORD")
 	if len(password) == 0 {
-		log.Fatal("Required environment variable VRNP_PASSWORD is not set")
-	}
-
-	clientAllowlist := strings.Split(os.Getenv("VRNP_CLIENT_ALLOWLIST"), ",")
-
-	// Use round-robin to send incoming requests to different servers
-	var efaClient atomic.Uint64
-	var efaClients []EFAClient
-	for _, efaClient := range allEfaClients {
-		if len(clientAllowlist) != 0 && slices.Contains(clientAllowlist, efaClient.GetName()) {
-			efaClients = append(efaClients, efaClient)
-		}
+		panic("Required environment variable VRNP_PASSWORD is not set")
 	}

 	http.HandleFunc("/departures", func(w http.ResponseWriter, r *http.Request) {
@ -182,8 +170,7 @@ func main() {
 			platform = &query["platform"][0]
 		}

-		c := efaClients[(efaClient.Add(1) - 1) % uint64(len(efaClients))]
-		ds, err := FetchDepartures(c, stopId)
+		ds, err := FetchDepartures(stopId)
 		if err != nil {
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return