Add configurable plugin system and move hardcoded IP to config

Introduces a plugin registry so the display mode is selectable per
device via the NixOS module config (defaults to "calendar"). Moves
the hardcoded render URL base into config.base_url. Adds tests
exercising the plugin system with a synthetic ICS feed.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

default.nix

@@ -35,11 +35,17 @@ in
       type = json.type;
       example = lib.literalExpression ''
         {
+          base_url = "http://192.168.50.124:2300";
+          devices = {
             unknown = {
+              plugin = "calendar";
+              settings = {
                 urls = ["https://user.fm/calendar/....ics"];
+              };
               refresh = 60;
               model = "inkplate_10";
             };
+          };
         }
       '';
 

src/plugins.test.ts

@@ -0,0 +1,127 @@
+import { describe, test, expect, beforeAll, afterAll } from 'bun:test';
+import type { Server } from 'bun';
+import { createPlugin } from './plugins';
+
+// --- Synthetic ICS ---
+
+const pad = (n: number) => n.toString().padStart(2, '0');
+const icsDate = (d: Date) =>
+  `${d.getFullYear()}${pad(d.getMonth() + 1)}${pad(d.getDate())}T${pad(d.getHours())}${pad(d.getMinutes())}00`;
+
+const now = new Date();
+const currentStart = new Date(now.getTime() - 30 * 60_000);
+const currentEnd = new Date(now.getTime() + 30 * 60_000);
+const nextStart = new Date(now.getTime() + 60 * 60_000);
+const nextEnd = new Date(now.getTime() + 120 * 60_000);
+const laterStart = new Date(now.getTime() + 180 * 60_000);
+const laterEnd = new Date(now.getTime() + 240 * 60_000);
+
+const ics = `BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//Test//Test//EN
+BEGIN:VEVENT
+DTSTART:${icsDate(currentStart)}
+DTEND:${icsDate(currentEnd)}
+SUMMARY:Current Meeting
+UID:test-current@test
+END:VEVENT
+BEGIN:VEVENT
+DTSTART:${icsDate(nextStart)}
+DTEND:${icsDate(nextEnd)}
+SUMMARY:Next Meeting
+UID:test-next@test
+END:VEVENT
+BEGIN:VEVENT
+DTSTART:${icsDate(laterStart)}
+DTEND:${icsDate(laterEnd)}
+SUMMARY:Later Meeting
+UID:test-later@test
+END:VEVENT
+END:VCALENDAR`;
+
+const fakeModel = {
+  width: 800,
+  height: 480,
+  css: { classes: { device: 'device', size: 'size', density: 'density' } },
+} as any;
+
+// --- ICS server ---
+
+let icsServer: Server;
+let icsUrl: string;
+
+beforeAll(() => {
+  icsServer = Bun.serve({
+    port: 0,
+    hostname: '127.0.0.1',
+    routes: {
+      '/cal.ics': () =>
+        new Response(ics, {
+          headers: { 'Content-Type': 'text/calendar' },
+        }),
+    },
+  });
+  icsUrl = `http://127.0.0.1:${icsServer.port}/cal.ics`;
+});
+
+afterAll(() => {
+  icsServer.stop();
+});
+
+// --- Tests ---
+
+describe('plugin registry', () => {
+  test('unknown plugin throws', () => {
+    expect(() => createPlugin('nonexistent', {})).toThrow(
+      'Unknown plugin: nonexistent'
+    );
+  });
+
+  test('calendar plugin creates an ICSRenderable', () => {
+    const plugin = createPlugin('calendar', { urls: [] });
+    expect(plugin.hash).toBe('');
+    expect(plugin.nextEvent).toBeUndefined();
+  });
+});
+
+describe('calendar plugin rendering', () => {
+  test('renders events from ICS feed', async () => {
+    const plugin = createPlugin('calendar', { urls: [icsUrl] });
+    const html = await plugin.render('full', fakeModel);
+
+    expect(html).toContain('Current Meeting');
+    expect(html).toContain('Next Meeting');
+    expect(html).toContain('Later Meeting');
+  });
+
+  test('shows BEZET when there is a current event', async () => {
+    const plugin = createPlugin('calendar', { urls: [icsUrl] });
+    const html = await plugin.render('full', fakeModel);
+
+    expect(html).toContain('BEZET');
+  });
+
+  test('computes hash after render', async () => {
+    const plugin = createPlugin('calendar', { urls: [icsUrl] });
+    await plugin.render('full', fakeModel);
+
+    expect(plugin.hash).toBeTruthy();
+  });
+
+  test('sets nextEvent to upcoming event start', async () => {
+    const plugin = createPlugin('calendar', { urls: [icsUrl] });
+    await plugin.render('full', fakeModel);
+
+    expect(plugin.nextEvent).toBeInstanceOf(Date);
+    const diff = Math.abs(plugin.nextEvent!.getTime() - nextStart.getTime());
+    expect(diff).toBeLessThan(120_000);
+  });
+
+  test('renders VRIJ with no events', async () => {
+    const plugin = createPlugin('calendar', { urls: [] });
+    const html = await plugin.render('full', fakeModel);
+
+    expect(html).toContain('VRIJ');
+    expect(html).not.toContain('BEZET');
+  });
+});

src/plugins.ts

@@ -0,0 +1,17 @@
+import type { Renderable } from './template';
+import { ICSRenderable } from './xlcalendar';
+
+type PluginFactory = (settings: Record<string, any>) => Renderable;
+
+const registry: Record<string, PluginFactory> = {
+  calendar: (settings) => new ICSRenderable(settings.urls ?? []),
+};
+
+export const createPlugin = (
+  name: string,
+  settings: Record<string, any>
+): Renderable => {
+  const factory = registry[name];
+  if (!factory) throw new Error(`Unknown plugin: ${name}`);
+  return factory(settings);
+};

src/template.ts

@@ -22,6 +22,8 @@ export type RenderMode =
   | 'half_vertical'
   | 'quadrant';
 export interface Renderable {
+  hash: string;
+  nextEvent?: Date;
   render(mode: RenderMode, model: DeviceModel): Promise<string>;
 }
 

src/web.ts

@@ -1,17 +1,21 @@
 import { SHA256 } from 'bun';
 import { devices } from './devices';
+import { createPlugin } from './plugins';
 import { makeScreenshot } from './render';
 import { render } from './template';
-import { ICSRenderable } from './xlcalendar';
 
 let renderMap = new Map();
 
-interface Configuration {
+interface DeviceConfiguration {
-  [mac: string]: {
+  plugin?: string;
-    urls: string[];
+  settings?: Record<string, any>;
   refresh?: number;
   model: string;
-  };
+}
+
+interface Configuration {
+  base_url: string;
+  devices: Record<string, DeviceConfiguration>;
 }
 
 const config: Configuration = JSON.parse(
@@ -40,15 +44,16 @@ Bun.serve({
       const id = req.headers.get('ID') ?? 'unknown';
       const newfriendly = id.replaceAll(':', '');
 
-      const device = config[id] ?? {
+      const device = config.devices[id] ?? {
-        urls: [],
+        plugin: 'calendar',
+        settings: {},
         refresh: undefined,
         model: 'inkplate_10',
       };
 
       console.log(`Rendering for ${id}..`);
 
-      let plugin = new ICSRenderable(device.urls);
+      let plugin = createPlugin(device.plugin ?? 'calendar', device.settings ?? {});
       const rendered = makeScreenshot(
         [[plugin, 'full']],
         devices.find((a) => a.name === device.model)!
@@ -74,7 +79,7 @@ Bun.serve({
 
       return Response.json({
         status: 0,
-        image_url: `http://192.168.50.124:2300/api/render/${id.toLowerCase()}/${plugin.hash ?? Math.random()}.png`,
+        image_url: `${config.base_url}/api/render/${id.toLowerCase()}/${plugin.hash ?? Math.random()}.png`,
         refresh_rate: nextRefresh.toString(),
         update_firmware: false,
         firmware_url: null,
@@ -87,13 +92,14 @@ Bun.serve({
       const id = req.headers.get('ID') ?? 'unknown';
       const newfriendly = id.replaceAll(':', '');
 
-      const device = config[id] ?? {
+      const device = config.devices[id] ?? {
-        urls: [],
+        plugin: 'calendar',
+        settings: {},
         refresh: undefined,
         model: 'inkplate_10',
       };
 
-      let plugin = new ICSRenderable(device.urls);
+      let plugin = createPlugin(device.plugin ?? 'calendar', device.settings ?? {});
       const rendered = await render(
         [[plugin, 'full']],
         devices.find((a) => a.name === device.model)!