Add OG and Twitter Card markup, generate OG profile images

closes #2

tasks/generate_og_profile_image.ts

@@ -0,0 +1,63 @@
+import Profile from "../models/profile.ts";
+import { checkIfFileExists, runCommand } from "../utils.ts";
+import { log } from "../log.ts";
+
+const tmpImgDir = "/tmp/substr/img";
+
+const createRoundedImage = function (profile: Profile) {
+  const command = [
+    'magick',
+    profile.picture,
+    '-resize', '256x256',
+    '(', '+clone', '-alpha', 'extract',
+    '-draw', "fill black polygon 0,0 0,128 128,0 fill white circle 128,128 128,0",
+    '(', '+clone', '-flip', ')', '-compose', 'Multiply', '-composite',
+    '(', '+clone', '-flop', ')', '-compose', 'Multiply', '-composite',
+    ')',
+    '-alpha', 'off',
+    '-compose', 'CopyOpacity',
+    '-composite',
+    `${tmpImgDir}/p-${profile.event.id}-rounded.png`
+  ];
+
+  return runCommand(command);
+}
+
+const createOgImage = async function (profile: Profile, ogImagePath: string, backgroundColor: string) {
+  const status = await createRoundedImage(profile);
+
+  if (status.success) {
+    const command = [
+      'magick',
+      `${tmpImgDir}/p-${profile.event.id}-rounded.png`,
+      '-resize', '256x256',
+      '-background', backgroundColor,
+      '-gravity', 'center',
+      '-extent', '1200x630',
+      '-size', '1200x630',
+      "-format", "png",
+      ogImagePath
+    ];
+
+    return runCommand(command);
+  }
+};
+
+const generateOgProfileImage = async function(profile: Profile) {
+  if (!profile.picture) return false;
+
+  const ogImagePath = `${tmpImgDir}/og-p-${profile.event.id}.png`;
+  const backgroundColor = "#333333";
+  const fileExists = await checkIfFileExists(ogImagePath);
+
+  if (!fileExists) {
+    const status = await createOgImage(profile, ogImagePath, backgroundColor);
+    if (status.success) {
+      log(`Created OG image for ${profile.username}: ${ogImagePath}`, "blue")
+    } else {
+      log(`Could not create OG image for ${profile.username}`, "yellow")
+    }
+  }
+}
+
+export default generateOgProfileImage;