add: elo data model and static rankings page

scripts/ingest-meal.js

@@ -4,6 +4,7 @@ const sharp = require("sharp");
 
 const { buildPages } = require("./build");
 const { buildThumbnails } = require("./generate-thumbnails");
+const { eloPath } = require("./lib/elo");
 const {
   getNextMealId,
   loadMeals,
@@ -15,6 +16,7 @@ const {
 const fullsDir = path.join(repoRoot, "images", "fulls");
 const thumbsDir = path.join(repoRoot, "images", "thumbs");
 const indexPath = path.join(repoRoot, "index.html");
+const rankingsPath = path.join(repoRoot, "rankings.html");
 const manifestPath = path.join(thumbsDir, ".thumbs-manifest.json");
 
 const FULL_IMAGE_QUALITY = 90;
@@ -123,28 +125,45 @@ async function writeFullImage(sourcePath, destinationPath) {
     .toFile(destinationPath);
 }
 
+function readOptionalFile(filePath) {
+  return fs.existsSync(filePath) ? fs.readFileSync(filePath, "utf8") : null;
+}
+
+async function restoreOptionalFile(filePath, previousContents) {
+  if (previousContents === null) {
+    if (fs.existsSync(filePath)) {
+      await fs.promises.unlink(filePath);
+    }
+
+    return;
+  }
+
+  if (previousContents !== undefined) {
+    fs.writeFileSync(filePath, previousContents);
+  }
+}
+
 async function rollback({
   createdFullPath,
   createdThumbPath,
+  previousElo,
   previousIndex,
   previousManifest,
   previousMeals,
+  previousRankings,
 }) {
   if (previousMeals !== undefined) {
     fs.writeFileSync(mealsPath, previousMeals);
   }
 
+  await restoreOptionalFile(eloPath, previousElo);
+
   if (previousIndex !== undefined) {
     fs.writeFileSync(indexPath, previousIndex);
   }
 
-  if (previousManifest === null) {
-    if (fs.existsSync(manifestPath)) {
-      await fs.promises.unlink(manifestPath);
-    }
-  } else if (previousManifest !== undefined) {
-    fs.writeFileSync(manifestPath, previousManifest);
-  }
+  await restoreOptionalFile(rankingsPath, previousRankings);
+  await restoreOptionalFile(manifestPath, previousManifest);
 
   if (createdThumbPath && fs.existsSync(createdThumbPath)) {
     await fs.promises.unlink(createdThumbPath);
@@ -169,10 +188,10 @@ async function ingestMeal(options) {
   }
 
   const previousMeals = fs.readFileSync(mealsPath, "utf8");
+  const previousElo = readOptionalFile(eloPath);
   const previousIndex = fs.readFileSync(indexPath, "utf8");
-  const previousManifest = fs.existsSync(manifestPath)
-    ? fs.readFileSync(manifestPath, "utf8")
-    : null;
+  const previousRankings = readOptionalFile(rankingsPath);
+  const previousManifest = readOptionalFile(manifestPath);
 
   await fs.promises.mkdir(fullsDir, { recursive: true });
 
@@ -185,9 +204,11 @@ async function ingestMeal(options) {
     await rollback({
       createdFullPath: fullPath,
       createdThumbPath: thumbPath,
+      previousElo,
       previousIndex,
       previousManifest,
       previousMeals,
+      previousRankings,
     });
     throw error;
   }