From e8ec13dc8df6707744e5e3d0cfadc810b9cddbc4 Mon Sep 17 00:00:00 2001
From: Daniel Bachler <daniel@danielbachler.de>
Date: Thu, 16 May 2024 19:05:09 +0200
Subject: [PATCH] =?UTF-8?q?=F0=9F=94=A8=20attempt=20naive=20rendering=20of?=
 =?UTF-8?q?=20csv=20file=20in=20CF=20function?=
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---
 functions/_common/grapherRenderer.ts | 67 ++++++++++++++++++++++------
 functions/grapher/csv/[slug].ts      | 51 +++++++++++++++++++++
 2 files changed, 104 insertions(+), 14 deletions(-)
 create mode 100644 functions/grapher/csv/[slug].ts

diff --git a/functions/_common/grapherRenderer.ts b/functions/_common/grapherRenderer.ts
index 34fc801c20b..e9d782e7d95 100644
--- a/functions/_common/grapherRenderer.ts
+++ b/functions/_common/grapherRenderer.ts
@@ -12,6 +12,7 @@ import LatoMedium from "../_common/fonts/LatoLatin-Medium.ttf.bin"
 import LatoBold from "../_common/fonts/LatoLatin-Bold.ttf.bin"
 import PlayfairSemiBold from "../_common/fonts/PlayfairDisplayLatin-SemiBold.ttf.bin"
 import { Env } from "../grapher/thumbnail/[slug].js"
+import { OwidTable } from "@ourworldindata/core-table"
 
 declare global {
     // eslint-disable-next-line no-var
@@ -126,19 +127,20 @@ const extractOptions = (params: URLSearchParams): ImageOptions => {
     return options as ImageOptions
 }
 
-async function fetchAndRenderGrapherToSvg({
-    slug,
-    options,
-    searchParams,
-    env,
-}: {
-    slug: string
-    options: ImageOptions
-    searchParams: URLSearchParams
-    env: Env
-}) {
-    const grapherLogger = new TimeLogger("grapher")
-
+async function initGrapher(
+    {
+        slug,
+        options,
+        searchParams,
+        env,
+    }: {
+        slug: string
+        options: ImageOptions
+        searchParams: URLSearchParams
+        env: Env
+    },
+    grapherLogger: TimeLogger
+) {
     // Fetch grapher config and extract it from the HTML
     const grapherConfig: GrapherInterface = await env.ASSETS.fetch(
         new URL(`/grapher/${slug}`, env.url)
@@ -165,9 +167,46 @@ async function fetchAndRenderGrapherToSvg({
     grapher.shouldIncludeDetailsInStaticExport = options.details
 
     grapherLogger.log("grapherInit")
+    return grapher
+}
+
+export async function fetchCsvForGrapher(slug: string, env: Env) {
+    const grapherLogger = new TimeLogger("grapher")
+    const grapher = await initGrapher(
+        {
+            slug,
+            options: TWITTER_OPTIONS,
+            searchParams: new URLSearchParams(""),
+            env,
+        },
+        grapherLogger
+    )
+    await grapher.downloadLegacyDataFromOwidVariableIds()
+    return new Response(grapher.inputTable.toPrettyCsv(), {
+        headers: {
+            "Content-Type": "text/csv",
+        },
+    })
+}
+
+async function fetchAndRenderGrapherToSvg({
+    slug,
+    options,
+    searchParams,
+    env,
+}: {
+    slug: string
+    options: ImageOptions
+    searchParams: URLSearchParams
+    env: Env
+}) {
+    const grapherLogger = new TimeLogger("grapher")
+    const grapher = await initGrapher(
+        { slug, options, searchParams, env },
+        grapherLogger
+    )
     const promises = []
     promises.push(grapher.downloadLegacyDataFromOwidVariableIds())
-
     if (options.details && grapher.detailsOrderedByReference.length) {
         promises.push(
             await fetch("https://ourworldindata.org/dods.json")
diff --git a/functions/grapher/csv/[slug].ts b/functions/grapher/csv/[slug].ts
new file mode 100644
index 00000000000..1424919b644
--- /dev/null
+++ b/functions/grapher/csv/[slug].ts
@@ -0,0 +1,51 @@
+import { fetchCsvForGrapher } from "../../_common/grapherRenderer.js"
+import { IRequestStrict, Router, error } from "itty-router"
+
+export interface Env {
+    ASSETS: {
+        fetch: typeof fetch
+    }
+    url: URL
+}
+
+const router = Router<IRequestStrict, [URL, Env, ExecutionContext]>()
+router
+    .get(
+        "/grapher/csv/:slug",
+        async ({ params: { slug } }, { searchParams: _ }, env) =>
+            fetchCsvForGrapher(slug, env)
+    )
+    .all("*", () => error(404, "Route not defined"))
+
+export const onRequestGet: PagesFunction = async (ctx) => {
+    const { request, env } = ctx
+
+    const url = new URL(request.url)
+    const shouldCache = !url.searchParams.has("nocache")
+
+    const cache = caches.default
+    if (shouldCache) {
+        const maybeCached = await cache.match(request)
+        if (maybeCached) return maybeCached
+    }
+
+    console.log("Handling", request.url, request.headers.get("User-Agent"))
+
+    return router
+        .handle(request, url, { ...env, url }, ctx)
+        .then((resp: Response) => {
+            if (shouldCache) {
+                resp.headers.set(
+                    "Cache-Control",
+                    "public, s-maxage=3600, max-age=3600"
+                )
+                ctx.waitUntil(caches.default.put(request, resp.clone()))
+            } else
+                resp.headers.set(
+                    "Cache-Control",
+                    "public, s-maxage=0, max-age=0, must-revalidate"
+                )
+            return resp
+        })
+        .catch((e) => error(500, e))
+}