From 91dfef52ea774ed4309b8ab3864e6b5e50055e76 Mon Sep 17 00:00:00 2001
From: Felix Roos <flix91@gmail.com>
Date: Sun, 29 May 2022 21:06:07 +0200
Subject: [PATCH] basic sample loader from github

---
 packages/webdirt/index.mjs   |  1 +
 packages/webdirt/sampler.mjs | 65 ++++++++++++++++++++++++++++++++++++
 packages/webdirt/webdirt.mjs | 19 +++++++++--
 3 files changed, 83 insertions(+), 2 deletions(-)
 create mode 100644 packages/webdirt/sampler.mjs

diff --git a/packages/webdirt/index.mjs b/packages/webdirt/index.mjs
index edafebd8..46a6887f 100644
--- a/packages/webdirt/index.mjs
+++ b/packages/webdirt/index.mjs
@@ -1 +1,2 @@
 export * from './webdirt.mjs';
+export * from './sampler.mjs';
diff --git a/packages/webdirt/sampler.mjs b/packages/webdirt/sampler.mjs
new file mode 100644
index 00000000..7a6e38b1
--- /dev/null
+++ b/packages/webdirt/sampler.mjs
@@ -0,0 +1,65 @@
+const bufferCache = {}; // string: Promise<ArrayBuffer>
+
+export const loadBuffer = (url, ac) => {
+  if (!bufferCache[url]) {
+    bufferCache[url] = fetch(url)
+      .then((res) => res.arrayBuffer())
+      .then((res) => ac.decodeAudioData(res));
+  }
+  return bufferCache[url];
+};
+
+/* export const playBuffer = (buffer, time = ac.currentTime, destination = ac.destination) => {
+  const src = ac.createBufferSource();
+  src.buffer = buffer;
+  src.connect(destination);
+  src.start(time);
+};
+
+export const playSample = async (url) => playBuffer(await loadBuffer(url)); */
+
+// https://estuary.mcmaster.ca/samples/resources.json
+// Array<{ "url":string, "bank": string, "n": number}>
+// ritchse/tidal-drum-machines/tree/main/machines/AkaiLinn
+const githubCache = {};
+let loaded;
+export const loadGithubSamples = async (path, nameFn) => {
+  if (githubCache[path]) {
+    return githubCache[path];
+  }
+  try {
+    console.log('load github path', path);
+    const [user, repo, ...folders] = path.split('/');
+    const baseUrl = `https://api.github.com/repos/${user}/${repo}/contents`;
+    const banks = await fetch(`${baseUrl}/${folders.join('/')}`).then((res) => res.json());
+    // fetch each subfolder
+    githubCache[path] = (
+      await Promise.all(
+        banks.map(async ({ name, path }) => ({
+          name,
+          content: await fetch(`${baseUrl}/${path}`)
+            .then((res) => res.json())
+            .catch((err) => {
+              console.error('could not load path', err);
+            }),
+        })),
+      )
+    )
+      .filter(({ content }) => !!content)
+      .reduce(
+        (acc, { name, content }) => ({
+          ...acc,
+          [nameFn?.(name) || name]: content.map(({ download_url }) => download_url),
+        }),
+        {},
+      );
+  } catch (err) {
+    console.error('failed to fetch github samples', err);
+    return;
+  }
+  loaded = githubCache[path];
+  console.log('loaded github path ', path);
+  return githubCache[path];
+};
+
+export const getLoadedSamples = () => loaded;
diff --git a/packages/webdirt/webdirt.mjs b/packages/webdirt/webdirt.mjs
index ea4eaa1f..0e6e63b0 100644
--- a/packages/webdirt/webdirt.mjs
+++ b/packages/webdirt/webdirt.mjs
@@ -1,6 +1,7 @@
 import * as strudel from '@strudel.cycles/core';
 const { Pattern } = strudel;
 import * as WebDirt from 'WebDirt';
+import { getLoadedSamples, loadBuffer } from './sampler.mjs';
 
 let webDirt;
 
@@ -62,7 +63,7 @@ export function loadWebDirt(config) {
 Pattern.prototype.webdirt = function () {
   // create a WebDirt object and initialize Web Audio context
   return this._withHap((hap) => {
-    const onTrigger = (time, e, currentTime) => {
+    const onTrigger = async (time, e, currentTime) => {
       if (!webDirt) {
         throw new Error('WebDirt not initialized!');
       }
@@ -71,7 +72,21 @@ Pattern.prototype.webdirt = function () {
       if (!s) {
         console.warn('webdirt: no "s" was set!');
       }
-      webDirt.playSample({ s, n, ...rest }, deadline);
+      const samples = getLoadedSamples();
+      if (!samples?.[s]) {
+        // try default samples
+        webDirt.playSample({ s, n, ...rest }, deadline);
+        return;
+      }
+      if (!samples?.[s]) {
+        console.warn(`webdirt: sample "${s}" not found in loaded samples`, samples);
+      } else {
+        const bank = samples[s];
+        const sampleUrl = bank[n % bank.length];
+        const buffer = await loadBuffer(sampleUrl, webDirt.ac);
+        const msg = { buffer: { buffer }, ...rest };
+        webDirt.playSample(msg, deadline);
+      }
     };
     return hap.setContext({ ...hap.context, onTrigger });
   });