From d8c7d76847b77290f7dfef6e1b2f258fbe544b1f Mon Sep 17 00:00:00 2001
From: Rob Dominguez <rob.dominguez@hasura.io>
Date: Tue, 2 Apr 2024 10:06:01 -0500
Subject: [PATCH] Fix: Add ability to reference external themes

---
 src/config.ts |  4 +++-
 src/theme.ts  | 20 ++++++++++++++++++--
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/src/config.ts b/src/config.ts
index f29821d8..7f12dbcb 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -377,7 +377,9 @@ export class MarpCLIConfig {
         return {
           advice: { use: '--theme-set', insteadOf: '--theme' },
           name: this.args.theme,
-          path: path.resolve(this.args.theme),
+          path: this.args.theme.includes(`http`)
+            ? this.args.theme
+            : path.resolve(this.args.theme),
         }
 
       if (this.conf.theme)
diff --git a/src/theme.ts b/src/theme.ts
index c77c6410..ed1d190d 100644
--- a/src/theme.ts
+++ b/src/theme.ts
@@ -3,7 +3,7 @@ import fs from 'fs'
 import path from 'path'
 import { Marpit } from '@marp-team/marpit'
 import { isDynamicPattern } from 'globby'
-import { warn } from './cli'
+import { warn, info } from './cli'
 import { isError } from './error'
 import { File } from './file'
 
@@ -33,7 +33,23 @@ export class Theme {
   }
 
   async load() {
-    this.readBuffer = await fs.promises.readFile(this.filename)
+    if (this.isUrl(this.filename)) {
+      // Fetch the content from a remote URL
+      const response = await fetch(this.filename)
+      this.readBuffer = Buffer.from(await response.text())
+    } else {
+      // Read the content from a local file
+      this.readBuffer = await fs.promises.readFile(this.filename)
+    }
+  }
+
+  private isUrl(filename: string): boolean {
+    try {
+      new URL(filename)
+      return true
+    } catch {
+      return false
+    }
   }
 
   private genUniqName() {