feat: ComposedAttachmentAdapter (#781)

packages/react/src/runtimes/attachment/ComposedAttachmentAdapter.ts

@@ -0,0 +1,98 @@
+import {
+  ComposerAttachment,
+  MessageAttachment,
+} from "../../context/stores/Attachment";
+import { AttachmentAdapter } from "./AttachmentAdapter";
+
+function fileMatchesAccept(file: File, acceptString: string) {
+  // Check if the accept string is "*", which allows any file
+  if (acceptString === "*") {
+    return true;
+  }
+
+  // Split the accept string into an array of allowed types
+  const allowedTypes = acceptString
+    .split(",")
+    .map((type) => type.trim().toLowerCase());
+
+  // Get the file's extension and MIME type
+  const fileExtension = "." + file.name.split(".").pop()!.toLowerCase();
+  const fileMimeType = file.type.toLowerCase();
+
+  for (const type of allowedTypes) {
+    // Check for file extension match
+    if (type.startsWith(".") && type === fileExtension) {
+      return true;
+    }
+
+    // Check for exact MIME type match
+    if (type.includes("/") && type === fileMimeType) {
+      return true;
+    }
+
+    if (type === "image/*" || type === "video/*" || type === "audio/*") {
+      // Check for wildcard MIME type match
+      if (type.endsWith("/*")) {
+        const generalType = type.split("/")[0]!;
+        if (fileMimeType.startsWith(generalType + "/")) {
+          return true;
+        }
+      }
+    }
+  }
+
+  return false;
+}
+
+export class ComposedAttachmentAdapter implements AttachmentAdapter {
+  private _adapters: AttachmentAdapter[];
+
+  public accept: string;
+
+  constructor(adapters: AttachmentAdapter[]) {
+    this._adapters = adapters;
+
+    const wildcardIdx = adapters.findIndex((a) => a.accept === "*");
+    if (wildcardIdx !== -1) {
+      if (wildcardIdx !== adapters.length - 1)
+        throw new Error(
+          "A wildcard adapter (handling all files) can only be specified as the last adapter.",
+        );
+
+      this.accept = "*";
+    } else {
+      this.accept = adapters.map((a) => a.accept).join(",");
+    }
+  }
+
+  public async add(state: { file: File }): Promise<ComposerAttachment> {
+    for (const adapter of this._adapters) {
+      if (fileMatchesAccept(state.file, adapter.accept)) {
+        return adapter.add(state);
+      }
+    }
+    throw new Error("No matching adapter found for file");
+  }
+
+  public async send(
+    attachment: ComposerAttachment,
+  ): Promise<MessageAttachment> {
+    const adapters = this._adapters.slice();
+    for (const adapter of adapters) {
+      if (fileMatchesAccept(attachment.file, adapter.accept)) {
+        return adapter.send(attachment);
+      }
+    }
+    throw new Error("No matching adapter found for attachment");
+  }
+
+  public async remove(attachment: ComposerAttachment): Promise<void> {
+    const adapters = this._adapters.slice();
+    for (const adapter of adapters) {
+      if (fileMatchesAccept(attachment.file, adapter.accept)) {
+        return adapter.remove(attachment);
+      }
+    }
+    throw new Error("No matching adapter found for attachment");
+  }
+}