feat(workbench): add file tree and hook up editor

packages/bolt/app/lib/stores/editor.ts

@@ -0,0 +1,96 @@
+import type { WebContainer } from '@webcontainer/api';
+import { atom, computed, map } from 'nanostores';
+import type { EditorDocument, ScrollPosition } from '../../components/editor/codemirror/CodeMirrorEditor';
+import type { FileMap } from './files';
+
+export type EditorDocuments = Record<string, EditorDocument>;
+
+export class EditorStore {
+  #webcontainer: Promise<WebContainer>;
+
+  selectedFile = atom<string | undefined>();
+  documents = map<EditorDocuments>({});
+
+  currentDocument = computed([this.documents, this.selectedFile], (documents, selectedFile) => {
+    if (!selectedFile) {
+      return undefined;
+    }
+
+    return documents[selectedFile];
+  });
+
+  constructor(webcontainerPromise: Promise<WebContainer>) {
+    this.#webcontainer = webcontainerPromise;
+  }
+
+  commitFileContent(_filePath: string) {
+    // TODO
+  }
+
+  setDocuments(files: FileMap) {
+    const previousDocuments = this.documents.value;
+
+    this.documents.set(
+      Object.fromEntries<EditorDocument>(
+        Object.entries(files)
+          .map(([filePath, dirent]) => {
+            if (dirent === undefined || dirent.type === 'folder') {
+              return undefined;
+            }
+
+            return [
+              filePath,
+              {
+                value: dirent.content,
+                commitPending: false,
+                filePath,
+                scroll: previousDocuments?.[filePath]?.scroll,
+              },
+            ] as [string, EditorDocument];
+          })
+          .filter(Boolean) as Array<[string, EditorDocument]>,
+      ),
+    );
+  }
+
+  setSelectedFile(filePath: string | undefined) {
+    this.selectedFile.set(filePath);
+  }
+
+  updateScrollPosition(filePath: string, position: ScrollPosition) {
+    const documents = this.documents.get();
+    const documentState = documents[filePath];
+
+    if (!documentState) {
+      return;
+    }
+
+    this.documents.setKey(filePath, {
+      ...documentState,
+      scroll: position,
+    });
+  }
+
+  updateFile(filePath: string, content: string): boolean {
+    const documents = this.documents.get();
+    const documentState = documents[filePath];
+
+    if (!documentState) {
+      return false;
+    }
+
+    const currentContent = documentState.value;
+    const contentChanged = currentContent !== content;
+
+    if (contentChanged) {
+      this.documents.setKey(filePath, {
+        ...documentState,
+        previousValue: !documentState.commitPending ? currentContent : documentState.previousValue,
+        commitPending: documentState.previousValue ? documentState.previousValue !== content : true,
+        value: content,
+      });
+    }
+
+    return contentChanged;
+  }
+}