1 files changed, 95 insertions, 0 deletions
diff --git a/tools/language-server/src/plugins/css/CSSDocument.ts b/tools/language-server/src/plugins/css/CSSDocument.ts
new file mode 100644
index 000000000..9f1839678
--- /dev/null
+++ b/tools/language-server/src/plugins/css/CSSDocument.ts
@@ -0,0 +1,95 @@
+import { Stylesheet, TextDocument } from 'vscode-css-languageservice';
+import { Position } from 'vscode-languageserver';
+import { getLanguageService } from './service';
+import { Document, DocumentMapper, ReadableDocument, TagInformation } from '../../core/documents/index';
+
+export interface CSSDocumentBase extends DocumentMapper, TextDocument {
+  languageId: string;
+  stylesheet: Stylesheet;
+}
+
+export class CSSDocument extends ReadableDocument implements DocumentMapper {
+  private styleInfo: Pick<TagInformation, 'attributes' | 'start' | 'end'>;
+  readonly version = this.parent.version;
+
+  public stylesheet: Stylesheet;
+  public languageId: string;
+
+  constructor(private parent: Document) {
+    super();
+
+    if (this.parent.styleInfo) {
+      this.styleInfo = this.parent.styleInfo;
+    } else {
+      this.styleInfo = {
+        attributes: {},
+        start: -1,
+        end: -1,
+      };
+    }
+
+    this.languageId = this.language;
+    this.stylesheet = getLanguageService(this.language).parseStylesheet(this);
+  }
+
+  /**
+   * Get the fragment position relative to the parent
+   * @param pos Position in fragment
+   */
+  getOriginalPosition(pos: Position): Position {
+    const parentOffset = this.styleInfo.start + this.offsetAt(pos);
+    return this.parent.positionAt(parentOffset);
+  }
+
+  /**
+   * Get the position relative to the start of the fragment
+   * @param pos Position in parent
+   */
+  getGeneratedPosition(pos: Position): Position {
+    const fragmentOffset = this.parent.offsetAt(pos) - this.styleInfo.start;
+    return this.positionAt(fragmentOffset);
+  }
+
+  /**
+   * Returns true if the given parent position is inside of this fragment
+   * @param pos Position in parent
+   */
+  isInGenerated(pos: Position): boolean {
+    const offset = this.parent.offsetAt(pos);
+    return offset >= this.styleInfo.start && offset <= this.styleInfo.end;
+  }
+
+  /**
+   * Get the fragment text from the parent
+   */
+  getText(): string {
+    return this.parent.getText().slice(this.styleInfo.start, this.styleInfo.end);
+  }
+
+  /**
+   * Returns the length of the fragment as calculated from the start and end positon
+   */
+  getTextLength(): number {
+    return this.styleInfo.end - this.styleInfo.start;
+  }
+
+  /**
+   * Return the parent file path
+   */
+  getFilePath(): string | null {
+    return this.parent.getFilePath();
+  }
+
+  getURL() {
+    return this.parent.getURL();
+  }
+
+  getAttributes() {
+    return this.styleInfo.attributes;
+  }
+
+  private get language() {
+    const attrs = this.getAttributes();
+    return attrs.lang || attrs.type || 'css';
+  }
+}