Adds CSS completions to VSCode extension (#214)

* Start on css completion

* Support for CSS completions

1 files changed, 95 insertions, 0 deletions

diff --git a/tools/astro-languageserver/src/plugins/css/CSSDocument.ts b/tools/astro-languageserver/src/plugins/css/CSSDocument.ts
new file mode 100644
index 000000000..90b28352c
--- /dev/null
+++ b/tools/astro-languageserver/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';
+    }
+}