Add vault context injection, frontmatter tool, vision idea

1 files changed, 168 insertions, 0 deletions

diff --git a/src/vault-context.ts b/src/vault-context.ts
new file mode 100644
index 0000000..80afa03
--- /dev/null
+++ b/src/vault-context.ts
@@ -0,0 +1,168 @@
+import type { App } from "obsidian";
+
+/**
+ * Collected vault context summary injected into the AI system prompt.
+ */
+export interface VaultContext {
+	vaultName: string;
+	totalNotes: number;
+	totalFolders: number;
+	folderTree: string;
+	tagTaxonomy: string;
+	recentFiles: string;
+}
+
+/**
+ * Build a folder tree string from the vault.
+ * Produces an indented tree like:
+ *   /
+ *   ├── folder-a/
+ *   │   ├── subfolder/
+ *   ├── folder-b/
+ */
+function buildFolderTree(app: App): string {
+	const folders = app.vault.getAllFolders(true);
+	// Build a map of parent → children folder names
+	const tree = new Map<string, string[]>();
+
+	for (const folder of folders) {
+		if (folder.isRoot()) continue;
+		const parentPath = folder.parent?.path ?? "/";
+		const key = parentPath === "/" || parentPath === "" ? "/" : parentPath;
+		if (!tree.has(key)) {
+			tree.set(key, []);
+		}
+		tree.get(key)!.push(folder.path);
+	}
+
+	const lines: string[] = [];
+
+	function walk(path: string, prefix: string): void {
+		const children = tree.get(path) ?? [];
+		children.sort();
+		for (let i = 0; i < children.length; i++) {
+			const child = children[i];
+			const isLast = i === children.length - 1;
+			const connector = isLast ? "└── " : "├── ";
+			const childPrefix = isLast ? "    " : "│   ";
+			// Show just the folder name, not the full path
+			const name = child.split("/").pop() ?? child;
+			lines.push(`${prefix}${connector}${name}/`);
+			walk(child, prefix + childPrefix);
+		}
+	}
+
+	lines.push("/");
+	walk("/", "");
+
+	return lines.join("\n");
+}
+
+/**
+ * Collect all tags in the vault with their usage counts.
+ * Returns a formatted string like: #tag1 (12), #tag2 (8), ...
+ */
+function buildTagTaxonomy(app: App): string {
+	const tagCounts = new Map<string, number>();
+	const files = app.vault.getMarkdownFiles();
+
+	for (const file of files) {
+		const cache = app.metadataCache.getFileCache(file);
+		if (cache === null) continue;
+
+		// Inline tags
+		if (cache.tags !== undefined) {
+			for (const tagEntry of cache.tags) {
+				const tag = tagEntry.tag.toLowerCase();
+				tagCounts.set(tag, (tagCounts.get(tag) ?? 0) + 1);
+			}
+		}
+
+		// Frontmatter tags
+		if (cache.frontmatter?.tags !== undefined) {
+			const fmTags = cache.frontmatter.tags;
+			if (Array.isArray(fmTags)) {
+				for (const raw of fmTags) {
+					const tag = typeof raw === "string"
+						? (raw.startsWith("#") ? raw.toLowerCase() : `#${raw.toLowerCase()}`)
+						: "";
+					if (tag !== "") {
+						tagCounts.set(tag, (tagCounts.get(tag) ?? 0) + 1);
+					}
+				}
+			}
+		}
+	}
+
+	if (tagCounts.size === 0) {
+		return "No tags in vault.";
+	}
+
+	// Sort by count descending
+	const sorted = [...tagCounts.entries()].sort((a, b) => b[1] - a[1]);
+
+	// Cap at 100 tags to avoid overwhelming context
+	const maxTags = 100;
+	const limited = sorted.slice(0, maxTags);
+	const lines = limited.map(([tag, count]) => `${tag} (${count})`);
+	const suffix = sorted.length > maxTags
+		? `\n...and ${sorted.length - maxTags} more tags.`
+		: "";
+
+	return lines.join(", ") + suffix;
+}
+
+/**
+ * Get the most recently modified files.
+ */
+function buildRecentFiles(app: App, maxFiles: number): string {
+	const files = app.vault.getMarkdownFiles();
+
+	// Sort by modification time descending
+	const sorted = [...files].sort((a, b) => b.stat.mtime - a.stat.mtime);
+	const limited = sorted.slice(0, maxFiles);
+
+	if (limited.length === 0) {
+		return "No notes in vault.";
+	}
+
+	return limited.map((f) => f.path).join("\n");
+}
+
+/**
+ * Collect the full vault context summary.
+ * This is cheap — all data comes from the metadata cache and vault indexes.
+ */
+export function collectVaultContext(app: App, maxRecentFiles: number): VaultContext {
+	const markdownFiles = app.vault.getMarkdownFiles();
+	const allFolders = app.vault.getAllFolders(false);
+
+	return {
+		vaultName: app.vault.getName(),
+		totalNotes: markdownFiles.length,
+		totalFolders: allFolders.length,
+		folderTree: buildFolderTree(app),
+		tagTaxonomy: buildTagTaxonomy(app),
+		recentFiles: buildRecentFiles(app, maxRecentFiles),
+	};
+}
+
+/**
+ * Format the vault context into a system prompt block.
+ */
+export function formatVaultContext(ctx: VaultContext): string {
+	return (
+		"VAULT CONTEXT (auto-injected summary of the user's Obsidian vault):\n\n" +
+		`Vault name: ${ctx.vaultName}\n` +
+		`Total notes: ${ctx.totalNotes}\n` +
+		`Total folders: ${ctx.totalFolders}\n\n` +
+		"Folder structure:\n" +
+		"```\n" +
+		ctx.folderTree + "\n" +
+		"```\n\n" +
+		"Tags in use:\n" +
+		ctx.tagTaxonomy + "\n\n" +
+		"Recently modified notes:\n" +
+		ctx.recentFiles
+	);
+}