adaptation related to meta-core api changes

packages/meta-fuse-core/src/kv/MetaCoreApiClient.ts

@@ -0,0 +1,121 @@
+/**
+ * MetaCoreApiClient — HTTP read client against meta-core for meta-fuse.
+ *
+ * meta-fuse needs to read file metadata (property GETs, full-record fetch,
+ * hashId enumeration) as it builds the VFS. After the api-mediated-access
+ * lockdown lands these go through meta-core's /meta/{hash} family instead
+ * of direct Redis reads.
+ *
+ * Only the methods meta-fuse actually calls are implemented. See
+ * meta-core docs/api-mediated-access.md for the full surface.
+ */
+
+export interface MetaCoreApiClientConfig {
+    apiUrl: string;
+    timeoutMs?: number;
+}
+
+export class MetaCoreApiClient {
+    private apiUrl: string;
+    private timeoutMs: number;
+
+    constructor(config: MetaCoreApiClientConfig) {
+        this.apiUrl = config.apiUrl.replace(/\/+$/, '');
+        this.timeoutMs = config.timeoutMs ?? 30000;
+    }
+
+    /**
+     * GET /meta/{hash}/{prop}. Returns the raw string value or null on 404.
+     * meta-core sends text/plain for property reads.
+     */
+    async getProperty(hashId: string, property: string): Promise<string | null> {
+        const path = `/meta/${encodeURIComponent(hashId)}/${this.encodePropertyPath(property)}`;
+        const url = `${this.apiUrl}${path}`;
+        const response = await fetch(url, {
+            method: 'GET',
+            signal: AbortSignal.timeout(this.timeoutMs),
+            headers: { Accept: 'text/plain' },
+        });
+        if (response.status === 404) return null;
+        if (!response.ok) {
+            throw new Error(`[MetaCoreApiClient] GET ${path} → ${response.status} ${response.statusText}`);
+        }
+        const text = await response.text();
+        return text === '' ? null : text;
+    }
+
+    /**
+     * GET /meta/{hash}. Returns the flat property map or null on 404.
+     */
+    async getMetadataFlat(hashId: string): Promise<Record<string, string> | null> {
+        const path = `/meta/${encodeURIComponent(hashId)}`;
+        const body = await this.fetchJsonAllowing404('GET', path);
+        if (body === null) return null;
+        const flat = (body as any)?.metadata;
+        if (!flat || typeof flat !== 'object') return null;
+        return flat as Record<string, string>;
+    }
+
+    /**
+     * GET /meta. Enumerates every known hashId.
+     */
+    async getAllHashIds(): Promise<string[]> {
+        const body = await this.fetchJson('GET', '/meta');
+        const ids = (body as any)?.hashIds;
+        return Array.isArray(ids) ? ids : [];
+    }
+
+    /**
+     * GET /health on meta-core. Used as the connectivity probe.
+     */
+    async health(): Promise<boolean> {
+        try {
+            const response = await fetch(`${this.apiUrl}/health`, {
+                method: 'GET',
+                signal: AbortSignal.timeout(Math.min(this.timeoutMs, 5000)),
+                headers: { Accept: 'application/json' },
+            });
+            return response.ok;
+        } catch {
+            return false;
+        }
+    }
+
+    private encodePropertyPath(property: string): string {
+        return property
+            .split('/')
+            .map(segment => encodeURIComponent(segment))
+            .join('/');
+    }
+
+    private async fetchJson(method: string, path: string): Promise<unknown> {
+        const url = `${this.apiUrl}${path}`;
+        const response = await fetch(url, {
+            method,
+            signal: AbortSignal.timeout(this.timeoutMs),
+            headers: { Accept: 'application/json' },
+        });
+        if (!response.ok) {
+            throw new Error(`[MetaCoreApiClient] ${method} ${path} → ${response.status} ${response.statusText}`);
+        }
+        const text = await response.text();
+        if (!text) return null;
+        try { return JSON.parse(text); } catch { return text; }
+    }
+
+    private async fetchJsonAllowing404(method: string, path: string): Promise<unknown> {
+        const url = `${this.apiUrl}${path}`;
+        const response = await fetch(url, {
+            method,
+            signal: AbortSignal.timeout(this.timeoutMs),
+            headers: { Accept: 'application/json' },
+        });
+        if (response.status === 404) return null;
+        if (!response.ok) {
+            throw new Error(`[MetaCoreApiClient] ${method} ${path} → ${response.status} ${response.statusText}`);
+        }
+        const text = await response.text();
+        if (!text) return null;
+        try { return JSON.parse(text); } catch { return text; }
+    }
+}