feat(upstream): Add upstream proxy/cache subsystem and integrate per-protocol upstreams

ts/pypi/classes.pypiupstream.ts

@@ -0,0 +1,211 @@
+import * as plugins from '../plugins.js';
+import { BaseUpstream } from '../upstream/classes.baseupstream.js';
+import type {
+  IProtocolUpstreamConfig,
+  IUpstreamFetchContext,
+  IUpstreamRegistryConfig,
+} from '../upstream/interfaces.upstream.js';
+
+/**
+ * PyPI-specific upstream implementation.
+ *
+ * Handles:
+ * - Simple API (HTML) - PEP 503
+ * - JSON API - PEP 691
+ * - Package file downloads (wheels, sdists)
+ * - Package name normalization
+ */
+export class PypiUpstream extends BaseUpstream {
+  protected readonly protocolName = 'pypi';
+
+  /** Local registry URL for rewriting download URLs */
+  private readonly localRegistryUrl: string;
+
+  constructor(
+    config: IProtocolUpstreamConfig,
+    localRegistryUrl: string,
+    logger?: plugins.smartlog.Smartlog,
+  ) {
+    super(config, logger);
+    this.localRegistryUrl = localRegistryUrl;
+  }
+
+  /**
+   * Fetch Simple API index (list of all packages) in HTML format.
+   */
+  public async fetchSimpleIndex(): Promise<string | null> {
+    const context: IUpstreamFetchContext = {
+      protocol: 'pypi',
+      resource: '*',
+      resourceType: 'index',
+      path: '/simple/',
+      method: 'GET',
+      headers: {
+        'accept': 'text/html',
+      },
+      query: {},
+    };
+
+    const result = await this.fetch(context);
+
+    if (!result || !result.success) {
+      return null;
+    }
+
+    if (Buffer.isBuffer(result.body)) {
+      return result.body.toString('utf8');
+    }
+
+    return typeof result.body === 'string' ? result.body : null;
+  }
+
+  /**
+   * Fetch Simple API package page (list of files) in HTML format.
+   */
+  public async fetchSimplePackage(packageName: string): Promise<string | null> {
+    const normalizedName = this.normalizePackageName(packageName);
+    const path = `/simple/${normalizedName}/`;
+
+    const context: IUpstreamFetchContext = {
+      protocol: 'pypi',
+      resource: packageName,
+      resourceType: 'simple',
+      path,
+      method: 'GET',
+      headers: {
+        'accept': 'text/html',
+      },
+      query: {},
+    };
+
+    const result = await this.fetch(context);
+
+    if (!result || !result.success) {
+      return null;
+    }
+
+    if (Buffer.isBuffer(result.body)) {
+      return result.body.toString('utf8');
+    }
+
+    return typeof result.body === 'string' ? result.body : null;
+  }
+
+  /**
+   * Fetch package metadata using JSON API (PEP 691).
+   */
+  public async fetchPackageJson(packageName: string): Promise<any | null> {
+    const normalizedName = this.normalizePackageName(packageName);
+    const path = `/simple/${normalizedName}/`;
+
+    const context: IUpstreamFetchContext = {
+      protocol: 'pypi',
+      resource: packageName,
+      resourceType: 'metadata',
+      path,
+      method: 'GET',
+      headers: {
+        'accept': 'application/vnd.pypi.simple.v1+json',
+      },
+      query: {},
+    };
+
+    const result = await this.fetch(context);
+
+    if (!result || !result.success) {
+      return null;
+    }
+
+    if (Buffer.isBuffer(result.body)) {
+      return JSON.parse(result.body.toString('utf8'));
+    }
+
+    return result.body;
+  }
+
+  /**
+   * Fetch full package info from PyPI JSON API (/pypi/{package}/json).
+   */
+  public async fetchPypiJson(packageName: string): Promise<any | null> {
+    const normalizedName = this.normalizePackageName(packageName);
+    const path = `/pypi/${normalizedName}/json`;
+
+    const context: IUpstreamFetchContext = {
+      protocol: 'pypi',
+      resource: packageName,
+      resourceType: 'pypi-json',
+      path,
+      method: 'GET',
+      headers: {
+        'accept': 'application/json',
+      },
+      query: {},
+    };
+
+    const result = await this.fetch(context);
+
+    if (!result || !result.success) {
+      return null;
+    }
+
+    if (Buffer.isBuffer(result.body)) {
+      return JSON.parse(result.body.toString('utf8'));
+    }
+
+    return result.body;
+  }
+
+  /**
+   * Fetch a package file (wheel or sdist) from upstream.
+   */
+  public async fetchPackageFile(packageName: string, filename: string): Promise<Buffer | null> {
+    const normalizedName = this.normalizePackageName(packageName);
+    const path = `/packages/${normalizedName}/${filename}`;
+
+    const context: IUpstreamFetchContext = {
+      protocol: 'pypi',
+      resource: packageName,
+      resourceType: 'package',
+      path,
+      method: 'GET',
+      headers: {
+        'accept': 'application/octet-stream',
+      },
+      query: {},
+    };
+
+    const result = await this.fetch(context);
+
+    if (!result || !result.success) {
+      return null;
+    }
+
+    return Buffer.isBuffer(result.body) ? result.body : Buffer.from(result.body);
+  }
+
+  /**
+   * Normalize a PyPI package name according to PEP 503.
+   * - Lowercase all characters
+   * - Replace runs of ., -, _ with single -
+   */
+  private normalizePackageName(name: string): string {
+    return name.toLowerCase().replace(/[-_.]+/g, '-');
+  }
+
+  /**
+   * Override URL building for PyPI-specific handling.
+   */
+  protected buildUpstreamUrl(
+    upstream: IUpstreamRegistryConfig,
+    context: IUpstreamFetchContext,
+  ): string {
+    let baseUrl = upstream.url;
+
+    // Remove trailing slash
+    if (baseUrl.endsWith('/')) {
+      baseUrl = baseUrl.slice(0, -1);
+    }
+
+    return `${baseUrl}${context.path}`;
+  }
+}