Telemetry and Utilities ❌ Internal API

/**
 * Implementation of telemetry context for collecting and serializing telemetry data
 */
class TelemetryContext implements ITelemetryContext, ITelemetryContextExt {
  /**
   * Set a telemetry property with a given prefix and property name
   * @param prefix - The prefix to organize related properties
   * @param property - The property name
   * @param value - The value to set (various telemetry-compatible types)
   */
  set(prefix: string, property: string, value: TelemetryEventPropertyTypeExt): void;
  
  /**
   * Set multiple telemetry properties at once with a given prefix
   * @param prefix - The prefix to organize related properties
   * @param property - The base property name
   * @param values - Record of property names to values
   */
  setMultiple(
    prefix: string,
    property: string,
    values: Record<string, TelemetryEventPropertyTypeExt>
  ): void;
  
  /**
   * Get a telemetry property value
   * @param prefix - The prefix of the property
   * @param property - The property name
   * @returns The stored value or undefined if not found
   */
  get(prefix: string, property: string): TelemetryEventPropertyTypeExt;
  
  /**
   * Serialize all telemetry data to a string format
   * @returns Serialized representation of all telemetry data
   */
  serialize(): string;
}

/**
 * Accepted header keys for requests coming to the runtime
 */
enum RuntimeHeaders {
  /** True to wait for a data store to be created and loaded before returning it */
  wait = "wait",
  
  /** True if the request is coming from an IFluidHandle */
  viaHandle = "viaHandle",
  
  /** True if the request is coming from a handle with a pending payload */
  payloadPending = "payloadPending"
}

/**
 * Encode compact ID to a compact string representation. Strings are returned as is, numbers are encoded
 * @param idArg - Input - either a non-negative integer or a string
 * @param prefix - Optional string prefix to add to the encoded result
 * @returns String representation of the input
 */
function encodeCompactIdToString(idArg: number | string, prefix?: string): string;

/**
 * Character set for encoding IDs. Must never be changed to avoid collisions with existing ids.
 */
const charSetForEncodingIds: "ABCDEFGHIJKLMNOPQRSTUVWXYZ(abcdefghijklmnopqrstuvwxyz)0123456789";

/**
 * Function to read blob contents from storage and parse the result from JSON
 */
type ReadAndParseBlob = <T>(id: string) => Promise<T>;

/**
 * Fetches the sequence number of the snapshot tree by examining the protocol
 * @param tree - Snapshot tree to examine
 * @param readAndParseBlob - Function to read blob contents from storage and parse the result from JSON
 * @returns Promise resolving to the sequence number
 */
function seqFromTree(
  tree: ISnapshotTree,
  readAndParseBlob: ReadAndParseBlob
): Promise<number>;

/**
 * Casts the public API for delta manager into the internal one, exposing access to APIs needed by the implementation
 * @param deltaManager - The public delta manager interface
 * @returns Internal delta manager interface with additional methods
 */
function toDeltaManagerInternal(
  deltaManager: IDeltaManagerErased
): IDeltaManager<ISequencedDocumentMessage, IDocumentMessage>;

/**
 * Casts the internal API for delta manager into the public type erased API for returning from public APIs
 * @param deltaManager - The internal delta manager interface
 * @returns Public type-erased delta manager interface
 */
function toDeltaManagerErased(
  deltaManager: IDeltaManager<ISequencedDocumentMessage, IDocumentMessage>
): IDeltaManagerErased;

// ❌ These imports will NOT work - APIs are internal
// import { 
//   TelemetryContext,
//   RuntimeHeaders,
//   encodeCompactIdToString,
//   seqFromTree,
//   toDeltaManagerInternal,
//   toDeltaManagerErased
// } from "@fluidframework/runtime-utils";

// Telemetry context usage
const telemetryContext = new TelemetryContext();

// Set individual properties
telemetryContext.set("performance", "loadTime", 1250);
telemetryContext.set("performance", "renderTime", 340);
telemetryContext.set("user", "id", "user123");

// Set multiple properties at once
telemetryContext.setMultiple("errors", "count", {
  "validation": 2,
  "network": 1,
  "timeout": 0
});

// Retrieve properties
const loadTime = telemetryContext.get("performance", "loadTime");
console.log("Load time:", loadTime);

// Serialize for logging/transmission
const serializedData = telemetryContext.serialize();
console.log("Telemetry data:", serializedData);

// Runtime headers usage
const request: IRequest = {
  url: "/datastore/component",
  headers: {
    [RuntimeHeaders.wait]: true,
    [RuntimeHeaders.viaHandle]: false,
    [RuntimeHeaders.payloadPending]: false
  }
};

// Check for specific headers
if (request.headers?.[RuntimeHeaders.wait]) {
  console.log("Client wants to wait for data store creation");
}

// ID encoding for compact storage
const numericId = 12345;
const encodedId = encodeCompactIdToString(numericId, "msg");
console.log("Encoded ID:", encodedId); // e.g., "msgABC123"

const stringId = "my-component";
const encodedStringId = encodeCompactIdToString(stringId, "comp");
console.log("String ID:", encodedStringId); // "compmy-component"

// Snapshot sequence number extraction
async function getSnapshotSequenceNumber(
  snapshotTree: ISnapshotTree,
  storage: IChannelStorageService
): Promise<number> {
  const readAndParseBlob = async <T>(id: string): Promise<T> => {
    const blob = await storage.readBlob(id);
    const text = new TextDecoder().decode(blob);
    return JSON.parse(text) as T;
  };
  
  return seqFromTree(snapshotTree, readAndParseBlob);
}

// Delta manager type casting
function setupDeltaManagerAccess(publicDeltaManager: IDeltaManagerErased) {
  // Cast to internal interface to access additional methods
  const internalDeltaManager = toDeltaManagerInternal(publicDeltaManager);
  
  // Use internal methods for framework operations
  internalDeltaManager.submitMessage(/* ... */);
  internalDeltaManager.flush();
  
  // Cast back to public interface when returning from APIs
  const publicInterface = toDeltaManagerErased(internalDeltaManager);
  return publicInterface;
}

// Hierarchical telemetry management
class ComponentTelemetryManager {
  private context = new TelemetryContext();
  private componentId: string;
  
  constructor(componentId: string) {
    this.componentId = componentId;
    this.context.set("component", "id", componentId);
    this.context.set("component", "startTime", Date.now());
  }
  
  // Track performance metrics
  trackPerformance(operation: string, duration: number): void {
    this.context.set("performance", operation, duration);
  }
  
  // Track errors with categorization
  trackError(category: string, error: Error): void {
    this.context.set("errors", `${category}_count`, 
      (this.context.get("errors", `${category}_count`) as number || 0) + 1
    );
    this.context.set("errors", `${category}_latest`, error.message);
  }
  
  // Track usage statistics
  trackUsage(feature: string, count: number = 1): void {
    const currentCount = this.context.get("usage", feature) as number || 0;
    this.context.set("usage", feature, currentCount + count);
  }
  
  // Get telemetry snapshot
  getSnapshot(): string {
    this.context.set("component", "snapshotTime", Date.now());
    return this.context.serialize();
  }
}

// Request header utilities
class RequestHeaderUtil {
  static createDataStoreRequest(
    path: string,
    options: {
      waitForCreation?: boolean;
      fromHandle?: boolean;
      payloadPending?: boolean;
    } = {}
  ): IRequest {
    const headers: Record<string, any> = {};
    
    if (options.waitForCreation) {
      headers[RuntimeHeaders.wait] = true;
    }
    
    if (options.fromHandle) {
      headers[RuntimeHeaders.viaHandle] = true;
    }
    
    if (options.payloadPending) {
      headers[RuntimeHeaders.payloadPending] = true;
    }
    
    return { url: path, headers };
  }
  
  static isWaitRequest(request: IRequest): boolean {
    return request.headers?.[RuntimeHeaders.wait] === true;
  }
  
  static isViaHandle(request: IRequest): boolean {
    return request.headers?.[RuntimeHeaders.viaHandle] === true;
  }
  
  static hasPayloadPending(request: IRequest): boolean {
    return request.headers?.[RuntimeHeaders.payloadPending] === true;
  }
}

// ID management system
class CompactIdManager {
  private idCounter = 0;
  private stringToId = new Map<string, number>();
  private idToString = new Map<number, string>();
  
  // Get or create a compact ID for a string
  getCompactId(identifier: string, prefix?: string): string {
    if (!this.stringToId.has(identifier)) {
      const numericId = this.idCounter++;
      this.stringToId.set(identifier, numericId);
      this.idToString.set(numericId, identifier);
    }
    
    const numericId = this.stringToId.get(identifier)!;
    return encodeCompactIdToString(numericId, prefix);
  }
  
  // Decode a compact ID back to original string
  decodeCompactId(compactId: string, prefix?: string): string | undefined {
    if (prefix && !compactId.startsWith(prefix)) {
      return undefined;
    }
    
    const idPart = prefix ? compactId.slice(prefix.length) : compactId;
    
    // This would require a decode function (not provided in the API)
    // but shows the pattern for managing compact IDs
    const numericId = this.decodeStringToNumber(idPart);
    return this.idToString.get(numericId);
  }
  
  private decodeStringToNumber(encoded: string): number {
    // Custom decoding logic would go here
    // This is a simplified example
    return parseInt(encoded, 36);
  }
}

// Snapshot analysis utilities
class SnapshotAnalyzer {
  constructor(
    private storage: IChannelStorageService
  ) {}
  
  async analyzeSnapshot(tree: ISnapshotTree): Promise<SnapshotAnalysis> {
    const readAndParseBlob = async <T>(id: string): Promise<T> => {
      const blob = await this.storage.readBlob(id);
      const text = new TextDecoder().decode(blob);
      return JSON.parse(text) as T;
    };
    
    const sequenceNumber = await seqFromTree(tree, readAndParseBlob);
    
    // Analyze tree structure
    const blobCount = this.countBlobs(tree);
    const treeDepth = this.calculateTreeDepth(tree);
    
    return {
      sequenceNumber,
      blobCount,
      treeDepth,
      timestamp: Date.now()
    };
  }
  
  private countBlobs(tree: ISnapshotTree, count = 0): number {
    for (const [_, value] of Object.entries(tree.trees ?? {})) {
      count = this.countBlobs(value, count);
    }
    return count + Object.keys(tree.blobs ?? {}).length;
  }
  
  private calculateTreeDepth(tree: ISnapshotTree, depth = 0): number {
    if (!tree.trees || Object.keys(tree.trees).length === 0) {
      return depth;
    }
    
    let maxChildDepth = depth;
    for (const childTree of Object.values(tree.trees)) {
      const childDepth = this.calculateTreeDepth(childTree, depth + 1);
      maxChildDepth = Math.max(maxChildDepth, childDepth);
    }
    
    return maxChildDepth;
  }
}

interface SnapshotAnalysis {
  sequenceNumber: number;
  blobCount: number;
  treeDepth: number;
  timestamp: number;
}