Serialization & Data Processing

/**
 * Serialization context containing encoding/decoding utilities
 * Flows through serialization pipeline providing consistent data processing
 */
interface SerdeContext {
  /** Base64 encoder function */
  base64Encoder?: Encoder;
  /** Base64 decoder function */
  base64Decoder?: Decoder;
  /** UTF-8 encoder function */
  utf8Encoder?: Encoder;
  /** UTF-8 decoder function */
  utf8Decoder?: Decoder;
  /** Stream collection utility */
  streamCollector?: StreamCollector;
  /** Logger for serialization debugging */
  logger?: Logger;
  /** Disable validation of body checksums */
  disableBodyChecksumValidation?: boolean;
  /** SHA-256 hash constructor */
  sha256?: HashConstructor;
  /** MD5 hash constructor */
  md5?: HashConstructor;
}

/**
 * SDK stream serialization context with additional stream utilities
 * Extended context for handling streaming data in AWS services
 */
interface SdkStreamSerdeContext extends SerdeContext {
  /** SDK stream utility functions */
  sdkStreamMixin?: SdkStreamMixin;
  /** Request stream hash calculator */
  requestHash?: StreamHasher;
  /** Response stream hash validator */
  responseHash?: StreamHasher;
}

/**
 * Generic encoder interface for converting data to encoded format
 * Used for base64, UTF-8, and other encoding operations
 */
interface Encoder {
  /**
   * Encode input data to target format
   * @param input - Data to encode
   * @returns Encoded data as Uint8Array
   */
  encode(input: string): Uint8Array;
}

/**
 * Generic decoder interface for converting encoded data back to original format
 * Used for base64, UTF-8, and other decoding operations
 */
interface Decoder {
  /**
   * Decode input data from encoded format
   * @param input - Encoded data to decode
   * @returns Decoded data as string
   */
  decode(input: Uint8Array): string;
}

/**
 * Stream collector interface for gathering streaming data
 * Used to collect and buffer streaming responses
 */
interface StreamCollector {
  /**
   * Collect stream data into a single buffer
   * @param stream - Input stream to collect
   * @returns Promise resolving to collected data
   */
  collect(stream: any): Promise<Uint8Array>;
}

import { Encoder, Decoder, StreamCollector, SerdeContext } from "@aws-sdk/types";

// Example base64 encoder/decoder implementation
const base64Encoder: Encoder = {
  encode: (input: string): Uint8Array => {
    const encoded = btoa(input);
    return new TextEncoder().encode(encoded);
  }
};

const base64Decoder: Decoder = {
  decode: (input: Uint8Array): string => {
    const encoded = new TextDecoder().decode(input);
    return atob(encoded);
  }
};

// Stream collector for gathering response data
const streamCollector: StreamCollector = {
  collect: async (stream: ReadableStream): Promise<Uint8Array> => {
    const reader = stream.getReader();
    const chunks: Uint8Array[] = [];
    
    try {
      while (true) {
        const { done, value } = await reader.read();
        if (done) break;
        chunks.push(value);
      }
    } finally {
      reader.releaseLock();
    }
    
    // Combine all chunks
    const totalLength = chunks.reduce((sum, chunk) => sum + chunk.length, 0);
    const result = new Uint8Array(totalLength);
    let offset = 0;
    
    for (const chunk of chunks) {
      result.set(chunk, offset);
      offset += chunk.length;
    }
    
    return result;
  }
};

// Create serialization context
const serdeContext: SerdeContext = {
  base64Encoder,
  base64Decoder,
  utf8Encoder: new TextEncoder(),
  utf8Decoder: new TextDecoder(),
  streamCollector,
  logger: console
};

/**
 * Request serializer interface for converting command input to HTTP requests
 * Transforms high-level command objects into wire-format HTTP requests
 */
interface RequestSerializer<InputType, RequestType = HttpRequest> {
  /**
   * Serialize command input to HTTP request
   * @param input - Command input object
   * @param context - Serialization context with utilities
   * @returns Promise resolving to serialized HTTP request
   */
  serialize(input: InputType, context: SerdeContext): Promise<RequestType>;
}

/**
 * Response deserializer interface for converting HTTP responses to command output
 * Transforms wire-format HTTP responses into high-level result objects
 */
interface ResponseDeserializer<OutputType, ResponseType = HttpResponse> {
  /**
   * Deserialize HTTP response to command output
   * @param response - HTTP response to deserialize
   * @param options - Deserialization options and context
   * @returns Promise resolving to deserialized output object
   */
  deserialize(
    response: ResponseType,
    options: DeserializeHandlerOptions & SerdeContext
  ): Promise<OutputType>;
}

/**
 * Endpoint bearer interface for objects that carry endpoint information
 * Used by serializers to determine target endpoints for requests
 */
interface EndpointBearer {
  /** Target endpoint configuration */
  endpoint: Endpoint;
}

import { 
  RequestSerializer, 
  ResponseDeserializer,
  SerdeContext,
  HttpRequest,
  HttpResponse 
} from "@aws-sdk/types";

// Example JSON request serializer
class JsonRequestSerializer implements RequestSerializer<any, HttpRequest> {
  async serialize(input: any, context: SerdeContext): Promise<HttpRequest> {
    const body = JSON.stringify(input);
    const encodedBody = context.utf8Encoder?.encode(body) || new TextEncoder().encode(body);
    
    return {
      method: "POST",
      protocol: "https:",
      hostname: "service.amazonaws.com",
      path: "/",
      headers: {
        "Content-Type": "application/x-amz-json-1.1",
        "Content-Length": encodedBody.length.toString()
      },
      body: encodedBody
    };
  }
}

// Example JSON response deserializer
class JsonResponseDeserializer implements ResponseDeserializer<any, HttpResponse> {
  async deserialize(response: HttpResponse, options: any): Promise<any> {
    if (response.statusCode !== 200) {
      throw new Error(`HTTP ${response.statusCode}: ${response.reason}`);
    }
    
    const bodyBytes = await options.streamCollector?.collect(response.body);
    const bodyText = options.utf8Decoder?.decode(bodyBytes) || 
                    new TextDecoder().decode(bodyBytes);
    
    return JSON.parse(bodyText);
  }
}

/**
 * SDK stream mixin interface providing stream utility functions
 * Extends basic streams with AWS SDK specific functionality
 */
interface SdkStreamMixin {
  /** Transform stream to different format */
  transformToByteArray(): Promise<Uint8Array>;
  /** Transform stream to string */
  transformToString(encoding?: string): Promise<string>;
  /** Transform stream to web stream */
  transformToWebStream(): ReadableStream;
}

/**
 * SDK stream type combining base stream with mixin functionality
 * Provides enhanced streaming capabilities for AWS services
 */
type SdkStream<BaseStream> = BaseStream & SdkStreamMixin;

/**
 * Utility type for objects that have SDK stream mixin capabilities
 * Used for type checking and stream enhancement
 */
type WithSdkStreamMixin<T> = T & {
  /** SDK stream mixin functions */
  [K in keyof SdkStreamMixin]: SdkStreamMixin[K];
};

/**
 * SDK stream mixin injector function type
 * Used to add SDK stream capabilities to base streams
 */
type SdkStreamMixinInjector = <T>(stream: T) => WithSdkStreamMixin<T>;

/**
 * AWS chunked encoding stream function
 * Creates streams with AWS-specific chunked encoding for large uploads
 */
interface GetAwsChunkedEncodingStream {
  /**
   * Create AWS chunked encoding stream
   * @param source - Source stream to encode
   * @param options - Encoding options
   * @returns Chunked encoded stream
   */
  (source: any, options: GetAwsChunkedEncodingStreamOptions): any;
}

/**
 * Options for AWS chunked encoding stream creation
 */
interface GetAwsChunkedEncodingStreamOptions {
  /** Chunk size in bytes */
  chunkSize?: number;
  /** Signature function for chunk signing */
  chunkSigner?: (chunk: Uint8Array) => Promise<string>;
  /** Request signature for initial chunk */
  requestSignature?: string;
  /** Signing key for chunk signatures */
  signingKey?: Uint8Array;
  /** Signature date for chunk signing */
  signingDate?: Date;
  /** AWS region for chunk signing */
  region?: string;
  /** Service name for chunk signing */
  service?: string;
}

import { 
  SdkStream,
  SdkStreamMixin,
  GetAwsChunkedEncodingStream,
  GetAwsChunkedEncodingStreamOptions 
} from "@aws-sdk/types";

// Example SDK stream enhancement
const sdkStreamMixin: SdkStreamMixin = {
  async transformToByteArray(): Promise<Uint8Array> {
    const reader = (this as any).getReader();
    const chunks: Uint8Array[] = [];
    
    try {
      while (true) {
        const { done, value } = await reader.read();
        if (done) break;
        chunks.push(value);
      }
    } finally {
      reader.releaseLock();
    }
    
    const totalLength = chunks.reduce((sum, chunk) => sum + chunk.length, 0);
    const result = new Uint8Array(totalLength);
    let offset = 0;
    
    for (const chunk of chunks) {
      result.set(chunk, offset);
      offset += chunk.length;
    }
    
    return result;
  },
  
  async transformToString(encoding = "utf-8"): Promise<string> {
    const bytes = await this.transformToByteArray();
    return new TextDecoder(encoding).decode(bytes);
  },
  
  transformToWebStream(): ReadableStream {
    return this as any; // Assume already a web stream
  }
};

// Create chunked encoding stream for large uploads
const createChunkedStream: GetAwsChunkedEncodingStream = (source, options) => {
  return new ReadableStream({
    start(controller) {
      // Implementation would create AWS chunked encoding
      // This is a simplified example
      const chunkSize = options.chunkSize || 64 * 1024; // 64KB chunks
      
      // Process source stream in chunks with AWS signatures
      // Implementation details would handle chunk formatting and signing
    }
  });
};

// Usage for large file uploads
const fileStream = new ReadableStream(/* file data */);
const chunkedOptions: GetAwsChunkedEncodingStreamOptions = {
  chunkSize: 1024 * 1024, // 1MB chunks
  region: "us-east-1",
  service: "s3",
  signingDate: new Date(),
  chunkSigner: async (chunk) => {
    // Sign individual chunk
    return "chunk-signature";
  }
};

const chunkedStream = createChunkedStream(fileStream, chunkedOptions);

/**
 * Document type for representing arbitrary JSON-like data structures
 * Used in DynamoDB and other services that handle flexible schemas
 */
type DocumentType = 
  | null
  | boolean
  | number
  | string
  | DocumentType[]
  | { [key: string]: DocumentType };

import { DocumentType } from "@aws-sdk/types";

// Example DynamoDB item as DocumentType
const dynamoItem: DocumentType = {
  id: "user123",
  name: "John Doe",
  age: 30,
  active: true,
  tags: ["developer", "typescript"],
  metadata: {
    created: "2023-01-01",
    updated: null
  }
};

// Function that processes document data
function processDocument(doc: DocumentType): void {
  if (typeof doc === "object" && doc !== null && !Array.isArray(doc)) {
    // Process object properties
    for (const [key, value] of Object.entries(doc)) {
      console.log(`${key}:`, value);
    }
  }
}