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import { Column } from "../query/decode.ts";import { PacketReader } from "./packet.ts";import { RowDescription } from "../query/query.ts";
export class Message {  public reader: PacketReader;
  constructor(    public type: string,    public byteCount: number,    public body: Uint8Array,  ) {    this.reader = new PacketReader(body);  }}
export interface Notice {  severity: string;  code: string;  message: string;  detail?: string;  hint?: string;  position?: string;  internalPosition?: string;  internalQuery?: string;  where?: string;  schema?: string;  table?: string;  column?: string;  dataType?: string;  constraint?: string;  file?: string;  line?: string;  routine?: string;}
export function parseBackendKeyMessage(  message: Message,): { pid: number; secret_key: number } {  return {    pid: message.reader.readInt32(),    secret_key: message.reader.readInt32(),  };}
/** * This function returns the command result tag from the command message */export function parseCommandCompleteMessage(message: Message): string {  return message.reader.readString(message.byteCount);}
/** * https://www.postgresql.org/docs/14/protocol-error-fields.html */export function parseNoticeMessage(message: Message): Notice {  // deno-lint-ignore no-explicit-any  const error_fields: any = {};
  let byte: number;  let field_code: string;  let field_value: string;
  while ((byte = message.reader.readByte())) {    field_code = String.fromCharCode(byte);    field_value = message.reader.readCString();
    switch (field_code) {      case "S":        error_fields.severity = field_value;        break;      case "C":        error_fields.code = field_value;        break;      case "M":        error_fields.message = field_value;        break;      case "D":        error_fields.detail = field_value;        break;      case "H":        error_fields.hint = field_value;        break;      case "P":        error_fields.position = field_value;        break;      case "p":        error_fields.internalPosition = field_value;        break;      case "q":        error_fields.internalQuery = field_value;        break;      case "W":        error_fields.where = field_value;        break;      case "s":        error_fields.schema = field_value;        break;      case "t":        error_fields.table = field_value;        break;      case "c":        error_fields.column = field_value;        break;      case "d":        error_fields.dataTypeName = field_value;        break;      case "n":        error_fields.constraint = field_value;        break;      case "F":        error_fields.file = field_value;        break;      case "L":        error_fields.line = field_value;        break;      case "R":        error_fields.routine = field_value;        break;      default:        // from Postgres docs        // > Since more field types might be added in future,        // > frontends should silently ignore fields of unrecognized type.        break;    }  }
  return error_fields;}
/** * Parses a row data message into an array of bytes ready to be processed as column values */// TODO// Research corner cases where parseRowData can return null values// deno-lint-ignore no-explicit-anyexport function parseRowDataMessage(message: Message): any[] {  const field_count = message.reader.readInt16();  const row = [];
  for (let i = 0; i < field_count; i++) {    const col_length = message.reader.readInt32();
    if (col_length == -1) {      row.push(null);      continue;    }
    // reading raw bytes here, they will be properly parsed later    row.push(message.reader.readBytes(col_length));  }
  return row;}
export function parseRowDescriptionMessage(message: Message): RowDescription {  const column_count = message.reader.readInt16();  const columns = [];
  for (let i = 0; i < column_count; i++) {    // TODO: if one of columns has 'format' == 'binary',    // all of them will be in same format?    const column = new Column(      message.reader.readCString(), // name      message.reader.readInt32(), // tableOid      message.reader.readInt16(), // index      message.reader.readInt32(), // dataTypeOid      message.reader.readInt16(), // column      message.reader.readInt32(), // typeModifier      message.reader.readInt16(), // format    );    columns.push(column);  }
  return new RowDescription(column_count, columns);}