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import { encode, EncodedArg } from "./encode.ts";import { Column, decode } from "./decode.ts";import { Notice } from "../connection/message.ts";
const commandTagRegexp = /^([A-Za-z]+)(?: (\d+))?(?: (\d+))?/;
type CommandType = (  | "INSERT"  | "DELETE"  | "UPDATE"  | "SELECT"  | "MOVE"  | "FETCH"  | "COPY");
export enum ResultType {  ARRAY,  OBJECT,}
export class RowDescription {  constructor(public columnCount: number, public columns: Column[]) {}}
/** * This function transforms template string arguments into a query * * ```ts * ["SELECT NAME FROM TABLE WHERE ID = ", " AND DATE < "] * // "SELECT NAME FROM TABLE WHERE ID = $1 AND DATE < $2" * ``` */export function templateStringToQuery<T extends ResultType>(  template: TemplateStringsArray,  args: QueryArguments,  result_type: T,): Query<T> {  const text = template.reduce((curr, next, index) => {    return `${curr}$${index}${next}`;  });
  return new Query(text, result_type, ...args);}
export interface QueryConfig {  args?: Array<unknown>;  encoder?: (arg: unknown) => EncodedArg;  name?: string;  text: string;}
export interface QueryObjectConfig extends QueryConfig {  /**   * This parameter superseeds query column names   *   * When specified, this names will be asigned to the results   * of the query in the order they were provided   *   * Fields must be unique and be in the range of (a-zA-Z0-9_), otherwise the query will throw before execution   *   * A field can not start with a number, just like JavaScript variables   */  fields?: string[];}
// TODO// Limit the type of parameters that can be passed// to a query/** * https://www.postgresql.org/docs/14/sql-prepare.html * * This arguments will be appended to the prepared statement passed * as query * * They will take the position according to the order in which they were provided * * ```ts * await my_client.queryArray( *  "SELECT ID, NAME FROM PEOPLE WHERE AGE > $1 AND AGE < $2", *  10, // $1 *  20, // $2 * ); * ``` */// deno-lint-ignore no-explicit-anyexport type QueryArguments = any[];
export class QueryResult {  public command!: CommandType;  public rowCount?: number;  public rowDescription?: RowDescription;  public warnings: Notice[] = [];
  constructor(public query: Query<ResultType>) {}
  /**   * This function is required to parse each column   * of the results   */  loadColumnDescriptions(description: RowDescription) {    this.rowDescription = description;  }
  handleCommandComplete(commandTag: string): void {    const match = commandTagRegexp.exec(commandTag);    if (match) {      this.command = match[1] as CommandType;      if (match[3]) {        // COMMAND OID ROWS        this.rowCount = parseInt(match[3], 10);      } else {        // COMMAND ROWS        this.rowCount = parseInt(match[2], 10);      }    }  }
  insertRow(_row: Uint8Array[]): void {    throw new Error("No implementation for insertRow is defined");  }}
export class QueryArrayResult<T extends Array<unknown> = Array<unknown>>  extends QueryResult {  public rows: T[] = [];
  insertRow(row_data: Uint8Array[]) {    if (!this.rowDescription) {      throw new Error(        "The row descriptions required to parse the result data weren't initialized",      );    }
    // Row description won't be modified after initialization    const row = row_data.map((raw_value, index) => {      const column = this.rowDescription!.columns[index];
      if (raw_value === null) {        return null;      }      return decode(raw_value, column);    }) as T;
    this.rows.push(row);  }}
export class QueryObjectResult<  T = Record<string, unknown>,> extends QueryResult {  public rows: T[] = [];
  insertRow(row_data: Uint8Array[]) {    if (!this.rowDescription) {      throw new Error(        "The row description required to parse the result data wasn't initialized",      );    }
    if (      this.query.fields &&      this.rowDescription.columns.length !== this.query.fields.length    ) {      throw new RangeError(        "The fields provided for the query don't match the ones returned as a result " +          `(${this.rowDescription.columns.length} expected, ${this.query.fields.length} received)`,      );    }
    // Row description won't be modified after initialization    const row = row_data.reduce(      (row: Record<string, unknown>, raw_value, index) => {        const column = this.rowDescription!.columns[index];
        // Find the field name provided by the user        // default to database provided name        const name = this.query.fields?.[index] ?? column.name;
        if (raw_value === null) {          row[name] = null;        } else {          row[name] = decode(raw_value, column);        }
        return row;      },      {},    );
    this.rows.push(row as T);  }}
export class Query<T extends ResultType> {  public args: EncodedArg[];  public fields?: string[];  public result_type: ResultType;  public text: string;
  constructor(config: QueryObjectConfig, result_type: T);  constructor(text: string, result_type: T, ...args: unknown[]);  constructor(    config_or_text: string | QueryObjectConfig,    result_type: T,    ...args: unknown[]  ) {    this.result_type = result_type;
    let config: QueryConfig;    if (typeof config_or_text === "string") {      config = { text: config_or_text, args };    } else {      const {        fields,        ...query_config      } = config_or_text;
      // Check that the fields passed are valid and can be used to map      // the result of the query      if (fields) {        const clean_fields = fields.filter((field) =>          /^[a-zA-Z_][a-zA-Z0-9_]*$/.test(field)        );        if (fields.length !== clean_fields.length) {          throw new TypeError(            "The fields provided for the query must contain only letters and underscores",          );        }
        if ((new Set(clean_fields)).size !== clean_fields.length) {          throw new TypeError(            "The fields provided for the query must be unique",          );        }
        this.fields = clean_fields;      }
      config = query_config;    }    this.text = config.text;    this.args = this.#prepareArgs(config);  }
  #prepareArgs(config: QueryConfig): EncodedArg[] {    const encodingFn = config.encoder ? config.encoder : encode;    return (config.args || []).map(encodingFn);  }}