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// Ported from Go:// https://github.com/golang/go/blob/go1.12.5/src/encoding/csv/// Copyright 2011 The Go Authors. All rights reserved. BSD license.// https://github.com/golang/go/blob/master/LICENSE// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
import { BufReader } from "../io/buffer.ts";import { TextProtoReader } from "../textproto/mod.ts";import { StringReader } from "../io/readers.ts";import { assert } from "../_util/assert.ts";import {  ERR_FIELD_COUNT,  ERR_INVALID_DELIM,  ParseError,  readRecord,} from "./csv/_io.ts";import type { LineReader, ReadOptions } from "./csv/_io.ts";
export {  ERR_BARE_QUOTE,  ERR_FIELD_COUNT,  ERR_INVALID_DELIM,  ERR_QUOTE,  ParseError,} from "./csv/_io.ts";export type { ReadOptions } from "./csv/_io.ts";export { NEWLINE, stringify, StringifyError } from "./csv_stringify.ts";
export type {  Column,  ColumnDetails,  DataItem,  StringifyOptions,} from "./csv_stringify.ts";
class TextProtoLineReader implements LineReader {  #tp: TextProtoReader;  constructor(bufReader: BufReader) {    this.#tp = new TextProtoReader(bufReader);  }
  async readLine() {    let line: string;    const r = await this.#tp.readLine();    if (r === null) return null;    line = r;
    // For backwards compatibility, drop trailing \r before EOF.    if (      (await this.isEOF()) && line.length > 0 && line[line.length - 1] === "\r"    ) {      line = line.substring(0, line.length - 1);    }
    // Normalize \r\n to \n on all input lines.    if (      line.length >= 2 &&      line[line.length - 2] === "\r" &&      line[line.length - 1] === "\n"    ) {      line = line.substring(0, line.length - 2);      line = line + "\n";    }
    return line;  }
  async isEOF() {    return (await this.#tp.r.peek(0)) === null;  }}
const INVALID_RUNE = ["\r", "\n", '"'];
function chkOptions(opt: ReadOptions): void {  if (!opt.separator) {    opt.separator = ",";  }  if (!opt.trimLeadingSpace) {    opt.trimLeadingSpace = false;  }  if (    INVALID_RUNE.includes(opt.separator) ||    (typeof opt.comment === "string" && INVALID_RUNE.includes(opt.comment)) ||    opt.separator === opt.comment  ) {    throw new Error(ERR_INVALID_DELIM);  }}
/** * Parse the CSV from the `reader` with the options provided and return `string[][]`. * * @param reader provides the CSV data to parse * @param opt controls the parsing behavior */export async function readMatrix(  reader: BufReader,  opt: ReadOptions = {    separator: ",",    trimLeadingSpace: false,    lazyQuotes: false,  },): Promise<string[][]> {  const result: string[][] = [];  let _nbFields: number | undefined;  let lineResult: string[];  let first = true;  let lineIndex = 0;  chkOptions(opt);
  const lineReader = new TextProtoLineReader(reader);  for (;;) {    const r = await readRecord(lineIndex, lineReader, opt);    if (r === null) break;    lineResult = r;    lineIndex++;    // If fieldsPerRecord is 0, Read sets it to    // the number of fields in the first record    if (first) {      first = false;      if (opt.fieldsPerRecord !== undefined) {        if (opt.fieldsPerRecord === 0) {          _nbFields = lineResult.length;        } else {          _nbFields = opt.fieldsPerRecord;        }      }    }
    if (lineResult.length > 0) {      if (_nbFields && _nbFields !== lineResult.length) {        throw new ParseError(lineIndex, lineIndex, null, ERR_FIELD_COUNT);      }      result.push(lineResult);    }  }  return result;}
/** * Parse the CSV string/buffer with the options provided. * * ColumnOptions provides the column definition * and the parse function for each entry of the * column. */export interface ColumnOptions {  /**   * Name of the column to be used as property   */  name: string;}
export interface ParseOptions extends ReadOptions {  /**   * If you provide `skipFirstRow: true` and `columns`, the first line will be skipped.   * If you provide `skipFirstRow: true` but not `columns`, the first line will be skipped and used as header definitions.   */  skipFirstRow?: boolean;
  /**   * If you provide `string[]` or `ColumnOptions[]`, those names will be used for header definition.   */  columns?: string[] | ColumnOptions[];}
/** * Csv parse helper to manipulate data. * Provides an auto/custom mapper for columns. * @param input Input to parse. Can be a string or BufReader. * @param opt options of the parser. * @returns If you don't provide `opt.skipFirstRow` and `opt.columns`, it returns `string[][]`. *   If you provide `opt.skipFirstRow` or `opt.columns`, it returns `Record<string, unkown>[]`. */export async function parse(  input: string | BufReader,): Promise<string[][]>;export async function parse(  input: string | BufReader,  opt: Omit<ParseOptions, "columns" | "skipFirstRow">,): Promise<string[][]>;export async function parse(  input: string | BufReader,  opt: Omit<ParseOptions, "columns"> & {    columns: string[] | ColumnOptions[];  },): Promise<Record<string, unknown>[]>;export async function parse(  input: string | BufReader,  opt: Omit<ParseOptions, "skipFirstRow"> & {    skipFirstRow: true;  },): Promise<Record<string, unknown>[]>;export async function parse(  input: string | BufReader,  opt: ParseOptions,): Promise<string[][] | Record<string, unknown>[]>;export async function parse(  input: string | BufReader,  opt: ParseOptions = {    skipFirstRow: false,  },): Promise<string[][] | Record<string, unknown>[]> {  let r: string[][];  if (input instanceof BufReader) {    r = await readMatrix(input, opt);  } else {    r = await readMatrix(new BufReader(new StringReader(input)), opt);  }  if (opt.skipFirstRow || opt.columns) {    let headers: ColumnOptions[] = [];    let i = 0;
    if (opt.skipFirstRow) {      const head = r.shift();      assert(head != null);      headers = head.map(        (e): ColumnOptions => {          return {            name: e,          };        },      );      i++;    }
    if (opt.columns) {      if (typeof opt.columns[0] !== "string") {        headers = opt.columns as ColumnOptions[];      } else {        const h = opt.columns as string[];        headers = h.map(          (e): ColumnOptions => {            return {              name: e,            };          },        );      }    }
    return r.map((e) => {      if (e.length !== headers.length) {        throw new Error(          `Error number of fields line: ${i}\nNumber of fields found: ${headers.length}\nExpected number of fields: ${e.length}`,        );      }      i++;      const out: Record<string, unknown> = {};      for (let j = 0; j < e.length; j++) {        out[headers[j].name] = e[j];      }      return out;    });  }  return r;}