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// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.// This module is browser compatible.
import {  convertRowToObject,  ERR_BARE_QUOTE,  ERR_FIELD_COUNT,  ERR_INVALID_DELIM,  ERR_QUOTE,  ParseError,  type ParseResult,  type ReadOptions,} from "./_io.ts";import { assert } from "../_util/asserts.ts";
export {  ERR_BARE_QUOTE,  ERR_FIELD_COUNT,  ERR_INVALID_DELIM,  ERR_QUOTE,  ParseError,  ReadOptions,};
const BYTE_ORDER_MARK = "\ufeff";
class Parser {  #input = "";  #cursor = 0;  #options: {    separator: string;    trimLeadingSpace: boolean;    comment?: string;    lazyQuotes?: boolean;    fieldsPerRecord?: number;  };  constructor({    separator = ",",    trimLeadingSpace = false,    comment,    lazyQuotes,    fieldsPerRecord,  }: ReadOptions = {}) {    this.#options = {      separator,      trimLeadingSpace,      comment,      lazyQuotes,      fieldsPerRecord,    };  }  #readLine(): string | null {    if (this.#isEOF()) return null;
    if (      !this.#input.startsWith("\r\n", this.#cursor) ||      !this.#input.startsWith("\n", this.#cursor)    ) {      let buffer = "";      let hadNewline = false;      while (this.#cursor < this.#input.length) {        if (this.#input.startsWith("\r\n", this.#cursor)) {          hadNewline = true;          this.#cursor += 2;          break;        }        if (          this.#input.startsWith("\n", this.#cursor)        ) {          hadNewline = true;          this.#cursor += 1;          break;        }        buffer += this.#input[this.#cursor];        this.#cursor += 1;      }      if (!hadNewline && buffer.endsWith("\r")) {        buffer = buffer.slice(0, -1);      }
      return buffer;    }    return null;  }  #isEOF(): boolean {    return this.#cursor >= this.#input.length;  }  #parseRecord(startLine: number): string[] | null {    let line = this.#readLine();    if (line === null) return null;    if (line.length === 0) {      return [];    }
    function runeCount(s: string): number {      // Array.from considers the surrogate pair.      return Array.from(s).length;    }
    let lineIndex = startLine + 1;
    // line starting with comment character is ignored    if (this.#options.comment && line[0] === this.#options.comment) {      return [];    }
    assert(this.#options.separator != null);
    let fullLine = line;    let quoteError: ParseError | null = null;    const quote = '"';    const quoteLen = quote.length;    const separatorLen = this.#options.separator.length;    let recordBuffer = "";    const fieldIndexes = [] as number[];    parseField:    for (;;) {      if (this.#options.trimLeadingSpace) {        line = line.trimStart();      }
      if (line.length === 0 || !line.startsWith(quote)) {        // Non-quoted string field        const i = line.indexOf(this.#options.separator);        let field = line;        if (i >= 0) {          field = field.substring(0, i);        }        // Check to make sure a quote does not appear in field.        if (!this.#options.lazyQuotes) {          const j = field.indexOf(quote);          if (j >= 0) {            const col = runeCount(              fullLine.slice(0, fullLine.length - line.slice(j).length),            );            quoteError = new ParseError(              startLine + 1,              lineIndex,              col,              ERR_BARE_QUOTE,            );            break parseField;          }        }        recordBuffer += field;        fieldIndexes.push(recordBuffer.length);        if (i >= 0) {          line = line.substring(i + separatorLen);          continue parseField;        }        break parseField;      } else {        // Quoted string field        line = line.substring(quoteLen);        for (;;) {          const i = line.indexOf(quote);          if (i >= 0) {            // Hit next quote.            recordBuffer += line.substring(0, i);            line = line.substring(i + quoteLen);            if (line.startsWith(quote)) {              // `""` sequence (append quote).              recordBuffer += quote;              line = line.substring(quoteLen);            } else if (line.startsWith(this.#options.separator)) {              // `","` sequence (end of field).              line = line.substring(separatorLen);              fieldIndexes.push(recordBuffer.length);              continue parseField;            } else if (0 === line.length) {              // `"\n` sequence (end of line).              fieldIndexes.push(recordBuffer.length);              break parseField;            } else if (this.#options.lazyQuotes) {              // `"` sequence (bare quote).              recordBuffer += quote;            } else {              // `"*` sequence (invalid non-escaped quote).              const col = runeCount(                fullLine.slice(0, fullLine.length - line.length - quoteLen),              );              quoteError = new ParseError(                startLine + 1,                lineIndex,                col,                ERR_QUOTE,              );              break parseField;            }          } else if (line.length > 0 || !(this.#isEOF())) {            // Hit end of line (copy all data so far).            recordBuffer += line;            const r = this.#readLine();            lineIndex++;            line = r ?? ""; // This is a workaround for making this module behave similarly to the encoding/csv/reader.go.            fullLine = line;            if (r === null) {              // Abrupt end of file (EOF or error).              if (!this.#options.lazyQuotes) {                const col = runeCount(fullLine);                quoteError = new ParseError(                  startLine + 1,                  lineIndex,                  col,                  ERR_QUOTE,                );                break parseField;              }              fieldIndexes.push(recordBuffer.length);              break parseField;            }            recordBuffer += "\n"; // preserve line feed (This is because TextProtoReader removes it.)          } else {            // Abrupt end of file (EOF on error).            if (!this.#options.lazyQuotes) {              const col = runeCount(fullLine);              quoteError = new ParseError(                startLine + 1,                lineIndex,                col,                ERR_QUOTE,              );              break parseField;            }            fieldIndexes.push(recordBuffer.length);            break parseField;          }        }      }    }    if (quoteError) {      throw quoteError;    }    const result = [] as string[];    let preIdx = 0;    for (const i of fieldIndexes) {      result.push(recordBuffer.slice(preIdx, i));      preIdx = i;    }    return result;  }  parse(input: string): string[][] {    this.#input = input.startsWith(BYTE_ORDER_MARK) ? input.slice(1) : input;    this.#cursor = 0;    const result: string[][] = [];    let _nbFields: number | undefined;    let lineResult: string[];    let first = true;    let lineIndex = 0;
    const INVALID_RUNE = ["\r", "\n", '"'];
    const options = this.#options;    if (      INVALID_RUNE.includes(options.separator) ||      (typeof options.comment === "string" &&        INVALID_RUNE.includes(options.comment)) ||      options.separator === options.comment    ) {      throw new Error(ERR_INVALID_DELIM);    }
    for (;;) {      const r = this.#parseRecord(lineIndex);      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 (options.fieldsPerRecord !== undefined) {          if (options.fieldsPerRecord === 0) {            _nbFields = lineResult.length;          } else {            _nbFields = options.fieldsPerRecord;          }        }      }
      if (lineResult.length > 0) {        if (_nbFields && _nbFields !== lineResult.length) {          throw new ParseError(lineIndex, lineIndex, null, ERR_FIELD_COUNT);        }        result.push(lineResult);      }    }    return result;  }}
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;
  /** List of names used for header definition. */  columns?: readonly string[];}
/** * Csv parse helper to manipulate data. * Provides an auto/custom mapper for columns. * * @example * ```ts * import { parse } from "https://deno.land/std@$STD_VERSION/csv/parse.ts"; * const string = "a,b,c\nd,e,f"; * * console.log( *   await parse(string, { *     skipFirstRow: false, *   }), * ); * // output: * // [["a", "b", "c"], ["d", "e", "f"]] * ``` * * @param input Input to parse. * @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 function parse(input: string, opt?: undefined): string[][];export function parse<const T extends ParseOptions>(  input: string,  opt: T,): ParseResult<ParseOptions, T>;export function parse<const T extends ParseOptions>(  input: string,  opt: T = { skipFirstRow: false } as T,): ParseResult<ParseOptions, T> {  const parser = new Parser(opt);  const r = parser.parse(input);
  if (opt.skipFirstRow || opt.columns) {    let headers: readonly string[] = [];
    if (opt.skipFirstRow) {      const head = r.shift();      assert(head != null);      headers = head;    }
    if (opt.columns) {      headers = opt.columns;    }
    const firstLineIndex = opt.skipFirstRow ? 1 : 0;    return r.map((row, i) => {      return convertRowToObject(row, headers, firstLineIndex + i);    }) as ParseResult<ParseOptions, T>;  }  return r as ParseResult<ParseOptions, T>;}