#TSV-String: Extract Range Columns

// Script Example of Business Process Automation
// for 'engine type: 3' ("GraalJS standard mode")
// cf. 'engine type: 2' ("GraalJS Nashorn compatible mode") (renamed from "GraalJS" at 20230526)


//////// START "main()" /////////////////////////////////////////////////////////////////
main();
function main(){ 

//// == Config Retrieving / 工程コンフィグの参照 ==
const strTsv        = configs.get        ( "StrConfA" );       // REQUIRED
  if( strTsv === "" ){
    throw new Error( "\n AutomatedTask ConfigError:" +
                     " Config {A: TSV} is empty \n" );
  }
  const arr2dTsv    = parseAsRectangular ( strTsv );           // as arr2dTSV[Y][X]
const strStartIndex = configs.get        ( "StrConfB1" );      // not required
  let numStartIndex = Number( strStartIndex );
  if ( isNaN(numStartIndex) ) {
    numStartIndex = 0;
  } else if ( numStartIndex < 0 ) {
    numStartIndex = arr2dTsv[0].length + numStartIndex;
  }
  if( arr2dTsv[0].length <= numStartIndex ){
    throw new Error( "\n AutomatedTask ConfigError:" +
                     " Start-Index must be less than the number of columns. \n" );
  }
const strEndIndex   = configs.get        ( "StrConfB2" );      // not required
  let numEndIndex = strEndIndex.trim() === "" ? NaN : Number( strEndIndex );
  if ( isNaN(numEndIndex) ) {
    numEndIndex = arr2dTsv[0].length;
  } else if ( numEndIndex < 0 ) {
    numEndIndex = arr2dTsv[0].length + numEndIndex;
  }
  if( numEndIndex <= numStartIndex ){
    throw new Error( "\n AutomatedTask ConfigError:" +
                     " Start-Index must be less than End-Index. \n" );
  }
const strPocketC    = configs.getObject ( "SelectConfC" );     // REQUIRED
const numPocketInY  = configs.getObject ( "SelectConfInY" );   // not required
const numPocketInX  = configs.getObject ( "SelectConfInX" );   // not required
const numPocketOutY = configs.getObject ( "SelectConfOutY" );  // not required
const numPocketOutX = configs.getObject ( "SelectConfOutX" );  // not required



//// == Data Retrieving / ワークフローデータの参照 ==
// (Nothing. Retrieved via Expression Language in Config Retrieving)



//// == Calculating / 演算 ==
let arrOutputTsv  = [];

for ( let i = 0; i < arr2dTsv.length; i++ ) {
  let arrTmp = arr2dTsv[i].slice( numStartIndex, numEndIndex );
  arrOutputTsv.push ( arrTmp.join( '\t' ) );
}



//// == Data Updating / ワークフローデータへの代入 ==
/// ref) Retrieving / Updating from ScriptTasks
/// https://questetra.zendesk.com/hc/en-us/articles/360024574771-R2301
/// https://questetra.zendesk.com/hc/ja/articles/360024574771-R2301

if ( strPocketC !== null ){ 
  engine.setData( strPocketC, arrOutputTsv?.join( '\n' ) ?? "" );
}

if ( numPocketInY !== null ){ 
  engine.setData( numPocketInY, new java.math.BigDecimal( arr2dTsv.length ) );
}
if ( numPocketInX !== null ){ 
  engine.setData( numPocketInX, new java.math.BigDecimal( arr2dTsv[0].length ) );
}
if ( numPocketOutY !== null ){ 
  engine.setData( numPocketOutY, new java.math.BigDecimal( arrOutputTsv.length ) );
}
if ( numPocketOutX !== null ){ 
  engine.setData( numPocketOutX, new java.math.BigDecimal( arrOutputTsv[0].split("\t").length ) );
}



} //////// END "main()" /////////////////////////////////////////////////////////////////



/**
 * Parses a TSV (Tab-Separated Values) string and returns a 2D array with rectangular shape.
 * This function ensures that each row in the resulting 2D array has the same number of columns,
 * equal to the widest row in the original TSV input. Shorter rows are padded with empty strings.
 * Blank lines in the input are ignored.
 * Additionally, the function logs the minimum and maximum column counts (excluding blank lines),
 * along with the total number of lines and count of blank lines.
 * 
 * TSV（タブ区切り値）形式の文字列を解析し、2次元の配列として整形して返します。
 * 入力されたTSV文字列を行単位で分割し、各行のセル数をそろえて「長方形（矩形）」の形に整えます。
 * 最もセル数が多い行に合わせて、セル数が足りない行には空文字列（""）を補完します。
 * 空行（中身が空の行）は無視されます。
 * また、最小列数・最大列数・全体の行数・空行の数をログに出力します（engine.log）。
 * 
 * 
 * @param {string} strTsv - The raw TSV string, with rows separated by newline characters (`\n`) 
 *                          and cells separated by tab characters (`\t`).
 * 
 * @returns {string[][]} A two-dimensional array where each sub-array represents a row from the TSV input,
 *                       padded with empty strings to ensure uniform column width.
 * 
 * @example
 * const tsv = "a\tb\tc\n1\t2\nx\ty\tz\tw\n";
 * const result = parseAsRectangular(tsv);
 * // result:
 * // [
 * //   ["a", "b", "c", ""],
 * //   ["1", "2", "", ""],
 * //   ["x", "y", "z", "w"]
 * // ]
 */

function parseAsRectangular( strTsv ){
  const arrTsv = strTsv.split("\n");

  /// Get numMinWidth and numMaxWidth (blank lines are excluded)
  let numMinWidth   = Infinity; // cf. String-Type Max: 1 million
  let numMaxWidth   = 0;
  let numBlanklines = 0;
  for( let i = 0; i < arrTsv.length; i++ ){
    if( arrTsv[i] === "" ){ // Skip blank lines
      numBlanklines += 1;
      continue;
    }
    let arrCells = arrTsv[i].split("\t");
    if( numMinWidth > arrCells.length ){ numMinWidth = arrCells.length; }
    if( numMaxWidth < arrCells.length ){ numMaxWidth = arrCells.length; }
  }
  engine.log( " AutomatedTask TsvDataCheck:" + 
              " MinWidth:" + numMinWidth +
              " MaxWidth:" + numMaxWidth +
              " Lines:" + arrTsv.length +
              " (BlankLines:" + numBlanklines + ")" );

  /// Get numMinWidth and numMaxWidth (blank lines are excluded)
  let arr2dTsv      = [];
  for( let i = 0; i < arrTsv.length; i++ ){
    if( arrTsv[i] === "" ){ // Skip blank lines
      continue;
    }
    let arrTmp = [];
    let arrCells = arrTsv[i].split("\t");
    for( let j = 0; j < numMaxWidth; j++ ){
      if( j < arrCells.length ){
        arrTmp[j] = arrCells[j];
      }else{
        arrTmp[j] = "";
      }
    }
    arr2dTsv.push( arrTmp );
  }

  return arr2dTsv;
}



/*
### NOTES
- When the process reaches this [Automated Step], the extraction is automatically executed.
    - This is a convenient add-on automated step for automating subsequent processes such as data integration and data aggregation.
- The specified column range (from the START index to just before the END index) is automatically extracted.
    - The column index starts at "0" (counting from the beginning, first column is `0`).
    - A negative value can also be set for the column index (counting from the end, last column is `-1`).
    - If the START index is omitted, extraction will start from the first column of the TSV.
    - If the END index is omitted, extraction will run up to the last column of the TSV.

### NOTES-ja
- 案件プロセスがこの自動工程に到達した際、TSVテキストが読み込まれ「抽出処理」が自動実行されます
    - データ連携やデータ集計など、後続処理の自動化を行う際に便利なアドオン自動工程です
- 指定の列範囲（STARTインデックスからENDインデックスの手前まで）が、自動抽出されます
    - 列インデックスは「0」から始まります（先頭から数える／先頭列は `0`）
    - 列インデックスには「負の値」も設定可能です（末尾から数える／末尾列は `-1`）
    - STARTインデックス指定が省略された場合、TSVの最初の列から抽出されます
    - ENDインデックス指定が省略された場合、TSVの最後の列までが抽出されます

### APPENDIX
- TSV (Tab Separated Values) text is assumed to be rectangular data.
    - TSV text: monthly sales summary, monthly access summary, PIVOT table, etc.
    - Non-rectangular data is automatically formatted with an empty string (adjusted to the longest number of columns).
    - Blank lines (including trailing newlines) are ignored.
- Indexes:
    - Indexes start from 0 (first column is `0`).
    - For example, the third column from the left (so-called column C) has index `2`.
    - Negative indexes are counted from the end (last column is `-1`).
    - For example, the third column from the right has index `-3`.
- The number of rows (height) and columns (width) of the input/output TSV can be stored in Numeric data.
- If the order of the output TSV columns should be changed, place a "TSV String, Convert" downstream in the workflow.
    - https://support.questetra.com/addons/tsv-string-convert-2021/

### APPENDIX-ja
- TSV（Tab Separated Values）テキストは、矩形データを前提とします
    - TSVテキスト: 月次売上集計、月次アクセス集計、PIVOTテーブル、など
    - 矩形でないデータは、空文字列によって自動整形されます（最も長い列数に合わせる）
    - 空行（末尾改行を含む）は無視されます
- インデックスの理解:
    - インデックスは0から始まります（先頭列は `0`）
    - 例えば、左から3番目の列（いわゆるC列）は、インデックス `2` となります
    - 負のインデックスは末尾から数えます（末尾列は `-1`）
    - 例えば、右から3番目の列は、インデックス `-3` となります
- インプットTSVおよびアウトプットTSVの行数（高さ）と列数（幅）を数値型データ項目に格納できます
- 出力TSV列の並び順が変更されるべきなら、ワークフロー下流に『TSV 文字列, 変換』を配置します
    - https://support.questetra.com/ja/addons/tsv-string-convert-2021/
*/