columns.js

"use strict";

var generate          = require("es5-ext/array/generate")
  , from              = require("es5-ext/array/from")
  , iterable          = require("es5-ext/iterable/validate-object")
  , isValue           = require("es5-ext/object/is-value")
  , stringifiable     = require("es5-ext/object/validate-stringifiable")
  , repeat            = require("es5-ext/string/#/repeat")
  , getStrippedLength = require("./get-stripped-length");

var push = Array.prototype.push;

module.exports = function (inputRows /*, options*/) {
	var options = Object(arguments[1])
	  , colsMeta = []
	  , colsOptions = options.columns || []
	  , rows = [];

	from(iterable(inputRows), function (row) {
		var rowRows = [[]];
		from(iterable(row), function (cellStr, columnIndex) {
			var cellRows = stringifiable(cellStr).split("\n");
			while (cellRows.length > rowRows.length) rowRows.push(generate(columnIndex, ""));
			cellRows.forEach(function (cellRow, rowRowIndex) {
				rowRows[rowRowIndex][columnIndex] = cellRow;
			});
		});
		push.apply(rows, rowRows);
	});

	return (
		rows
			.map(function (row) {
				return from(iterable(row), function (str, index) {
					var col = colsMeta[index], strLength;
					if (!col) col = colsMeta[index] = { width: 0 };
					str = stringifiable(str);
					strLength = getStrippedLength(str);
					if (strLength > col.width) col.width = strLength;
					return { str: str, length: strLength };
				});
			})
			.map(function (row) {
				return row
					.map(function (item, index) {
						var pad, align = "left", colOptions = colsOptions && colsOptions[index];
						align = colOptions && colOptions.align === "right" ? "right" : "left";
						pad = repeat.call(" ", colsMeta[index].width - item.length);
						if (align === "left") return item.str + pad;
						return pad + item.str;
					})
					.join(isValue(options.sep) ? options.sep : " | ");
			})
			.join("\n") + "\n"
	);
};