thebespokepixel/truwrap

/* ────────╮
 │ truwrap │ WrapTool
 ╰─────────┴─────────────────────────────────────────────────────────────────── */

import createTokeniser from './tokeniser.js'
import createLineFitter from './line-fitter.js'

/**
 * Class that actually wraps the text.
 * @private
 */
class WrapTool {
    /**
     * Create a new line wrapping tool.
     * @param  {options} $0 - The supplied options
     * @param  {number} $0.left       - The left margins
     * @param  {number} $0.width      - The width of the view, in chars
     * @param  {RegExp}  $0.tokenRegex - An optional regex passed to the Tokeniser
     */
    constructor({
        mode,
        left,
        width,
        tabWidth,
        tokenRegex,
    }) {
        this.mode = mode
        this.margin = ' '.repeat(left)
        this.desiredWidth = width
        this.tabWidth = tabWidth
        this.tokeniser = createTokeniser(mode, tokenRegex)
    }

    /**
     * Apply instance settings to source text.
     * @param  {string} text - The text that require wrapping to the view.
     * @return {string}      - Text with wrapping applied.
     */
    wrap(text) {
        this.lines = []
        const tokens = this.tokeniser.process(text)

        let currentLine = createLineFitter(this.mode, this.margin, this.desiredWidth, this.tabWidth)

        while (tokens.length > 0) {
            const overflow = currentLine.add(tokens.shift())
            if (overflow) {
                this.lines.push(currentLine.toString())
                currentLine = createLineFitter(this.mode, this.margin, this.desiredWidth, this.tabWidth)
                if (overflow !== true && overflow !== false) {
                    tokens.unshift(overflow)
                }
            }
        }

        this.lines.push(currentLine.toString())
        return this.lines.map(line => this.tokeniser.restore(line)).join('\n')
    }
}

/**
 * Creates a wrap tool.
 * @private
 * @param      {Object}    options  The options
 * @return     {WrapTool}  The wrap tool.
 */
export default function createWrapTool(options) {
    return new WrapTool(options)
}