text: const color = require('kleur');
  const Prompt = require('./prompt');
  const { cursor } = require('sisteransi');
  const { style, clear, strip, figures } = require('../util');
  
  /**
   * TextPrompt Base Element
   * @param {Object} opts Options
   * @param {String} opts.message Message
   * @param {String} [opts.style='default'] Render style
   * @param {String} [opts.initial] Default value
   * @param {Function} [opts.validate] Validate function
   * @param {Stream} [opts.stdin] The Readable stream to listen to
   * @param {Stream} [opts.stdout] The Writable stream to write readline data to
   * @param {String} [opts.error] The invalid error label
   */
  class TextPrompt extends Prompt {
    constructor(opts={}) {
      super(opts);
      this.transform = style.render(opts.style);
      this.scale = this.transform.scale;
      this.msg = opts.message;
      this.initial = opts.initial || ``;
      this.validator = opts.validate || (() => true);
      this.value = ``;
      this.errorMsg = opts.error || `Please Enter A Valid Value`;
      this.cursor = Number(!!this.initial);
      this.clear = clear(``);
      this.render();
    }
  
    set value(v) {
      if (!v && this.initial) {
        this.placeholder = true;
        this.rendered = color.gray(this.transform.render(this.initial));
      } else {
        this.placeholder = false;
        this.rendered = this.transform.render(v);
      }
      this._value = v;
      this.fire();
    }
  
    get value() {
      return this._value;
    }
  
    reset() {
      this.value = ``;
      this.cursor = Number(!!this.initial);
      this.fire();
      this.render();
    }
  
    abort() {
      this.value = this.value || this.initial;
      this.done = this.aborted = true;
      this.error = false;
      this.red = false;
      this.fire();
      this.render();
      this.out.write('\n');
      this.close();
    }
  
    async validate() {
      let valid = await this.validator(this.value);
      if (typeof valid === `string`) {
        this.errorMsg = valid;
        valid = false;
      }
      this.error = !valid;
    }
  
    async submit() {
      this.value = this.value || this.initial;
      await this.validate();
      if (this.error) {
        this.red = true;
        this.fire();
        this.render();
        return;
      }
      this.done = true;
      this.aborted = false;
      this.fire();
      this.render();
      this.out.write('\n');
      this.close();
    }
  
    next() {
      if (!this.placeholder) return this.bell();
      this.value = this.initial;
      this.cursor = this.rendered.length;
      this.fire();
      this.render();
    }
  
    moveCursor(n) {
      if (this.placeholder) return;
      this.cursor = this.cursor+n;
    }
  
    _(c, key) {
      let s1 = this.value.slice(0, this.cursor);
      let s2 = this.value.slice(this.cursor);
      this.value = `${s1}${c}${s2}`;
      this.red = false;
      this.cursor = this.placeholder ? 0 : s1.length+1;
      this.render();
    }
  
    delete() {
      if (this.cursor === 0) return this.bell();
      let s1 = this.value.slice(0, this.cursor-1);
      let s2 = this.value.slice(this.cursor);
      this.value = `${s1}${s2}`;
      this.red = false;
      this.moveCursor(-1);
      this.render();
    }
  
    deleteForward() {
      if(this.cursor*this.scale >= this.rendered.length || this.placeholder) return this.bell();
      let s1 = this.value.slice(0, this.cursor);
      let s2 = this.value.slice(this.cursor+1);
      this.value = `${s1}${s2}`;
      this.red = false;
      this.render();
    }
  
    first() {
      this.cursor = 0;
      this.render();
    }
  
    last() {
      this.cursor = this.value.length;
      this.render();
    }
  
    left() {
      if (this.cursor <= 0 || this.placeholder) return this.bell();
      this.moveCursor(-1);
      this.render();
    }
  
    right() {
      if (this.cursor*this.scale >= this.rendered.length || this.placeholder) return this.bell();
      this.moveCursor(1);
      this.render();
    }
  
    render() {
      if (this.closed) return;
      super.render();
      let erase = (this.lines ? cursor.down(this.lines) : ``)+this.clear;
      this.lines = 0;
  
      let prompt = [
        style.symbol(this.done, this.aborted),
        color.bold(this.msg),
        style.delimiter(this.done),
        this.red ? color.red(this.rendered) : this.rendered
      ].join(` `);
  
      let error = ``;
      if (this.error) {
        let lines = this.errorMsg.split(`\n`);
        error += lines.reduce((a, l, i) => a += `\n${i ? ' ' : figures.pointerSmall} ${color.red().italic(l)}`, ``);
        this.lines = lines.length;
      }
  
      let position = ``;
      if (this.lines) {
        position += cursor.up(this.lines);
        position += cursor.left+cursor.to(strip(prompt).length);
      }
      position += cursor.move(this.placeholder ?
        -this.initial.length*this.scale :
        -this.rendered.length+this.cursor*this.scale
      );
  
      this.out.write(erase+prompt+error+position);
      this.clear = clear(prompt+error);
    }
  }
  
  module.exports = TextPrompt;
  