/**
 * Refactored by zhennann
 * (C) 2010 Charlie Robbins
 * MIT LICENCE
 */

import { getText } from '@cabloy/localeutil';

import { SPLAT } from './types.ts';

const formatRegExp = /%[scdjifoO%]/g;
const escapedPercent = /%%/g;

class Splatter {
  options: any;
  constructor(opts) {
    this.options = opts;
  }

  _splat(info, tokens) {
    const msg = info.message;
    const splat = info[SPLAT] || info.splat || [];
    const percents = msg.match(escapedPercent);
    const escapes = (percents && percents.length) || 0;

    // The expected splat is the number of tokens minus the number of escapes
    // e.g.
    // - { expectedSplat: 3 } '%d %s %j'
    // - { expectedSplat: 5 } '[%s] %d%% %d%% %s %j'
    //
    // Any "meta" will be arugments in addition to the expected splat size
    // regardless of type. e.g.
    //
    // logger.log('info', '%d%% %s %j', 100, 'wow', { such: 'js' }, { thisIsMeta: true });
    // would result in splat of four (4), but only three (3) are expected. Therefore:
    //
    // extraSplat = 3 - 4 = -1
    // metas = [100, 'wow', { such: 'js' }, { thisIsMeta: true }].splice(-1, -1 * -1);
    // splat = [100, 'wow', { such: 'js' }]
    const expectedSplat = tokens.length - escapes;
    const extraSplat = expectedSplat - splat.length;
    const metas = extraSplat < 0 ? splat.splice(extraSplat, -1 * extraSplat) : [];

    // Now that { splat } has been separated from any potential { meta }. we
    // can assign this to the `info` object and write it to our format stream.
    // If the additional metas are **NOT** objects or **LACK** enumerable properties
    // you are going to have a bad time.
    const metalen = metas.length;
    if (metalen) {
      for (let i = 0; i < metalen; i++) {
        Object.assign(info, metas[i]);
      }
    }

    info.message = getText(msg, ...splat);
    return info;
  }

  transform(info) {
    const msg = info.message;
    const splat = info[SPLAT] || info.splat;

    // No need to process anything if splat is undefined
    if (!splat || !splat.length) {
      return info;
    }

    // Extract tokens, if none available default to empty array to
    // ensure consistancy in expected results
    const tokens = msg && msg.match && msg.match(formatRegExp);

    // This condition will take care of inputs with info[SPLAT]
    // but no tokens present
    if (!tokens && (splat || splat.length)) {
      const metas = splat.length > 1 ? splat.splice(0) : splat;

      // Now that { splat } has been separated from any potential { meta }. we
      // can assign this to the `info` object and write it to our format stream.
      // If the additional metas are **NOT** objects or **LACK** enumerable properties
      // you are going to have a bad time.
      const metalen = metas.length;
      if (metalen) {
        for (let i = 0; i < metalen; i++) {
          Object.assign(info, metas[i]);
        }
      }

      return info;
    }

    if (tokens) {
      return this._splat(info, tokens);
    }

    return info;
  }
}

export function splatter(opts?) {
  return new Splatter(opts);
}