'use strict';

function L10nError(message, id, lang) {
  this.name = 'L10nError';
  this.message = message;
  this.id = id;
  this.lang = lang;
}
L10nError.prototype = Object.create(Error.prototype);
L10nError.prototype.constructor = L10nError;

function load(type, url) {
  return new Promise(function(resolve, reject) {
    const xhr = new XMLHttpRequest();

    if (xhr.overrideMimeType) {
      xhr.overrideMimeType(type);
    }

    xhr.open('GET', url, true);

    if (type === 'application/json') {
      xhr.responseType = 'json';
    }

    xhr.addEventListener('load', function io_onload(e) {
      if (e.target.status === 200 || e.target.status === 0) {
        // Sinon.JS's FakeXHR doesn't have the response property
        resolve(e.target.response || e.target.responseText);
      } else {
        reject(new L10nError('Not found: ' + url));
      }
    });
    xhr.addEventListener('error', reject);
    xhr.addEventListener('timeout', reject);

    // the app: protocol throws on 404, see https://bugzil.la/827243
    try {
      xhr.send(null);
    } catch (e) {
      if (e.name === 'NS_ERROR_FILE_NOT_FOUND') {
        // the app: protocol throws on 404, see https://bugzil.la/827243
        reject(new L10nError('Not found: ' + url));
      } else {
        throw e;
      }
    }
  });
}

const io = {
  extra: function(code, ver, path, type) {
    return navigator.mozApps.getLocalizationResource(
      code, ver, path, type);
  },
  app: function(code, ver, path, type) {
    switch (type) {
      case 'text':
        return load('text/plain', path);
      case 'json':
        return load('application/json', path);
      default:
        throw new L10nError('Unknown file type: ' + type);
    }
  },
};

function fetchResource$1(res, { code, src, ver }) {
  const url = res.replace('{locale}', code);
  const type = res.endsWith('.json') ? 'json' : 'text';
  return io[src](code, ver, url, type);
}

const KNOWN_MACROS = ['plural'];
const MAX_PLACEABLE_LENGTH = 2500;

// Unicode bidi isolation characters
const FSI = '\u2068';
const PDI = '\u2069';

const resolutionChain = new WeakSet();

function format(ctx, lang, args, entity) {
  if (typeof entity === 'string') {
    return [{}, entity];
  }

  if (resolutionChain.has(entity)) {
    throw new L10nError('Cyclic reference detected');
  }

  resolutionChain.add(entity);

  let rv;
  // if format fails, we want the exception to bubble up and stop the whole
  // resolving process;  however, we still need to remove the entity from the
  // resolution chain
  try {
    rv = resolveValue(
      {}, ctx, lang, args, entity.value, entity.index);
  } finally {
    resolutionChain.delete(entity);
  }
  return rv;
}

function resolveIdentifier(ctx, lang, args, id) {
  if (KNOWN_MACROS.indexOf(id) > -1) {
    return [{}, ctx._getMacro(lang, id)];
  }

  if (args && args.hasOwnProperty(id)) {
    if (typeof args[id] === 'string' || (typeof args[id] === 'number' &&
        !isNaN(args[id]))) {
      return [{}, args[id]];
    } else {
      throw new L10nError('Arg must be a string or a number: ' + id);
    }
  }

  // XXX: special case for Node.js where still:
  // '__proto__' in Object.create(null) => true
  if (id === '__proto__') {
    throw new L10nError('Illegal id: ' + id);
  }

  const entity = ctx._getEntity(lang, id);

  if (entity) {
    return format(ctx, lang, args, entity);
  }

  throw new L10nError('Unknown reference: ' + id);
}

function subPlaceable(locals, ctx, lang, args, id) {
  let newLocals, value;

  try {
    [newLocals, value] = resolveIdentifier(ctx, lang, args, id);
  } catch (err) {
    return [{ error: err }, FSI + '{{ ' + id + ' }}' + PDI];
  }

  if (typeof value === 'number') {
    const formatter = ctx._getNumberFormatter(lang);
    return [newLocals, formatter.format(value)];
  }

  if (typeof value === 'string') {
    // prevent Billion Laughs attacks
    if (value.length >= MAX_PLACEABLE_LENGTH) {
      throw new L10nError('Too many characters in placeable (' +
                          value.length + ', max allowed is ' +
                          MAX_PLACEABLE_LENGTH + ')');
    }
    return [newLocals, FSI + value + PDI];
  }

  return [{}, FSI + '{{ ' + id + ' }}' + PDI];
}

function interpolate(locals, ctx, lang, args, arr) {
  return arr.reduce(function([localsSeq, valueSeq], cur) {
    if (typeof cur === 'string') {
      return [localsSeq, valueSeq + cur];
    } else {
      const [, value] = subPlaceable(locals, ctx, lang, args, cur.name);
      // wrap the substitution in bidi isolate characters
      return [localsSeq, valueSeq + value];
    }
  }, [locals, '']);
}

function resolveSelector(ctx, lang, args, expr, index) {
  //XXX: Dehardcode!!!
  let selectorName;
  if (index[0].type === 'call' && index[0].expr.type === 'prop' &&
      index[0].expr.expr.name === 'cldr') {
    selectorName = 'plural';
  } else {
    selectorName = index[0].name;
  }
  const selector = resolveIdentifier(ctx, lang, args, selectorName)[1];

  if (typeof selector !== 'function') {
    // selector is a simple reference to an entity or args
    return selector;
  }

  const argValue = index[0].args ?
    resolveIdentifier(ctx, lang, args, index[0].args[0].name)[1] : undefined;

  if (selectorName === 'plural') {
    // special cases for zero, one, two if they are defined on the hash
    if (argValue === 0 && 'zero' in expr) {
      return 'zero';
    }
    if (argValue === 1 && 'one' in expr) {
      return 'one';
    }
    if (argValue === 2 && 'two' in expr) {
      return 'two';
    }
  }

  return selector(argValue);
}

function resolveValue(locals, ctx, lang, args, expr, index) {
  if (!expr) {
    return [locals, expr];
  }

  if (typeof expr === 'string' ||
      typeof expr === 'boolean' ||
      typeof expr === 'number') {
    return [locals, expr];
  }

  if (Array.isArray(expr)) {
    return interpolate(locals, ctx, lang, args, expr);
  }

  // otherwise, it's a dict
  if (index) {
    // try to use the index in order to select the right dict member
    const selector = resolveSelector(ctx, lang, args, expr, index);
    if (selector in expr) {
      return resolveValue(locals, ctx, lang, args, expr[selector]);
    }
  }

  // if there was no index or no selector was found, try the default
  // XXX 'other' is an artifact from Gaia
  const defaultKey = expr.__default || 'other';
  if (defaultKey in expr) {
    return resolveValue(locals, ctx, lang, args, expr[defaultKey]);
  }

  throw new L10nError('Unresolvable value');
}

const locales2rules = {
  'af': 3,
  'ak': 4,
  'am': 4,
  'ar': 1,
  'asa': 3,
  'az': 0,
  'be': 11,
  'bem': 3,
  'bez': 3,
  'bg': 3,
  'bh': 4,
  'bm': 0,
  'bn': 3,
  'bo': 0,
  'br': 20,
  'brx': 3,
  'bs': 11,
  'ca': 3,
  'cgg': 3,
  'chr': 3,
  'cs': 12,
  'cy': 17,
  'da': 3,
  'de': 3,
  'dv': 3,
  'dz': 0,
  'ee': 3,
  'el': 3,
  'en': 3,
  'eo': 3,
  'es': 3,
  'et': 3,
  'eu': 3,
  'fa': 0,
  'ff': 5,
  'fi': 3,
  'fil': 4,
  'fo': 3,
  'fr': 5,
  'fur': 3,
  'fy': 3,
  'ga': 8,
  'gd': 24,
  'gl': 3,
  'gsw': 3,
  'gu': 3,
  'guw': 4,
  'gv': 23,
  'ha': 3,
  'haw': 3,
  'he': 2,
  'hi': 4,
  'hr': 11,
  'hu': 0,
  'id': 0,
  'ig': 0,
  'ii': 0,
  'is': 3,
  'it': 3,
  'iu': 7,
  'ja': 0,
  'jmc': 3,
  'jv': 0,
  'ka': 0,
  'kab': 5,
  'kaj': 3,
  'kcg': 3,
  'kde': 0,
  'kea': 0,
  'kk': 3,
  'kl': 3,
  'km': 0,
  'kn': 0,
  'ko': 0,
  'ksb': 3,
  'ksh': 21,
  'ku': 3,
  'kw': 7,
  'lag': 18,
  'lb': 3,
  'lg': 3,
  'ln': 4,
  'lo': 0,
  'lt': 10,
  'lv': 6,
  'mas': 3,
  'mg': 4,
  'mk': 16,
  'ml': 3,
  'mn': 3,
  'mo': 9,
  'mr': 3,
  'ms': 0,
  'mt': 15,
  'my': 0,
  'nah': 3,
  'naq': 7,
  'nb': 3,
  'nd': 3,
  'ne': 3,
  'nl': 3,
  'nn': 3,
  'no': 3,
  'nr': 3,
  'nso': 4,
  'ny': 3,
  'nyn': 3,
  'om': 3,
  'or': 3,
  'pa': 3,
  'pap': 3,
  'pl': 13,
  'ps': 3,
  'pt': 3,
  'rm': 3,
  'ro': 9,
  'rof': 3,
  'ru': 11,
  'rwk': 3,
  'sah': 0,
  'saq': 3,
  'se': 7,
  'seh': 3,
  'ses': 0,
  'sg': 0,
  'sh': 11,
  'shi': 19,
  'sk': 12,
  'sl': 14,
  'sma': 7,
  'smi': 7,
  'smj': 7,
  'smn': 7,
  'sms': 7,
  'sn': 3,
  'so': 3,
  'sq': 3,
  'sr': 11,
  'ss': 3,
  'ssy': 3,
  'st': 3,
  'sv': 3,
  'sw': 3,
  'syr': 3,
  'ta': 3,
  'te': 3,
  'teo': 3,
  'th': 0,
  'ti': 4,
  'tig': 3,
  'tk': 3,
  'tl': 4,
  'tn': 3,
  'to': 0,
  'tr': 0,
  'ts': 3,
  'tzm': 22,
  'uk': 11,
  'ur': 3,
  've': 3,
  'vi': 0,
  'vun': 3,
  'wa': 4,
  'wae': 3,
  'wo': 0,
  'xh': 3,
  'xog': 3,
  'yo': 0,
  'zh': 0,
  'zu': 3
};

// utility functions for plural rules methods
function isIn(n, list) {
  return list.indexOf(n) !== -1;
}
function isBetween(n, start, end) {
  return typeof n === typeof start && start <= n && n <= end;
}

// list of all plural rules methods:
// map an integer to the plural form name to use
const pluralRules = {
  '0': function() {
    return 'other';
  },
  '1': function(n) {
    if ((isBetween((n % 100), 3, 10))) {
      return 'few';
    }
    if (n === 0) {
      return 'zero';
    }
    if ((isBetween((n % 100), 11, 99))) {
      return 'many';
    }
    if (n === 2) {
      return 'two';
    }
    if (n === 1) {
      return 'one';
    }
    return 'other';
  },
  '2': function(n) {
    if (n !== 0 && (n % 10) === 0) {
      return 'many';
    }
    if (n === 2) {
      return 'two';
    }
    if (n === 1) {
      return 'one';
    }
    return 'other';
  },
  '3': function(n) {
    if (n === 1) {
      return 'one';
    }
    return 'other';
  },
  '4': function(n) {
    if ((isBetween(n, 0, 1))) {
      return 'one';
    }
    return 'other';
  },
  '5': function(n) {
    if ((isBetween(n, 0, 2)) && n !== 2) {
      return 'one';
    }
    return 'other';
  },
  '6': function(n) {
    if (n === 0) {
      return 'zero';
    }
    if ((n % 10) === 1 && (n % 100) !== 11) {
      return 'one';
    }
    return 'other';
  },
  '7': function(n) {
    if (n === 2) {
      return 'two';
    }
    if (n === 1) {
      return 'one';
    }
    return 'other';
  },
  '8': function(n) {
    if ((isBetween(n, 3, 6))) {
      return 'few';
    }
    if ((isBetween(n, 7, 10))) {
      return 'many';
    }
    if (n === 2) {
      return 'two';
    }
    if (n === 1) {
      return 'one';
    }
    return 'other';
  },
  '9': function(n) {
    if (n === 0 || n !== 1 && (isBetween((n % 100), 1, 19))) {
      return 'few';
    }
    if (n === 1) {
      return 'one';
    }
    return 'other';
  },
  '10': function(n) {
    if ((isBetween((n % 10), 2, 9)) && !(isBetween((n % 100), 11, 19))) {
      return 'few';
    }
    if ((n % 10) === 1 && !(isBetween((n % 100), 11, 19))) {
      return 'one';
    }
    return 'other';
  },
  '11': function(n) {
    if ((isBetween((n % 10), 2, 4)) && !(isBetween((n % 100), 12, 14))) {
      return 'few';
    }
    if ((n % 10) === 0 ||
        (isBetween((n % 10), 5, 9)) ||
        (isBetween((n % 100), 11, 14))) {
      return 'many';
    }
    if ((n % 10) === 1 && (n % 100) !== 11) {
      return 'one';
    }
    return 'other';
  },
  '12': function(n) {
    if ((isBetween(n, 2, 4))) {
      return 'few';
    }
    if (n === 1) {
      return 'one';
    }
    return 'other';
  },
  '13': function(n) {
    if ((isBetween((n % 10), 2, 4)) && !(isBetween((n % 100), 12, 14))) {
      return 'few';
    }
    if (n !== 1 && (isBetween((n % 10), 0, 1)) ||
        (isBetween((n % 10), 5, 9)) ||
        (isBetween((n % 100), 12, 14))) {
      return 'many';
    }
    if (n === 1) {
      return 'one';
    }
    return 'other';
  },
  '14': function(n) {
    if ((isBetween((n % 100), 3, 4))) {
      return 'few';
    }
    if ((n % 100) === 2) {
      return 'two';
    }
    if ((n % 100) === 1) {
      return 'one';
    }
    return 'other';
  },
  '15': function(n) {
    if (n === 0 || (isBetween((n % 100), 2, 10))) {
      return 'few';
    }
    if ((isBetween((n % 100), 11, 19))) {
      return 'many';
    }
    if (n === 1) {
      return 'one';
    }
    return 'other';
  },
  '16': function(n) {
    if ((n % 10) === 1 && n !== 11) {
      return 'one';
    }
    return 'other';
  },
  '17': function(n) {
    if (n === 3) {
      return 'few';
    }
    if (n === 0) {
      return 'zero';
    }
    if (n === 6) {
      return 'many';
    }
    if (n === 2) {
      return 'two';
    }
    if (n === 1) {
      return 'one';
    }
    return 'other';
  },
  '18': function(n) {
    if (n === 0) {
      return 'zero';
    }
    if ((isBetween(n, 0, 2)) && n !== 0 && n !== 2) {
      return 'one';
    }
    return 'other';
  },
  '19': function(n) {
    if ((isBetween(n, 2, 10))) {
      return 'few';
    }
    if ((isBetween(n, 0, 1))) {
      return 'one';
    }
    return 'other';
  },
  '20': function(n) {
    if ((isBetween((n % 10), 3, 4) || ((n % 10) === 9)) && !(
        isBetween((n % 100), 10, 19) ||
        isBetween((n % 100), 70, 79) ||
        isBetween((n % 100), 90, 99)
        )) {
      return 'few';
    }
    if ((n % 1000000) === 0 && n !== 0) {
      return 'many';
    }
    if ((n % 10) === 2 && !isIn((n % 100), [12, 72, 92])) {
      return 'two';
    }
    if ((n % 10) === 1 && !isIn((n % 100), [11, 71, 91])) {
      return 'one';
    }
    return 'other';
  },
  '21': function(n) {
    if (n === 0) {
      return 'zero';
    }
    if (n === 1) {
      return 'one';
    }
    return 'other';
  },
  '22': function(n) {
    if ((isBetween(n, 0, 1)) || (isBetween(n, 11, 99))) {
      return 'one';
    }
    return 'other';
  },
  '23': function(n) {
    if ((isBetween((n % 10), 1, 2)) || (n % 20) === 0) {
      return 'one';
    }
    return 'other';
  },
  '24': function(n) {
    if ((isBetween(n, 3, 10) || isBetween(n, 13, 19))) {
      return 'few';
    }
    if (isIn(n, [2, 12])) {
      return 'two';
    }
    if (isIn(n, [1, 11])) {
      return 'one';
    }
    return 'other';
  }
};

function getPluralRule(code) {
  // return a function that gives the plural form name for a given integer
  const index = locales2rules[code.replace(/-.*$/, '')];
  if (!(index in pluralRules)) {
    return function() { return 'other'; };
  }
  return pluralRules[index];
}

// Safari 9 and iOS 9 does not support Intl
const L20nIntl = typeof Intl !== 'undefined' ?
  Intl : {
  NumberFormat: function() {
    return {
      format: function(v) {
        return v;
      }
    };
  }
};

class Context {
  constructor(env, langs, resIds) {
    this.langs = langs;
    this.resIds = resIds;
    this.env = env;
    this.emit = (type, evt) => env.emit(type, evt, this);
  }

  _formatTuple(lang, args, entity, id, key) {
    try {
      return format(this, lang, args, entity);
    } catch (err) {
      err.id = key ? id + '::' + key : id;
      err.lang = lang;
      this.emit('resolveerror', err);
      return [{ error: err }, err.id];
    }
  }

  _formatEntity(lang, args, entity, id) {
    const [, value] = this._formatTuple(lang, args, entity, id);

    const formatted = {
      value,
      attrs: null,
    };

    if (entity.attrs) {
      formatted.attrs = Object.create(null);
      for (let key in entity.attrs) {
        /* jshint -W089 */
        const [, attrValue] = this._formatTuple(
          lang, args, entity.attrs[key], id, key);
        formatted.attrs[key] = attrValue;
      }
    }

    return formatted;
  }

  _formatValue(lang, args, entity, id) {
    return this._formatTuple(lang, args, entity, id)[1];
  }

  fetch(langs = this.langs) {
    if (langs.length === 0) {
      return Promise.resolve(langs);
    }

    return Promise.all(
      this.resIds.map(
        resId => this.env._getResource(langs[0], resId))
    ).then(() => langs);
  }

  _resolve(langs, keys, formatter, prevResolved) {
    const lang = langs[0];

    if (!lang) {
      return reportMissing.call(this, keys, formatter, prevResolved);
    }

    let hasUnresolved = false;

    const resolved = keys.map((key, i) => {
      if (prevResolved && prevResolved[i] !== undefined) {
        return prevResolved[i];
      }
      const [id, args] = Array.isArray(key) ?
        key : [key, undefined];
      const entity = this._getEntity(lang, id);

      if (entity) {
        return formatter.call(this, lang, args, entity, id);
      }

      this.emit('notfounderror',
        new L10nError('"' + id + '"' + ' not found in ' + lang.code,
          id, lang));
      hasUnresolved = true;
    });

    if (!hasUnresolved) {
      return resolved;
    }

    return this.fetch(langs.slice(1)).then(
      nextLangs => this._resolve(nextLangs, keys, formatter, resolved));
  }

  formatEntities(...keys) {
    return this.fetch().then(
      langs => this._resolve(langs, keys, this._formatEntity));
  }

  formatValues(...keys) {
    return this.fetch().then(
      langs => this._resolve(langs, keys, this._formatValue));
  }

  _getEntity(lang, id) {
    const cache = this.env.resCache;

    // Look for `id` in every resource in order.
    for (let i = 0, resId; resId = this.resIds[i]; i++) {
      const resource = cache.get(resId + lang.code + lang.src);
      if (resource instanceof L10nError) {
        continue;
      }
      if (id in resource) {
        return resource[id];
      }
    }
    return undefined;
  }

  _getNumberFormatter(lang) {
    if (!this.env.numberFormatters) {
      this.env.numberFormatters = new Map();
    }
    if (!this.env.numberFormatters.has(lang)) {
      const formatter = L20nIntl.NumberFormat(lang);
      this.env.numberFormatters.set(lang, formatter);
      return formatter;
    }
    return this.env.numberFormatters.get(lang);
  }

  // XXX in the future macros will be stored in localization resources together 
  // with regular entities and this method will not be needed anymore
  _getMacro(lang, id) {
    switch(id) {
      case 'plural':
        return getPluralRule(lang.code);
      default:
        return undefined;
    }
  }

}

function reportMissing(keys, formatter, resolved) {
  const missingIds = new Set();

  keys.forEach((key, i) => {
    if (resolved && resolved[i] !== undefined) {
      return;
    }
    const id = Array.isArray(key) ? key[0] : key;
    missingIds.add(id);
    resolved[i] = formatter === this._formatValue ?
      id : {value: id, attrs: null};
  });

  this.emit('notfounderror', new L10nError(
    '"' + Array.from(missingIds).join(', ') + '"' +
    ' not found in any language', missingIds));

  return resolved;
}

var MAX_PLACEABLES = 100;

var PropertiesParser = {
  patterns: null,
  entryIds: null,
  emit: null,

  init: function() {
    this.patterns = {
      comment: /^\s*#|^\s*$/,
      entity: /^([^=\s]+)\s*=\s*(.*)$/,
      multiline: /[^\\]\\$/,
      index: /\{\[\s*(\w+)(?:\(([^\)]*)\))?\s*\]\}/i,
      unicode: /\\u([0-9a-fA-F]{1,4})/g,
      entries: /[^\r\n]+/g,
      controlChars: /\\([\\\n\r\t\b\f\{\}\"\'])/g,
      placeables: /\{\{\s*([^\s]*?)\s*\}\}/,
    };
  },

  parse: function(emit, source) {
    if (!this.patterns) {
      this.init();
    }
    this.emit = emit;

    var entries = {};

    var lines = source.match(this.patterns.entries);
    if (!lines) {
      return entries;
    }
    for (var i = 0; i < lines.length; i++) {
      var line = lines[i];

      if (this.patterns.comment.test(line)) {
        continue;
      }

      while (this.patterns.multiline.test(line) && i < lines.length) {
        line = line.slice(0, -1) + lines[++i].trim();
      }

      var entityMatch = line.match(this.patterns.entity);
      if (entityMatch) {
        try {
          this.parseEntity(entityMatch[1], entityMatch[2], entries);
        } catch (e) {
          if (!this.emit) {
            throw e;
          }
        }
      }
    }
    return entries;
  },

  parseEntity: function(id, value, entries) {
    var name, key;

    var pos = id.indexOf('[');
    if (pos !== -1) {
      name = id.substr(0, pos);
      key = id.substring(pos + 1, id.length - 1);
    } else {
      name = id;
      key = null;
    }

    var nameElements = name.split('.');

    if (nameElements.length > 2) {
      throw this.error('Error in ID: "' + name + '".' +
          ' Nested attributes are not supported.');
    }

    var attr;
    if (nameElements.length > 1) {
      name = nameElements[0];
      attr = nameElements[1];

      if (attr[0] === '$') {
        throw this.error('Attribute can\'t start with "$"');
      }
    } else {
      attr = null;
    }

    this.setEntityValue(name, attr, key, this.unescapeString(value), entries);
  },

  setEntityValue: function(id, attr, key, rawValue, entries) {
    var value = rawValue.indexOf('{{') > -1 ?
      this.parseString(rawValue) : rawValue;

    var isSimpleValue = typeof value === 'string';
    var root = entries;

    var isSimpleNode = typeof entries[id] === 'string';

    if (!entries[id] && (attr || key || !isSimpleValue)) {
      entries[id] = Object.create(null);
      isSimpleNode = false;
    }

    if (attr) {
      if (isSimpleNode) {
        const val = entries[id];
        entries[id] = Object.create(null);
        entries[id].value = val;
      }
      if (!entries[id].attrs) {
        entries[id].attrs = Object.create(null);
      }
      if (!entries[id].attrs && !isSimpleValue) {
        entries[id].attrs[attr] = Object.create(null);
      }
      root = entries[id].attrs;
      id = attr;
    }

    if (key) {
      isSimpleNode = false;
      if (typeof root[id] === 'string') {
        const val = root[id];
        root[id] = Object.create(null);
        root[id].index = this.parseIndex(val);
        root[id].value = Object.create(null);
      }
      root = root[id].value;
      id = key;
      isSimpleValue = true;
    }

    if (isSimpleValue) {
      if (id in root) {
        throw this.error('Duplicated id: ' + id);
      }
      root[id] = value;
    } else {
      if (!root[id]) {
        root[id] = Object.create(null);
      }
      root[id].value = value;
    }
  },

  parseString: function(str) {
    var chunks = str.split(this.patterns.placeables);
    var complexStr = [];

    var len = chunks.length;
    var placeablesCount = (len - 1) / 2;

    if (placeablesCount >= MAX_PLACEABLES) {
      throw this.error('Too many placeables (' + placeablesCount +
                          ', max allowed is ' + MAX_PLACEABLES + ')');
    }

    for (var i = 0; i < chunks.length; i++) {
      if (chunks[i].length === 0) {
        continue;
      }
      if (i % 2 === 1) {
        complexStr.push({type: 'idOrVar', name: chunks[i]});
      } else {
        complexStr.push(chunks[i]);
      }
    }
    return complexStr;
  },

  unescapeString: function(str) {
    if (str.lastIndexOf('\\') !== -1) {
      str = str.replace(this.patterns.controlChars, '$1');
    }
    return str.replace(this.patterns.unicode, function(match, token) {
      return String.fromCodePoint(parseInt(token, 16));
    });
  },

  parseIndex: function(str) {
    var match = str.match(this.patterns.index);
    if (!match) {
      throw new L10nError('Malformed index');
    }
    if (match[2]) {
      return [{
        type: 'call',
        expr: {
          type: 'prop',
          expr: {
            type: 'glob',
            name: 'cldr'
          },
          prop: 'plural',
          cmpt: false
        }, args: [{
          type: 'idOrVar',
          name: match[2]
        }]
      }];
    } else {
      return [{type: 'idOrVar', name: match[1]}];
    }
  },

  error: function(msg, type = 'parsererror') {
    const err = new L10nError(msg);
    if (this.emit) {
      this.emit(type, err);
    }
    return err;
  }
};

const MAX_PLACEABLES$1 = 100;

var L20nParser = {
  parse: function(emit, string) {
    this._source = string;
    this._index = 0;
    this._length = string.length;
    this.entries = Object.create(null);
    this.emit = emit;

    return this.getResource();
  },

  getResource: function() {
    this.getWS();
    while (this._index < this._length) {
      try {
        this.getEntry();
      } catch (e) {
        if (e instanceof L10nError) {
          // we want to recover, but we don't need it in entries
          this.getJunkEntry();
          if (!this.emit) {
            throw e;
          }
        } else {
          throw e;
        }
      }

      if (this._index < this._length) {
        this.getWS();
      }
    }

    return this.entries;
  },

  getEntry: function() {
    if (this._source[this._index] === '<') {
      ++this._index;
      const id = this.getIdentifier();
      if (this._source[this._index] === '[') {
        ++this._index;
        return this.getEntity(id, this.getItemList(this.getExpression, ']'));
      }
      return this.getEntity(id);
    }

    if (this._source.startsWith('/*', this._index)) {
      return this.getComment();
    }

    throw this.error('Invalid entry');
  },

  getEntity: function(id, index) {
    if (!this.getRequiredWS()) {
      throw this.error('Expected white space');
    }

    const ch = this._source[this._index];
    const hasIndex = index !== undefined;
    const value = this.getValue(ch, hasIndex, hasIndex);
    let attrs;

    if (value === undefined) {
      if (ch === '>') {
        throw this.error('Expected ">"');
      }
      attrs = this.getAttributes();
    } else {
      const ws1 = this.getRequiredWS();
      if (this._source[this._index] !== '>') {
        if (!ws1) {
          throw this.error('Expected ">"');
        }
        attrs = this.getAttributes();
      }
    }

    // skip '>'
    ++this._index;

    if (id in this.entries) {
      throw this.error('Duplicate entry ID "' + id, 'duplicateerror');
    }
    if (!attrs && !index && typeof value === 'string') {
      this.entries[id] = value;
    } else {
      this.entries[id] = {
        value,
        attrs,
        index
      };
    }
  },

  getValue: function(
    ch = this._source[this._index], index = false, required = true) {
    switch (ch) {
      case '\'':
      case '"':
        return this.getString(ch, 1);
      case '{':
        return this.getHash(index);
    }

    if (required) {
      throw this.error('Unknown value type');
    }

    return;
  },

  getWS: function() {
    let cc = this._source.charCodeAt(this._index);
    // space, \n, \t, \r
    while (cc === 32 || cc === 10 || cc === 9 || cc === 13) {
      cc = this._source.charCodeAt(++this._index);
    }
  },

  getRequiredWS: function() {
    const pos = this._index;
    let cc = this._source.charCodeAt(pos);
    // space, \n, \t, \r
    while (cc === 32 || cc === 10 || cc === 9 || cc === 13) {
      cc = this._source.charCodeAt(++this._index);
    }
    return this._index !== pos;
  },

  getIdentifier: function() {
    const start = this._index;
    let cc = this._source.charCodeAt(this._index);

    if ((cc >= 97 && cc <= 122) || // a-z
        (cc >= 65 && cc <= 90) ||  // A-Z
        cc === 95) {               // _
      cc = this._source.charCodeAt(++this._index);
    } else {
      throw this.error('Identifier has to start with [a-zA-Z_]');
    }

    while ((cc >= 97 && cc <= 122) || // a-z
           (cc >= 65 && cc <= 90) ||  // A-Z
           (cc >= 48 && cc <= 57) ||  // 0-9
           cc === 95) {               // _
      cc = this._source.charCodeAt(++this._index);
    }

    return this._source.slice(start, this._index);
  },

  getUnicodeChar: function() {
    for (let i = 0; i < 4; i++) {
      let cc = this._source.charCodeAt(++this._index);
      if ((cc > 96 && cc < 103) || // a-f
          (cc > 64 && cc < 71) ||  // A-F
          (cc > 47 && cc < 58)) {  // 0-9
        continue;
      }
      throw this.error('Illegal unicode escape sequence');
    }
    this._index++;
    return String.fromCharCode(
      parseInt(this._source.slice(this._index - 4, this._index), 16));
  },

  stringRe: /"|'|{{|\\/g,
  getString: function(opchar, opcharLen) {
    const body = [];
    let placeables = 0;

    this._index += opcharLen;
    const start = this._index;

    let bufStart = start;
    let buf = '';

    while (true) {
      this.stringRe.lastIndex = this._index;
      const match = this.stringRe.exec(this._source);

      if (!match) {
        throw this.error('Unclosed string literal');
      }

      if (match[0] === '"' || match[0] === '\'') {
        if (match[0] !== opchar) {
          this._index += opcharLen;
          continue;
        }
        this._index = match.index + opcharLen;
        break;
      }

      if (match[0] === '{{') {
        if (placeables > MAX_PLACEABLES$1 - 1) {
          throw this.error('Too many placeables, maximum allowed is ' +
              MAX_PLACEABLES$1);
        }
        placeables++;
        if (match.index > bufStart || buf.length > 0) {
          body.push(buf + this._source.slice(bufStart, match.index));
          buf = '';
        }
        this._index = match.index + 2;
        this.getWS();
        body.push(this.getExpression());
        this.getWS();
        this._index += 2;
        bufStart = this._index;
        continue;
      }

      if (match[0] === '\\') {
        this._index = match.index + 1;
        const ch2 = this._source[this._index];
        if (ch2 === 'u') {
          buf += this._source.slice(bufStart, match.index) +
            this.getUnicodeChar();
        } else if (ch2 === opchar || ch2 === '\\') {
          buf += this._source.slice(bufStart, match.index) + ch2;
          this._index++;
        } else if (this._source.startsWith('{{', this._index)) {
          buf += this._source.slice(bufStart, match.index) + '{{';
          this._index += 2;
        } else {
          throw this.error('Illegal escape sequence');
        }
        bufStart = this._index;
      }
    }

    if (body.length === 0) {
      return buf + this._source.slice(bufStart, this._index - opcharLen);
    }

    if (this._index - opcharLen > bufStart || buf.length > 0) {
      body.push(buf + this._source.slice(bufStart, this._index - opcharLen));
    }

    return body;
  },

  getAttributes: function() {
    const attrs = Object.create(null);

    while (true) {
      this.getAttribute(attrs);
      const ws1 = this.getRequiredWS();
      const ch = this._source.charAt(this._index);
      if (ch === '>') {
        break;
      } else if (!ws1) {
        throw this.error('Expected ">"');
      }
    }
    return attrs;
  },

  getAttribute: function(attrs) {
    const key = this.getIdentifier();
    let index;

    if (this._source[this._index]=== '[') {
      ++this._index;
      this.getWS();
      index = this.getItemList(this.getExpression, ']');
    }
    this.getWS();
    if (this._source[this._index] !== ':') {
      throw this.error('Expected ":"');
    }
    ++this._index;
    this.getWS();
    const hasIndex = index !== undefined;
    const value = this.getValue(undefined, hasIndex);

    if (key in attrs) {
      throw this.error('Duplicate attribute "' + key, 'duplicateerror');
    }

    if (!index && typeof value === 'string') {
      attrs[key] = value;
    } else {
      attrs[key] = {
        value,
        index
      };
    }
  },

  getHash: function(index) {
    const items = Object.create(null);

    ++this._index;
    this.getWS();

    let defKey;

    while (true) {
      const [key, value, def] = this.getHashItem();
      items[key] = value;

      if (def) {
        if (defKey) {
          throw this.error('Default item redefinition forbidden');
        }
        defKey = key;
      }
      this.getWS();

      const comma = this._source[this._index] === ',';
      if (comma) {
        ++this._index;
        this.getWS();
      }
      if (this._source[this._index] === '}') {
        ++this._index;
        break;
      }
      if (!comma) {
        throw this.error('Expected "}"');
      }
    }

    if (defKey) {
      items.__default = defKey;
    } else if (!index) {
      throw this.error('Unresolvable Hash Value');
    }

    return items;
  },

  getHashItem: function() {
    let defItem = false;
    if (this._source[this._index] === '*') {
      ++this._index;
      defItem = true;
    }

    const key = this.getIdentifier();
    this.getWS();
    if (this._source[this._index] !== ':') {
      throw this.error('Expected ":"');
    }
    ++this._index;
    this.getWS();

    return [key, this.getValue(), defItem];
  },

  getComment: function() {
    this._index += 2;
    const start = this._index;
    const end = this._source.indexOf('*/', start);

    if (end === -1) {
      throw this.error('Comment without a closing tag');
    }

    this._index = end + 2;
  },

  getExpression: function () {
    let exp = this.getPrimaryExpression();

    while (true) {
      let ch = this._source[this._index];
      if (ch === '.' || ch === '[') {
        ++this._index;
        exp = this.getPropertyExpression(exp, ch === '[');
      } else if (ch === '(') {
        ++this._index;
        exp = this.getCallExpression(exp);
      } else {
        break;
      }
    }

    return exp;
  },

  getPropertyExpression: function(idref, computed) {
    let exp;

    if (computed) {
      this.getWS();
      exp = this.getExpression();
      this.getWS();
      if (this._source[this._index] !== ']') {
        throw this.error('Expected "]"');
      }
      ++this._index;
    } else {
      exp = this.getIdentifier();
    }

    return {
      type: 'prop',
      expr: idref,
      prop: exp,
      cmpt: computed
    };
  },

  getCallExpression: function(callee) {
    this.getWS();

    return {
      type: 'call',
      expr: callee,
      args: this.getItemList(this.getExpression, ')')
    };
  },

  getPrimaryExpression: function() {
    const ch = this._source[this._index];

    switch (ch) {
      case '$':
        ++this._index;
        return {
          type: 'var',
          name: this.getIdentifier()
        };
      case '@':
        ++this._index;
        return {
          type: 'glob',
          name: this.getIdentifier()
        };
      default:
        return {
          type: 'id',
          name: this.getIdentifier()
        };
    }
  },

  getItemList: function(callback, closeChar) {
    const items = [];
    let closed = false;

    this.getWS();

    if (this._source[this._index] === closeChar) {
      ++this._index;
      closed = true;
    }

    while (!closed) {
      items.push(callback.call(this));
      this.getWS();
      let ch = this._source.charAt(this._index);
      switch (ch) {
        case ',':
          ++this._index;
          this.getWS();
          break;
        case closeChar:
          ++this._index;
          closed = true;
          break;
        default:
          throw this.error('Expected "," or "' + closeChar + '"');
      }
    }

    return items;
  },


  getJunkEntry: function() {
    const pos = this._index;
    let nextEntity = this._source.indexOf('<', pos);
    let nextComment = this._source.indexOf('/*', pos);

    if (nextEntity === -1) {
      nextEntity = this._length;
    }
    if (nextComment === -1) {
      nextComment = this._length;
    }

    let nextEntry = Math.min(nextEntity, nextComment);

    this._index = nextEntry;
  },

  error: function(message, type = 'parsererror') {
    const pos = this._index;

    let start = this._source.lastIndexOf('<', pos - 1);
    const lastClose = this._source.lastIndexOf('>', pos - 1);
    start = lastClose > start ? lastClose + 1 : start;
    const context = this._source.slice(start, pos + 10);

    const msg = message + ' at pos ' + pos + ': `' + context + '`';
    const err = new L10nError(msg);
    if (this.emit) {
      this.emit(type, err);
    }
    return err;
  },
};

// Walk an entry node searching for content leaves
function walkEntry(entry, fn) {
  if (typeof entry === 'string') {
    return fn(entry);
  }

  const newEntry = Object.create(null);

  if (entry.value) {
    newEntry.value = walkValue(entry.value, fn);
  }

  if (entry.index) {
    newEntry.index = entry.index;
  }

  if (entry.attrs) {
    newEntry.attrs = Object.create(null);
    for (let key in entry.attrs) {
      newEntry.attrs[key] = walkEntry(entry.attrs[key], fn);
    }
  }

  return newEntry;
}

function walkValue(value, fn) {
  if (typeof value === 'string') {
    return fn(value);
  }

  // skip expressions in placeables
  if (value.type) {
    return value;
  }

  const newValue = Array.isArray(value) ? [] : Object.create(null);
  const keys = Object.keys(value);

  for (let i = 0, key; (key = keys[i]); i++) {
    newValue[key] = walkValue(value[key], fn);
  }

  return newValue;
}

/* Pseudolocalizations
 *
 * pseudo is a dict of strategies to be used to modify the English
 * context in order to create pseudolocalizations.  These can be used by
 * developers to test the localizability of their code without having to
 * actually speak a foreign language.
 *
 * Currently, the following pseudolocales are supported:
 *
 *   fr-x-psaccent - Ȧȧƈƈḗḗƞŧḗḗḓ Ḗḗƞɠŀīīşħ
 *
 *     In Accented English all English letters are replaced by accented
 *     Unicode counterparts which don't impair the readability of the content.
 *     This allows developers to quickly test if any given string is being
 *     correctly displayed in its 'translated' form.  Additionally, simple
 *     heuristics are used to make certain words longer to better simulate the
 *     experience of international users.
 *
 *   ar-x-psbidi - ɥsıʅƃuƎ ıpıԐ
 *
 *     Bidi English is a fake RTL locale.  All words are surrounded by
 *     Unicode formatting marks forcing the RTL directionality of characters.
 *     In addition, to make the reversed text easier to read, individual
 *     letters are flipped.
 *
 *     Note: The name above is hardcoded to be RTL in case code editors have
 *     trouble with the RLO and PDF Unicode marks.  In reality, it should be
 *     surrounded by those marks as well.
 *
 * See https://bugzil.la/900182 for more information.
 *
 */

function createGetter(id, name) {
  let _pseudo = null;

  return function getPseudo() {
    if (_pseudo) {
      return _pseudo;
    }

    const reAlphas = /[a-zA-Z]/g;
    const reVowels = /[aeiouAEIOU]/g;
    const reWords = /[^\W0-9_]+/g;
    // strftime tokens (%a, %Eb), template {vars}, HTML entities (&#x202a;)
    // and HTML tags.
    const reExcluded = /(%[EO]?\w|\{\s*.+?\s*\}|&[#\w]+;|<\s*.+?\s*>)/;

    const charMaps = {
      'fr-x-psaccent':
        'ȦƁƇḒḖƑƓĦĪĴĶĿḾȠǾƤɊŘŞŦŬṼẆẊẎẐ[\\]^_`ȧƀƈḓḗƒɠħīĵķŀḿƞǿƥɋřşŧŭṽẇẋẏẑ',
      'ar-x-psbidi':
        // XXX Use pɟפ˥ʎ as replacements for ᗡℲ⅁⅂⅄. https://bugzil.la/1007340
        '∀ԐↃpƎɟפHIſӼ˥WNOԀÒᴚS⊥∩ɅＭXʎZ[\\]ᵥ_,ɐqɔpǝɟƃɥıɾʞʅɯuodbɹsʇnʌʍxʎz',
    };

    const mods = {
      'fr-x-psaccent': val =>
        val.replace(reVowels, match => match + match.toLowerCase()),

      // Surround each word with Unicode formatting codes, RLO and PDF:
      //   U+202E:   RIGHT-TO-LEFT OVERRIDE (RLO)
      //   U+202C:   POP DIRECTIONAL FORMATTING (PDF)
      // See http://www.w3.org/International/questions/qa-bidi-controls
      'ar-x-psbidi': val =>
        val.replace(reWords, match => '\u202e' + match + '\u202c'),
    };

    // Replace each Latin letter with a Unicode character from map
    const replaceChars =
      (map, val) => val.replace(
        reAlphas, match => map.charAt(match.charCodeAt(0) - 65));

    const transform =
      val => replaceChars(charMaps[id], mods[id](val));

    // apply fn to translatable parts of val
    const apply = (fn, val) => {
      if (!val) {
        return val;
      }

      const parts = val.split(reExcluded);
      const modified = parts.map(function(part) {
        if (reExcluded.test(part)) {
          return part;
        }
        return fn(part);
      });
      return modified.join('');
    };

    return _pseudo = {
      name: transform(name),
      process: str => apply(transform, str)
    };
  };
}

const pseudo = Object.defineProperties(Object.create(null), {
  'fr-x-psaccent': {
    enumerable: true,
    get: createGetter('fr-x-psaccent', 'Runtime Accented')
  },
  'ar-x-psbidi': {
    enumerable: true,
    get: createGetter('ar-x-psbidi', 'Runtime Bidi')
  }
});

function emit(listeners, ...args) {
  const type = args.shift();

  if (listeners['*']) {
    listeners['*'].slice().forEach(
      listener => listener.apply(this, args));
  }

  if (listeners[type]) {
    listeners[type].slice().forEach(
      listener => listener.apply(this, args));
  }
}

function addEventListener(listeners, type, listener) {
  if (!(type in listeners)) {
    listeners[type] = [];
  }
  listeners[type].push(listener);
}

function removeEventListener(listeners, type, listener) {
  const typeListeners = listeners[type];
  const pos = typeListeners.indexOf(listener);
  if (pos === -1) {
    return;
  }

  typeListeners.splice(pos, 1);
}

class Env$1 {
  constructor(fetchResource) {
    this.fetchResource = fetchResource;

    this.resCache = new Map();
    this.resRefs = new Map();
    this.numberFormatters = null;
    this.parsers = {
      properties: PropertiesParser,
      l20n: L20nParser,
    };

    const listeners = {};
    this.emit = emit.bind(this, listeners);
    this.addEventListener = addEventListener.bind(this, listeners);
    this.removeEventListener = removeEventListener.bind(this, listeners);
  }

  createContext(langs, resIds) {
    const ctx = new Context(this, langs, resIds);
    resIds.forEach(resId => {
      const usedBy = this.resRefs.get(resId) || 0;
      this.resRefs.set(resId, usedBy + 1);
    });

    return ctx;
  }

  destroyContext(ctx) {
    ctx.resIds.forEach(resId => {
      const usedBy = this.resRefs.get(resId) || 0;

      if (usedBy > 1) {
        return this.resRefs.set(resId, usedBy - 1);
      }

      this.resRefs.delete(resId);
      this.resCache.forEach((val, key) =>
        key.startsWith(resId) ? this.resCache.delete(key) : null);
    });
  }

  _parse(syntax, lang, data) {
    const parser = this.parsers[syntax];
    if (!parser) {
      return data;
    }

    const emit = (type, err) => this.emit(type, amendError(lang, err));
    return parser.parse.call(parser, emit, data);
  }

  _create(lang, entries) {
    if (lang.src !== 'pseudo') {
      return entries;
    }

    const pseudoentries = Object.create(null);
    for (let key in entries) {
      pseudoentries[key] = walkEntry(
        entries[key], pseudo[lang.code].process);
    }
    return pseudoentries;
  }

  _getResource(lang, res) {
    const cache = this.resCache;
    const id = res + lang.code + lang.src;

    if (cache.has(id)) {
      return cache.get(id);
    }

    const syntax = res.substr(res.lastIndexOf('.') + 1);

    const saveEntries = data => {
      const entries = this._parse(syntax, lang, data);
      cache.set(id, this._create(lang, entries));
    };

    const recover = err => {
      err.lang = lang;
      this.emit('fetcherror', err);
      cache.set(id, err);
    };

    const langToFetch = lang.src === 'pseudo' ?
      { code: 'en-US', src: 'app', ver: lang.ver } :
      lang;

    const resource = this.fetchResource(res, langToFetch)
      .then(saveEntries, recover);

    cache.set(id, resource);

    return resource;
  }
}

function amendError(lang, err) {
  err.lang = lang;
  return err;
}

exports.fetchResource = fetchResource$1;
exports.Env = Env$1;