/* global LZString loadScript */
'use strict';

// eslint-disable-next-line no-var
var [chromeLocal, chromeSync] = [
  chrome.storage.local,
  chrome.storage.sync,
].map(storage => {
  const wrapper = {
    get(options) {
      return new Promise(resolve => {
        storage.get(options, data => resolve(data));
      });
    },
    set(data) {
      return new Promise(resolve => {
        storage.set(data, () => resolve(data));
      });
    },
    remove(keyOrKeys) {
      return new Promise(resolve => {
        storage.remove(keyOrKeys, resolve);
      });
    },
    getValue(key) {
      return wrapper.get(key).then(data => data[key]);
    },
    setValue(key, value) {
      return wrapper.set({[key]: value});
    },
    loadLZStringScript() {
      return Promise.resolve(
        window.LZString ||
        loadScript('/vendor/lz-string/lz-string-unsafe.js').then(() => {
          window.LZString = window.LZStringUnsafe;
        }));
    },
    getLZValue(key) {
      return wrapper.getLZValues([key]).then(data => data[key]);
    },
    getLZValues(keys) {
      return Promise.all([
        wrapper.get(keys),
        wrapper.loadLZStringScript(),
      ]).then(([data = {}]) => {
        for (const key of keys) {
          const value = data[key];
          data[key] = value && tryJSONparse(LZString.decompressFromUTF16(value));
        }
        return data;
      });
    },
    setLZValue(key, value) {
      return wrapper.loadLZStringScript().then(() =>
        wrapper.set({
          [key]: LZString.compressToUTF16(JSON.stringify(value)),
        }));
    }
  };
  return wrapper;
});


function styleSectionsEqual({sections: a}, {sections: b}) {
  if (!a || !b) {
    return undefined;
  }
  if (a.length !== b.length) {
    return false;
  }
  // order of sections should be identical to account for the case of multiple
  // sections matching the same URL because the order of rules is part of cascading
  return a.every((sectionA, index) => propertiesEqual(sectionA, b[index]));

  function propertiesEqual(secA, secB) {
    for (const name of ['urlPrefixes', 'urls', 'domains', 'regexps']) {
      if (!equalOrEmpty(secA[name], secB[name], 'every', arrayMirrors)) {
        return false;
      }
    }
    return equalOrEmpty(secA.code, secB.code, 'substr', (a, b) => a === b);
  }

  function equalOrEmpty(a, b, telltale, comparator) {
    const typeA = a && typeof a[telltale] === 'function';
    const typeB = b && typeof b[telltale] === 'function';
    return (
      (a === null || a === undefined || (typeA && !a.length)) &&
      (b === null || b === undefined || (typeB && !b.length))
    ) || typeA && typeB && a.length === b.length && comparator(a, b);
  }

  function arrayMirrors(array1, array2) {
    return (
      array1.every(el => array2.includes(el)) &&
      array2.every(el => array1.includes(el))
    );
  }
}