'use strict'
const _ = require('lodash')
const resolveStorageData = require('./resolveStorageData')
const resolveStorageNotes = require('./resolveStorageNotes')
const consts = require('browser/lib/consts')
const path = require('path')
const fs = require('fs')
const CSON = require('@rokt33r/season')
/**
 * @return {Object} all storages and notes
 * ```
 * {
 *   storages: [...],
 *   notes: [...]
 * }
 * ```
 *
 * This method deals with 3 patterns.
 * 1. v1
 * 2. legacy
 * 3. empty directory
 */

function init () {
  const fetchStorages = function () {
    let rawStorages
    try {
      rawStorages = JSON.parse(window.localStorage.getItem('storages'))
      // Remove storages who's location is inaccesible.
      rawStorages = rawStorages.filter(storage => fs.existsSync(storage.path))
      if (!_.isArray(rawStorages)) throw new Error('Cached data is not valid.')
    } catch (e) {
      console.warn('Failed to parse cached data from localStorage', e)
      rawStorages = []
      window.localStorage.setItem('storages', JSON.stringify(rawStorages))
    }
    return Promise.all(rawStorages
      .map(resolveStorageData))
  }

  const fetchNotes = function (storages) {
    const findNotesFromEachStorage = storages
      .map((storage) => {
        return resolveStorageNotes(storage)
          .then((notes) => {
            let unknownCount = 0
            notes.forEach((note) => {
              if (note && !storage.folders.some((folder) => note.folder === folder.key)) {
                unknownCount++
                storage.folders.push({
                  key: note.folder,
                  color: consts.FOLDER_COLORS[(unknownCount - 1) % 7],
                  name: 'Unknown ' + unknownCount
                })
              }
            })
            if (unknownCount > 0) {
              CSON.writeFileSync(path.join(storage.path, 'boostnote.json'), _.pick(storage, ['folders', 'version']))
            }
            return notes
          })
      })
    return Promise.all(findNotesFromEachStorage)
      .then(function concatNoteGroup (noteGroups) {
        return noteGroups.reduce(function (sum, group) {
          return sum.concat(group)
        }, [])
      })
      .then(function returnData (notes) {
        return {
          storages,
          notes
        }
      })
  }

  return Promise.resolve(fetchStorages())
    .then((storages) => {
      return storages
        .filter((storage) => {
          if (!_.isObject(storage)) return false
          return true
        })
    })
    .then(fetchNotes)
}
module.exports = init