'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
      .filter(storage => fs.existsSync(storage.path))
      .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) {
            try {
              CSON.writeFileSync(
                path.join(storage.path, 'boostnote.json'),
                _.pick(storage, ['folders', 'version'])
              )
            } catch (e) {
              console.log(
                'Error writting boostnote.json: ' + e + ' from init.js'
              )
            }
          }
          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