import * as plugins from './npmextra.plugins'
import * as paths from './npmextra.paths'

import { Task, TaskOnce } from 'taskbuffer'

export type TKeyValueStore = 'path' | 'gitProject' | 'custom'

/**
 * kvStore is a simple key vlaue store to store data about projects between runs
 */
export class KeyValueStore {
  dataObject: any
  deletedObject: any = {}
  initialReadTask = new TaskOnce({
    taskFunction: async () => {
      this.dataObject = plugins.smartfile.fs.toObjectSync(this.filePath)
    }
  })
  syncTask = new Task({
    buffered: true,
    bufferMax: 2,
    execDelay: 500,
    taskFunction: async () => {
      this.dataObject = plugins.smartlodash.merge(
        {},
        plugins.smartfile.fs.toObjectSync(this.filePath),
        this.dataObject
      )
      for (let key in this.deletedObject) {
        delete this.dataObject[key]
      }
      this.deletedObject = {}
      await plugins.smartfile.memory.toFs(
        JSON.stringify(this.dataObject),
        this.filePath
      )
    },
    name: 'syncTask'
  })
  type: TKeyValueStore // the type of the kvStore
  identity: string // the identity of the kvStore
  filePath: string // the filePath of the kvStore

  /**
   * the constructor of keyvalue store
   * @param typeArg
   * @param customStringArg
   */
  constructor(typeArg: TKeyValueStore, customStringArg: string) {
    // set kvStoreType
    this.type = typeArg
    this.identity = customStringArg
    this.initFilePath()
  }

  /**
   * reads all keyValue pairs at once and returns them
   */
  async readAll () {
    await this.initialReadTask.trigger()
    this.syncTask.trigger()
    return this.dataObject
  }

  /**
   * reads a keyValueFile from disk
   */
  async read (keyArg: string) {
    let data = await this.readAll()
    return data[keyArg]
  }

  /**
   * writes a key value file to disk
   */
  async write (keyValueObject) {
    plugins.smartlodash.merge(this.dataObject, keyValueObject)
    this.syncTask.trigger()
  }

  /**
   * wipes a key value store from disk
   */
  async wipe () {
    for (let key in this.dataObject) {
      this.deletedObject[key] = this.dataObject[key]
    }
  }

  /**
   * updates a value
   */
  async update (keyObject) {

  }

  /**
   * computes the identity
   */
  private initFilePath () {
    // determine the right base directory
    let baseDir: string
    if (this.type === 'custom') {
      baseDir = paths.kvCustomDir
    } else if (this.type === 'gitProject') {
      baseDir = paths.kvGitDir
    } else if (this.type === 'path') {

      baseDir = paths.kvPathDir
    }
    this.filePath = plugins.path.join(baseDir, this.identity + '.json')
    plugins.smartfile.fs.ensureDirSync(paths.kvCustomDir)
    plugins.smartfile.fs.ensureDirSync(paths.kvGitDir)
    plugins.smartfile.fs.ensureDirSync(paths.kvPathDir)
    plugins.smartfile.fs.ensureFileSync(this.filePath, '{}')
  }
}