//
// Copyright © 2020, 2021 Anticrm Platform Contributors.
// Copyright © 2021 Hardcore Engineering Inc.
//
// Licensed under the Eclipse Public License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License. You may
// obtain a copy of the License at https://www.eclipse.org/legal/epl-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//
// See the License for the specific language governing permissions and
// limitations under the License.
//

import core, {
  AnyAttribute, ArrOf, AttachedDoc, Class, Client, Collection, Doc, DocumentQuery,
  FindOptions, FindResult, getCurrentAccount, Ref, RefTo, Tx, TxOperations, TxResult
} from '@anticrm/core'
import login from '@anticrm/login'
import { getMetadata } from '@anticrm/platform'
import { LiveQuery as LQ } from '@anticrm/query'
import { onDestroy } from 'svelte'

let liveQuery: LQ
let client: TxOperations

const txListeners: Array<((tx: Tx) => void)> = []

export function addTxListener (l: (tx: Tx) => void): void {
  txListeners.push(l)
}

class UIClient extends TxOperations implements Client {
  constructor (client: Client, private readonly liveQuery: LQ) {
    super(client, getCurrentAccount()._id)
  }

  override async tx (tx: Tx): Promise<TxResult> {
    return await super.tx(tx)
  }
}

export function getClient (): TxOperations {
  return client
}

export function setClient (_client: Client): void {
  liveQuery = new LQ(_client)
  client = new UIClient(_client, liveQuery)
  _client.notify = (tx: Tx) => {
    liveQuery.tx(tx).catch((err) => console.log(err))

    txListeners.forEach(it => it(tx))
  }
}

export class LiveQuery {
  unsubscribe = () => {}

  constructor () {
    onDestroy(() => {
      console.log('onDestroy query')
      this.unsubscribe()
    })
  }

  query<T extends Doc>(
    _class: Ref<Class<T>>,
    query: DocumentQuery<T>,
    callback: (result: FindResult<T>) => void,
    options?: FindOptions<T>
  ): void {
    this.unsubscribe()
    const unsub = liveQuery.query(_class, query, callback, options)
    this.unsubscribe = () => {
      unsub()
      this.unsubscribe = () => {}
    }
  }
}

export function createQuery (): LiveQuery {
  return new LiveQuery()
}

export function getFileUrl (file: string): string {
  const uploadUrl = getMetadata(login.metadata.UploadUrl)
  const token = getMetadata(login.metadata.LoginToken)
  const url = `${uploadUrl as string}?file=${file}&token=${token as string}`
  return url
}

export async function getBlobURL (blob: Blob): Promise<string> {
  return await new Promise((resolve) => {
    const reader = new FileReader()

    reader.addEventListener('load', () => resolve(reader.result as string), false)
    reader.readAsDataURL(blob)
  })
}

/**
 * @public
 */
export function getAttributePresenterClass (attribute: AnyAttribute): Ref<Class<Doc>> {
  let attrClass = attribute.type._class
  if (attrClass === core.class.RefTo) {
    attrClass = (attribute.type as RefTo<Doc>).to
  }
  if (attrClass === core.class.Collection) {
    attrClass = (attribute.type as Collection<AttachedDoc>).of
  }
  if (attrClass === core.class.ArrOf) {
    attrClass = (attribute.type as ArrOf<AttachedDoc>).of._class
  }
  return attrClass
}