import { Injectable } from '@angular/core';
import { Dexie, EntityTable, liveQuery } from 'Dexie';
import { err, ok } from 'neverthrow';
import { z } from 'zod';
import { from, Observable, Subject } from 'rxjs';
import { filter, switchMap } from 'rxjs/operators';
import { MessageInputDTO } from '../../dto/message/messageInputDtO';


const tableSchema = z.object({
  id: z.any().optional(),
  messageId: z.string().optional(),
  roomId: z.string().uuid(),
  senderId: z.number(),
  message: z.string(),
  messageType: z.number(),
  canEdit: z.boolean(),
  oneShot: z.boolean(),
  sentAt: z.string().optional(),
  requireUnlock: z.boolean(),
  sender: z.object({
    wxUserId: z.number(),
    wxFullName: z.string(),
    wxeMail: z.string(),
    userPhoto: z.string(),
  }),
  sending: z.boolean().optional()
})


export type TableMessage = z.infer<typeof tableSchema>

// Database declaration (move this to its own module also)
export const messageDataSource = new Dexie('chat-message') as Dexie & {
  message: EntityTable<TableMessage, 'id'>;
};

messageDataSource.version(1).stores({
  message: '++id, roomId, senderId, message, messageType, canEdit, oneShot, requireUnlock, messageId'
});

@Injectable({
  providedIn: 'root'
})
export class MessageLocalDataSourceService {

  messageSubject = new Subject();

  constructor() {

    messageDataSource.message.hook('creating', (primKey, obj, trans) => {
      // const newMessage = await trans.table('message').get(primKey);
      this.messageSubject.next(obj);
      // return newMessage
    })
  }


  async sendMessage(data: MessageInputDTO) {

    (data as TableMessage).sending = true

    try {
      const result = await messageDataSource.message.add(data)
      return ok(result as string)
    } catch (e) {
      return err(false)
    }

  }


  async createMessage(data: MessageInputDTO) {

    try {
      const result = await messageDataSource.message.add(data)
      return ok(result as string)
    } catch (e) {
      return err(false)
    }

  }


  async update(data: TableMessage ) {

    try {
      const result = await messageDataSource.message.update(data.id, data)
      return ok(result)
    } catch (e) {
      return err(false)
    }

  }


  async findOrUpdate(data: TableMessage) {
    const findResult = await this.findMessageById(data.messageId)

    if(findResult.isOk()) {
      return this.update({...findResult.value, ...data})
    } else  {
      return this.createMessage(data)
    }
  }

  getItemsLive(roomId: string) {
    return liveQuery(() =>
      messageDataSource.message.where('roomId').equals(roomId).sortBy('id')
    )
  }


  async findMessageById(messageId: string) {
    try {
      const a = await messageDataSource.message.where('messageId').equals(messageId).first()

      if(a) {
        return ok(a)
      } else {
        return err('not found')
      }

    } catch (e) {
      return err('DB error')
    }

  }


  subscribeToNewMessage(roomId: string): Observable<TableMessage>  {
    return this.messageSubject.pipe(
      filter((message: TableMessage) =>
        message.roomId === roomId
      )
    )
  }
}