lipp/node-jet

'use strict'

import JsonRPC from '../../2_jsonrpc/index.js'
import { FetchParams, MethodParams } from '../messages.js'
import { ValueType } from '../types.js'
import { createPathMatcher } from './path_matcher.js'
import { Route } from './route.js'
import { create as createValueMatcher } from './value_matcher.js'

/** A subscription corresponds to a fetch request.
 * Each subscription contains all the routes that match the subscription  */
export class Subscription {
  owner?: JsonRPC
  id: string
  messages: MethodParams[] = []
  routes: Route[] = []
  pathMatcher: (path: string) => boolean
  valueMatcher: (value: ValueType | undefined) => boolean
  constructor(msg: FetchParams, peer: JsonRPC | undefined = undefined) {
    this.pathMatcher = createPathMatcher(msg)
    this.valueMatcher = createValueMatcher(msg)
    this.owner = peer
    this.id = msg.id
  }

  close = () => {
    this.routes.forEach((route) => {
      route.removeListener('Change', this.handleChange)
      route.removeListener('Remove', this.handleRemove)
    })
  }

  handleChange = (path: string, value: ValueType) =>
    this.enqueue({ path: path, event: 'Change', value })
  handleRemove = (path: string) => this.enqueue({ path: path, event: 'Remove' })
  addRoute = (route: Route) => {
    this.routes.push(route)
    if (this.valueMatcher(route.value)) {
      this.enqueue({
        path: route.path,
        event: 'Add',
        value: route.value
      })
    }

    route.addListener('Change', this.handleChange)
    route.addListener('Remove', this.handleRemove)
  }
  setRoutes = (routes: Route[]) => {
    routes.forEach((route) => this.addRoute(route))
  }
  matchesPath = (path: string) => this.pathMatcher(path)
  matchesValue = (value: ValueType | undefined) => this.valueMatcher(value)

  enqueue = (msg: MethodParams) => {
    this.messages.push(msg)
  }

  send = () => {
    this.messages.forEach((msg) => this.owner?.queue(msg, this.id))
    this.owner?.send()
    this.messages = []
  }
}