import { createSimAdminClient } from '../core.js'

function sameInstance(a, b) {
  return a && b && JSON.stringify(a) === JSON.stringify(b)
}

export class ClientRegistry {
  constructor({ createClient = createSimAdminClient } = {}) {
    this.createClient = createClient
    this.clients = new Map()
  }
  reconcile(instances) {
    const previous = this.clients
    const nextClients = new Map()
    const staged = []
    try {
      for (const instance of instances) {
        const current = previous.get(instance.id)
        const next = current && sameInstance(current.instance, instance) ? current : this.createClient(instance)
        nextClients.set(instance.id, next)
        if (next !== current && ![...previous.values()].includes(next)) staged.push(next)
      }
    } catch (error) {
      for (const client of staged) { client.close?.(); client.jar?.clear?.() }
      throw error
    }
    this.clients = nextClients
    for (const [id, client] of previous) {
      if (nextClients.get(id) !== client) { client.close?.(); client.jar?.clear?.() }
    }
    return this
  }
  get(id) { return this.clients.get(id) }
  values() { return this.clients.values() }
  delete(id) {
    const client = this.clients.get(id)
    if (!client) return false
    client.close?.()
    client.jar?.clear?.()
    return this.clients.delete(id)
  }
  close() {
    for (const id of [...this.clients.keys()]) this.delete(id)
  }
}