/**
 * Recipients Store
 */

import { ref } from 'vue'
import { defineStore } from 'pinia'
import { recipientService } from '../services/recipientService'
import type { MessageAddressInterface } from '@MailManager/types/message'

/** Minimum characters before a lookup fires. */
const MIN_QUERY_LENGTH = 3

/** Debounce window for keystroke-driven searches. */
const DEBOUNCE_MS = 250

export const useRecipientLookupStore = defineStore('mailRecipientsStore', () => {
  const suggestions = ref<MessageAddressInterface[]>([])
  const searching = ref(false)

  let debounceTimer: ReturnType<typeof setTimeout> | null = null
  // Monotonic token so out-of-order/stale responses are discarded.
  let requestToken = 0

  function cancelPending() {
    if (debounceTimer) {
      clearTimeout(debounceTimer)
      debounceTimer = null
    }
  }

  /**
   * Clear suggestions and cancel any in-flight lookup.
   */
  function clear() {
    cancelPending()
    requestToken++
    suggestions.value = []
    searching.value = false
  }

  /**
   * Debounced contact search. Queries shorter than MIN_QUERY_LENGTH clear the
   * suggestion list without hitting the backend.
   */
  function search(query: string) {
    const trimmed = (query ?? '').trim()
    cancelPending()

    if (trimmed.length < MIN_QUERY_LENGTH) {
      requestToken++
      suggestions.value = []
      searching.value = false
      return
    }

    searching.value = true
    const token = ++requestToken

    debounceTimer = setTimeout(async () => {
      try {
        const matches = await recipientService.search(trimmed)
        if (token !== requestToken) {
          return
        }
        suggestions.value = matches
      } catch (error: any) {
        if (token === requestToken) {
          suggestions.value = []
        }
        console.error('[Mail][Recipient Lookup] - Search failed:', error)
      } finally {
        if (token === requestToken) {
          searching.value = false
        }
      }
    }, DEBOUNCE_MS)
  }

  return {
    suggestions,
    searching,
    search,
    clear,
  }
})