import { useQuery } from '@tanstack/react-query'
import { useEffect, useRef, useState } from 'react'

import { Button } from '@/components/ui/button'
import { countsUseLatest } from '@/lib/counts'
import { fetchCountsCandidates } from '@/lib/countsDefinitions'
import { countsKeys } from '@/lib/queryKeys'
import { useLocale } from '@/lib/useLocale'
import { useUITranslation } from '@/lib/useUITranslation'
import { inputClass } from '@/lib/utils'

import type { DialogueFormControls } from '@/lib/dialogues/useDialogue'
import type { CountsResource } from '@/lib/counts'
import type { CountsCandidate } from '@/lib/countsDefinitions'


type CandidateSource = {
    resource: CountsResource; field: string; params?: URLSearchParams }

const CandidatePicker = (
    { source, choices = [], categories = [], initial, maximum, controls, onSelect }: {
	source?: CandidateSource; choices?: CountsCandidate[]
	categories?: { value: string; label: string }[]
	initial: (string | number | boolean)[]; maximum: number
	controls: DialogueFormControls; onSelect: (values: string[]) => void },
) => {
  const { label, message } = useUITranslation ('counts')
  const locale = useLocale ()
  const [selected, setSelected] = useState (() => new Set (initial.map (String)))
  const [columns, setColumns] = useState (['id', 'name', 'category', 'kind'])
  const [draft, setDraft] = useState ('')
  const [search, setSearch] = useState ('')
  const [category, setCategory] = useState ('')
  const [page, setPage] = useState (1)
  const params = source?.params ?? new URLSearchParams ()
  const point = useRef (params.get ('execution_at'))
  const resource = source?.resource ?? 'posts'
  const request = new URLSearchParams ({
      field: source?.field ?? '', query: search, page: String (page) })
  for (const key of ['timezone', 'at', 'execution_at'])
    if (params.has (key)) request.set (key, params.get (key)!)
  if (countsUseLatest (params)) request.delete ('at')
  if (category) request.set ('category', category)
  const dynamic = source != null
  const { data, isFetching: fetching, isError: errorFlg } = useQuery ({
      queryKey: countsKeys.candidates (resource, request.toString (), locale), enabled: dynamic,
      queryFn: ({ signal }) => {
	const pinned = new URLSearchParams (request)
	if (point.current != null) pinned.set ('execution_at', point.current)
	return fetchCountsCandidates (resource, pinned, locale, signal)
      }, retry: false, staleTime: 0, gcTime: 0 })
  useEffect (() => {
    if (data != null) point.current = data.executionAt
  }, [data])
  useEffect (() => {
    controls.setActions ([{ label: label ('counts:pattern.selection'),
	onSelect: () => onSelect ([...selected]) }])
  }, [controls, label, onSelect, selected])
  const rows = dynamic ? data?.rows ?? [] : choices.filter (row =>
      row.name?.includes (search))
  const headings: Record<string, string> = {
      id: 'columns.resourceId', name: 'columns.name', category: 'common:categoryLabel',
      kind: 'columns.kind' }
  const referenceFlg = ['tags', 'tags_json', 'tags.id', 'members'].includes (source?.field ?? '')
  const available =
      dynamic
      ? (referenceFlg ? ['id', 'name', 'category', 'kind'] : ['id', 'name']) : ['name']
  const visible = available.filter (column => columns.includes (column))
  const cell = (row: CountsCandidate, column: string) => {
    if (column === 'category')
      return row.category == null ? '' : message (`common:categories.${row.category}`).text
    if (column === 'kind')
    {
      const key = row.kind === 'group' ? 'resources.tag_groups' : `kinds.${row.kind}`
      return row.kind == null ? '' : message (key).text
    }
    return column === 'id' ? row.id : row.name
  }
  return <div className="min-w-0 space-y-2">
    <div className="flex min-w-0 items-center gap-2">
      <input className={inputClass (false, 'h-9 min-w-0 flex-1')}
	  aria-label={message ('common:search').text} value={draft} maxLength={1000}
	  onChange={event => {
	    const value = event.target.value
	    if (new TextEncoder ().encode (value).length <= 1000) setDraft (value)
	  }}
	  onKeyDown={event => {
	    if (event.key !== 'Enter') return
	    event.preventDefault ()
	    setSearch (draft)
	    setPage (1)
	  }}/>
      <Button type="button" onClick={() => { setSearch (draft); setPage (1) }}>
	{label ('common:search')}</Button>
    </div>
    {categories.length > 0 && <select className={inputClass (false, 'h-9 w-full')}
	aria-label={message ('common:categoryLabel').text} value={category}
	onChange={event => { setCategory (event.target.value); setPage (1) }}>
      <option value=""/>
      {categories.map (choice => <option key={choice.value} value={choice.value}>
	{message (choice.label).text}</option>)}
    </select>}
    <fieldset className="flex flex-wrap items-center gap-2 text-sm">
      <legend>{label ('counts:pattern.columns')}</legend>
      {available.map (column => <label key={column} className="inline-flex items-center gap-1">
	<input type="checkbox" checked={columns.includes (column)} onChange={event =>
	    setColumns (previous => event.target.checked ? [...previous, column]
		: previous.filter (value => value !== column))}/>{label (headings[column])}
      </label>)}
    </fieldset>
    <p className="text-sm">{label ('counts:pattern.value')}{'：'}
      {label (dynamic ? 'columns.resourceId' : 'common:categoryLabel')}
    </p>
    <Button type="button" variant="ghost" size="sm" onClick={() => setSelected (new Set ())}>
      {label ('shared:actions.reset')}</Button>
    {errorFlg && <p role="alert">{label ('common:fetchError')}</p>}
    <div className="max-h-[40dvh] overflow-auto" aria-busy={fetching}>
      <table className="w-full text-left text-sm">
	<thead><tr><th className="p-2">{label ('counts:pattern.selection')}</th>
	  {visible.map (column => <th key={column} className="p-2">
	    {label (headings[column])}</th>)}
	</tr></thead>
	<tbody>{rows.map (row => <tr key={`${row.kind ?? ''}:${row.value}`}
	    className="border-t dark:border-slate-700">
	  <td className="p-2"><input type="checkbox" checked={selected.has (row.value)}
	      aria-label={row.name ?? String (row.id ?? '')}
	      disabled={maximum !== 1 && !selected.has (row.value) && selected.size >= maximum}
	      onChange={event => setSelected (previous => {
		const next = new Set (maximum === 1 ? [] : previous)
		if (event.target.checked) next.add (row.value)
		else next.delete (row.value)
		return next
	      })}/></td>
	  {visible.map (column => <td key={column} className="break-words p-2">
	    {cell (row, column)}</td>)}
	</tr>)}</tbody>
      </table>
    </div>
    {dynamic && <div className="flex items-center justify-between gap-2">
      <Button type="button" variant="outline" disabled={page === 1 || fetching}
	  onClick={() => setPage (previous => previous - 1)}>
	{label ('common:pagination.previous')}</Button>
      <span>{page}</span>
      <Button type="button" variant="outline"
	  disabled={!data?.more || page >= 100_000 || fetching}
	  onClick={() => setPage (previous => previous + 1)}>
	{label ('common:pagination.next')}</Button>
    </div>}
  </div>
}


export default CandidatePicker
export type { CandidateSource }