AfiS-Aktensystem/web/app/(app)/faelle/[caseNumber]/SectionEditor.tsx

'use client'

import { useEffect, useRef, useState, useTransition } from 'react'
import { de } from '@/lib/i18n/de'
import { saveSectionAction } from './sectionActions'

type Props = {
  caseNumber: string
  fieldKey: string
  label: string
  type: string
  options?: string[]
  help?: string
  requiredToClose?: boolean
  initialValue: unknown
  initialVersion: number
  readOnly: boolean
}

const AUTOSAVE_MS = 2000

/**
 * Ein Abschnitt zum Bearbeiten.
 *
 * Entwürfe werden alle zwei Sekunden **lokal** gesichert, damit ein
 * versehentlicher Tab-Wechsel keinen Text kostet. Gespeichert wird erst auf
 * Knopfdruck: ein Abschnitt ist der Sachstand der Akte, nicht ein Chatbeitrag.
 * Siehe docs/09-performance-und-ux.md.
 *
 * Beim Speichern geht die geladene Version mit. Weicht sie ab, gibt es kein
 * stilles Überschreiben, sondern beide Fassungen nebeneinander.
 */
export function SectionEditor(props: Props) {
  const speicherSchluessel = `afis:abschnitt:${props.caseNumber}:${props.fieldKey}`
  const [value, setValue] = useState(() => normalise(props.initialValue, props.type))
  const [version, setVersion] = useState(props.initialVersion)
  const [conflict, setConflict] = useState<{ value: unknown; version: number } | null>(null)
  const [error, setError] = useState<string | null>(null)
  const [saved, setSaved] = useState(false)
  const [draftKept, setDraftKept] = useState(false)
  const [pending, startTransition] = useTransition()
  const timer = useRef<ReturnType<typeof setTimeout> | null>(null)

  // Entwurf aus dem letzten Besuch übernehmen, falls er neuer ist.
  useEffect(() => {
    try {
      const stored = localStorage.getItem(speicherSchluessel)
      if (stored !== null && stored !== normalise(props.initialValue, props.type)) {
        setValue(stored)
        setDraftKept(true)
      }
    } catch {
      // Privates Fenster oder gesperrter Speicher: dann eben ohne Entwurf.
    }
  }, [speicherSchluessel, props.initialValue, props.type])

  function change(next: string) {
    setValue(next)
    setSaved(false)
    if (timer.current) clearTimeout(timer.current)
    timer.current = setTimeout(() => {
      try {
        localStorage.setItem(speicherSchluessel, next)
        setDraftKept(true)
      } catch {
        // still ignorieren, der Entwurf ist eine Bequemlichkeit
      }
    }, AUTOSAVE_MS)
  }

  function submit(override?: unknown, baseVersion = version) {
    setError(null)
    startTransition(async () => {
      const result = await saveSectionAction({
        caseNumber: props.caseNumber,
        fieldKey: props.fieldKey,
        value: override ?? parse(value, props.type),
        baseVersion,
      })

      if (result.ok) {
        setVersion(result.version)
        setConflict(null)
        setSaved(true)
        setDraftKept(false)
        try {
          localStorage.removeItem(speicherSchluessel)
        } catch {
          // egal
        }
        return
      }

      if (result.conflict) setConflict(result.current)
      else setError(result.error)
    })
  }

  if (props.readOnly) {
    return (
      <p className="mt-1 max-w-(--container-measure) text-sm whitespace-pre-wrap">
        {String(value || '—')}
      </p>
    )
  }

  return (
    <div className="mt-1.5">
      {props.type === 'select' ? (
        <select
          value={value}
          onChange={(event) => change(event.target.value)}
          className="border border-line bg-raised px-3 py-2 text-sm"
        >
          <option value="">—</option>
          {props.options?.map((option) => (
            <option key={option} value={option}>
              {option}
            </option>
          ))}
        </select>
      ) : props.type === 'longtext' ? (
        <textarea
          value={value}
          onChange={(event) => change(event.target.value)}
          rows={6}
          className="block w-full max-w-(--container-measure) border border-line bg-raised px-3 py-2 text-sm"
        />
      ) : (
        <input
          type={props.type === 'date' ? 'date' : props.type === 'number' ? 'number' : 'text'}
          value={value}
          onChange={(event) => change(event.target.value)}
          className="block w-full max-w-(--container-measure) border border-line bg-raised px-3 py-2 text-sm"
        />
      )}

      <div className="mt-2 flex flex-wrap items-center gap-3 text-2xs">
        <button
          type="button"
          onClick={() => submit()}
          disabled={pending}
          className="border border-line bg-raised px-3 py-1 font-condensed text-accent disabled:text-text-dim"
        >
          {pending ? de.section.saving : de.section.save}
        </button>
        {version > 0 ? (
          <span className="font-mono text-text-dim">{de.section.version(version)}</span>
        ) : null}
        {saved ? <span className="font-condensed text-text-dim">{de.section.saved}</span> : null}
        {draftKept && !saved ? (
          <span className="font-condensed text-text-dim">{de.section.draftKept}</span>
        ) : null}
        {error ? <span className="font-condensed text-stamp-4">{error}</span> : null}
      </div>

      {conflict ? (
        <div className="mt-3 border border-stamp-4 p-3">
          <p className="font-condensed text-2xs text-stamp-4">{de.section.conflict}</p>
          <div className="mt-3 grid gap-4 md:grid-cols-2">
            <div>
              <p className="font-condensed text-2xs text-text-dim">{de.section.mine}</p>
              <p className="mt-1 border-l-(length:--spacing-edge) border-steel pl-3 text-sm whitespace-pre-wrap">
                {value}
              </p>
              <button
                type="button"
                onClick={() => submit(parse(value, props.type), conflict.version)}
                className="mt-2 font-condensed text-2xs text-accent"
              >
                {de.section.takeMine}
              </button>
            </div>
            <div>
              <p className="font-condensed text-2xs text-text-dim">{de.section.theirs}</p>
              <p className="mt-1 border-l-(length:--spacing-edge) border-line pl-3 text-sm whitespace-pre-wrap">
                {String(conflict.value ?? '')}
              </p>
              <button
                type="button"
                onClick={() => {
                  setValue(normalise(conflict.value, props.type))
                  setVersion(conflict.version)
                  setConflict(null)
                }}
                className="mt-2 font-condensed text-2xs text-accent"
              >
                {de.section.takeTheirs}
              </button>
            </div>
          </div>
        </div>
      ) : null}
    </div>
  )
}

function normalise(value: unknown, _type: string): string {
  if (value === null || value === undefined) return ''
  if (Array.isArray(value)) return value.join(', ')
  return String(value)
}

function parse(value: string, type: string): unknown {
  if (type === 'number') return value === '' ? null : Number(value)
  if (type === 'multiselect' || type === 'checklist') {
    return value.split(',').map((part) => part.trim()).filter(Boolean)
  }
  return value === '' ? null : value
}