'use client'

import { useEffect, useRef, useState } from 'react'
import { authFetch, getApiBase } from '../../lib/auth'
import type { Row } from './IdentityReviewPanel'

type Preview = {
  revision: string; server_id: string; row: Row
  before: { jellyfin_user_id: string | null; seerr_user_id: number | null }
  seerr_users: { id: number; name: string; jellyfin_id: string | null }[]
  scope: string
  action: string
}

export default function ResolveIdentityLink({ row, accounts, onClose, onSaved }: {
  row: Row; accounts: { id: string; name: string }[]; onClose: () => void; onSaved: () => void
}) {
  const dialog = useRef<HTMLDialogElement>(null)
  const controller = useRef<AbortController | null>(null)
  const [chosen, setChosen] = useState(row.candidate_jellyfin_id ?? '')
  const [inspectSeerr, setInspectSeerr] = useState('')
  const [createSeerr, setCreateSeerr] = useState(false)
  const [preview, setPreview] = useState<Preview | null>(null)
  const [busy, setBusy] = useState(false)
  const [saving, setSaving] = useState(false)
  const [error, setError] = useState('')

  useEffect(() => {
    const previous = document.activeElement as HTMLElement | null
    const overflow = document.body.style.overflow
    document.body.style.overflow = 'hidden'
    dialog.current?.showModal()
    return () => {
      controller.current?.abort()
      document.body.style.overflow = overflow
      previous?.focus()
    }
  }, [])

  const submit = async (confirm: boolean) => {
    if (!chosen || busy || saving || (confirm && !preview?.row.can_confirm)) return
    const abort = new AbortController()
    controller.current = abort
    setError('')
    if (confirm) setSaving(true)
    else { setBusy(true); setPreview(null) }
    try {
      const response = await authFetch(`${getApiBase()}/admin/identities/repair/${confirm ? 'confirm' : 'check'}`, {
        method: 'POST', signal: abort.signal, headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ user_id: row.user.id, jellyfin_user_id: chosen, create_seerr: createSeerr, ...(confirm ? { revision: preview?.revision } : {}) }),
      })
      const data = await response.json().catch(() => ({}))
      if (!response.ok) throw new Error(response.status === 401 ? 'Your session has ended. Sign in again.' : typeof data.detail === 'string' ? data.detail : 'Could not check the account links. Try again.')
      if (!abort.signal.aborted) {
        if (confirm) onSaved()
        else setPreview(data)
      }
    } catch (err) {
      if (!abort.signal.aborted) {
        setError(err instanceof Error ? err.message : 'Could not resolve the link.')
        setPreview(null)
      }
    } finally { if (!abort.signal.aborted) { setBusy(false); setSaving(false) } }
  }

  return <dialog ref={dialog} className="identity-resolve-dialog" aria-labelledby="resolve-title" onCancel={(event) => { event.preventDefault(); if (!saving) onClose() }}>
    <div className="identity-resolve-content">
      <header><h2 id="resolve-title">Review account repair</h2><button type="button" className="ghost-button" onClick={onClose} disabled={saving}>Close</button></header>
      <p>Review <strong>{row.user.username}</strong> (Magent {row.user.id}) against their Jellyfin account. Confirm that these identities belong to the same person before repairing Magent.</p>
      <label>Jellyfin account<select value={chosen} disabled={saving} onChange={(event) => {
        controller.current?.abort(); setBusy(false); setPreview(null); setError(''); setCreateSeerr(false); setChosen(event.target.value)
      }}><option value="">Choose an account</option>{[...accounts].sort((a, b) => a.name.localeCompare(b.name)).map((account) => <option key={account.id} value={account.id}>{account.name} — {account.id}</option>)}</select></label>
      <label className="identity-import-option"><span><input type="checkbox" checked={createSeerr} disabled={busy || saving} onChange={(event) => { setCreateSeerr(event.target.checked); setPreview(null) }} /> This person has no existing Seerr account. Import only the selected Jellyfin account if it is missing.</span></label>
      <button type="button" onClick={() => void submit(false)} disabled={!chosen || busy || saving}>{busy ? 'Checking all platform links…' : 'Preview repair'}</button>
      {error && <p className="error-banner" role="alert">{error}</p>}
      {busy && <p role="status">Checking live IDs and whether another Magent account already owns this identity.</p>}
      {preview && <section className="identity-confirm-panel" aria-label="Selected account links" aria-live="polite">
        <h3>{preview.row.can_confirm ? 'Ready to repair' : 'This link needs attention'}</h3>
        <p className="identity-meta">Jellyfin server <code>{preview.server_id ?? 'Unavailable'}</code></p>
        <div className="identity-mapping">
          <div><strong>Current Magent links</strong><p>Jellyfin: <code>{preview.before.jellyfin_user_id ?? 'Not linked'}</code></p><p>Seerr: {preview.before.seerr_user_id ?? 'Not linked'}</p></div>
          <div><strong>Proposed Magent links</strong><p>Jellyfin: <code>{preview.row.candidate_jellyfin_id}</code></p><p>Seerr: {preview.row.seerr.length === 1 ? preview.row.seerr[0].id : preview.action === 'import_seerr' ? 'Assigned by Seerr during import' : 'Not verified'}</p></div>
        </div>
        <dl className="identity-mapping">
          <div><dt>Jellyfin</dt><dd>{preview.row.jellyfin?.name ?? 'Account not found'}<code>{preview.row.candidate_jellyfin_id}</code></dd></div>
          <div><dt>Seerr</dt><dd>{preview.row.seerr.length ? preview.row.seerr.map((account) => `${account.name} (ID ${account.id})`).join(', ') : 'No matching Jellyfin ID. Check this user’s Jellyfin account link in Seerr, then check again.'}</dd></div>
          <div><dt>Jellystat</dt><dd><code>{preview.row.jellystat.id ?? 'Not verified'}</code>{preview.row.jellystat.state === 'matched' ? 'Same Jellyfin ID verified' : preview.row.jellystat.state === 'missing' ? 'This ID is missing from Jellystat. Check its Jellyfin sync, then check again.' : 'Could not verify this ID. Check the Jellystat connection and try again.'}</dd></div>
        </dl>
        {preview.row.issues.length > 0 && <ul className="identity-issues">{preview.row.issues.map((issue) => <li key={issue}>{issue}</li>)}</ul>}
        {preview.row.state === 'unavailable' && <p>A required service is unavailable. Restore its connection and check again.</p>}
        {preview.row.seerr.length !== 1 && <div className="identity-upstream-guidance">
          <h3>Check the existing Seerr account</h3>
          <p>Choose an account to inspect its current Jellyfin ID. This selection does not change or link it.</p>
          <label>Seerr account to inspect<select value={inspectSeerr} onChange={(event) => setInspectSeerr(event.target.value)}><option value="">Choose an existing account</option>{preview.seerr_users.map((account) => <option key={account.id} value={account.id}>{account.name} (ID {account.id})</option>)}</select></label>
          {preview.seerr_users.filter((account) => String(account.id) === inspectSeerr).map((account) => <p key={account.id}>Current Jellyfin ID: <code>{account.jellyfin_id ?? 'Not linked'}</code></p>)}
          <p>If this is the same person, use Seerr's account settings to reconnect their existing account to Jellyfin, then preview again. Linking requires that user's Jellyfin sign-in in Seerr. Keep the existing Seerr account to preserve its requests and settings.</p>
          <p>If they have never had a Seerr account, import just their Jellyfin account from Seerr's Users page, then preview again. Do not import a second account to work around an existing identity mismatch.</p>
        </div>}
        <p>{preview.scope}</p>
        <p>Repair records the previous and new links, your administrator name and the time. Live IDs and duplicate ownership are rechecked before the change is saved.</p>
        {preview.before.jellyfin_user_id && preview.before.jellyfin_user_id !== preview.row.candidate_jellyfin_id && <p>Changing the Jellyfin identity also revokes identity-bound email subscriptions. The user will need to opt in again.</p>}
        <button type="button" disabled={!preview.row.can_confirm || saving} onClick={() => void submit(true)}>{saving ? 'Rechecking and saving…' : preview.action === 'import_seerr' ? 'Import Seerr account and repair links' : 'Confirm repair'}</button>
      </section>}
    </div>
  </dialog>
}