'use client'

import { useCallback, useEffect, useState, type FormEvent, type KeyboardEvent } from 'react'
import { useRouter } from 'next/navigation'
import { authFetch, clearToken, getApiBase, getToken } from '../lib/auth'

type ProfileInfo = {
  username: string
  email?: string | null
  role: string
  auth_provider: string
  password_change_supported?: boolean
  password_provider?: 'local' | 'jellyfin' | null
}
type ActivityEntry = {
  ip: string
  user_agent: string
  first_seen_at: string
  last_seen_at: string
}
type ProfileResponse = {
  user: ProfileInfo
  stats?: { total: number; ready: number; in_progress: number }
  activity?: { recent: ActivityEntry[] }
}
type Notice = { tone: 'status' | 'error'; message: string } | null
type ProfileTab = 'overview' | 'security' | 'activity'
const TABS: { key: ProfileTab; label: string }[] = [
  { key: 'overview', label: 'Account' },
  { key: 'security', label: 'Security' },
  { key: 'activity', label: 'Activity' },
]
const normalizeTab = (value: string | null): ProfileTab => value === 'security' || value === 'activity' ? value : 'overview'
const formatDate = (value?: string) => {
  if (!value) return 'Not recorded'
  const date = new Date(value)
  return Number.isNaN(date.valueOf()) ? 'Not recorded' : date.toLocaleString(undefined, { dateStyle: 'medium', timeStyle: 'short' })
}
const deviceName = (agent: string) => {
  const value = (agent || '').toLowerCase()
  const browser = value.includes('edg/') ? 'Edge' : value.includes('firefox/') || value.includes('fxios/') ? 'Firefox'
    : value.includes('chrome/') || value.includes('crios/') ? 'Chrome' : value.includes('safari/') ? 'Safari' : 'Browser'
  const device = /iphone|ipad/.test(value) ? 'iOS' : value.includes('android') ? 'Android'
    : value.includes('windows') ? 'Windows' : value.includes('macintosh') ? 'Mac' : value.includes('linux') ? 'Linux' : ''
  return device ? `${browser} on ${device}` : browser
}
const responseMessage = async (response: Response, fallback: string) => {
  const data = await response.json().catch(() => null)
  return typeof data?.detail === 'string' && data.detail.trim() ? data.detail : fallback
}

export default function ProfilePage() {
  const router = useRouter()
  const [data, setData] = useState<ProfileResponse | null>(null)
  const [loading, setLoading] = useState(true)
  const [loadError, setLoadError] = useState('')
  const [activeTab, setActiveTab] = useState<ProfileTab>('overview')
  const [email, setEmail] = useState('')
  const [emailSaving, setEmailSaving] = useState(false)
  const [emailNotice, setEmailNotice] = useState<Notice>(null)
  const [currentPassword, setCurrentPassword] = useState('')
  const [newPassword, setNewPassword] = useState('')
  const [confirmPassword, setConfirmPassword] = useState('')
  const [passwordSaving, setPasswordSaving] = useState(false)
  const [passwordNotice, setPasswordNotice] = useState<Notice>(null)
  const [showAllActivity, setShowAllActivity] = useState(false)

  const loadProfile = useCallback(async () => {
    if (!getToken()) { router.replace('/login'); return }
    setLoading(true)
    setLoadError('')
    try {
      const response = await authFetch(`${getApiBase()}/auth/profile`)
      if (response.status === 401) { clearToken(); router.replace('/login'); return }
      if (!response.ok) throw new Error('Could not load your profile. Please try again.')
      const profile = await response.json() as ProfileResponse
      setData(profile)
      setEmail(profile.user.email ?? '')
    } catch {
      setLoadError('Could not load your profile. Please try again.')
    } finally {
      setLoading(false)
    }
  }, [router])

  useEffect(() => { void loadProfile() }, [loadProfile])
  useEffect(() => {
    const syncTab = () => setActiveTab(normalizeTab(new URLSearchParams(window.location.search).get('tab')))
    syncTab()
    window.addEventListener('popstate', syncTab)
    return () => window.removeEventListener('popstate', syncTab)
  }, [])

  const selectTab = (tab: ProfileTab) => {
    setActiveTab(tab)
    router.replace(tab === 'overview' ? '/profile' : `/profile?tab=${tab}`, { scroll: false })
  }
  const tabKeyDown = (event: KeyboardEvent<HTMLButtonElement>, index: number) => {
    let next = index
    if (event.key === 'ArrowRight') next = (index + 1) % TABS.length
    else if (event.key === 'ArrowLeft') next = (index + TABS.length - 1) % TABS.length
    else if (event.key === 'Home') next = 0
    else if (event.key === 'End') next = TABS.length - 1
    else return
    event.preventDefault()
    selectTab(TABS[next].key)
    document.getElementById(`profile-tab-${TABS[next].key}`)?.focus()
  }

  const saveEmail = async (event: FormEvent<HTMLFormElement>) => {
    event.preventDefault()
    if (emailSaving) return
    setEmailSaving(true)
    setEmailNotice(null)
    try {
      const response = await authFetch(`${getApiBase()}/auth/profile/email`, {
        method: 'PUT', headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ email: email.trim() || null }),
      })
      if (response.status === 401) { clearToken(); router.replace('/login'); return }
      if (!response.ok) throw new Error(await responseMessage(response, 'Could not save your email. Please try again.'))
      const result = await response.json()
      const saved = typeof result.email === 'string' ? result.email : ''
      setData((current) => current ? { ...current, user: { ...current.user, email: saved || null } } : current)
      setEmail(saved)
      setEmailNotice({ tone: 'status', message: saved ? 'Email saved.' : 'Email removed.' })
    } catch (error) {
      setEmailNotice({ tone: 'error', message: error instanceof Error ? error.message : 'Could not save your email.' })
    } finally { setEmailSaving(false) }
  }

  const savePassword = async (event: FormEvent<HTMLFormElement>) => {
    event.preventDefault()
    if (passwordSaving) return
    setPasswordNotice(null)
    if (newPassword.trim().length < 8) {
      setPasswordNotice({ tone: 'error', message: 'Use at least 8 characters for your new password.' })
      return
    }
    if (newPassword !== confirmPassword) {
      setPasswordNotice({ tone: 'error', message: 'The new passwords do not match.' })
      return
    }
    setPasswordSaving(true)
    try {
      const response = await authFetch(`${getApiBase()}/auth/password`, {
        method: 'POST', headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ current_password: currentPassword, new_password: newPassword }),
      })
      if (!response.ok) throw new Error(await responseMessage(response, 'Could not change your password. Please try again.'))
      const result = await response.json()
      setCurrentPassword(''); setNewPassword(''); setConfirmPassword('')
      setPasswordNotice({ tone: 'status', message: result.provider === 'jellyfin'
        ? 'Password updated for Grizzlyflix and Magent. Seerr uses the same password.'
        : 'Password updated.' })
    } catch (error) {
      setPasswordNotice({ tone: 'error', message: error instanceof Error ? error.message : 'Could not change your password.' })
    } finally { setPasswordSaving(false) }
  }

  const user = data?.user
  const passwordProvider = user?.password_provider ?? (user?.auth_provider === 'jellyfin' ? 'jellyfin' : 'local')
  const canChangePassword = user?.password_change_supported ?? ['local', 'jellyfin'].includes(user?.auth_provider ?? '')
  const emailChanged = email.trim() !== (user?.email ?? '')
  const recent = data?.activity?.recent ?? []
  const notice = (value: Notice) => value && <p className={`account-notice is-${value.tone}`} role={value.tone === 'error' ? 'alert' : 'status'}>{value.message}</p>

  return (
    <main className="account-page">
      <header className="account-heading">
        <div><span className="account-eyebrow">YOUR ACCOUNT</span><h1>My profile</h1></div>
        {user && <div className="account-identity"><span className="account-avatar" aria-hidden="true">{user.username.slice(0, 1).toUpperCase()}</span><div><strong>{user.username}</strong><span>{user.role === 'admin' ? 'Administrator' : 'Member'}</span></div></div>}
      </header>

      {loading ? <p className="account-empty" role="status">Loading your profile…</p> : loadError ? (
        <div className="account-empty"><p role="alert">{loadError}</p><button type="button" className="account-secondary" onClick={() => void loadProfile()}>Try again</button></div>
      ) : user && <>
        <div className="account-tabs" role="tablist" aria-label="Profile sections">
          {TABS.map((tab, index) => <button key={tab.key} id={`profile-tab-${tab.key}`} type="button" role="tab"
            aria-selected={activeTab === tab.key} aria-controls={`profile-panel-${tab.key}`} tabIndex={activeTab === tab.key ? 0 : -1}
            onKeyDown={(event) => tabKeyDown(event, index)} onClick={() => selectTab(tab.key)}>{tab.label}</button>)}
        </div>

        <section className="account-panel" id="profile-panel-overview" role="tabpanel" aria-labelledby="profile-tab-overview" hidden={activeTab !== 'overview'}>
          <div className="account-section-intro"><h2>Contact email</h2><p>For password recovery and updates on your reported issues.</p></div>
          <form className="account-form" onSubmit={saveEmail}>
            <label htmlFor="profile-email">Email address</label>
            <input id="profile-email" name="email" type="email" autoComplete="email" placeholder="you@example.com" value={email} disabled={emailSaving}
              onChange={(event) => { setEmail(event.target.value); setEmailNotice(null) }} />
            {!user.email && <p className="account-hint">Add an email so we can let you know when a fix is ready.</p>}
            {user.email && !email.trim() && <p className="account-hint">Saving without an email stops account and issue emails.</p>}
            {notice(emailNotice)}
            <div className="account-form-actions">
              <button type="submit" className="account-primary" disabled={emailSaving || !emailChanged}>{emailSaving ? 'Saving…' : 'Save email'}</button>
              {emailChanged && <button type="button" className="account-secondary" disabled={emailSaving} onClick={() => { setEmail(user.email ?? ''); setEmailNotice(null) }}>Discard</button>}
            </div>
          </form>
          <div className="account-connected"><span className="account-connection-dot" aria-hidden="true" /><span>{user.auth_provider === 'jellyfin' ? 'Connected with your Grizzlyflix account' : user.auth_provider === 'local' ? 'Signed in with a Magent account' : 'Signed in with your media account'}</span></div>
        </section>

        <section className="account-panel" id="profile-panel-security" role="tabpanel" aria-labelledby="profile-tab-security" hidden={activeTab !== 'security'}>
          <div className="account-section-intro"><h2>Change password</h2><p>{passwordProvider === 'jellyfin' ? 'One password for Grizzlyflix, Seerr and Magent.' : 'Keep your Magent account secure.'}</p></div>
          {canChangePassword ? <form className="account-form" onSubmit={savePassword}>
            <fieldset disabled={passwordSaving}>
              <label htmlFor="profile-current-password">Current password</label>
              <input id="profile-current-password" type="password" autoComplete="current-password" value={currentPassword} onChange={(event) => setCurrentPassword(event.target.value)} required />
              <label htmlFor="profile-new-password">New password</label>
              <input id="profile-new-password" type="password" autoComplete="new-password" aria-describedby="password-length" value={newPassword} onChange={(event) => setNewPassword(event.target.value)} minLength={8} required />
              <p id="password-length" className="account-hint">At least 8 characters.</p>
              <label htmlFor="profile-confirm-password">Confirm new password</label>
              <input id="profile-confirm-password" type="password" autoComplete="new-password" value={confirmPassword} onChange={(event) => setConfirmPassword(event.target.value)} minLength={8} required />
            </fieldset>
            {notice(passwordNotice)}
            <div className="account-form-actions"><button type="submit" className="account-primary" disabled={passwordSaving}>{passwordSaving ? 'Updating…' : 'Update password'}</button></div>
          </form> : <p className="account-empty">Password changes are managed by your sign-in provider. Contact an administrator for help.</p>}
        </section>

        <section className="account-panel" id="profile-panel-activity" role="tabpanel" aria-labelledby="profile-tab-activity" hidden={activeTab !== 'activity'}>
          <div className="account-section-intro"><h2>Your activity</h2><p>Your requests and recent account access.</p></div>
          {data?.stats && <div className="account-request-summary"><div><strong>{data.stats.total}</strong><span>Requests</span></div><div><strong>{data.stats.ready}</strong><span>Ready to watch</span></div><a href="/">View my requests <span aria-hidden="true">↗</span></a></div>}
          <h3 className="account-list-heading">Recent account access</h3>
          {recent.length ? <ul className="account-access-list">
            {(showAllActivity ? recent : recent.slice(0, 5)).map((entry, index) => <li key={`${entry.ip}-${entry.last_seen_at}-${index}`}>
              <div className="account-access-summary"><strong>{deviceName(entry.user_agent)}</strong><time dateTime={entry.last_seen_at}>{formatDate(entry.last_seen_at)}</time></div>
              <details><summary>Connection details</summary><dl><div><dt>IP address</dt><dd>{entry.ip || 'Not recorded'}</dd></div><div><dt>First seen</dt><dd>{formatDate(entry.first_seen_at)}</dd></div></dl></details>
            </li>)}
          </ul> : <p className="account-empty">No recent activity yet.</p>}
          {recent.length > 5 && <button className="account-secondary" type="button" onClick={() => setShowAllActivity(!showAllActivity)}>{showAllActivity ? 'Show less' : 'Show all activity'}</button>}
        </section>
      </>}
    </main>
  )
}