'use client'

import { useCallback, useEffect, useState } from 'react'
import { useRouter } from 'next/navigation'
import { authFetch, getApiBase } from '../lib/auth'
import PageHeading from '../ui/PageHeading'
import { type Stats, BreakdownCard, RecentArtwork, StatsNavigation, StreamingCard, ViewingChart, dateLabel, number } from './components'
import './stats.css'

export default function InsightsPage() {
  const router = useRouter()
  const [days, setDays] = useState(30)
  const [data, setData] = useState<Stats | null>(null)
  const [busy, setBusy] = useState(true)
  const [error, setError] = useState('')
  const [revision, setRevision] = useState(0)
  const load = useCallback(async (signal: AbortSignal) => {
    setBusy(true)
    setError('')
    setData(null)
    try {
      const response = await authFetch(`${getApiBase()}/insights?days=${days}`, { signal })
      if (response.status === 401) { router.replace('/login?next=%2Finsights'); return }
      if (response.status === 403) throw new Error('Your account cannot access viewing stats. Please contact an administrator.')
      if (!response.ok) {
        const result = await response.json().catch(() => ({}))
        throw new Error(typeof result.detail === 'string' ? result.detail : 'Your viewing stats are temporarily unavailable. Please try again shortly.')
      }
      const result = await response.json() as Stats
      if (!signal.aborted) setData(result)
    } catch (err) {
      if (!signal.aborted) setError(err instanceof Error ? err.message : 'Could not load your stats.')
    } finally {
      if (!signal.aborted) setBusy(false)
    }
  }, [days, router])

  useEffect(() => {
    const controller = new AbortController()
    void load(controller.signal)
    return () => controller.abort()
  }, [load, revision])

  const summary = data?.summary
  return (
    <main className="stats-page">
      <PageHeading title="My Stats" description="Your viewing, in numbers. Watch time, favourite stories, and the requests that started it all." actions={<button className="ghost-button" type="button" disabled={busy} onClick={() => setRevision((value) => value + 1)}>{busy ? 'Loading…' : 'Refresh stats'}</button>} />
      <StatsNavigation />
      <div className="stats-toolbar">
        <fieldset className="stats-period"><legend className="stats-sr-only">Stats period</legend>{[7, 30, 90, 365].map((value) => <button type="button" key={value} aria-pressed={days === value} onClick={() => setDays(value)}>{value === 365 ? 'Past year' : `${value} days`}</button>)}</fieldset>
        <p className="stats-source"><span className={data?.state === 'ready' ? 'stats-source-dot is-ready' : 'stats-source-dot'} />From Jellystat{data?.updated_at && <span> · Updated {new Date(data.updated_at).toLocaleTimeString(undefined, { hour: '2-digit', minute: '2-digit' })}</span>}</p>
      </div>
      {busy && <div className="stats-state" role="status"><span className="stats-state-symbol" aria-hidden="true">◷</span><h2>Gathering your stats</h2><p>Fetching your viewing history from Jellystat.</p></div>}
      {error && <div className="stats-state" role="alert"><h2>Stats couldn’t load</h2><p>{error}</p><button type="button" className="ghost-button" onClick={() => setRevision((value) => value + 1)}>Try again</button></div>}
      {data?.state === 'not_configured' && <section className="stats-state"><span className="stats-state-symbol" aria-hidden="true">▥</span><h2>Your viewing story starts here</h2><p>{data.is_admin ? 'Connect your Jellystat instance to bring personal viewing stats into Magent.' : 'Viewing stats will appear here once your administrator connects Jellystat.'}</p>{data.is_admin && <a className="stats-action" href="/admin/jellystat">Connect Jellystat</a>}</section>}
      {data?.state === 'unlinked' && <section className="stats-state"><h2>Link your viewing account</h2><p>Your Magent account needs a Jellyfin identity to find your stats. Sign in using Jellyfin, or ask your administrator to sync Jellyfin users.</p></section>}
      {summary && <>
        <section className="stats-metrics" aria-label="Viewing totals">
          <article className="stats-metric stats-metric-accent"><span>Minutes watched</span><strong>{number(summary.minutes)}</strong><small>{number(summary.minutes / 60)} hours across {number(summary.plays)} plays</small></article>
          <article className="stats-metric"><span>Movies played</span><strong>{number(summary.movies)}</strong><small>Different movies you pressed play on</small></article>
          <article className="stats-metric"><span>Episodes played</span><strong>{number(summary.episodes)}</strong><small>Different episodes in your history</small></article>
          <article className="stats-metric"><span>Requests made</span><strong>{number(data.requests.total)}</strong><small>{number(data.requests.movies)} movies · {number(data.requests.tv)} TV requests</small></article>
        </section>
        {summary.plays === 0 && <div className="stats-notice" role="status">No viewing history in this period yet. Try a longer period, or come back after your next watch.</div>}
        <div className="stats-main-grid">
          <ViewingChart key={`${days}-${revision}`} daily={data.daily ?? []} />
          <section className="stats-panel stats-highlights"><div className="stats-panel-heading"><h2>A little watch history</h2></div>
            <div className="stats-highlight"><span className="stats-highlight-number">{summary.current_streak}<small> days</small></span><div><strong>Current streak</strong><p>Consecutive viewing days through today or yesterday.</p></div></div>
            <div className="stats-highlight"><span className="stats-highlight-number">{summary.longest_streak}<small> days</small></span><div><strong>Longest run</strong><p>Your best streak in this period.</p></div></div>
            <div className="stats-highlight"><span className="stats-highlight-number">{summary.active_days}<small> days</small></span><div><strong>Time for a story</strong><p>Days with at least a minute watched.</p></div></div>
          </section>
        </div>
        <div className="stats-three-grid">
          <section className="stats-panel"><div className="stats-panel-heading"><h2>Most watched</h2><span className="stats-unit">By minutes</span></div>{data.top_titles?.length ? <ol className="stats-top-titles">{data.top_titles.map((title, index) => <li key={`${title.title}-${index}`}><span className="stats-rank">{String(index + 1).padStart(2, '0')}</span><div><strong>{title.title}</strong><small>{title.type === 'series' ? 'TV series' : title.type === 'movie' ? 'Movie' : 'Other media'} · {title.plays} plays</small></div><span>{number(title.minutes)}<small>min</small></span></li>)}</ol> : <p className="stats-muted">Your favourites will find their place here.</p>}</section>
          <BreakdownCard title="Your players" rows={data.clients ?? []} />
          <StreamingCard rows={data.methods ?? []} transcoding={data.transcoding} />
        </div>
      </>}
      {data && <div className="stats-main-grid">
        {summary && <section className="stats-panel stats-history"><div className="stats-panel-heading"><h2>Recently watched</h2><span className="stats-unit">Latest 20 plays</span></div>{data.recent?.length ? <div className="stats-history-list">{data.recent.map((play) => <article key={play.id}><RecentArtwork key={play.artwork_url ?? play.id} url={play.artwork_url} type={play.type} /><div className="stats-history-title"><strong>{play.series || play.title}</strong><small>{play.series ? `${play.episode} · ${play.title}` : play.type === 'movie' ? 'Movie' : 'Media'}</small><span>{play.client} · {play.method}</span></div><div className="stats-history-time"><strong>{number(play.minutes)} min</strong><time dateTime={play.played_at}>{dateLabel(play.played_at)}</time></div></article>)}</div> : <p className="stats-muted">Plays recorded by Jellystat will appear here.</p>}</section>}
        <section className="stats-panel stats-requests"><div className="stats-panel-heading"><h2>Your requests</h2><a href="/">View all</a></div><div className="stats-request-total"><strong>{data.requests.total}</strong><span>submitted in the past {days} days</span></div><div className="stats-request-counts"><span><strong>{data.requests.pending}</strong> Pending</span><span><strong>{data.requests.approved}</strong> Approved</span><span><strong>{data.requests.declined}</strong> Declined</span></div>{data.requests.recent.length > 0 ? <ul className="stats-request-list">{data.requests.recent.map((request) => <li key={request.request_id}><a href={`/requests/${request.request_id}`}>{request.title || `Request ${request.request_id}`}<span aria-hidden="true">↗</span></a></li>)}</ul> : <p className="stats-muted">Something on your watchlist? <a href="/new-requests">Make a request.</a></p>}</section>
      </div>}
      {summary && <p className="stats-footnote">Private to your account · Stats come from Jellystat and may take a minute to refresh. Counts describe plays, including unfinished watches. Movies are identified from Jellystat’s movie libraries; other media still contributes to watch time. Charts and streaks use UTC and the activity dates recorded by Jellystat.</p>}
    </main>
  )
}