import { useMemo } from 'react'
import { useNavigate } from 'react-router-dom'
import { motion } from 'framer-motion'
import { ArrowRight, Star, MoonStars } from '../../lib/icons'
import { useTmdbDiscoverMovies, useTmdbDiscoverTv, useTmdbTrending } from '../../hooks/use-tmdb'
import { useLibraryByTmdbId, useLibraryGenreDistribution } from '../../hooks/use-jellyfin'
import { usePreferencesStore } from '../../stores/preferences-store'
import { filterToMissing } from '../../pages/discover/helpers'
import { tmdbMovieGenreId, tmdbTvGenreId } from '../../lib/tmdb-genres'
import type { TmdbDiscoverItem } from '../../api/tmdb'

const TMDB_IMG = 'https://image.tmdb.org/t/p'

interface Props {
  kind: 'movie' | 'tv'
}

/**
 * Personalized "tonight" pick. Reads the user's library genre
 * distribution, finds their top genre, and picks one highly-rated
 * unowned title from that genre as a featured spotlight.
 *
 * Falls back to TMDB trending-day for cold-start users (small or no
 * library), so the component always renders something useful.
 *
 * The card mirrors the older SpotlightHero visually but reframes the
 * copy: this isn't "what's hot on TMDB", it's "we read what you
 * actually watch".
 */
export default function TonightHero({ kind }: Props) {
  const navigate = useNavigate()
  const hideAdult = usePreferencesStore(s => s.hideAdult)
  const lib = useLibraryByTmdbId()
  const dist = useLibraryGenreDistribution()

  // Top genre across the user's library, if we have enough material to
  // call it a real signal. Below 30 items we treat the user as
  // cold-start and fall back to a non-personalized pick.
  const topGenre = useMemo(() => {
    const data = dist.data
    if (!data || data.total < 30) return null
    const sorted = [...data.counts.entries()].sort((a, b) => b[1] - a[1])
    return sorted[0]?.[0] || null
  }, [dist.data])

  const genreId = topGenre
    ? kind === 'movie'
      ? tmdbMovieGenreId(topGenre)
      : tmdbTvGenreId(topGenre)
    : null

  const personalizedParams = genreId
    ? {
        with_genres: String(genreId),
        'vote_count.gte': '2000',
        'vote_average.gte': '7.5',
        sort_by: 'popularity.desc',
      }
    : ({} as Record<string, string>)

  const personalMovies = useTmdbDiscoverMovies(kind === 'movie' && genreId ? personalizedParams : {})
  const personalTv = useTmdbDiscoverTv(kind === 'tv' && genreId ? personalizedParams : {})
  const personalData = kind === 'movie' ? personalMovies.data : personalTv.data

  // Cold-start fallback: trending-day, same as the old Spotlight.
  const trending = useTmdbTrending(kind, 'day')

  const pick = useMemo(() => {
    // Personalized pool wins when present + non-empty.
    const personalRaw = (personalData?.results || []).map(m => ({ ...m, media_type: kind }))
    const personalPool = filterToMissing(personalRaw, lib.data, hideAdult, m => !!m.adult)
      .filter(m => m.backdrop_path && m.overview)
    if (personalPool.length > 0) {
      return { item: personalPool[0], reason: 'personalized' as const, genre: topGenre }
    }
    // Fallback: trending-day filtered to unowned.
    const trendRaw = trending.data?.results || []
    const trendPool = filterToMissing(trendRaw, lib.data, hideAdult, m => !!m.adult)
      .filter(m => m.backdrop_path && m.overview)
    if (trendPool.length > 0) {
      return { item: trendPool[0], reason: 'trending' as const, genre: null }
    }
    return null
  }, [personalData, trending.data, lib.data, hideAdult, kind, topGenre])

  if (!pick) return null

  const item = pick.item as TmdbDiscoverItem
  const title: string = item.title || item.name || ''
  const overview: string = item.overview || ''
  const backdrop = `${TMDB_IMG}/w1280${item.backdrop_path}`
  const year = (item.release_date || item.first_air_date || '').slice(0, 4)
  const rating = typeof item.vote_average === 'number' ? item.vote_average.toFixed(1) : null
  const mediaType: 'movie' | 'tv' = (item.media_type === 'tv' || item.first_air_date) ? 'tv' : 'movie'

  function open() {
    navigate(`/item/tmdb-${mediaType}-${item.id}`)
  }

  const eyebrowText = pick.reason === 'personalized'
    ? `Tonight - because you watch a lot of ${pick.genre?.toLowerCase()}`
    : 'Tonight - trending picks'

  return (
    <motion.section
      initial={{ opacity: 0, y: 12 }}
      animate={{ opacity: 1, y: 0 }}
      transition={{ duration: 0.55, ease: [0.16, 1, 0.3, 1] }}
      className="mx-7 mb-9 relative rounded-2xl overflow-hidden ring-1 ring-border bg-elevated/40 shadow-[0_24px_48px_-16px_rgba(0,0,0,0.65)] h-[200px] sm:h-[240px] md:h-[300px] lg:h-[380px] xl:h-[440px]"
    >
      <motion.img
        key={item.id}
        initial={{ scale: 1.04, opacity: 0 }}
        animate={{ scale: 1, opacity: 1 }}
        transition={{ duration: 1.2, ease: [0.16, 1, 0.3, 1] }}
        src={backdrop}
        alt=""
        className="absolute inset-0 w-full h-full object-cover"
      />
      <div className="absolute inset-0 bg-gradient-to-r from-void via-void/82 to-void/10" />
      <div className="absolute inset-0 bg-gradient-to-t from-void/95 via-void/30 to-transparent" />
      <div className="absolute inset-0 noise pointer-events-none" />

      <button
        onClick={open}
        className="absolute inset-0 z-10 group cursor-pointer focus-ring rounded-2xl"
        aria-label={`Open ${title}`}
      >
        <div className="absolute left-0 right-0 bottom-0 p-7 md:p-9 text-left max-w-3xl">
          <div className="flex items-center gap-2 mb-2.5">
            <MoonStars size={12} className="text-accent" />
            <span className="text-[10.5px] uppercase tracking-[0.2em] font-semibold text-accent">
              {eyebrowText}
            </span>
          </div>
          <h2 className="font-display text-[26px] md:text-[34px] font-bold tracking-tight text-text-1 leading-[1.05] mb-2.5">
            {title}
          </h2>
          <div className="flex items-center gap-2.5 text-[12px] text-text-3 mb-3.5 tabular-nums">
            {year && <span>{year}</span>}
            {year && rating && <span className="text-text-5">·</span>}
            {rating && (
              <span className="inline-flex items-center gap-1 text-accent">
                <Star size={11} fill="currentColor" stroke={0} />
                {rating}
              </span>
            )}
            <span className="text-text-5">·</span>
            <span className="uppercase tracking-[0.14em] text-[10.5px] font-semibold text-text-3">
              {mediaType === 'tv' ? 'Series' : 'Movie'}
            </span>
          </div>
          <p className="text-[13px] text-text-2 leading-relaxed line-clamp-2 mb-5 max-w-xl">
            {overview}
          </p>
          <span className="inline-flex items-center gap-2 h-10 px-5 rounded-full bg-accent text-void text-[13px] font-semibold tracking-tight transition-transform duration-200 group-hover:scale-[1.03] group-active:scale-[0.97] shadow-[0_8px_24px_-8px_rgba(245,182,66,0.5)]">
            View details
            <ArrowRight size={14} stroke={2.25} />
          </span>
        </div>
      </button>
    </motion.section>
  )
}
