import { state } from '../state'
import { SkipSegment } from '../types'
import { displayTimeFromAbsolute } from '../timeline'
import { resolveActiveSegments, renderSegments } from '../skip/segments'
import { updateSubtitleOptions } from '../subtitles'
import { updateQualityOptions } from '../quality'
import { updateModeButtons } from '../mode'
import { updateOverlay, isAutoplayEnabled, updateEpisodeHighlight, switchEpisodeRange } from './ui'
import { markEpisodeTransition } from '../progress'

export const goToNextEpisode = async (): Promise<void> => {
  const currentEp = Number.parseInt(state.currentEpisode, 10)
  if (!currentEp) return

  if (state.totalEpisodes > 0 && currentEp >= state.totalEpisodes) {
    import('./complete').then(m => m.completeAnime(currentEp))
    return
  }

  if (!isAutoplayEnabled()) return

  const nextEp = currentEp + 1
  markEpisodeTransition(nextEp)

  try {
    const res = await fetch(`/api/watch/episode/${state.malID}/${nextEp}`)
    if (!res.ok) {
      sessionStorage.setItem('mal:autoplay-next', 'true')
      const url = new URL(window.location.href)
      url.searchParams.set('ep', String(nextEp))
      window.location.href = url.toString()
      return
    }

    const data = await res.json()

    state.modeSources = data.mode_sources ?? {}
    state.availableModes = data.available_modes ?? []

    const fallback = state.availableModes.find(m => state.modeSources[m]?.token)
    if (!fallback) {
      sessionStorage.setItem('mal:autoplay-next', 'true')
      const url = new URL(window.location.href)
      url.searchParams.set('ep', String(nextEp))
      window.location.href = url.toString()
      return
    }

    state.video.src = `${state.streamURL}?mode=${encodeURIComponent(fallback)}&token=${encodeURIComponent(state.modeSources[fallback].token)}`
    state.video.load()
    if (!state.video.paused) state.video.play().catch(() => {})

    state.currentEpisode = String(nextEp)
    state.pendingSeekTime = null
    state.completionSent = false
    state.completionAttempts = 0
    state.activeSubtitles = []

    updateSubtitleOptions()
    updateQualityOptions()
    updateModeButtons()
    updateOverlay(state.currentEpisode, data.episode_title ?? '')

    if (data.segments?.length) {
      state.parsedSegments = data.segments
        .map((s: SkipSegment) => ({ ...s, start: Number(s.start) || 0, end: Number(s.end) || 0 }))
        .filter((s: SkipSegment) => s.end > s.start)
      resolveActiveSegments()
      renderSegments()
    }

    state.episodeList?.querySelectorAll('[data-episode-id]').forEach(el => el.classList.remove('bg-accent/20'))
    const newListEl = state.episodeList?.querySelector(`[data-episode-id="${nextEp}"]`)
    newListEl?.classList.add('bg-accent/20')

    if (state.episodeGrid) {
      state.episodeGrid.querySelectorAll('[data-episode-id]').forEach(el => {
        el.classList.remove('bg-accent/20', 'ring-2', 'ring-accent', 'text-accent')
      })
      switchEpisodeRange(Math.floor((nextEp - 1) / 100))
      const newGridEl = state.episodeGrid.querySelector(`[data-episode-id="${nextEp}"]`)
      newGridEl?.classList.add('bg-accent/20', 'ring-2', 'ring-accent', 'text-accent')
    }

    const url = new URL(window.location.href)
    url.searchParams.set('ep', String(nextEp))
    history.pushState(null, '', url.toString())
    state.transitionEpisode = null
  } catch {
    sessionStorage.setItem('mal:autoplay-next', 'true')
    const url = new URL(window.location.href)
    url.searchParams.set('ep', String(nextEp))
    window.location.href = url.toString()
  }
}