// Voyager 2's web interface (from voyager 1's). No framework; all Usenet-derived
// text is rendered with textContent, never as HTML.

const $ = (selector) => document.querySelector(selector)
const FILTERS = ['readable', 'complete', 'unlocked']
/** Text inputs that narrow a search: size bounds in MB. */
const FIELDS = ['min_size', 'max_size']
/** What a probed article was (probe_candidates.kind). */
const KIND_LABELS = {
  archive: 'Archive start',
  par2: 'Par2 index',
  lone: 'Single file',
  '7z-tail': '7z end',
}
const SOURCE_LABELS = {
  stem: 'Filename',
  subject: 'Subject',
  post: 'Post id',
}
/** Where a known password came from (release_passwords.source). */
const PASSWORD_SOURCES = {
  nzb: "from the spot's NZB",
  'spot-title': "from the spot's title",
  'spot-text': "from the spot's text",
}
/** Newznab categories (lib/newznab/categories.ts). */
const CATEGORIES = [
  [1000, 'Console', []],
  [2000, 'Movies', [[2030, 'SD'], [2040, 'HD'], [2045, 'UHD']]],
  [3000, 'Audio', [[3010, 'MP3'], [3030, 'Audiobook'], [3040, 'Lossless']]],
  [4000, 'PC', [[4050, 'Games']]],
  [5000, 'TV', [[5030, 'SD'], [5040, 'HD'], [5045, 'UHD'], [5070, 'Anime']]],
  [6000, 'XXX', [[6040, 'x264'], [6045, 'UHD'], [6060, 'ImgSet'], [6070, 'Other']]],
  [7000, 'Books', [[7020, 'Ebook'], [7030, 'Comics']]],
  [8000, 'Other', [[8010, 'Misc']]],
]
function categoryLabel(id) {
  for (const [parent, name, subs] of CATEGORIES) {
    if (Math.floor(id / 1000) * 1000 !== parent) continue
    const sub = subs.find(([s]) => s === id)
    return sub ? `${name} > ${sub[1]}` : name
  }
  return 'Other'
}

const state = {
  q: '',
  sort: 'newest',
  source: '',
  cat: '',
  poster: '',
  min_size: '',
  max_size: '',
  readable: false,
  complete: false,
  unlocked: false,
  page: 1,
  release: null,
}
let requestId = 0
let searchAbort = null

// --- Formatting ------------------------------------------------------------

function formatSize(bytes) {
  if (!bytes) return '–'
  const units = ['B', 'KB', 'MB', 'GB', 'TB']
  let value = bytes
  let unit = 0
  while (value >= 1000 && unit < units.length - 1) {
    value /= 1000
    unit++
  }
  return `${value >= 100 || unit === 0 ? Math.round(value) : value.toFixed(1)} ${units[unit]}`
}

const number = new Intl.NumberFormat()

function formatAge(date) {
  if (!date) return ''
  const seconds = (Date.now() - new Date(date).getTime()) / 1000
  if (seconds < 90) return 'just now'
  const steps = [
    [60, 'minute'],
    [3600, 'hour'],
    [86400, 'day'],
    [2592000, 'month'],
    [31536000, 'year'],
  ]
  let [size, name] = steps[0]
  for (const step of steps) if (seconds >= step[0]) [size, name] = step
  const n = Math.floor(seconds / size)
  return `${n} ${name}${n === 1 ? '' : 's'} ago`
}

function el(tag, props = {}, ...children) {
  const node = document.createElement(tag)
  for (const [key, value] of Object.entries(props)) {
    if (value === undefined || value === null || value === false) continue
    if (key === 'class') node.className = value
    else if (key === 'text') node.textContent = value
    else if (key.startsWith('on')) node.addEventListener(key.slice(2), value)
    else node.setAttribute(key, value === true ? '' : value)
  }
  for (const child of children.flat()) {
    if (child === null || child === undefined || child === false) continue
    node.append(child instanceof Node ? child : document.createTextNode(String(child)))
  }
  return node
}

function badge(text, tone = '', title) {
  return el('span', { class: `badge${tone ? ` badge-${tone}` : ''}`, text, title })
}

// --- URL state -------------------------------------------------------------

function readUrl() {
  const params = new URLSearchParams(location.search)
  state.q = params.get('q') ?? ''
  state.sort = params.get('sort') ?? 'newest'
  state.source = params.get('source') ?? ''
  state.cat = params.get('cat') ?? ''
  state.poster = params.get('poster') ?? ''
  for (const k of FIELDS) state[k] = params.get(k) ?? ''
  for (const f of FILTERS) state[f] = params.get(f) === '1'
  state.release = params.get('release') ? Number(params.get('release')) : null
}

function writeUrl(push = false) {
  const params = new URLSearchParams()
  if (state.q) params.set('q', state.q)
  if (state.sort !== 'newest') params.set('sort', state.sort)
  if (state.source) params.set('source', state.source)
  if (state.cat) params.set('cat', state.cat)
  if (state.poster) params.set('poster', state.poster)
  for (const k of FIELDS) if (state[k]) params.set(k, state[k])
  for (const f of FILTERS) if (state[f]) params.set(f, '1')
  if (state.release) params.set('release', String(state.release))
  const url = `${location.pathname}${params.size ? `?${params}` : ''}`
  history[push ? 'pushState' : 'replaceState'](null, '', url)
}

function syncControls() {
  $('#q').value = state.q
  $('#sort').value = state.sort
  $('#source').value = state.source
  $('#cat').value = state.cat
  for (const k of FIELDS) $(`#${k}`).value = state[k]
  for (const f of FILTERS) {
    document.querySelector(`[data-filter="${f}"]`).setAttribute('aria-pressed', String(state[f]))
  }
  $('#poster-filter').hidden = !state.poster
  $('#poster-filter-label').textContent = `Poster: ${state.poster}`
}

// --- API -------------------------------------------------------------------

async function api(path, { signal } = {}) {
  const response = await fetch(path, { headers: { accept: 'application/json' }, signal })
  if (!response.ok) throw new Error(`${response.status} ${response.statusText}`)
  return response.json()
}

function searchParams(page) {
  const params = new URLSearchParams({ sort: state.sort, page: String(page), per_page: '50' })
  if (state.q) params.set('q', state.q)
  if (state.source) params.set('source', state.source)
  if (state.cat) params.set('cat', state.cat)
  if (state.poster) params.set('poster', state.poster)
  for (const k of FIELDS) if (state[k]) params.set(k, state[k])
  for (const f of FILTERS) if (state[f]) params.set(f, '1')
  return params
}

// --- Stats -----------------------------------------------------------------

async function loadStats() {
  try {
    const stats = await api('/api/v1/stats')
    const readable = stats.releases ? Math.round((100 * stats.readableReleases) / stats.releases) : 0
    // Estimated from Postgres statistics and a sample.
    const about = stats.approximate ? '≈ ' : ''
    const percent = ({ done, total }) => {
      const p = total ? (100 * done) / total : 0
      return `${p < 10 ? p.toFixed(1) : Math.round(p)}%`
    }
    const items = [
      ['Releases', about + number.format(stats.releases)],
      ['Readable', `${about}${readable}%`],
      ['Files', about + number.format(stats.files)],
      ['Size', about + formatSize(stats.size)],
      ['History', percent(stats.history)],
      ...(stats.pass.total < stats.history.total ? [['Pass', percent(stats.pass)]] : []),
      ['Live', formatAge(stats.tailIndexedAt) || '–'],
    ]
    $('#stats').replaceChildren(...items.map(([dt, dd]) => el('div', {}, el('dt', { text: dt }), el('dd', { text: dd }))))
  } catch {
    // Stats are decoration; the page works without them.
  }
}

// --- Results ---------------------------------------------------------------

function releaseRow(release) {
  const row = $('#row-template').content.firstElementChild.cloneNode(true)
  row.dataset.id = release.id
  if (release.id === state.release) row.classList.add('selected')

  const name = row.querySelector('.release-name')
  name.textContent = release.name
  if (!release.readable) name.classList.add('obfuscated')

  const meta = [
    formatAge(release.postedAt),
    release.poster ? release.poster.replace(/\s*<.*>$/, '') : 'obfuscated poster',
    release.groups?.length ? release.groups[0] + (release.groups.length > 1 ? ` +${release.groups.length - 1}` : '') : '',
  ].filter(Boolean)
  row.querySelector('.release-meta').textContent = meta.join(' · ')
  if (release.innerName) {
    const inner = row.querySelector('.release-inner')
    inner.textContent = release.innerName
    inner.title = 'Found inside by reading its articles'
    inner.hidden = false
  }

  const badges = row.querySelector('.badges')
  const files = `${release.fileCount} ${release.fileCount === 1 ? 'file' : 'files'}`
  if (release.complete) badges.append(badge(files, 'good', 'Complete'))
  else if (release.fileTotal) badges.append(badge(`${release.fileCount}/${release.fileTotal}`, 'warn', 'Files present / announced'))
  else badges.append(badge(files))
  if (release.passworded && release.passwordKnown) badges.append(badge('Password known', 'warn', 'Its archive is encrypted; the password is in the NZB'))
  else if (release.passworded) badges.append(badge('Password', 'bad', 'Its archive is encrypted: a password is needed'))
  if (!release.settled) badges.append(badge('Collecting', 'accent', 'Recently seen: more files may still arrive'))
  if (release.category && release.category !== 8010) badges.append(badge(categoryLabel(release.category), '', 'Category (from the name, the inner name, a spot or the groups)'))
  if (release.source && release.source !== 'stem' && release.source !== 'subject') {
    badges.append(badge(SOURCE_LABELS[release.source] ?? release.source, 'accent', 'How this release was recognised'))
  }

  row.querySelector('.release-size').textContent = formatSize(release.size)
  const nzb = row.querySelector('.nzb')
  nzb.href = `/api/v1/releases/${release.id}/nzb`
  row.querySelector('.release-main').addEventListener('click', () => openRelease(release.id, true))
  return row
}

async function loadResults({ append = false } = {}) {
  const id = ++requestId
  if (!append) state.page = 1
  // A newer search makes the running one pointless: cancel it.
  searchAbort?.abort()
  const abort = (searchAbort = new AbortController())
  $('#more').hidden = true
  if (!append) {
    $('#summary').textContent = 'Searching…'
    $('#empty').hidden = true
    // The old rows no longer match the search; grey them out until the new ones arrive.
    $('#list').classList.add('stale')
    $('.results').setAttribute('aria-busy', 'true')
  }

  try {
    const result = await api(`/api/v1/releases?${searchParams(state.page)}`, { signal: abort.signal })
    if (id !== requestId) return // a newer search superseded this one
    $('#list').classList.remove('stale')
    $('.results').removeAttribute('aria-busy')
    const rows = result.releases.map(releaseRow)
    if (append) $('#list').append(...rows)
    else $('#list').replaceChildren(...rows)

    const shown = $('#list').children.length
    $('#summary').textContent =
      result.total === 0 ? '' : `${number.format(result.total)}${result.totalCapped ? '+' : ''} ${result.total === 1 ? 'release' : 'releases'}` +
        (shown < result.total ? ` · showing ${number.format(shown)}` : '')
    $('#empty').hidden = result.total !== 0
    $('#more').hidden = shown >= result.total && !result.totalCapped
  } catch (error) {
    if (id !== requestId) return
    $('#list').classList.remove('stale')
    $('.results').removeAttribute('aria-busy')
    $('#summary').textContent = `Search failed: ${error.message}`
  }
}

let debounce
function scheduleSearch() {
  clearTimeout(debounce)
  debounce = setTimeout(() => {
    writeUrl()
    loadResults()
  }, 220)
}

// --- Detail drawer ---------------------------------------------------------

function fact(label, value) {
  if (value === null || value === undefined || value === '') return null
  return el('div', {}, el('dt', { text: label }), el('dd', {}, value))
}

function section(title, note, content) {
  return [el('h3', { class: 'section-title' }, title, note ? el('small', { text: note }) : null), content]
}

function renderDetail(release) {
  $('#detail-name').textContent = release.name
  $('#detail-source').textContent = `Recognised by ${SOURCE_LABELS[release.source] ?? release.source ?? 'filename'} · ${categoryLabel(release.category)}`

  const actions = el(
    'div',
    { class: 'actions' },
    el('a', { class: 'button button-primary', href: `/api/v1/releases/${release.id}/nzb` },
      el('span', { text: 'Download NZB' })),
    el('button', {
      class: 'button',
      type: 'button',
      text: 'Copy name',
      onclick: async (event) => {
        await navigator.clipboard?.writeText(release.name)
        event.target.textContent = 'Copied'
        setTimeout(() => (event.target.textContent = 'Copy name'), 1200)
      },
    })
  )

  const poster = release.poster
    ? el('button', {
        class: 'link-button',
        type: 'button',
        text: release.poster.replace(/\s*<.*>$/, ''),
        title: 'Show releases by this poster',
        onclick: () => {
          state.poster = release.poster
          closeRelease()
          syncControls()
          writeUrl(true)
          loadResults()
        },
      })
    : 'Random per article (obfuscated)'

  const facts = el(
    'dl',
    { class: 'facts' },
    fact('Size', formatSize(release.size)),
    fact('Files', release.fileTotal ? `${release.fileCount} of ${release.fileTotal}` : `${release.fileCount} posted`),
    fact('Articles', number.format(release.segments)),
    fact('Posted', release.postedAt ? `${new Date(release.postedAt).toLocaleString()} (${formatAge(release.postedAt)})` : null),
    fact('Poster', poster),
    fact('Groups', release.groups?.join(', ')),
    fact('Indexed', release.firstSeenAt ? `${new Date(release.firstSeenAt).toLocaleString()} (${formatAge(release.firstSeenAt)})` : null),
    fact('Inside', release.innerName),
    fact('Inspected', release.inspectedAt ? `${new Date(release.inspectedAt).toLocaleString()} (${formatAge(release.inspectedAt)})` : null)
  )

  const notices = []
  if (!release.settledAt) {
    notices.push(el('div', { class: 'notice notice-warn', text: 'Recently seen: more files of this release may still arrive. The NZB has what is indexed so far.' }))
  }
  const passwords = release.passwords ?? []
  if (passwords.length) {
    notices.push(el('div', { class: 'notice notice-warn' },
      el('span', { text: `${passwords.length === 1 ? 'Password' : 'Passwords'} (the first is in the NZB): ` }),
      ...passwords.map((p, i) => el('span', {}, i ? ', ' : '', el('code', { text: p.password }), ` (${PASSWORD_SOURCES[p.source] ?? p.source})`))))
  } else if (release.passworded) {
    notices.push(el('div', { class: 'notice notice-bad', text: 'Passworded: its archive has encrypted entries or headers. The password is not in the index.' }))
  }
  if (!release.readable && !release.innerName) {
    notices.push(el('div', { class: 'notice', text: release.inspectedAt
      ? 'Obfuscated file names, and its articles did not say more.'
      : 'Obfuscated file names: what this release holds is only known once its articles are read (phase 2).' }))
  }

  const files = el('table', { class: 'file-table' },
    el('tbody', {}, release.files.map((f) =>
      el('tr', {},
        el('td', { class: 'name' }, f.name),
        el('td', { class: 'num', text: formatSize(f.size) }),
        el('td', { class: 'num', text: `${f.parts} ${f.parts === 1 ? 'part' : 'parts'}` })))))

  const inspections = release.inspections ?? []
  const contents = inspections.length
    ? el('div', { class: 'contents' }, inspections.map((i) =>
        el('div', { class: 'inspection' },
          el('div', { class: 'inspection-head' },
            el('span', { class: 'name', text: i.yencName || '(no name)' }),
            badge(KIND_LABELS[i.kind] ?? i.kind),
            i.type ? badge(i.type) : null,
            i.passworded ? badge('Encrypted', 'bad') : null),
          i.names?.length
            ? el('ul', { class: 'inspection-names' }, i.names.map((n) => el('li', { text: n })))
            : null,
          i.entries > (i.names?.length ?? 0)
            ? el('small', { text: `${number.format(i.entries)} in all; the largest shown` })
            : null)))
    : null

  $('#detail').replaceChildren(
    actions,
    ...notices,
    facts,
    ...(contents ? section('Contents', `${inspections.length} ${inspections.length === 1 ? 'article' : 'articles'} read`, contents) : []),
    ...section('Files', `${release.files.length} posted`, files)
  )
}

async function openRelease(id, push = false) {
  state.release = id
  writeUrl(push)
  document.querySelectorAll('.release.selected').forEach((r) => r.classList.remove('selected'))
  document.querySelector(`.release[data-id="${id}"]`)?.classList.add('selected')

  $('#drawer').hidden = false
  $('#scrim').hidden = false
  $('#detail-name').textContent = ''
  $('#detail-source').textContent = ''
  $('#detail').replaceChildren(...Array.from({ length: 6 }, () => el('div', { class: 'skeleton' })))
  $('#close').focus()
  try {
    renderDetail(await api(`/api/v1/releases/${id}`))
  } catch (error) {
    $('#detail').replaceChildren(el('p', { class: 'empty', text: `Could not load this release (${error.message}).` }))
  }
}

function closeRelease(push = false) {
  if (!state.release) return
  const id = state.release
  state.release = null
  $('#drawer').hidden = true
  $('#scrim').hidden = true
  writeUrl(push)
  document.querySelector(`.release[data-id="${id}"] .release-main`)?.focus()
}

// --- Wiring ----------------------------------------------------------------

$('#q').addEventListener('input', (event) => {
  state.q = event.target.value.trim()
  scheduleSearch()
})
for (const k of FIELDS) {
  $(`#${k}`).addEventListener('input', (event) => {
    state[k] = event.target.value.trim()
    scheduleSearch()
  })
}
$('#sort').addEventListener('change', (event) => {
  state.sort = event.target.value
  writeUrl()
  loadResults()
})
for (const [parent, name, subs] of CATEGORIES) {
  $('#cat').append(el('option', { value: String(parent), text: name }), ...subs.map(([id, sub]) => el('option', { value: String(id), text: `${name} > ${sub}` })))
}
$('#cat').addEventListener('change', (event) => {
  state.cat = event.target.value
  writeUrl()
  loadResults()
})
$('#source').addEventListener('change', (event) => {
  state.source = event.target.value
  writeUrl()
  loadResults()
})
for (const button of document.querySelectorAll('[data-filter]')) {
  button.addEventListener('click', () => {
    const f = button.dataset.filter
    state[f] = !state[f]
    button.setAttribute('aria-pressed', String(state[f]))
    writeUrl()
    loadResults()
  })
}
$('#poster-clear').addEventListener('click', () => {
  state.poster = ''
  syncControls()
  writeUrl()
  loadResults()
})
$('#more').addEventListener('click', () => {
  state.page++
  loadResults({ append: true })
})
$('#close').addEventListener('click', () => closeRelease(true))
$('#scrim').addEventListener('click', () => closeRelease(true))

document.addEventListener('keydown', (event) => {
  if (event.key === 'Escape') closeRelease(true)
  if (event.key === '/' && document.activeElement !== $('#q')) {
    event.preventDefault()
    $('#q').focus()
    $('#q').select()
  }
})

window.addEventListener('popstate', () => {
  const previous = { ...state }
  readUrl()
  syncControls()
  const searchChanged = ['q', 'sort', 'source', 'cat', 'poster', ...FIELDS, ...FILTERS].some((k) => previous[k] !== state[k])
  if (searchChanged) loadResults()
  if (state.release && state.release !== previous.release) openRelease(state.release)
  if (!state.release && previous.release) {
    $('#drawer').hidden = true
    $('#scrim').hidden = true
  }
})

readUrl()
syncControls()
loadStats()
loadResults()
if (state.release) openRelease(state.release)