// OVE — music service metadata (v6.6 / v6.7 / v6.8.1), shared by client + server.
//
// The Settings tab lets a visitor log in to their own music services by
// pasting that service's login cookie(s). The blob is encrypted in the
// browser (src/lib/music-sessions.ts) and is only ever sent to this site's
// own server transiently — to resolve links the visitor plays — never
// stored there.
//
// v6.7 adds `streamStatus` + `comingSoonNote`: the music-service framework
// marks which services can be STREAMED today (yt-dlp) and which are
// registered ahead of a later update (Spotify / Apple Music — DRM-locked).
// The server-side provider registry lives in src/lib/server/music-providers.ts.
//
// v6.8.1 adds the cookie-paste toolkit (bottom of this file): one shared
// parser for the three formats the login box accepts (raw Cookie header,
// Netscape cookies.txt, Cookie-Editor JSON), live validation for the dialog
// (catches the "pasted a single cookie's value" mistake — e.g. LOGIN_INFO
// alone cannot authenticate) and the netscape/header staging the resolve
// route uses. One parser for both sides means validation and staging can
// never drift apart.
//
// This module is pure data + pure functions (no DOM, no node APIs) so both
// the client components and the /api/resolve route can import it.

export type ServiceId = 'youtube' | 'soundcloud' | 'spotify' | 'apple'

/**
 * Whether links of a service can be streamed today. 'live' = resolvable
 * through yt-dlp and playable; 'coming-soon' = the framework is registered
 * (logins are already saved) and playback ships in a later update.
 */
export type StreamStatus = 'live' | 'coming-soon'

export interface ServiceDef {
  id: ServiceId
  /** Display name shown in the login dialog + settings chips. */
  name: string
  /** Two-letter monogram for the chip (brand colors below). */
  monogram: string
  /** Static brand color for the monogram dot (theme-independent). */
  brandColor: string
  /** Hostnames (and their subdomains) whose links this login unlocks. */
  domains: string[]
  /** Domain the cookie header should be scoped to (Netscape format). */
  cookieDomain: string
  /** Short blurb shown in the login dialog. */
  blurb: string
  /** Cookie acquisition instructions (numbered steps, rendered as a list). */
  steps: string[]
  /** Cookie names a WORKING login paste must carry (paste validation hints —
   *  a paste missing these gets an honest warning in the login dialog).
   *  Undefined when there is no reliable signal for the service. */
  criticalCookies?: string[]
  /** Honest limitation note, if any (DRM…). */
  note?: string
  /** Can links of this service be streamed today? 'live' = resolvable+playable
   *  through yt-dlp; 'coming-soon' = framework registered, playback ships in a
   *  later update. */
  streamStatus: StreamStatus
  /** Required when streamStatus === 'coming-soon': the note shown when a
   *  visitor tries to play a link of this service. */
  comingSoonNote?: string
}

export const SERVICES: ServiceDef[] = [
  {
    id: 'youtube',
    name: 'YouTube / YouTube Music',
    monogram: 'YT',
    brandColor: '#ff0033',
    domains: ['youtube.com', 'youtu.be', 'music.youtube.com'],
    cookieDomain: '.youtube.com',
    blurb:
      'One Google login covers both YouTube and YouTube Music — playlists, liked music and uploads, and no more "confirm you are not a bot" walls.',
    steps: cookieSteps(
      'youtube.com (or music.youtube.com)',
      'Paste the whole thing below — a working YouTube login is the FULL set of ~20 cookies (SID, SAPISID, __Secure-3PSID, LOGIN_INFO, …), never a single cookie on its own.',
    ),
    criticalCookies: ['SID', 'HSID', 'SSID', 'SAPISID', '__Secure-3PSID', 'LOGIN_INFO'],
    streamStatus: 'live',
  },
  {
    id: 'soundcloud',
    name: 'SoundCloud',
    monogram: 'SC',
    brandColor: '#ff5500',
    domains: ['soundcloud.com', 'snd.sc'],
    cookieDomain: '.soundcloud.com',
    blurb:
      'Access your private playlists, likes and sets from the Link button on this machine.',
    steps: cookieSteps(
      'soundcloud.com',
      'Paste the whole thing below — the cookie that carries your login is oauth_token (plus a few others).',
    ),
    criticalCookies: ['oauth_token'],
    streamStatus: 'live',
  },
  {
    id: 'spotify',
    name: 'Spotify',
    monogram: 'SP',
    brandColor: '#1db954',
    domains: ['spotify.com', 'open.spotify.com'],
    cookieDomain: '.spotify.com',
    blurb: 'Store your Spotify login so playlist links resolve with your account.',
    note: 'Spotify streams are DRM-protected, so playback of Spotify links is not possible yet — your login is saved for when support arrives.',
    steps: cookieSteps(
      'open.spotify.com',
      'Paste the whole thing below — the cookie that carries your login is sp_dc.',
    ),
    criticalCookies: ['sp_dc'],
    streamStatus: 'coming-soon',
    comingSoonNote:
      'Spotify playback is coming in a later update — your saved Spotify login will be used automatically the moment it ships. Meanwhile, YouTube, SoundCloud and direct-file links work today.',
  },
  {
    id: 'apple',
    name: 'Apple Music',
    monogram: 'AM',
    brandColor: '#fb5c74',
    domains: ['music.apple.com', 'apple.com'],
    cookieDomain: '.apple.com',
    blurb: 'Store your Apple Music login so library links resolve with your account.',
    note: 'Apple Music streams are DRM-protected, so playback of Apple Music links is not possible yet — your login is saved for when support arrives.',
    steps: cookieSteps('music.apple.com', 'Paste the whole thing below.'),
    streamStatus: 'coming-soon',
    comingSoonNote:
      'Apple Music playback is coming in a later update — your saved Apple Music login will be used automatically the moment it ships. Meanwhile, YouTube, SoundCloud and direct-file links work today.',
  },
]

/**
 * Shared "how to copy your login" steps — two acquisition paths in order of
 * ease: (1) a one-click cookies.txt extension export, (2) DevTools → Network
 * → the "cookie:" request-header row. The last step is per-service and says
 * what a WORKING paste looks like (the full set, never a single cookie).
 */
function cookieSteps(host: string, lastStep: string): string[] {
  return [
    `Open ${host} in this browser and make sure you are logged in.`,
    'Easiest (one click): install a cookie exporter — “Get cookies.txt LOCALLY” on Chrome/Edge/Brave or “cookies.txt” on Firefox. Open that page, click the extension, choose Export — then drag the downloaded file straight into the box below (no need to open or copy anything).',
    'No extension? Press F12 → Network tab → reload the page → click the first request in the list (the page itself). The list stays empty until you reload with the tab open.',
    'Scroll down to the “Request Headers” section → find the “cookie:” row → right-click its value → Copy value. (In Firefox this lives on the request’s Headers tab too.)',
    lastStep,
  ]
}

const SERVICE_IDS = new Set<string>(SERVICES.map((s) => s.id))

export function isServiceId(v: unknown): v is ServiceId {
  return typeof v === 'string' && SERVICE_IDS.has(v)
}

export function serviceDef(id: ServiceId): ServiceDef {
  const def = SERVICES.find((s) => s.id === id)
  if (!def) throw new Error(`Unknown service: ${id}`)
  return def
}

/**
 * Match a URL against the service domains (host equals or is a subdomain).
 * Returns the service a link belongs to, or null for foreign links.
 */
export function serviceForUrl(url: string): ServiceId | null {
  let host: string
  try {
    host = new URL(url).hostname.toLowerCase()
  } catch {
    return null
  }
  if (host.startsWith('www.')) host = host.slice(4)
  for (const s of SERVICES) {
    for (const d of s.domains) {
      const dd = d.startsWith('www.') ? d.slice(4) : d
      if (host === dd || host.endsWith(`.${dd}`)) return s.id
    }
  }
  return null
}

// ---- cookie paste toolkit (v6.8.1) ------------------------------------------
//
// The login box accepts three paste formats, and BOTH the login dialog's
// live validation and the /api/resolve staging funnel through this one
// parser so they can never disagree about what a paste contains:
//   • raw Cookie header  "NAME=VALUE; NAME2=VALUE2; …"  (DevTools → Network)
//   • Netscape cookies.txt export (tab-separated 7-field lines, from
//     exporter extensions like "Get cookies.txt LOCALLY" / "cookies.txt")
//   • Cookie-Editor JSON export  [{"name":"SID","value":"…","domain":"…"}, …]

export interface ParsedCookie {
  name: string
  value: string
  /** Domain as written in the paste (netscape / json exports). Absent on
   *  raw header pastes — those are implicitly scoped to the service. */
  domain?: string
}

export type CookiePasteFormat = 'header' | 'netscape' | 'json' | 'unknown'

/** Strip tabs/newlines so a pasted token can never corrupt a TSV line. */
function cookieToken(s: string): string {
  return s.replace(/[\t\r\n]+/g, ' ').trim()
}

/** Parse a paste into its cookies, detecting the format. Never throws. */
export function parseCookiePaste(
  text: string,
): { format: CookiePasteFormat; cookies: ParsedCookie[] } {
  const trimmed = text.trim()
  if (trimmed.length === 0) return { format: 'unknown', cookies: [] }

  // Cookie-Editor style JSON export.
  if (trimmed.startsWith('[')) {
    try {
      const arr: unknown = JSON.parse(trimmed)
      if (Array.isArray(arr)) {
        const cookies: ParsedCookie[] = []
        for (const e of arr) {
          if (e === null || typeof e !== 'object') continue
          const o = e as Record<string, unknown>
          if (typeof o.name !== 'string' || typeof o.value !== 'string') continue
          const name = cookieToken(o.name)
          const value = cookieToken(o.value)
          if (!name || !value) continue
          const domain = typeof o.domain === 'string' ? cookieToken(o.domain) : ''
          cookies.push(domain ? { name, value, domain } : { name, value })
        }
        if (cookies.length > 0) return { format: 'json', cookies }
      }
    } catch {
      /* not JSON — fall through to the other formats */
    }
  }

  // Netscape cookies.txt — tab-separated 7-field lines.
  const tsvLines = trimmed
    .split(/\r?\n/)
    .map((l) => l.trim())
    .filter((l) => l.length > 0 && !l.startsWith('#') && l.split('\t').length >= 7)
  if (tsvLines.length > 0) {
    const cookies: ParsedCookie[] = []
    for (const line of tsvLines) {
      const f = line.split('\t')
      const [d, , , , , name, value] = f
      const n = cookieToken(name)
      const v = cookieToken(value)
      if (!n || !v) continue
      cookies.push({ name: n, value: v, domain: cookieToken(d) || undefined })
    }
    if (cookies.length > 0) return { format: 'netscape', cookies }
  }

  // Raw Cookie header: "k=v; k2=v2" (possibly wrapped over several lines).
  // Values keep inner '=' (base64 padding); the FIRST '=' splits the pair.
  const cookies: ParsedCookie[] = []
  for (const raw of trimmed.split(/[;\n]/)) {
    const s = raw.trim()
    if (!s) continue
    const eq = s.indexOf('=')
    if (eq <= 0) continue
    const name = cookieToken(s.slice(0, eq))
    const value = cookieToken(s.slice(eq + 1))
    if (name && value) cookies.push({ name, value })
  }
  if (cookies.length > 0) return { format: 'header', cookies }
  return { format: 'unknown', cookies: [] }
}

export interface CookiePasteValidation {
  format: CookiePasteFormat
  /** cookies recognized in the paste */
  count: number
  /** critical login cookies (ServiceDef.criticalCookies) missing from it */
  missingCritical: string[]
  /** the paste parses AND carries the service's login cookies */
  looksGood: boolean
}

/**
 * Live-check a paste for the login dialog. A paste that is a single
 * cookie's VALUE (no NAME= pairs at all — e.g. a bare LOGIN_INFO string
 * copied from the DevTools Storage tab) parses as 'unknown'; a paste with
 * pairs but without the service's auth cookies lists them as missing.
 * Either way the dialog shows an honest "this will not log you in" hint.
 */
export function validateCookiePaste(service: ServiceId, text: string): CookiePasteValidation {
  const { format, cookies } = parseCookiePaste(text)
  const critical = serviceDef(service).criticalCookies ?? []
  const names = new Set(cookies.map((c) => c.name))
  const missingCritical = critical.filter((n) => !names.has(n))
  const looksGood =
    format !== 'unknown' &&
    (critical.length > 0 ? missingCritical.length === 0 : cookies.length >= 4)
  return { format, count: cookies.length, missingCritical, looksGood }
}

/**
 * Normalize a paste into a Netscape cookies.txt body (for the transient
 * 0600 temp file yt-dlp reads via --cookies) + a "name=value; …" header
 * (forwarded to the stream proxy, service-domain cookies only). Returns
 * null when nothing parseable was pasted.
 *
 *   • raw header pastes are scoped to the service's cookie domain;
 *   • JSON entries keep their own domain when it belongs to the service
 *     (foreign-site entries are dropped — an exporter grab from the wrong
 *     site must never leak into the jar);
 *   • netscape exports pass through with all their domains + real expiries.
 */
export function cookiePasteToNetscape(
  text: string,
  service: ServiceId,
): { netscape: string; header: string } | null {
  const { format, cookies } = parseCookiePaste(text)
  if (cookies.length === 0) return null
  const domain = serviceDef(service).cookieDomain
  const root = domain.replace(/^\./, '').toLowerCase()
  const inService = (d: string | undefined): boolean => {
    if (!d) return true // header pastes / JSON entries without a domain
    const dd = d.replace(/^\./, '').toLowerCase()
    return dd === root || dd.endsWith(`.${root}`)
  }

  if (format === 'netscape') {
    const body = text
      .trim()
      .split(/\r?\n/)
      .map((l) => l.trim())
      .filter((l) => l.length > 0 && !l.startsWith('#') && l.split('\t').length >= 7)
    const header = cookies
      .filter((c) => inService(c.domain))
      .map((c) => `${c.name}=${c.value}`)
    return {
      netscape: `# Netscape HTTP Cookie File\n${body.join('\n')}\n`,
      header: header.join('; '),
    }
  }

  const expiry = '2147483647'
  const lines: string[] = []
  const headerPairs: string[] = []
  for (const c of cookies) {
    if (format === 'json' && !inService(c.domain)) continue
    const secure =
      c.name.startsWith('__Secure-') || c.name.startsWith('__Host-') ? 'TRUE' : 'FALSE'
    lines.push(`${domain}\tTRUE\t/\t${secure}\t${expiry}\t${c.name}\t${c.value}`)
    headerPairs.push(`${c.name}=${c.value}`)
  }
  if (lines.length === 0) return null
  return {
    netscape: `# Netscape HTTP Cookie File\n${lines.join('\n')}\n`,
    header: headerPairs.join('; '),
  }
}