const { createClient } = require('./httpClient')
const streamDb = require('./streamDb')

const BODY_ERROR_KEYWORDS = ['error', 'not found', '404', 'no encontrado', 'expired', 'removed']

const validatorClient = createClient({
  timeout: 8000,
  maxRedirects: 3,
  headers: {
    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 Chrome/120.0.0.0 Safari/537.36',
  },
})

async function validateUrl(url) {
  const inicio = Date.now()
  try {
    const res = await validatorClient.get(url, {
      maxRedirects: 3,
      validateStatus: () => true,
    })
    const responseMs = Date.now() - inicio
    const statusCode = res.status
    const body = typeof res.data === 'string' ? res.data : String(res.data || '')

    if (statusCode < 200 || statusCode >= 400) {
      return { isAlive: false, responseMs, statusCode, error: `HTTP ${statusCode}` }
    }

    const bodyLower = body.toLowerCase()
    for (const keyword of BODY_ERROR_KEYWORDS) {
      if (bodyLower.includes(keyword)) {
        return { isAlive: false, responseMs, statusCode, error: `Body contiene "${keyword}"` }
      }
    }

    return { isAlive: true, responseMs, statusCode, error: null }
  } catch (err) {
    return { isAlive: false, responseMs: Date.now() - inicio, statusCode: null, error: err.message }
  }
}

function refreshInBackground(tmdbId, oldStreams, newScrapeResults, providerName, contentType) {
  setImmediate(async () => {
    try {
      const oldUrls = new Set(oldStreams.map(s => s.url))
      const newUrls = new Set(newScrapeResults.map(s => s.url))

      // 1. Logear streams nuevos
      if (newScrapeResults.length > 0) {
        const title = newScrapeResults[0]?.title || null
        await streamDb.logStreams(tmdbId, providerName, contentType, newScrapeResults, title)
      }

      // 2. Links que desaparecieron del scrape → validar
      const disappeared = oldStreams.filter(s => !newUrls.has(s.url))
      for (const stream of disappeared) {
        const result = await validateUrl(stream.url)
        await streamDb.logCheck(stream.url, result)

        if (result.isAlive) {
          await streamDb.markAlive(stream.url, stream.provider)
        } else {
          await streamDb.markDead(stream.url, stream.provider)
        }
      }

      // 3. Links nuevos que no estaban → validar antes de confirmar
      const fresh = newScrapeResults.filter(s => !oldUrls.has(s.url))
      for (const stream of fresh) {
        const result = await validateUrl(stream.url)
        await streamDb.logCheck(stream.url, result)

        if (!result.isAlive) {
          await streamDb.markDead(stream.url, providerName)
        }
      }
    } catch (err) {
      console.error(`[StreamValidator] Error en refresh para ${tmdbId}:`, err.message)
    }
  })
}

module.exports = { validateUrl, refreshInBackground }