const crypto = require('crypto')

function clone(value) {
  if (value === undefined || value === null) return value
  return JSON.parse(JSON.stringify(value))
}

function asString(value) {
  if (typeof value === 'string') return value.trim()
  if (value && typeof value === 'object' && typeof value.src === 'string') return value.src.trim()
  return ''
}

function normalizeCmsList(list) {
  if (!Array.isArray(list)) return []

  return list.reduce((result, source) => {
    if (!source || typeof source !== 'object') return result
    const item = clone(source)
    const type = typeof item.type === 'string' ? item.type : ''
    if (!type) return result

    if (type === 'image') {
      item.image = item.image && typeof item.image === 'object' ? item.image : {}
      item.image.src = asString(item.image.src)
      item.image.alt = typeof item.image.alt === 'string' ? item.image.alt : ''
    } else if (type === 'video') {
      item.video = item.video && typeof item.video === 'object' ? item.video : {}
      item.video.src = asString(item.video.src)
      item.video.poster = asString(item.video.poster)
      item.video.duration = Number(item.video.duration) || 0
    } else if (type === 'text' || type === 'title') {
      item.text = typeof item.text === 'string' ? item.text : ''
      item.html = typeof item.html === 'string' ? item.html : ''
      item.delta = item.delta && typeof item.delta === 'object' ? item.delta : {}
    } else if (type === 'vote') {
      item.vote = item.vote && typeof item.vote === 'object' ? item.vote : {}
      item.vote.vote_id = typeof item.vote.vote_id === 'string' && item.vote.vote_id
        ? item.vote.vote_id
        : createVoteId()
      item.vote.voteTitle = typeof item.vote.voteTitle === 'string' ? item.vote.voteTitle.trim() : ''
      item.vote.voteLst = Array.isArray(item.vote.voteLst)
        ? item.vote.voteLst
          .filter(option => option && typeof option.value === 'string' && option.value.trim())
          .map(option => ({ ...option, value: option.value.trim() }))
        : []
    }

    if (type === 'image' && !item.image.src) return result
    if (type === 'video' && !item.video.src) return result
    if (type === 'text' || type === 'title') {
      const hasDelta = Array.isArray(item.delta.ops) && item.delta.ops.length > 0
      if (!hasDelta && !item.html && !item.text) return result
    }
    if (type === 'vote' && item.vote.voteLst.length < 2) return result

    result.push(item)
    return result
  }, [])
}

function createVoteId() {
  return `vote_${Date.now().toString(36)}_${crypto.randomBytes(6).toString('hex')}`
}

function textOps(item) {
  const delta = item && item.delta
  if (delta && Array.isArray(delta.ops) && delta.ops.length) return clone(delta.ops)
  if (item && item.text) return [{ insert: item.text }]
  return []
}

function appendParagraphBreak(ops) {
  if (!ops.length) return ops
  const last = ops[ops.length - 1]
  if (typeof last.insert === 'string' && last.insert.endsWith('\n')) return ops
  ops.push({ insert: '\n' })
  return ops
}

function cmsLstToDelta(list) {
  const cmsLst = normalizeCmsList(list)
  const ops = []

  for (const item of cmsLst) {
    if (item.type === 'text' || item.type === 'title') {
      const itemOps = textOps(item)
      ops.push(...itemOps)
      appendParagraphBreak(ops)
      continue
    }

    if (item.type === 'image' && item.image.src) {
      ops.push({ insert: { image: item.image.src }, attributes: item.image.alt ? { alt: item.image.alt } : undefined })
      ops.push({ insert: '\n' })
      continue
    }

    if (item.type === 'video' && item.video.src) {
      ops.push({
        insert: { video: item.video.src },
        attributes: item.video.poster ? { poster: item.video.poster } : undefined
      })
      ops.push({ insert: '\n' })
      continue
    }

    if (item.type === 'vote' && item.vote.voteTitle) {
      ops.push({ insert: `${item.vote.voteTitle}\n` })
    }
  }

  return { ops: ops.map(op => {
    if (op.attributes === undefined) {
      const copy = { ...op }
      delete copy.attributes
      return copy
    }
    return op
  }) }
}

function getArticleText(content, cmsLst) {
  const values = []
  if (content && Array.isArray(content.ops)) {
    for (const op of content.ops) {
      if (typeof op.insert === 'string') values.push(op.insert)
    }
  }
  for (const item of normalizeCmsList(cmsLst)) {
    if (item.type === 'text' || item.type === 'title') values.push(item.text || '')
    if (item.type === 'vote') {
      values.push(item.vote.voteTitle || '')
      values.push(...item.vote.voteLst.map(option => option.value))
    }
    if (item.type === 'video') values.push(item.text || '')
  }
  return values.join('\n').trim()
}

function getArticleImages(content, cmsLst) {
  const images = []
  if (content && Array.isArray(content.ops)) {
    for (const op of content.ops) {
      if (op && op.insert && typeof op.insert.image === 'string') images.push(op.insert.image)
    }
  }
  for (const item of normalizeCmsList(cmsLst)) {
    if (item.type === 'image' && item.image.src) images.push(item.image.src)
    if (item.type === 'video' && item.video.poster) images.push(item.video.poster)
  }
  return [...new Set(images)]
}

function hasRenderableContent(content, cmsLst) {
  return Boolean(
    (content && Array.isArray(content.ops) && content.ops.some(op => op && op.insert !== undefined)) ||
    normalizeCmsList(cmsLst).length
  )
}

module.exports = {
  clone,
  normalizeCmsList,
  cmsLstToDelta,
  createVoteId,
  getArticleText,
  getArticleImages,
  hasRenderableContent
}