// npm view [pkg [pkg ...]]

const byteSize = require('byte-size')
const color = require('ansicolors')
const columns = require('cli-columns')
const log = require('npmlog')
const npa = require('npm-package-arg')
const npm = require('./npm.js')
const { packument } = require('pacote')
const path = require('path')
const { inspect, promisify } = require('util')
const relativeDate = require('tiny-relative-date')
const semver = require('semver')
const style = require('ansistyles')
const usageUtil = require('./utils/usage')

const fs = require('fs')
const readFile = promisify(fs.readFile)
const jsonParse = require('json-parse-even-better-errors')
const readJson = async file => jsonParse(await readFile(file, 'utf8'))

const usage = usageUtil(
  'view',
  'npm view [<@scope>/]<pkg>[@<version>] [<field>[.subfield]...]'
)

const cmd = (args, cb) => view(args).then(() => cb()).catch(cb)

const completion = async (opts, cb) => {
  if (opts.conf.argv.remain.length <= 2) {
    // There used to be registry completion here, but it stopped
    // making sense somewhere around 50,000 packages on the registry
    return cb()
  }
  // have the package, get the fields
  const config = { ...npm.flatOptions, fullMetadata: true, preferOnline: true }
  const { defaultTag } = config
  const spec = npa(opts.conf.argv.remain[2])
  const pckmnt = await packument(spec, config)
  const dv = pckmnt.versions[pckmnt['dist-tags'][defaultTag]]
  pckmnt.versions = Object.keys(pckmnt.versions).sort(semver.compareLoose)
  const fields = getFields(pckmnt).concat(getFields(dv))
  return cb(null, fields)

  function getFields (d, f, pref) {
    f = f || []
    if (!d)
      return f
    pref = pref || []
    Object.keys(d).forEach(function (k) {
      if (k.charAt(0) === '_' || k.indexOf('.') !== -1)
        return
      const p = pref.concat(k).join('.')
      f.push(p)
      if (Array.isArray(d[k])) {
        d[k].forEach(function (val, i) {
          const pi = p + '[' + i + ']'
          if (val && typeof val === 'object')
            getFields(val, f, [p])
          else
            f.push(pi)
        })
        return
      }
      if (typeof d[k] === 'object')
        getFields(d[k], f, [p])
    })
    return f
  }
}

const view = async args => {
  if (!args.length)
    args = ['.']

  const opts = { ...npm.flatOptions, preferOnline: true, fullMetadata: true }
  const pkg = args.shift()
  let nv
  if (/^[.]@/.test(pkg))
    nv = npa.resolve(null, pkg.slice(2))
  else
    nv = npa(pkg)

  const name = nv.name
  const local = (name === '.' || !name)

  if (opts.global && local)
    throw new Error('Cannot use view command in global mode.')

  if (local) {
    const dir = npm.prefix
    const manifest = await readJson(path.resolve(dir, 'package.json'))
    if (!manifest.name)
      throw new Error('Invalid package.json, no "name" field')
    const p = manifest.name
    nv = npa(p)
    if (pkg && ~pkg.indexOf('@'))
      nv.rawSpec = pkg.split('@')[pkg.indexOf('@')]

    await fetchAndRead(nv, args, opts)
  } else
    await fetchAndRead(nv, args, opts)
}

const fetchAndRead = async (nv, args, opts) => {
  // get the data about this package
  let version = nv.rawSpec || npm.flatOptions.defaultTag

  const pckmnt = await packument(nv, opts)

  if (pckmnt['dist-tags'] && pckmnt['dist-tags'][version])
    version = pckmnt['dist-tags'][version]

  if (pckmnt.time && pckmnt.time.unpublished) {
    const u = pckmnt.time.unpublished
    const er = new Error('Unpublished by ' + u.name + ' on ' + u.time)
    er.statusCode = 404
    er.code = 'E404'
    er.pkgid = pckmnt._id
    throw er
  }

  const results = []
  const versions = pckmnt.versions || {}
  pckmnt.versions = Object.keys(versions).sort(semver.compareLoose)
  if (!args.length)
    args = ['']

  // remove readme unless we asked for it
  if (args.indexOf('readme') === -1)
    delete pckmnt.readme

  Object.keys(versions).forEach(function (v) {
    if (semver.satisfies(v, version, true)) {
      args.forEach(arg => {
        // remove readme unless we asked for it
        if (args.indexOf('readme') !== -1)
          delete versions[v].readme

        results.push(showFields(pckmnt, versions[v], arg))
      })
    }
  })
  let retval = results.reduce(reducer, {})

  if (args.length === 1 && args[0] === '') {
    retval = cleanBlanks(retval)
    log.silly('view', retval)
  }

  if (
    !opts.json &&
    args.length === 1 &&
    args[0] === ''
  ) {
    // general view
    pckmnt.version = version
    await Promise.all(
      results.map((v) => prettyView(pckmnt, v[Object.keys(v)[0]][''], opts))
    )
    return retval
  } else {
    // view by field name
    await printData(retval, pckmnt._id, opts)
    return retval
  }
}

const prettyView = async (packument, manifest, opts) => {
  // More modern, pretty printing of default view
  const unicode = opts.unicode
  const tags = []

  Object.keys(packument['dist-tags']).forEach((t) => {
    const version = packument['dist-tags'][t]
    tags.push(`${style.bright(color.green(t))}: ${version}`)
  })
  const unpackedSize = manifest.dist.unpackedSize &&
    byteSize(manifest.dist.unpackedSize)
  const licenseField = manifest.license || 'Proprietary'
  const info = {
    name: color.green(manifest.name),
    version: color.green(manifest.version),
    bins: Object.keys(manifest.bin || {}).map(color.yellow),
    versions: color.yellow(packument.versions.length + ''),
    description: manifest.description,
    deprecated: manifest.deprecated,
    keywords: (packument.keywords || []).map(color.yellow),
    license: typeof licenseField === 'string'
      ? licenseField
      : (licenseField.type || 'Proprietary'),
    deps: Object.keys(manifest.dependencies || {}).map((dep) => {
      return `${color.yellow(dep)}: ${manifest.dependencies[dep]}`
    }),
    publisher: manifest._npmUser && unparsePerson({
      name: color.yellow(manifest._npmUser.name),
      email: color.cyan(manifest._npmUser.email),
    }),
    modified: !packument.time ? undefined
    : color.yellow(relativeDate(packument.time[packument.version])),
    maintainers: (packument.maintainers || []).map((u) => unparsePerson({
      name: color.yellow(u.name),
      email: color.cyan(u.email),
    })),
    repo: (
      manifest.bugs && (manifest.bugs.url || manifest.bugs)
    ) || (
      manifest.repository && (manifest.repository.url || manifest.repository)
    ),
    site: (
      manifest.homepage && (manifest.homepage.url || manifest.homepage)
    ),
    tags,
    tarball: color.cyan(manifest.dist.tarball),
    shasum: color.yellow(manifest.dist.shasum),
    integrity: manifest.dist.integrity && color.yellow(manifest.dist.integrity),
    fileCount: manifest.dist.fileCount && color.yellow(manifest.dist.fileCount),
    unpackedSize: unpackedSize && color.yellow(unpackedSize.value) + ' ' + unpackedSize.unit,
  }
  if (info.license.toLowerCase().trim() === 'proprietary')
    info.license = style.bright(color.red(info.license))
  else
    info.license = color.green(info.license)

  console.log('')
  console.log(
    style.underline(style.bright(`${info.name}@${info.version}`)) +
    ' | ' + info.license +
    ' | deps: ' + (info.deps.length ? color.cyan(info.deps.length) : color.green('none')) +
    ' | versions: ' + info.versions
  )
  info.description && console.log(info.description)
  if (info.repo || info.site)
    info.site && console.log(color.cyan(info.site))

  const warningSign = unicode ? ' ⚠️ ' : '!!'
  info.deprecated && console.log(
    `\n${style.bright(color.red('DEPRECATED'))}${
      warningSign
    } - ${info.deprecated}`
  )

  if (info.keywords.length) {
    console.log('')
    console.log('keywords:', info.keywords.join(', '))
  }

  if (info.bins.length) {
    console.log('')
    console.log('bin:', info.bins.join(', '))
  }

  console.log('')
  console.log('dist')
  console.log('.tarball:', info.tarball)
  console.log('.shasum:', info.shasum)
  info.integrity && console.log('.integrity:', info.integrity)
  info.unpackedSize && console.log('.unpackedSize:', info.unpackedSize)

  const maxDeps = 24
  if (info.deps.length) {
    console.log('')
    console.log('dependencies:')
    console.log(columns(info.deps.slice(0, maxDeps), { padding: 1 }))
    if (info.deps.length > maxDeps)
      console.log(`(...and ${info.deps.length - maxDeps} more.)`)
  }

  if (info.maintainers && info.maintainers.length) {
    console.log('')
    console.log('maintainers:')
    info.maintainers.forEach((u) => console.log('-', u))
  }

  console.log('')
  console.log('dist-tags:')
  console.log(columns(info.tags))

  if (info.publisher || info.modified) {
    let publishInfo = 'published'
    if (info.modified)
      publishInfo += ` ${info.modified}`
    if (info.publisher)
      publishInfo += ` by ${info.publisher}`
    console.log('')
    console.log(publishInfo)
  }
}

function cleanBlanks (obj) {
  const clean = {}
  Object.keys(obj).forEach(function (version) {
    clean[version] = obj[version]['']
  })
  return clean
}

function reducer (l, r) {
  if (r) {
    Object.keys(r).forEach(function (v) {
      l[v] = l[v] || {}
      Object.keys(r[v]).forEach(function (t) {
        l[v][t] = r[v][t]
      })
    })
  }

  return l
}

// return whatever was printed
function showFields (data, version, fields) {
  const o = {}
  ;[data, version].forEach(function (s) {
    Object.keys(s).forEach(function (k) {
      o[k] = s[k]
    })
  })
  return search(o, fields.split('.'), version.version, fields)
}

function search (data, fields, version, title) {
  let field
  const tail = fields
  while (!field && fields.length)
    field = tail.shift()
  fields = [field].concat(tail)
  let o
  if (!field && !tail.length) {
    o = {}
    o[version] = {}
    o[version][title] = data
    return o
  }
  let index = field.match(/(.+)\[([^\]]+)\]$/)
  if (index) {
    field = index[1]
    index = index[2]
    if (data[field] && data[field][index])
      return search(data[field][index], tail, version, title)
    else
      field = field + '[' + index + ']'
  }
  if (Array.isArray(data)) {
    if (data.length === 1)
      return search(data[0], fields, version, title)

    let results = []
    data.forEach(function (data, i) {
      const tl = title.length
      const newt = title.substr(0, tl - fields.join('.').length - 1) +
                 '[' + i + ']' + [''].concat(fields).join('.')
      results.push(search(data, fields.slice(), version, newt))
    })
    results = results.reduce(reducer, {})
    return results
  }
  if (!data[field])
    return undefined
  data = data[field]
  if (tail.length) {
    // there are more fields to deal with.
    return search(data, tail, version, title)
  }
  o = {}
  o[version] = {}
  o[version][title] = data
  return o
}

async function printData (data, name, opts) {
  const versions = Object.keys(data)
  let msg = ''
  let msgJson = []
  const includeVersions = versions.length > 1
  let includeFields

  versions.forEach(function (v) {
    const fields = Object.keys(data[v])
    includeFields = includeFields || (fields.length > 1)
    if (opts.json)
      msgJson.push({})
    fields.forEach(function (f) {
      let d = cleanup(data[v][f])
      if (fields.length === 1 && opts.json)
        msgJson[msgJson.length - 1][f] = d

      if (includeVersions || includeFields || typeof d !== 'string') {
        if (opts.json)
          msgJson[msgJson.length - 1][f] = d
        else {
          d = inspect(d, {
            showHidden: false,
            depth: 5,
            colors: npm.color,
            maxArrayLength: null,
          })
        }
      } else if (typeof d === 'string' && opts.json)
        d = JSON.stringify(d)

      if (!opts.json) {
        if (f && includeFields)
          f += ' = '
        msg += (includeVersions ? name + '@' + v + ' ' : '') +
               (includeFields ? f : '') + d + '\n'
      }
    })
  })

  if (opts.json) {
    if (msgJson.length && Object.keys(msgJson[0]).length === 1) {
      const k = Object.keys(msgJson[0])[0]
      msgJson = msgJson.map(function (m) {
        return m[k]
      })
    }
    if (msgJson.length === 1)
      msg = JSON.stringify(msgJson[0], null, 2) + '\n'
    else if (msgJson.length > 1)
      msg = JSON.stringify(msgJson, null, 2) + '\n'
  }

  // disable the progress bar entirely, as we can't meaningfully update it if
  // we may have partial lines printed.
  log.disableProgress()

  // only log if there is something to log
  if (msg !== '')
    console.log(msg.trim())
}

function cleanup (data) {
  if (Array.isArray(data))
    return data.map(cleanup)

  if (!data || typeof data !== 'object')
    return data

  const keys = Object.keys(data)
  if (keys.length <= 3 &&
      data.name &&
      (keys.length === 1 ||
       (keys.length === 3 && data.email && data.url) ||
       (keys.length === 2 && (data.email || data.url))))
    data = unparsePerson(data)

  return data
}
function unparsePerson (d) {
  return d.name +
    (d.email ? ' <' + d.email + '>' : '') +
    (d.url ? ' (' + d.url + ')' : '')
}

module.exports = Object.assign(cmd, { completion, usage })
