const log = require('npmlog')
const npa = require('npm-package-arg')
const npmFetch = require('npm-registry-fetch')
const pacote = require('pacote')

const otplease = require('./utils/otplease.js')
const readLocalPkg = require('./utils/read-local-package.js')
const BaseCommand = require('./base-command.js')

class Owner extends BaseCommand {
  /* istanbul ignore next - see test/lib/load-all-commands.js */
  static get name () {
    return 'owner'
  }

  /* istanbul ignore next - see test/lib/load-all-commands.js */
  static get usage () {
    return [
      'add <user> [<@scope>/]<pkg>',
      'rm <user> [<@scope>/]<pkg>',
      'ls [<@scope>/]<pkg>',
    ]
  }

  async completion (opts) {
    const argv = opts.conf.argv.remain
    if (argv.length > 3)
      return []

    if (argv[1] !== 'owner')
      argv.unshift('owner')

    if (argv.length === 2)
      return ['add', 'rm', 'ls']

    // reaches registry in order to autocomplete rm
    if (argv[2] === 'rm') {
      const pkgName = await readLocalPkg(this.npm)
      if (!pkgName)
        return []

      const spec = npa(pkgName)
      const data = await pacote.packument(spec, {
        ...this.npm.flatOptions,
        fullMetadata: true,
      })
      if (data && data.maintainers && data.maintainers.length)
        return data.maintainers.map(m => m.name)
    }
    return []
  }

  exec (args, cb) {
    this.owner(args).then(() => cb()).catch(cb)
  }

  async owner ([action, ...args]) {
    const opts = this.npm.flatOptions
    switch (action) {
      case 'ls':
      case 'list':
        return this.ls(args[0], opts)
      case 'add':
        return this.add(args[0], args[1], opts)
      case 'rm':
      case 'remove':
        return this.rm(args[0], args[1], opts)
      default:
        throw this.usageError()
    }
  }

  async ls (pkg, opts) {
    if (!pkg) {
      const pkgName = await readLocalPkg(this.npm)
      if (!pkgName)
        throw this.usageError()

      pkg = pkgName
    }

    const spec = npa(pkg)

    try {
      const packumentOpts = { ...opts, fullMetadata: true }
      const { maintainers } = await pacote.packument(spec, packumentOpts)
      if (!maintainers || !maintainers.length)
        this.npm.output('no admin found')
      else
        this.npm.output(maintainers.map(o => `${o.name} <${o.email}>`).join('\n'))

      return maintainers
    } catch (err) {
      log.error('owner ls', "Couldn't get owner data", pkg)
      throw err
    }
  }

  async add (user, pkg, opts) {
    if (!user)
      throw this.usageError()

    if (!pkg) {
      const pkgName = await readLocalPkg(this.npm)
      if (!pkgName)
        throw this.usageError()

      pkg = pkgName
    }
    log.verbose('owner add', '%s to %s', user, pkg)

    const spec = npa(pkg)
    return this.putOwners(spec, user, opts,
      (newOwner, owners) => this.validateAddOwner(newOwner, owners))
  }

  async rm (user, pkg, opts) {
    if (!user)
      throw this.usageError()

    if (!pkg) {
      const pkgName = await readLocalPkg(this.npm)
      if (!pkgName)
        throw this.usageError()

      pkg = pkgName
    }
    log.verbose('owner rm', '%s from %s', user, pkg)

    const spec = npa(pkg)
    return this.putOwners(spec, user, opts,
      (rmOwner, owners) => this.validateRmOwner(rmOwner, owners))
  }

  async putOwners (spec, user, opts, validation) {
    const uri = `/-/user/org.couchdb.user:${encodeURIComponent(user)}`
    let u = ''

    try {
      u = await npmFetch.json(uri, opts)
    } catch (err) {
      log.error('owner mutate', `Error getting user data for ${user}`)
      throw err
    }

    if (user && (!u || !u.name || u.error)) {
      throw Object.assign(
        new Error(
          "Couldn't get user data for " + user + ': ' + JSON.stringify(u)
        ),
        { code: 'EOWNERUSER' }
      )
    }

    // normalize user data
    u = { name: u.name, email: u.email }

    const data = await pacote.packument(spec, { ...opts, fullMetadata: true })

    // save the number of maintainers before validation for comparison
    const before = data.maintainers ? data.maintainers.length : 0

    const m = validation(u, data.maintainers)
    if (!m)
      return // invalid owners

    const body = {
      _id: data._id,
      _rev: data._rev,
      maintainers: m,
    }
    const dataPath = `/${spec.escapedName}/-rev/${encodeURIComponent(data._rev)}`
    const res = await otplease(opts, opts => {
      return npmFetch.json(dataPath, {
        ...opts,
        method: 'PUT',
        body,
        spec,
      })
    })

    if (!res.error) {
      if (m.length < before)
        this.npm.output(`- ${user} (${spec.name})`)
      else
        this.npm.output(`+ ${user} (${spec.name})`)
    } else {
      throw Object.assign(
        new Error('Failed to update package: ' + JSON.stringify(res)),
        { code: 'EOWNERMUTATE' }
      )
    }
    return res
  }

  validateAddOwner (newOwner, owners) {
    owners = owners || []
    for (const o of owners) {
      if (o.name === newOwner.name) {
        log.info(
          'owner add',
          'Already a package owner: ' + o.name + ' <' + o.email + '>'
        )
        return false
      }
    }
    return [
      ...owners,
      newOwner,
    ]
  }

  validateRmOwner (rmOwner, owners) {
    let found = false
    const m = owners.filter(function (o) {
      var match = (o.name === rmOwner.name)
      found = found || match
      return !match
    })

    if (!found) {
      log.info('owner rm', 'Not a package owner: ' + rmOwner.name)
      return false
    }

    if (!m.length) {
      throw Object.assign(
        new Error(
          'Cannot remove all owners of a package. Add someone else first.'
        ),
        { code: 'EOWNERRM' }
      )
    }

    return m
  }
}
module.exports = Owner
