'use strict'

const { struct, superstruct } = require('superstruct')
const { optional, list } = struct

// Define custom types
const s = superstruct({
  types: {
    transport: value => {
      if (value.length === 0) return 'ERROR_EMPTY'
      value.forEach(i => {
        if (!i.dial) return 'ERR_NOT_A_TRANSPORT'
      })
      return true
    },
    protector: value => {
      if (!value.protect) return 'ERR_NOT_A_PROTECTOR'
      return true
    }
  }
})

const modulesSchema = s({
  connEncryption: optional(list([s('object|function')])),
  // this is hacky to simulate optional because interface doesnt work correctly with it
  // change to optional when fixed upstream
  connProtector: s('undefined|protector'),
  contentRouting: optional(list(['object'])),
  dht: optional(s('null|function|object')),
  pubsub: optional(s('null|function|object')),
  peerDiscovery: optional(list([s('object|function')])),
  peerRouting: optional(list(['object'])),
  streamMuxer: optional(list([s('object|function')])),
  transport: 'transport'
})

const configSchema = s({
  peerDiscovery: s('object', {
    autoDial: true
  }),
  relay: s({
    enabled: 'boolean',
    hop: optional(s({
      enabled: 'boolean',
      active: 'boolean'
    }, {
      // HOP defaults
      enabled: false,
      active: false
    }))
  }, {
    // Relay defaults
    enabled: true
  }),
  // DHT config
  dht: s('object?', {
    // DHT defaults
    enabled: false,
    kBucketSize: 20,
    randomWalk: {
      enabled: false, // disabled waiting for https://github.com/libp2p/js-libp2p-kad-dht/issues/86
      queriesPerPeriod: 1,
      interval: 300e3,
      timeout: 10e3
    }
  }),
  // Pubsub config
  pubsub: s('object?', {
    // Pubsub defaults
    enabled: true,
    emitSelf: true,
    signMessages: true,
    strictSigning: true
  })
}, {})

const optionsSchema = s({
  switch: 'object?',
  connectionManager: s('object', {
    minPeers: 25
  }),
  datastore: 'object?',
  peerInfo: 'object',
  peerBook: 'object?',
  modules: modulesSchema,
  config: configSchema
})

module.exports.validate = (opts) => {
  const [error, options] = optionsSchema.validate(opts)

  // Improve errors throwed, reduce stack by throwing here and add reason to the message
  if (error) {
    throw new Error(`${error.message}${error.reason ? ' - ' + error.reason : ''}`)
  } else {
    // Throw when dht is enabled but no dht module provided
    if (options.config.dht.enabled) {
      s('function|object')(options.modules.dht)
    }
  }

  if (options.config.peerDiscovery.autoDial === undefined) {
    options.config.peerDiscovery.autoDial = true
  }

  return options
}