'use strict'

const Buffer = require('safe-buffer').Buffer

const ciDetect = require('@npmcli/ci-detect')
const checkResponse = require('./check-response.js')
const config = require('./config.js')
const getAuth = require('./auth.js')
const fetch = require('make-fetch-happen')
const JSONStream = require('minipass-json-stream')
const npa = require('npm-package-arg')
const qs = require('querystring')
const url = require('url')
const zlib = require('minizlib')
const Minipass = require('minipass')

// WhatWG URL throws if it's not fully resolved
const urlIsValid = u => {
  try {
    return !!new url.URL(u)
  } catch (_) {
    return false
  }
}

module.exports = regFetch
function regFetch (uri, opts) {
  opts = config(opts)
  const registry = (
    (opts.spec && pickRegistry(opts.spec, opts)) ||
    opts.registry ||
    /* istanbul ignore next: default set in figgy pudding config  */
    'https://registry.npmjs.org/'
  )

  if (!urlIsValid(uri)) {
    uri = `${
      registry.trim().replace(/\/?$/g, '')
    }/${
      uri.trim().replace(/^\//, '')
    }`
  }

  const method = opts.method ||
    /* istanbul ignore next: default set in figgy pudding config */
    'GET'

  // through that takes into account the scope, the prefix of `uri`, etc
  const startTime = Date.now()
  const headers = getHeaders(registry, uri, opts)
  let body = opts.body
  const bodyIsStream = Minipass.isStream(body)
  const bodyIsPromise = body &&
    typeof body === 'object' &&
    typeof body.then === 'function'

  if (body && !bodyIsStream && !bodyIsPromise && typeof body !== 'string' && !Buffer.isBuffer(body)) {
    headers['content-type'] = headers['content-type'] || 'application/json'
    body = JSON.stringify(body)
  } else if (body && !headers['content-type']) {
    headers['content-type'] = 'application/octet-stream'
  }

  if (opts.gzip) {
    headers['content-encoding'] = 'gzip'
    if (bodyIsStream) {
      const gz = new zlib.Gzip()
      body.on('error', /* istanbul ignore next: unlikely and hard to test */
        err => gz.emit('error', err))
      body = body.pipe(gz)
    } else if (!bodyIsPromise) {
      body = new zlib.Gzip().end(body).concat()
    }
  }

  if (opts.query) {
    const q = typeof opts.query === 'string'
      ? qs.parse(opts.query)
      : opts.query

    const parsed = new url.URL(uri)
    Object.keys(q).forEach(key => {
      if (q[key] !== undefined) {
        parsed.searchParams.set(key, q[key])
      }
    })
    uri = url.format(parsed)
  }

  const doFetch = (body) => fetch(uri, {
    agent: opts.agent,
    algorithms: opts.algorithms,
    body,
    cache: getCacheMode(opts),
    cacheManager: opts.cache,
    ca: opts.ca,
    cert: opts.cert,
    headers,
    integrity: opts.integrity,
    key: opts.key,
    localAddress: opts['local-address'],
    maxSockets: opts.maxsockets,
    memoize: opts.memoize,
    method: method,
    noProxy: opts['no-proxy'] || opts.noproxy,
    proxy: opts['https-proxy'] || opts.proxy,
    referer: opts.refer,
    retry: opts.retry != null ? opts.retry : {
      retries: opts['fetch-retries'],
      factor: opts['fetch-retry-factor'],
      minTimeout: opts['fetch-retry-mintimeout'],
      maxTimeout: opts['fetch-retry-maxtimeout']
    },
    strictSSL: !!opts['strict-ssl'],
    timeout: opts.timeout
  }).then(res => checkResponse(
    method, res, registry, startTime, opts
  ))

  return Promise.resolve(body).then(doFetch)
}

module.exports.json = fetchJSON
function fetchJSON (uri, opts) {
  return regFetch(uri, opts).then(res => res.json())
}

module.exports.json.stream = fetchJSONStream
function fetchJSONStream (uri, jsonPath, opts) {
  opts = config(opts)
  const parser = JSONStream.parse(jsonPath, opts.mapJson)
  regFetch(uri, opts).then(res =>
    res.body.on('error',
      /* istanbul ignore next: unlikely and difficult to test */
      er => parser.emit('error', er)).pipe(parser)
  ).catch(er => parser.emit('error', er))
  return parser
}

module.exports.pickRegistry = pickRegistry
function pickRegistry (spec, opts) {
  spec = npa(spec)
  opts = config(opts)
  let registry = spec.scope &&
    opts[spec.scope.replace(/^@?/, '@') + ':registry']

  if (!registry && opts.scope) {
    registry = opts[opts.scope.replace(/^@?/, '@') + ':registry']
  }

  if (!registry) {
    registry = opts.registry ||
      /* istanbul ignore next: default set by figgy pudding config */
      'https://registry.npmjs.org/'
  }

  return registry
}

function getCacheMode (opts) {
  return opts.offline
    ? 'only-if-cached'
    : opts['prefer-offline']
      ? 'force-cache'
      : opts['prefer-online']
        ? 'no-cache'
        : 'default'
}

function getHeaders (registry, uri, opts) {
  const headers = Object.assign({
    'npm-in-ci': !!(
      opts['is-from-ci'] || ciDetect()
    ),
    'npm-scope': opts['project-scope'],
    'npm-session': opts['npm-session'],
    'user-agent': opts['user-agent'],
    referer: opts.refer
  }, opts.headers)

  const auth = getAuth(registry, opts)
  // If a tarball is hosted on a different place than the manifest, only send
  // credentials on `alwaysAuth`
  const shouldAuth = (
    auth.alwaysAuth ||
    new url.URL(uri).host === new url.URL(registry).host
  )
  if (shouldAuth && auth.token) {
    headers.authorization = `Bearer ${auth.token}`
  } else if (shouldAuth && auth.username && auth.password) {
    const encoded = Buffer.from(
      `${auth.username}:${auth.password}`, 'utf8'
    ).toString('base64')
    headers.authorization = `Basic ${encoded}`
  } else if (shouldAuth && auth._auth) {
    headers.authorization = `Basic ${auth._auth}`
  }
  if (shouldAuth && auth.otp) {
    headers['npm-otp'] = auth.otp
  }
  return headers
}