flaska/flaska.mjs

import os from 'os'
import crypto from 'crypto'
import path from 'path'
import http from 'http'
import stream from 'stream'
import fs from 'fs/promises'
import fsSync from 'fs'
import { URL } from 'url'
import { Buffer } from 'buffer'
import zlib from 'zlib'

function getDb() {
  // Take from @thi-ng/mime which is a reduced mime-db
  let MimeTypeDbRaw = Buffer.from('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
  let inbetween = JSON.parse(zlib.brotliDecompressSync(MimeTypeDbRaw).toString())

  let res = {}
  for (let groupID in inbetween) {
    const group = inbetween[groupID];
    for (let type in group) {
        const mime = groupID + "/" + type;
        for (let e of group[type].split(",")) {
            const isLowPri = e[0] === "*";
            const ext = isLowPri ? e.substr(1) : e;
            let coll = res[ext];
            !coll && (coll = res[ext] = []);
            isLowPri ? coll.push(mime) : coll.unshift(mime);
        }
    }
  }
  return res
}

export const MimeTypeDb = getDb()

/**
 * Router
 */

// Taken from https://github.com/nfp-projects/koa-lite/blob/master/lib/statuses.js
const statuses = {
  100: 'Continue', 101: 'Switching Protocols', 102: 'Processing', 103: 'Early Hints',
  200: 'OK', 201: 'Created', 202: 'Accepted', 203: 'Non-Authoritative Information', 204: 'No Content', 205: 'Reset Content', 206: 'Partial Content', 207: 'Multi-Status', 208: 'Already Reported', 226: 'IM Used',
  300: 'Multiple Choices', 301: 'Moved Permanently', 302: 'Found', 303: 'See Other', 304: 'Not Modified', 305: 'Use Proxy', 306: '(Unused)', 307: 'Temporary Redirect', 308: 'Permanent Redirect',
  400: 'Bad Request', 401: 'Unauthorized', 402: 'Payment Required', 403: 'Forbidden', 404: 'Not Found', 405: 'Method Not Allowed', 406: 'Not Acceptable', 407: 'Proxy Authentication Required', 408: 'Request Timeout', 409: 'Conflict', 410: 'Gone', 411: 'Length Required', 412: 'Precondition Failed', 413: 'Payload Too Large', 414: 'URI Too Long', 415: 'Unsupported Media Type', 416: 'Range Not Satisfiable', 417: 'Expectation Failed', 418: 'I\'m a teapot', 421: 'Misdirected Request', 422: 'Unprocessable Entity', 423: 'Locked', 424: 'Failed Dependency', 425: 'Too Early', 426: 'Upgrade Required', 428: 'Precondition Required', 429: 'Too Many Requests', 431: 'Request Header Fields Too Large', 451: 'Unavailable For Legal Reasons',
  500: 'Internal Server Error', 501: 'Not Implemented', 502: 'Bad Gateway', 503: 'Service Unavailable', 504: 'Gateway Timeout', 505: 'HTTP Version Not Supported', 506: 'Variant Also Negotiates', 507: 'Insufficient Storage', 508: 'Loop Detected', 509: 'Bandwidth Limit Exceeded', 510: 'Not Extended', 511: 'Network Authentication Required',
  redirect: {
    300: true,
    301: true,
    302: true,
    303: true,
    305: true,
    307: true,
    308: true
  },
  empty: {
    204: true,
    205: true,
    304: true
  }
}

function assertIsHandler(handler, name) {
  if (typeof(handler) !== 'function') {
    throw new Error(`${name} was called with a handler that was not a function`)
  }
}

export function QueryHandler() {
  return function(ctx) {
    ctx.query = (new URL(ctx.req.url, 'http://localhost')).searchParams
  }
}

export function JsonHandler(org = {}) {
  let opts = {
    sizeLimit: org.sizeLimit || (10 * 1024)
  }
  return function(ctx) {
    const buffers = [];
    let size = 0

    return new Promise(function(res, rej) {
      ctx.req.on('data', chunk => {
        size += chunk.length
        if (size > opts.sizeLimit) {
          return rej(new HttpError(413, `Body limit of ${opts.sizeLimit} bytes reached with ${size} bytes`))
        }

        buffers.push(chunk)
      })
      ctx.req.on('end', () => {
        res()
      })
    })
    .then(function() {
      if (!buffers.length) {
        ctx.req.body = {}
        return
      }

      const data = Buffer.concat(buffers).toString();

      try {
        ctx.req.body = JSON.parse(data)
      } catch (err) {
        return Promise.reject(new HttpError(400, `Invalid JSON: ${err.message}`, {
          status: 400,
          message: `Invalid JSON: ${err.message}`,
          request: data,
        }))
      }
    })
  }
}

export function CorsHandler(opts = {}) {
  const options = {
    allowedMethods: opts.allowedMethods || 'GET,HEAD,PUT,POST,DELETE,PATCH',
    allowedOrigins: opts.allowedOrigins || [],
    allowedHeaders: opts.allowedHeaders,
    credentials: opts.credentials || false,
    exposeHeaders: opts.exposeHeaders || '',
    maxAge: opts.maxAge || '',
  }
  const allowAll = options.allowedOrigins.includes('*')

  return function(ctx) {
    // Always add vary header on origin. Prevent caches from
    // accidentally caching wrong preflight request
    ctx.headers['Vary'] = 'Origin'

    // Set status to 204 if OPTIONS. Just handy for flaska and
    // other checking.
    if (ctx.method === 'OPTIONS') {
      ctx.status = 204
    }

    // Check origin is specified. Nothing needs to be done if
    // there is no origin or it doesn't match
    let origin = ctx.req.headers['origin']
    if (!origin || (!allowAll && !options.allowedOrigins.includes(origin))) {
      return
    }

    // Set some extra headers if this is a pre-flight. Most of
    // these are not needed during a normal request.
    if (ctx.method === 'OPTIONS') {
      if (!ctx.req.headers['access-control-request-method']) {
        return
      }

      if (options.maxAge) {
        ctx.headers['Access-Control-Max-Age'] = options.maxAge
      }

      let reqHeaders = options.allowedHeaders
                  || ctx.req.headers['access-control-request-headers']
      if (reqHeaders && options.allowedHeaders !== false) {
        ctx.headers['Access-Control-Allow-Headers'] = reqHeaders
      }
      ctx.headers['Access-Control-Allow-Methods'] = options.allowedMethods
    } else {
      if (options.exposeHeaders) {
        ctx.headers['Access-Control-Expose-Headers'] = options.exposeHeaders
      }
    }

    ctx.headers['Access-Control-Allow-Origin'] = origin

    if (options.credentials) {
      ctx.headers['Access-Control-Allow-Credentials'] = 'true'
    }
  }
}

export function FormidableHandler(formidable, org = {}) {
  let lastDateString = ''
  let incrementor = 1

  let opts = {
    rename: true,
    parseFields: org.parseFields || false,
    uploadDir: org.uploadDir || os.tmpdir(),
    filename: org.filename || function(file) {
      let prefix = new Date()
        .toISOString()
        .replace(/-/g, '')
        .replace('T', '_')
        .replace(/:/g, '')
        .replace(/\..+/, '_')

      // Prevent accidental overwriting if two file uploads with
      // same name get uploaded at exact same second.
      if (prefix === lastDateString) {
        prefix += incrementor.toString().padStart('2', '0') + '_'
        incrementor++
      } else {
        lastDateString = prefix
        incrementor
      }

      return prefix + file.name
    },
    maxFileSize: org.maxFileSize || 8 * 1024 * 1024,
    maxFieldsSize: org.maxFieldsSize || 10 * 1024,
    maxFields: org.maxFields || 50,
  }
  if (org.rename != null) {
    opts.rename = org.rename
  }

  // For testing/stubbing purposes
  let rename = formidable.fsRename || fs.rename

  return function(ctx) {
    let form = formidable.IncomingForm()
    form.uploadDir = opts.uploadDir
    form.maxFileSize = opts.maxFileSize
    form.maxFieldsSize = opts.maxFieldsSize
    form.maxFields = opts.maxFields

    return new Promise(function(res, rej) {
      form.parse(ctx.req, function(err, fields, files) {
        if (err) return rej(new HttpError(400, err.message))

        if (opts.parseFields) {
          Object.keys(fields).forEach(function(key) {
            try {
              fields[key] = JSON.parse(fields[key])
            } catch { }
          })
        }

        ctx.req.body = fields
        ctx.req.files = files
        ctx.req.file = null


        if (!ctx.req.files) {
          return res()
        }

        let keys = Object.keys(files).filter(key => Boolean(ctx.req.files[key]))

        Promise.all(
          keys.map(key => {
            let filename
            let target

            try {
              filename = opts.filename(ctx.req.files[key]) || ctx.req.files[key].name
              target = path.join(opts.uploadDir, filename)
            } catch (err) {
              return Promise.reject(err)
            }

            return rename(ctx.req.files[key].path, target)
            .then(function() {
              if (!ctx.req.files[key].type || ctx.req.files[key].type === 'application/octet-stream') {
                let found = MimeTypeDb[path.extname(filename).slice(1)]
                ctx.req.files[key].type = found && found[0] || 'application/octet-stream'
              }
              ctx.req.files[key].path = target
              ctx.req.files[key].filename = filename
            })
          })
        )
        .then(() => {
          if (keys.length === 1 && keys[0] === 'file') {
            ctx.req.file = ctx.req.files.file
          }
          res()
        }, rej)
      })
    })
  }
}

export class HttpError extends Error {
  constructor(statusCode, message, body = null) {
    super(message);

    Error.captureStackTrace(this, HttpError);

    let proto = Object.getPrototypeOf(this);
    proto.name = 'HttpError';

    this.status = statusCode
    this.body = body
  }
}

const RangeRegexTester = /bytes=(\d+)-(\d+)?/

export class FileResponse {
  constructor(filepath, stat) {
    this.filepath = filepath
    this.stat = stat
  }

  handleRequest(ctx, useFs = fsSync) {
    let etag = '"' + this.stat.ino + '-' + this.stat.size + '-' + this.stat.mtime.getTime() + '"'
    let lastModified = this.stat.mtime.toUTCString()
    let lastModifiedRounded = Date.parse(lastModified)

    if (ctx.req.headers['if-match'] && ctx.req.headers['if-match'] !== etag) {
      throw new HttpError(412, `Request if-match pre-condition failed`)
    }
    if (ctx.req.headers['if-unmodified-since']) {
      let check = Date.parse(ctx.req.headers['if-unmodified-since'])
      if (!check || check < lastModifiedRounded) {
        throw new HttpError(412, `Request if-unmodified-since pre-condition failed`)
      }
    }

    ctx.headers['Etag'] = etag

    if (ctx.req.headers['if-none-match']) {
      let split = ctx.req.headers['if-none-match'].split(',')
      for (let check of split) {
        if (check.trim() === etag) {
          ctx.status = 304
          return null
        }
      }
    } else if (ctx.req.headers['if-modified-since']) {
      let check = Date.parse(ctx.req.headers['if-modified-since'])
      if (check >= lastModifiedRounded) {
        ctx.status = 304
        return null
      }
    }

    let readOptions = {}
    let size = this.stat.size

    if (ctx.req.headers['range']) {
      let match = RangeRegexTester.exec(ctx.req.headers['range'])

      let ifRange = ctx.req.headers['if-range']
      if (ifRange) {
        if (ifRange[0] === '"' && ifRange !== etag) {
          match = null
        } else if (ifRange[0] !== '"') {
          let check = Date.parse(ifRange)
          if (!check || check < lastModifiedRounded) {
            match = null
          }
        }
      }

      if (match) {
        let start = Number(match[1])
        let end = size - 1
        if (match[2]) {
          end = Math.min(Number(match[2]), size - 1)
        }

        if (start >= size) {
          throw new HttpError(416, `Out of range start ${start} outside of ${size} bounds`)
        }

        if (start <= end) {
          size = end - start + 1
          readOptions.start = start
          readOptions.end = end
          ctx.headers['Content-Range'] = start + '-' + end + '/' + this.stat.size
          ctx.status = 206
        }
      }
    }

    let ext = path.extname(this.filepath).slice(1)
    let found = MimeTypeDb[ext]
    if (found) {
      ctx.type = found[found.length - 1]
    }

    ctx.headers['Last-Modified'] = lastModified
    ctx.headers['Content-Length'] = size
    if (ctx.method !== 'HEAD') {
      let stream = useFs.createReadStream(this.filepath, readOptions)
      return stream
    }
    return null
  }
}

/*
 * --- Router ---
*/

class RouterError extends Error {
  constructor(route1, route2, ...params) {
    // Pass remaining arguments (including vendor specific ones) to parent constructor
    super(...params);

    // Maintains proper stack trace for where our error was thrown (only available on V8)
    if (Error.captureStackTrace) {
      Error.captureStackTrace(this, RouterError);
    }

    this.name = "RouterError";
    this.routeA = route1
    this.routeB = route2
  }
}

function Child(split, x, i) {
  this.path = null
  this.isParams = split[x].isParams ? split[x].word : null
  this.isFullParams = split[x].isFullParams ? split[x].word : null
  this.paramVarName = split[x].paramVarName ?? null
  this.char = !this.isParams && !this.isFullParams ? split[x].word[i] || '/' : null
  this.count = 0
  this.children = []
}

const regParamPrefix = /^::?/
const regCleanNonAschii = /(?![a-zA-Z_])./g
const regCleanRest = /_+/g
const regStarDoubleParam = /::[^:/]+/g
const regStarSingleParam = /:[^:/]+/g
const spaces = '                                                                                                                                                                                                                                                                '

export class FlaskaRouter {
  constructor() {
    this.paths = []
    this.registeredPaths = new Set()
  }

  addRoute(path, middlewares, orgHandler) {
    if (path[0] !== '/')
      throw new RouterError(null, null, `addRoute("${path}") path must start with forward slash`)

    let cleaned = path
    if (cleaned.indexOf('/:') >= 0) {
      cleaned = cleaned.replace(regStarDoubleParam, '**').replace(regStarSingleParam, '*')
      if (cleaned.indexOf(':') > 0) {
        throw new RouterError(null, null, `addRoute("${path}") path has missing name or word between two forward slashes`)
      }
      if (cleaned.indexOf('**/') > 0) {
        throw new RouterError(null, null, `addRoute("${path}") cannot add anything after a full param route`)
      }
    }
    if (cleaned.indexOf('//') >= 0) {
      throw new RouterError(null, null, `addRoute("${path}") path has missing name or word between two forward slashes`)
    }

    let size = this.registeredPaths.size
    if (this.registeredPaths.add(cleaned).size === size) {
      throw new RouterError(null, null, `addRoute("${path}") found an existing route with same path of ${cleaned}`)
    }

    let handlers = []
    if (Array.isArray(middlewares)) {
      handlers.push(...middlewares)
      if (typeof(orgHandler) !== 'function') {
        throw new RouterError(orgHandler, null, `addRoute("${path}") was called with a handler that was not a function`)
      }
    } else {
      handlers.push(middlewares)
    }
    if (orgHandler) {
      handlers.push(orgHandler)
    }
    for (let handler of handlers) {
      if (typeof(handler) !== 'function') {
        throw new RouterError(handler, null, `addRoute("${path}") was called with a handler that was not a function`)
      }
    }

    this.paths.push({
      path,
      handlers
    })
  }

  __buildChild(x, i, splitPaths) {
    let splitPath = splitPaths[0]
    let letter = new Child(splitPath.split, x, i)

    let consume = []
    if (splitPath.split.length === x + 1
        && (splitPath.split[x].isParams
            || splitPath.split[x].isFullParams
            || splitPath.split[x].word.length === i + 1)) {
      letter.path = splitPath.entry
      letter.count += 1
    } else {
      consume = [splitPath]
    }

    for (let y = 1; y < splitPaths.length; y++) {
      let checkPath = splitPaths[y]
      if (!checkPath.split[x]
          || checkPath.split[x].isParams !== splitPath.split[x].isParams
          || checkPath.split[x].isFullParams !== splitPath.split[x].isFullParams
          || !checkPath.split[x].isParams
              && !checkPath.split[x].isFullParams
              && (checkPath.split[x].word[i] || '/') !== letter.char) break
      consume.push(checkPath)
    }

    letter.count += consume.length
    if (splitPath.split[x].word.length === i || splitPath.split[x].isParams || splitPath.split[x].isFullParams) {
      x++
      i = -1
    }
    while (consume.length) {
      letter.children.push(this.__buildChild(x, i + 1, consume))
      consume.splice(0, letter.children[letter.children.length - 1].count)
    }
    return letter
  }

  __buildTree(splitPaths) {
    let builder = []
    while (splitPaths.length) {
      builder.push(this.__buildChild(0, 0, splitPaths))
      splitPaths.splice(0, builder[builder.length - 1].count)
    }
    return builder
  }

  __splitAndSortPaths(paths, separateStatic = true) {
    let staticPaths = new Map()
    let paramsPaths = []
    let collator = new Intl.Collator('en', { sensitivity: 'accent' });
    let sealed = Object.seal({})

    paths.forEach(function(entry) {
      if (entry.path[0] !== '/') throw new RouterError(entry, null, 'Specified route was missing forward slash at start')

      // Collect static paths separately
      if (entry.path.indexOf('/:') < 0 && separateStatic) {
        return staticPaths.set(entry.path, {
          path: entry,
          params: sealed,
        })
      }

      // Collect params path separately
      paramsPaths.push({
        split: entry.path.slice(1).split(/\//g).map(function(word) {
          let actualWord = word.replace(regParamPrefix, '')
          return {
            word: actualWord,
            isParams: word[0] === ':' && word[1] !== ':',
            isFullParams: word[0] === ':' && word[1] === ':',
            paramVarName: word[0] === ':'
              ? actualWord.replace(regCleanNonAschii, '_').replace(regCleanRest, '_')
              : null
          }
        }),
        entry,
      })
    })
    paramsPaths.sort(function(aGroup, bGroup) {
      let length = Math.max(aGroup.split.length, bGroup.split.length)
      for (let x = 0; x < length; x++) {
        let a = aGroup.split[x]
        let b = bGroup.split[x]
        if (!a) return -1
        if (!b) return 1
        // Full params go last
        if (a.isFullParams && b.isFullParams) throw new RouterError(aGroup.entry, bGroup.entry, 'Two full path routes found on same level')
        if (a.isFullParams) return 1
        if (b.isFullParams) return -1
        // Params go second last
        if (a.isParams && !b.isParams) return 1
        if (!a.isParams && b.isParams) return -1
        // otherwise sort alphabetically if not identical
        if (a.word !== b.word) return collator.compare(a.word, b.word)
      }
      throw new RouterError(aGroup, bGroup, 'Two identical paths were found')
    })

    return {
      staticPaths,
      paramsPaths,
    }
  }


  __getIndex(offset, additions, params) {
    return (offset + additions)
      + (params.length
          ? ' + ' + params.map(a => `offset${a[1]}`).join(' + ')
          : '')
  }

  __treeIntoCompiledCodeReturnPath(indentString, paths, branch, params, pathParamMapIndex) {
    let pathIndex = paths.indexOf(branch.path)
    if (pathIndex < 0) {
      throw new RouterError(branch.path, null, 'InternalError: Specified path was not found in paths')
    }
    let mapIndex = pathParamMapIndex.size + 1
    pathParamMapIndex.set(mapIndex, pathIndex)
    let output = '\n' + indentString + `return {`
    output += '\n' + indentString + `  path: paths_${mapIndex},`
    if (params.length) {
      output += '\n' + indentString + `  params: {`
      for (let param of params) {
        output += '\n' + indentString + `    ${param[0]}: s${param[1]},`
      }
      output += '\n' + indentString + `  },`
    } else {
      output += '\n' + indentString + `  {},`
    }
    output += '\n' + indentString + `}`
    return output
  }

  __treeIntoCompiledCodeBranch(paths, branches, indent = 0, params = [], pathParamMapIndex) {
    let output = ''
    let indentation = spaces.slice(0, (indent - params.length) * 2)
    let addEndBracket = true

    for (let i = 0; i < branches.length; i++) {
      let branch = branches[i]
      if (i > 0) {
        if (!branch.isParams && !branch.isFullParams) {
          output += ' else '
        } else {
          // output += '} //'
          output += '\n' + indentation
        }
      }

      if (!branch.isParams && !branch.isFullParams) {
        output += `if (str.charCodeAt(${this.__getIndex(indent, 0, params)}) === ${branch.char.charCodeAt(0)}) { // ${branch.char}`

        if (branch.path) {
          output += '\n' + indentation + `  if (strLength === ${this.__getIndex(indent, 1, params)}) {`
          output += this.__treeIntoCompiledCodeReturnPath(indentation + '    ', paths, branch, params, pathParamMapIndex)
          output += '\n' + indentation + `  }`
        }
      } else {
        addEndBracket = false
        let paramVarName = (params.length + 1) + '_' + branch.paramVarName
        output += `let s${paramVarName} = str.slice(${this.__getIndex(indent, 0, params)}${branch.isFullParams ? '' : `, str.indexOf('/', ${this.__getIndex(indent, 0, params)}) >>> 0`})`
        output += '\n' + indentation + `let offset${paramVarName} = s${paramVarName}.length`
        output += '\n' + indentation
        params.push([branch.isParams || branch.isFullParams, paramVarName])

        if (branch.isFullParams) {
          output += this.__treeIntoCompiledCodeReturnPath(indentation, paths, branch, params, pathParamMapIndex)
        } else if (branch.path) {
          output += '\n' + indentation + `if (strLength === ${this.__getIndex(indent, 0, params)}) {`
          output += this.__treeIntoCompiledCodeReturnPath(indentation + '  ', paths, branch, params, pathParamMapIndex)
          output += '\n' + indentation + `}`
        }
      }

      if (branch.children.length) {
        if (branch.path) {
          output += ' else '
        } else {
          output += '\n' + indentation + '  '
        }
        output += this.__treeIntoCompiledCodeBranch(paths, branch.children, indent + 1, params.slice(), pathParamMapIndex)
      }
      if (addEndBracket) {
        output += '\n' + indentation + '} '
      }
    }
    return output
  }

  __treeIntoCompiledCodeClosure(paths, tree, staticList) {
    let pathParamMapIndex = new Map()
    let output = ''
    let prefix = ''
    if (staticList.size > 0) {
      output += '\n  let checkStatic = staticList.get(str)'
      output += '\n  if(checkStatic) {'
      output += '\n    return checkStatic'
      output += '\n  }'
    }
    if (tree.length) {
      output += '\n  let strLength = str.length'
      output += '\n  ' + this.__treeIntoCompiledCodeBranch(paths, tree, 1, [], pathParamMapIndex)

    }
    output += '\n  return null'
    output += '\n}'
    pathParamMapIndex.forEach(function (val, key) {
      prefix += `let paths_${key} = paths[${val}]\n`
    })
    output = prefix + 'return function flaskaFastRouter(str) {\n  "use strict";' + output

    return new Function('paths', 'staticList', output)(paths, staticList)
  }

  compile() {
    let splitPaths = this.__splitAndSortPaths(this.paths)
    let tree = this.__buildTree(splitPaths.paramsPaths.slice())
    this.match = this.__treeIntoCompiledCodeClosure(this.paths, tree, splitPaths.staticPaths)
  }

  match(url) {
    this.compile()
    return this.match(url)
  }
}

/**
 * Flaska
 */
export class Flaska {
  constructor(opts = {}, orgHttp = http, orgStream = stream) {
    this._before = []
    this._beforeCompiled = null
    this._beforeAsync = []
    this._beforeAsyncCompiled = null
    this._after = []
    this._afterCompiled = null
    this._afterAsync = []
    this._afterAsyncCompiled = null
    this._on404 = function(ctx) {
      if (ctx.body == null && ctx.status !== 204) {
        ctx.status = 404
        ctx.body = {
          status: 404,
          message: statuses[404],
        }
      }
    }
    this._backuperror = this._onerror = function(err, ctx) {
      ctx.log.error(err)
      if (err instanceof HttpError) {
        ctx.status = err.status
        ctx.body = err.body || {
          status: err.status,
          message: statuses[err.status] || statuses[500],
        }
      } else {
        ctx.status = 500
        ctx.body = {
          status: 500,
          message: statuses[500],
        }
      }
    }
    this._onreqerror = function(err, ctx) {
      if (err.message !== 'aborted') {
        ctx.log.error(err)
        ctx.res.statusCode = ctx.statusCode = 400
      }
      ctx.res.end()
    }
    this._onreserror = function(err, ctx) {
      ctx.log.error(err)
    }

    let options = {
      defaultHeaders: opts.defaultHeaders || {
        'Server': 'Flaska',
        'X-Content-Type-Options': 'nosniff',
        'Content-Security-Policy': `default-src 'self'; style-src 'self' 'unsafe-inline'; img-src * data: blob:; font-src 'self' data:; object-src 'none'; frame-ancestors 'none'`,
        'Cross-Origin-Opener-Policy': 'same-origin',
        'Cross-Origin-Resource-Policy': 'same-origin',
        'Cross-Origin-Embedder-Policy': 'require-corp',
      },
      log: opts.log || {
        fatal: console.error.bind(console),
        error: console.error.bind(console),
        warn: console.log.bind(console),
        info: console.log.bind(console),
        debug: console.debug.bind(console),
        trace: console.debug.bind(console),
        log: console.log.bind(console),
      },
      nonce: opts.nonce || [],
      nonceCacheLength: opts.nonceCacheLength || 25
    }

    if (opts.appendHeaders) {
      let appendKeys = Object.keys(opts.appendHeaders)
      for (let key of appendKeys) {
        options.defaultHeaders[key] = opts.appendHeaders[key]
      }
    }

    if (!options.defaultHeaders && options.nonce.length) {
      // throw error
    }

    let headerKeys = Object.keys(options.defaultHeaders)
    let constructFunction = ''

    if (options.nonce.length) {
      this._nonces = new Array(options.nonceCacheLength)
      this._noncesIndex = this._nonces.length - 1

      for (let i = 0; i < this._nonces.length; i++) {
        this._nonces[i] = crypto.randomBytes(16).toString('base64')
      }

      constructFunction += `
let nonce = this._nonces[this._noncesIndex] || crypto.randomBytes(16).toString('base64');
this._noncesIndex--;
ctx.state.nonce = nonce;
`
    }

    constructFunction += 'ctx.headers = {'
    constructFunction += `'Date': new Date().toUTCString(),`
    for (let key of headerKeys) {
      if (key === 'Content-Security-Policy' && options.nonce.length) {
        let groups = options.defaultHeaders[key].split(';')
        for (let ni = 0; ni < options.nonce.length; ni++) {
          let found = false
          for (let x = 0; x < groups.length; x++) {
            if (groups[x].trim().startsWith(options.nonce[ni])) {
              groups[x] = groups[x].trimEnd() + ` 'nonce-$'`
              found = true
              break
            }
          }
          if (!found) {
            groups.push(` ${options.nonce[ni]} 'nonce-$'`)
          }
        }
        groups = groups.join(';').replace(/\'/g, "\\'").split('$')
        constructFunction += `'${key}': '${groups.join(`' + nonce + '`)}',`
      } else {
        constructFunction += `'${key}': '${options.defaultHeaders[key].replace(/\'/g, "\\'")}',`
      }
    }
    constructFunction += '};'

    // console.log(constructFunction)

    if (options.nonce.length) {
      this.before(new Function('crypto', 'ctx', constructFunction).bind(this, crypto))
      this.after(new Function('crypto', 'ctx', `
        this._noncesIndex = Math.max(this._noncesIndex, -1);
        if (this._noncesIndex < this._nonces.length - 1) {
          this._noncesIndex++;
          this._nonces[this._noncesIndex] = crypto.randomBytes(16).toString('base64');
        }
      `).bind(this, crypto))
    } else {
      this.before(new Function('ctx', constructFunction).bind(this))
    }

    this.log = options.log
    this.http = orgHttp
    this.stream = orgStream
    this.server = null
    this.routers = {
      'GET': new FlaskaRouter(),
      'POST': new FlaskaRouter(),
      'PUT': new FlaskaRouter(),
      'DELETE': new FlaskaRouter(),
      'OPTIONS': new FlaskaRouter(),
      'PATCH': new FlaskaRouter(),
    }
    // HEAD and GET should be identical
    this.routers['HEAD'] = this.routers['GET']

    this.get = this.routers.GET.addRoute.bind(this.routers.GET)
    this.post = this.routers.POST.addRoute.bind(this.routers.POST)
    this.put = this.routers.PUT.addRoute.bind(this.routers.PUT)
    this.delete = this.routers.DELETE.addRoute.bind(this.routers.DELETE)
    this.options = this.routers.OPTIONS.addRoute.bind(this.routers.OPTIONS)
    this.patch = this.routers.PATCH.addRoute.bind(this.routers.PATCH)
  }

  devMode() {
    this._backuperror = this._onerror = function(err, ctx) {
      ctx.log.error(err)
      if (err instanceof HttpError) {
        ctx.status = err.status
        ctx.body = err.body || {
          status: err.status,
          message: `${statuses[err.status] || statuses[500]}: ${err.message}`,
          stack: err.stack || '',
        }
      } else {
        ctx.status = 500
        ctx.body = {
          status: 500,
          message: `${statuses[500]}: ${err.message}`,
          stack: err.stack || '',
        }
      }
    }
  }

  on404(handler) {
    assertIsHandler(handler, 'on404()')
    this._on404 = handler
  }

  onerror(handler) {
    assertIsHandler(handler, 'onerror()')
    this._onerror = handler
  }

  onreqerror(handler) {
    assertIsHandler(handler, 'onreqerror()')
    this._onreqerror = handler
  }

  onreserror(handler) {
    assertIsHandler(handler, 'onreserror()')
    this._onreserror = handler
  }

  before(handler) {
    assertIsHandler(handler, 'before()')
    this._before.push(handler)
  }

  beforeAsync(handler) {
    assertIsHandler(handler, 'beforeAsync()')
    this._beforeAsync.push(handler)
  }

  after(handler) {
    assertIsHandler(handler, 'after()')
    this._after.push(handler)
  }

  afterAsync(handler) {
    assertIsHandler(handler, 'afterAsync()')
    this._afterAsync.push(handler)
  }

  __requestStart(req, res) {
    let url = req.url
    let search = ''
    let hasSearch = url.indexOf('?')

    if (hasSearch > 0) {
      search = url.slice(hasSearch)
      url = url.slice(0, hasSearch)
    }

    let ctx = {
      log: this.log,
      req: req,
      res: res,
      method: req.method,
      url: url,
      search: search,
      state: {},
      status: 200,
      query: new Map(),
      body: null,
      type: null,
      length: null,
    }

    req.on('error', (err) => {
      if (err.message === 'aborted') {
        ctx.aborted = true
      }
      this._onreqerror(err, ctx)
      this.__requestEnded(ctx)
    })
    res.on('error', (err) => {
      this._onreserror(err, ctx)
    })

    res.on('finish', () => {
      this.__requestEnded(ctx)
    })

    try {
      this._beforeCompiled(ctx)
      if (this._beforeAsyncCompiled) {
        return this._beforeAsyncCompiled(ctx)
          .then(() => {
            this.__requestStartInternal(ctx)
          }).catch(err => {
            this.__requestEnd(err, ctx)
          })
      }
      this.__requestStartInternal(ctx)
    }
    catch (err) {
      this.__requestEnd(err, ctx)
    }
  }

  __requestStartInternal(ctx) {
    let route = this.routers[ctx.method].match(ctx.url)
    if (!route) {
      let middle = this._on404(ctx)
      if (middle && middle.then) {
        return middle.then(() => {
          this.__requestEnd(null, ctx)
        }, err => {
          this.__requestEnd(err, ctx)
        })
      }
      return this.__requestEnd(null, ctx)
    }

    ctx.params = route.params

    let handlers = this.__runHandlers(ctx, route.path.handlers, 0)

    if (handlers && handlers.then) {
      return handlers.then(() => {
        this.__requestEnd(null, ctx)
      }, err => {
        this.__requestEnd(err, ctx)
      })
    }

    this.__requestEnd(null, ctx)
  }

  __runHandlers(ctx, middles, index) {
    for (let i = index; i < middles.length; i++) {
      let res = middles[i](ctx)
      if (res && res.then) {
        return res.then(() => {
          return this.__runHandlers(ctx, middles, i + 1)
        })
      }
    }
  }

  __requestEnd(orgErr, ctx) {
    let err = orgErr
    let handleUsed = Boolean(ctx.body && ctx.body.handleRequest)
    if (handleUsed) {
      try {
        ctx.body = ctx.body.handleRequest(ctx)
      } catch (newErr) {
        err = newErr
      }
    }
    if (err) {
      try {
        this._onerror(err, ctx)
      } catch (err) {
        this._backuperror(err, ctx)
      }
    }

    if (ctx.res.writableEnded) {
      return
    }

    if (ctx.body == null && !handleUsed && ctx.status === 200) {
      ctx.status = 204
    }

    if (statuses.empty[ctx.status]) {
      ctx.res.writeHead(ctx.status, ctx.headers)
      return ctx.res.end()
    }

    let body = ctx.body

    // Special handling for files
    if (body && typeof(body.pipe) === 'function') {
      // Be smart when handling file handles, auto detect mime-type
      // based off of the extension of the file.
      if (!ctx.type && body.path) {
        let ext = path.extname(body.path).slice(1)
        if (ext && MimeTypeDb[ext]) {
          let found = MimeTypeDb[ext]
          ctx.type = found[found.length - 1]
        }
      }
      ctx.headers['Content-Type'] = ctx.type || 'application/octet-stream'

      ctx.res.writeHead(ctx.status, ctx.headers)

      if (ctx.method !== 'HEAD') {
        return this.stream.pipeline(body, ctx.res, function() { })
      } else {
        try {
          body.destroy()
        } catch { }
        return ctx.res.end()
      }
    }

    let length = 0

    if (body instanceof Buffer) {
      length = body.byteLength
      ctx.type = ctx.type || 'application/octet-stream'
    } else if (typeof(body) === 'object' && body) {
      body = JSON.stringify(body)
      length = Buffer.byteLength(body)
      ctx.type = 'application/json; charset=utf-8'
    } else if (body) {
      body = body.toString()
      length = Buffer.byteLength(body)
      ctx.type = ctx.type || 'text/plain; charset=utf-8'
    }

    if (ctx.type) {
      ctx.headers['Content-Type'] = ctx.type
    }
    if (!ctx.headers['Content-Length']) {
      ctx.headers['Content-Length'] = length
    }

    ctx.res.writeHead(ctx.status, ctx.headers)
    if (body && ctx.method !== 'HEAD') {
      ctx.res.end(body)
    } else {
      ctx.res.end()
    }
  }

  __requestEnded(ctx) {
    if (ctx.finished) return
    ctx.finished = true

    // Prevent accidental leaking
    if (ctx.body && ctx.body.pipe && !ctx.body.closed) {
      ctx.body.destroy()
    }
    this._afterCompiled(ctx)
    if (this._afterAsyncCompiled) {
      return this._afterAsyncCompiled(ctx).then()
    }
  }

  __compile() {
    let types = ['before', 'after']
    for (let i = 0; i < types.length; i++) {
      let type = types[i]
      let args = ''
      let body = ''
      for (let i = 0; i < this['_' + type].length; i++) {
        args += `a${i}, `
        body += `a${i}(ctx);`
      }
      args += 'ctx'

      let func = new Function(args, body)
      this[`_${type}Compiled`] = func.bind(this, ...this['_' + type])

      if (this[`_${type}Async`].length) {
        args = ''
        body = 'return Promise.all(['
        for (let i = 0; i < this[`_${type}Async`].length; i++) {
          args += `a${i}, `
          body += `a${i}(ctx),`
        }
        args += 'ctx'
        body += '])'
        func = new Function(args, body)
        this[`_${type}AsyncCompiled`] = func.bind(this, ...this[`_${type}Async`])
      }
    }
    this.routers.GET.compile()
    this.routers.POST.compile()
    this.routers.PUT.compile()
    this.routers.DELETE.compile()
    this.routers.OPTIONS.compile()
    this.routers.PATCH.compile()
  }

  __create() {
    this.__compile()
    this.server = this.http.createServer(this.__requestStart.bind(this))

    this.server.on('connection', function (socket) {
      // Set socket idle timeout in milliseconds
      socket.setTimeout(1000 * 60 * 5) // 5 minutes

      // Wait for timeout event (socket will emit it when idle timeout elapses)
      socket.on('timeout', function () {
        // Call destroy again
        socket.destroy();
      })
    })
  }

  listen(port, orgIp, orgcb) {
    let ip = orgIp
    let cb = orgcb
    if (!cb && typeof(orgIp) === 'function') {
      ip = '::'
      cb = orgIp
    }
    if (typeof(port) !== 'number') {
      throw new Error('Flaska.listen() called with non-number in port')
    }

    this.__create()

    this.server.listen(port, ip, cb)
  }

  listenAsync(port, ip = '::') {
    if (typeof(port) !== 'number') {
      return Promise.reject(new Error('Flaska.listen() called with non-number in port'))
    }

    this.__create()

    if (this.server.listenAsync && typeof(this.server.listenAsync) === 'function') {
      return this.server.listenAsync(port, ip)
    }

    return new Promise((res, rej) => {
      this.server.listen(port, ip, function(err) {
        if (err) return rej(err)
        return res()
      })
    })
  }

  closeAsync() {
    if (!this.server) return Promise.resolve()

    return new Promise((res, rej) => {
      this.server.close(function(err) {
        if (err) { return rej(err) }

        // Waiting 0.1 second for it to close down
        setTimeout(res, 100)
      })
      this.server.closeAllConnections()
    })
  }
}