#!/usr/bin/env node
// vi: ft=javascript

var net = require('net')
var path = require('path')
var fs = require('fs')
var parseDatUrl = require('parse-dat-url')
var parseUrl = require('url').parse
var datDns = require('dat-dns')()
var memo = require('asyncmemo')
var hyperdrive = require('hyperdrive')
var crypto = require('crypto')
var h = require('hyperscript')
var hyperdiscovery = require('hyperdiscovery')

var dilloDir = path.join(process.env.HOME, '.dillo')
var dpidKeysPath = path.join(dilloDir, 'dpid_comm_keys')
var archivesPath = path.join(dilloDir, 'dat', 'archives')

var dpidKeys = fs.readFileSync(dpidKeysPath, {encoding: 'ascii'}).split(/\s+/)

function readManifest(archive, cb) {
  archive.readFile('dat.json', function (err, data) {
    var manifest
    if (!err) try { manifest = JSON.parse(data) } catch(e) {}
    if (manifest) return cb(null, manifest)
    archive.readFile('CNAME', 'ascii', function (err, data) {
      if (err) return cb('Not found')
      cb(null, {title: data})
    })
  })
}

var archives = {}
var getArchive = memo({cache: {
  has: function (key) { return key in archives },
  get: function (key) { return archives[key] },
  set: function (key, value) { archives[key] = value},
}}, function (key, cb) {
  var archive
  try {
    var archivePath = path.join(archivesPath, key.substr(0, 2), key.substr(2))
    archive = hyperdrive(archivePath, key, {sparse: true})
  } catch(e) {
    return cb(e)
  }
  archive.ready(function (err) {
    if (err) return cb(err)
    console.log('[dat dpi] swarming', archive.key.toString('hex'))
    archive.swarm = hyperdiscovery(archive, {
      stream: function (info) {
        var stream = archive.replicate({
          live: true
        })
        stream.address = info.type + ':' + (info.host || '?') + ':' + (info.port || '?')
        return stream
      }
    })
  })
  archive.on('content', function () { 
    cb(null, archive)
    readManifest(archive, function (err, manifest) {
      if (err) return
      archive.manifest = manifest
    })
  })
  archive.on('error', cb)
})

function DpiReq(socket) {
  this.socket = socket
  this._inBuffer = ''
  socket.on('data', this.onData.bind(this))
  socket.on('close', this.onClose.bind(this))
  socket.on('error', this.onError.bind(this))
}

DpiReq.prototype.onData = function (data) {
  this._inBuffer += data.toString('ascii')
  for (var i = 0; i < this.commands.length; i++) {
    var cmd = this.commands[i]
    var m = cmd[0].exec(this._inBuffer)
    if (!m) continue
    this._inBuffer = this._inBuffer.slice(m[0].length)
    cmd[1].call(this, m)
  }
}

DpiReq.prototype.onClose = function () {
  this.closed = true
}

DpiReq.prototype.onError = function (err) {
  // console.trace('[dat dpi]', err)
  this.closed = true
}

DpiReq.prototype.reload = function (url) {
  this.socket.end("<cmd='reload_request' url='" + url + "' '>")
}

DpiReq.prototype.sendStatus = function (msg) {
  this.socket.write("<cmd='send_status_message' msg='" + msg + "' '>")
}

DpiReq.prototype.writeHeader = function (type) {
  this.socket.write("<cmd='start_send_page' url='" + this.url + "' '>")
  this.socket.write('Content-type: ' + type + '\r\n\r\n')
}

DpiReq.prototype.serveError = function (err) {
  this.writeHeader('text/plain')
  this.socket.end(err && err.stack || err)
}

DpiReq.prototype.getAddress = function () {
  return this.socket.remoteAddress + ':' + this.socket.remotePort
}

DpiReq.prototype.serveStat = function (st) {
  this.writeHeader('text/plain')
  this.socket.end(JSON.stringify(st, 0, 2))
}

var typeIcons = {
  updir: h('img', {alt: 'up', src: 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAAGXRFWHRTb2Z0d2FyZQBBZG9iZSBJbWFnZVJlYWR5ccllPAAAAKxJREFUeNpi/P//PwMlgImBQjAMDGBBF2BkZISz09LSwCE8a9YsuCBGoIMEkDEMJCUl/b90+QoYg9i41LNgc1ZycvL/hMQkhgcPH4H5iUnJIJf9nzt3LiNBL2RkZPwPj4hk4BMUYuDh44MEFDMLQ0xsHAMrKyvIJYyEwuDLiuXLeP7+/Qv3EihcmJmZGZiYmL5gqEcPFKBiAyDFjCPQ/wLVX8BrwGhSJh0ABBgAsetR5KBfw9EAAAAASUVORK5CYII='}),
  directory: h('img', {alt: 'directory', src: 'data:image/png;base64,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'}),
  file: h('img', {src: 'data:image/png;base64,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'}),
}

function compareFileStats(a, b) {
  return ((b.type === 'directory') - (a.type === 'directory'))
      || (b.name.localeCompare(a.name))
}

DpiReq.prototype.serveDirectory = function () {
  if (this.closed) return
  var files = []
  var self = this
  var pathname = this.pathname
  if (!/\/$/.test(pathname)) pathname += '/'
  this.archive.readdir(pathname, {cached: true}, function (err, names) {
    if (err) return self.serveError(err)
    self.writeHeader('text/html')
    ;(function next() {
      var name = names.pop()
      if (name == null) return gotStats()
      self.archive.stat(pathname + name, function (err, st) {
        if (err) {
          self.socket.write(h('pre', err.stack || err).outerHTML)
          st = {}
        } else {
          st.type = st.isDirectory() ? 'directory' : 'file'
        }
        if (st.isDirectory()) st.size = null
        st.name = name
        if (st.mtime.getTime() === 0) st.mtime = null
        files.push(st)
        next()
      })
    }())
  })
  function gotStats() {
    files.sort(compareFileStats)
    if (pathname !== '/') {
      files.unshift({
        name: '..',
        type: 'updir'
      })
    }
    self.socket.end('<!doctype html>' + h('html', [
      h('head', [
        h('title', pathname)
      ]),
      h('body', [
        h('h4', pathname),
        h('table', files.map(function (file) {
          var suffix = file.type === 'directory' ? '/' : ''
          return h('tr', [
            h('td', (typeIcons[file.type] || '')),
            h('td', h('a', {href: pathname + file.name + suffix}, file.name)),
            h('td', file.mtime == null ? '' : file.mtime),
            h('td', {align: 'right'}, file.size == null ? '' : file.size)
          ])
        }))
      ])
    ]).outerHTML)
  }
}

function detectContentType(pathname) {
  var m = /[^.]*$/.exec(pathname)
  switch (m && m[0]) {
    case 'htm':
    case 'html': return 'text/html'
    case 'png': return 'image/png'
    case 'gif': return 'image/gif'
    case 'jpg': return 'image/jpeg'
    default: return 'text/plain'
  }
}

function withTimeout(fn, ms) {
  return function (arg, cb) {
    var timeout = setTimeout(function () {
      if (!cb) return
      var _cb = cb
      cb = null
      _cb()
    }, ms)
    fn(arg, function (err, res) {
      if (!cb) return
      clearTimeout(timeout)
      var _cb = cb
      cb = null
      _cb(err, res)
    })
  }
}

DpiReq.prototype.serveFile = function () {
  if (this.closed) return
  this.writeHeader(detectContentType(this.pathname))
  this.archive.createReadStream(this.pathname).pipe(this.socket)
}

DpiReq.prototype.statFile = function (pathname, cb) {
  var self = this
  this.archive.stat(pathname, function (err, st) {
    if (err) return cb(err)
    st.pathname = pathname
    cb(null, st)
  })
}

DpiReq.prototype.statDirectory = function (pathname, cb) {
  var self = this
  self.statFile(pathname + '/index.html', function (err, st) {
    if (!err) return cb(null, st)
    self.statFile(pathname, cb)
  })
}

DpiReq.prototype.stat = function (pathname, cb) {
  var self = this
  if (/\/\/$/.test(pathname)) return self.statFile(pathname.replace(/\/$/, ''), cb)
  if (/\/$/.test(pathname)) return self.statDirectory(pathname, cb)
  self.statFile(pathname, function (err, st) {
    if (err) return self.statFile(pathname + '.html', cb)
    if (st.isDirectory()) return self.statDirectory(pathname, cb)
    cb(null, st)
  })
}

DpiReq.prototype.serveTimedout = function (urlp) {
  this.writeHeader('text/html')
  this.socket.end(h('h3', 'Timed out').outerHTML)
}

DpiReq.prototype.serveNotFound = function (urlp) {
  this.writeHeader('text/html')
  this.socket.end(h('h3', 'Not found').outerHTML)
}

function unswarm(key, cb) {
  var archive = archives[key]
  if (!archive) return cb(new Error('missing archive'))
  delete archives[key]
  archive.swarm.close()
  archive.close(cb)
}

DpiReq.prototype.serveDashboard = function () {
  var self = this
  var q = self.urlp.query
  if (q.unswarm) {
    self.sendStatus('unswarming ' + q.key)
    return unswarm(q.key, function (err) {
      if (err) return self.serveError(err)
      return self.reload(q.reload)
    })
  }
  if (q.restart) {
    self.sendStatus('restarting')
    self.reload(q.reload)
    return process.exit(0)
  }

  this.writeHeader('text/html')
  self.socket.end('<!doctype html>' + h('html', [
    h('head', [
      h('title', 'Dat')
    ]),
    h('body', [
      h('form', {action: ''}, [
        h('input', {type: 'submit', name: 'restart', value: 'Restart'}),
        h('input', {type: 'hidden', name: 'reload', value: self.url})
      ]),
      h('h3', 'Archives'),
      Object.keys(archives).length === 0 ? [
        h('p', 'None')
      ] : Object.keys(archives).map(function (key) {
        var archive = archives[key]
        var description = archive.manifest && archive.manifest.description
        var title = archive.manifest && archive.manifest.title 
        var href = 'dat://' + key
        var versionedHref = href + '+' + archive.version
        return [
          h('p', [
            h('a', {href: href}, title || h('code', key)),
            description ? [' - ', String(description)] : '', h('br'),
            'version ', h('a', {href: versionedHref}, archive.version)
          ]),
          h('blockquote', [
            h('h3', 'Peers'),
            archive.swarm.connections.length === 0 ? [
              'None'
            ] : archive.swarm.connections.map(function (stream) {
              return h('div', h('code', stream.address))
            }),
            h('form', {action: ''}, [
              h('input', {type: 'hidden', name: 'key', value: key}),
              h('input', {type: 'hidden', name: 'reload', value: self.url}),
              h('input', {type: 'submit', name: 'unswarm', value: 'unswarm'}),
            ])
          ])
        ]
      })
    ])
  ]).outerHTML)
}

DpiReq.prototype.serveDat = function () {
  var self = this
  self.urlp = parseDatUrl(self.url, true)
  if (!self.urlp.host) return self.serveError('Archive not found')
  self.sendStatus('resolving name')
  datDns.resolveName(self.urlp.host, {
    ignoreCachedMiss: true,
    noDnsOverHttps: true
  }, function (err, key) {
    if (err) return self.serveError(err)
    if (!key) return cb(new TypeError('resolve failed'))
    self.sendStatus('getting archive')
    withTimeout(getArchive, 10000)(key, function (err, archive) {
      if (err) return self.serveError(err)
      if (!archive) return self.serveTimedout(self.urlp)
      try { if (self.urlp.version) archive = archive.checkout(+self.urlp.version) }
      catch(e) { return self.serveError(err) }
      self.archive = archive
      self.sendStatus('serving file')
      self.serve()
    })
  })
}

DpiReq.prototype.serveInternal = function () {
  this.urlp = parseUrl(this.url, true)
  if (this.urlp.pathname === '/dat/') return this.serveDashboard()
  this.serveNotFound()
}

DpiReq.prototype.serve = function () {
  var self = this
  if (self.closed) return
  var pathname = self.urlp.pathname || '/'
  try { pathname = decodeURIComponent(pathname) }
  catch(e) {}
  self.stat(pathname, function (err, st) {
    if (err) return self.serveNotFound(err)
    self.pathname = st.pathname
    if (self.urlp.query.stat) return self.serveStat(st)
    if (st.isDirectory()) return self.serveDirectory()
    self.serveFile()
  })
}

function DpiReq_onAuth(m) {
  this.authed = (m[1] == dpidKeys[1])
  if (!this.authed) {
    console.error('[dat dpi] bad auth from', this.getAddress())
    return this.socket.end()
  }
  this.authed = true
}

function DpiReq_onOpenUrl(m) {
  if (!this.authed) {
    console.error('[dat dpi] un-authed request from', this.getAddress())
    return this.socket.end()
  }
  this.url = m[1]
  if (this.url.startsWith('dat:')) return this.serveDat()
  if (this.url.startsWith('dpi:/dat/')) return this.serveInternal()
  this.serveError('Not found')
}

function DpiReq_onBye(m) {
  if (!this.authed) {
    console.error('[dat dpi] un-authed bye from', this.getAddress())
    return this.socket.end()
  }
  console.log('[dat dpi] stopping')
  process.exit(0)
}

DpiReq.prototype.commands = [
  [/^<cmd='auth' msg='([^']*)' '>/, DpiReq_onAuth],
  [/^<cmd='open_url' url='(.*?)' '>/, DpiReq_onOpenUrl],
  [/^<cmd='DpiBye' '>/, DpiReq_onBye],
]

net.createServer({allowHalfOpen: true}, function (c) {
  new DpiReq(c)
}).listen(process.stdin, function () {
  console.log('[dat dpi] started')
})