var fs = require('fs')
var http = require('http')
var path = require('path')
var url = require('url')
var qs = require('querystring')
var util = require('util')
var ref = require('ssb-ref')
var pull = require('pull-stream')
var ssbGit = require('ssb-git-repo')
var toPull = require('stream-to-pull-stream')
var cat = require('pull-cat')
var GitRepo = require('pull-git-repo')
var u = require('./lib/util')
var markdown = require('./lib/markdown')
var paginate = require('./lib/paginate')
var asyncMemo = require('asyncmemo')
var multicb = require('multicb')
var schemas = require('ssb-msg-schemas')
var Issues = require('ssb-issues')
var PullRequests = require('ssb-pull-requests')
var paramap = require('pull-paramap')
var Mentions = require('ssb-mentions')
var many = require('pull-many')
var ident = require('pull-identify-filetype')
var mime = require('mime-types')
var moment = require('moment')
var LRUCache = require('lrucache')

var hlCssPath = path.resolve(require.resolve('highlight.js'), '../../styles')
var emojiPath = path.resolve(require.resolve('emoji-named-characters'), '../pngs')

function ParamError(msg) {
  var err = Error.call(this, msg)
  err.name = ParamError.name
  return err
}
util.inherits(ParamError, Error)

function parseAddr(str, def) {
  if (!str) return def
  var i = str.lastIndexOf(':')
  if (~i) return {host: str.substr(0, i), port: str.substr(i+1)}
  if (isNaN(str)) return {host: str, port: def.port}
  return {host: def.host, port: str}
}

function tryDecodeURIComponent(str) {
  if (!str || (str[0] == '%' && ref.isBlobId(str)))
    return str
  try {
    str = decodeURIComponent(str)
  } finally {
    return str
  }
}

function getContentType(filename) {
  var ext = u.getExtension(filename)
  return contentTypes[ext] || u.imgMimes[ext] || 'text/plain; charset=utf-8'
}

var contentTypes = {
  css: 'text/css'
}

function readReqForm(req, cb) {
  pull(
    toPull(req),
    pull.collect(function (err, bufs) {
      if (err) return cb(err)
      var data
      try {
        data = qs.parse(Buffer.concat(bufs).toString('ascii'))
      } catch(e) {
        return cb(e)
      }
      cb(null, data)
    })
  )
}

var msgTypes = {
  'git-repo': true,
  'git-update': true,
  'issue': true,
  'pull-request': true
}

var _httpServer

module.exports = {
  name: 'git-ssb-web',
  version: require('./package').version,
  manifest: {},
  init: function (ssb, config, reconnect) {
    // close existing server. when scuttlebot plugins get a deinit method, we
    // will close it in that instead it
    if (_httpServer)
      _httpServer.close()

    var web = new GitSSBWeb(ssb, config, reconnect)
    _httpSserver = web.httpServer

    return {}
  }
}

function GitSSBWeb(ssb, config, reconnect) {
  this.ssb = ssb
  this.config = config
  this.reconnect = reconnect

  if (config.logging && config.logging.level)
    this.logLevel = this.logLevels.indexOf(config.logging.level)
  this.ssbAppname = config.appname || 'ssb'
  this.isPublic = config.public
  this.getVotes = require('./lib/votes')(ssb)
  this.getMsg = asyncMemo({cache: new LRUCache(100)}, ssb.get)
  this.issues = Issues.init(ssb)
  this.pullReqs = PullRequests.init(ssb)
  this.getRepo = asyncMemo({
    cache: new LRUCache(32)
  }, function (id, cb) {
    this.getMsg(id, function (err, msg) {
      if (err) return cb(err)
      ssbGit.getRepo(ssb, {key: id, value: msg}, {live: true}, cb)
    })
  })

  this.about = function (id, cb) { cb(null, {name: id}) }
  ssb.whoami(function (err, feed) {
    this.myId = feed.id
    this.about = require('./lib/about')(ssb, this.myId)
  }.bind(this))

  this.i18n = require('./lib/i18n')(path.join(__dirname, 'locale'), 'en')
  this.users = require('./lib/users')(this)
  this.repos = require('./lib/repos')(this)

  var webConfig = config['git-ssb-web'] || {}
  var addr = parseAddr(config.listenAddr, {
    host: webConfig.host || 'localhost',
    port: webConfig.port || 7718
  })
  this.listen(addr.host, addr.port)
}

var G = GitSSBWeb.prototype

G.logLevels = ['error', 'warning', 'notice', 'info']
G.logLevel = G.logLevels.indexOf('notice')

G.log = function (level) {
  if (this.logLevels.indexOf(level) > this.logLevel) return
  console.log.apply(console, [].slice.call(arguments, 1))
}

G.listen = function (host, port) {
  this.httpServer = http.createServer(G_onRequest.bind(this))
  this.httpServer.listen(port, host, function () {
    var hostName = ~host.indexOf(':') ? '[' + host + ']' : host
    this.log('notice', 'Listening on http://' + hostName + ':' + port + '/')
  }.bind(this))
}

G.getRepoName = function (ownerId, repoId, cb) {
  this.about.getName({
    owner: ownerId,
    target: repoId
  }, cb)
}

G.getRepoFullName = function (author, repoId, cb) {
  var done = multicb({ pluck: 1, spread: true })
  this.getRepoName(author, repoId, done())
  this.about.getName(author, done())
  done(cb)
}

G.addAuthorName = function () {
  var about = this.about
  return paramap(function (msg, cb) {
    var author = msg && msg.value && msg.value.author
    if (!author) return cb(null, msg)
    about.getName(author, function (err, authorName) {
      msg.authorName = authorName
      cb(err, msg)
    })
  }, 8)
}

/* Serving a request */

function serve(req, res) {
  return pull(
    pull.filter(function (data) {
      if (Array.isArray(data)) {
        res.writeHead.apply(res, data)
        return false
      }
      return true
    }),
    toPull(res)
  )
}

function G_onRequest(req, res) {
  this.log('info', req.method, req.url)
  req._u = url.parse(req.url, true)
  var locale = req._u.query.locale ||
    (/locale=([^;]*)/.exec(req.headers.cookie) || [])[1]
  var reqLocales = req.headers['accept-language']
  this.i18n.pickCatalog(reqLocales, locale, function (err, t) {
    if (err) return pull(this.serveError(req, err, 500), serve(req, res))
    req._t = t
    req._locale = t.locale
    pull(this.handleRequest(req), serve(req, res))
  }.bind(this))
}

G.handleRequest = function (req) {
  var path = req._u.pathname.slice(1)
  var dirs = ref.isLink(path) ? [path] :
    path.split(/\/+/).map(tryDecodeURIComponent)
  var dir = dirs[0]

  if (req.method == 'POST')
    return this.handlePOST(req, dir)

  if (dir == '')
    return this.serveIndex(req)
  else if (dir == 'search')
    return this.serveSearch(req)
  else if (ref.isBlobId(dir))
    return this.serveBlob(req, dir)
  else if (ref.isMsgId(dir))
    return this.serveMessage(req, dir, dirs.slice(1))
  else if (ref.isFeedId(dir))
    return this.users.serveUserPage(req, dir, dirs.slice(1))
  else if (dir == 'static')
    return this.serveFile(req, dirs)
  else if (dir == 'highlight')
    return this.serveFile(req, [hlCssPath].concat(dirs.slice(1)), true)
  else if (dir == 'emoji')
    return this.serveFile(req, [emojiPath].concat(dirs.slice(1)), true)
  else
    return this.serve404(req)
}

G.handlePOST = function (req, dir) {
  var self = this
  if (self.isPublic)
    return self.serveBuffer(405, req._t('error.POSTNotAllowed'))
  return u.readNext(function (cb) {
    readReqForm(req, function (err, data) {
      if (err) return cb(null, self.serveError(req, err, 400))
      if (!data) return cb(null, self.serveError(req,
        new ParamError(req._t('error.MissingData')), 400))

      switch (data.action) {
        case 'fork-prompt':
          return cb(null, self.serveRedirect(req,
            u.encodeLink([data.id, 'fork'])))

        case 'fork':
          if (!data.id)
            return cb(null, self.serveError(req,
              new ParamError(req._t('error.MissingId')), 400))
          return ssbGit.createRepo(self.ssb, {upstream: data.id},
            function (err, repo) {
              if (err) return cb(null, self.serveError(req, err))
              cb(null, self.serveRedirect(req, u.encodeLink(repo.id)))
            })

        case 'vote':
          var voteValue = +data.value || 0
          if (!data.id)
            return cb(null, self.serveError(req,
              new ParamError(req._t('error.MissingId')), 400))
          var msg = schemas.vote(data.id, voteValue)
          return self.ssb.publish(msg, function (err) {
            if (err) return cb(null, self.serveError(req, err))
            cb(null, self.serveRedirect(req, req.url))
          })

      case 'repo-name':
        if (!data.id)
          return cb(null, self.serveError(req,
            new ParamError(req._t('error.MissingId')), 400))
        if (!data.name)
          return cb(null, self.serveError(req,
            new ParamError(req._t('error.MissingName')), 400))
        var msg = schemas.name(data.id, data.name)
        return self.ssb.publish(msg, function (err) {
          if (err) return cb(null, self.serveError(req, err))
          cb(null, self.serveRedirect(req, req.url))
        })

      case 'comment':
        if (!data.id)
          return cb(null, self.serveError(req,
            new ParamError(req._t('error.MissingId')), 400))
        var msg = schemas.post(data.text, data.id, data.branch || data.id)
        msg.issue = data.issue
        msg.repo = data.repo
        if (data.open != null)
          Issues.schemas.reopens(msg, data.id)
        if (data.close != null)
          Issues.schemas.closes(msg, data.id)
        var mentions = Mentions(data.text)
        if (mentions.length)
          msg.mentions = mentions
        return self.ssb.publish(msg, function (err) {
          if (err) return cb(null, self.serveError(req, err))
          cb(null, self.serveRedirect(req, req.url))
        })

      case 'new-issue':
        var msg = Issues.schemas.new(dir, data.text)
        var mentions = Mentions(data.text)
        if (mentions.length)
          msg.mentions = mentions
        return self.ssb.publish(msg, function (err, msg) {
          if (err) return cb(null, self.serveError(req, err))
          cb(null, self.serveRedirect(req, u.encodeLink(msg.key)))
        })

      case 'new-pull':
        var msg = PullRequests.schemas.new(dir, data.branch,
          data.head_repo, data.head_branch, data.text)
        var mentions = Mentions(data.text)
        if (mentions.length)
          msg.mentions = mentions
        return self.ssb.publish(msg, function (err, msg) {
          if (err) return cb(null, self.serveError(req, err))
          cb(null, self.serveRedirect(req, u.encodeLink(msg.key)))
        })

      case 'markdown':
        return cb(null, self.serveMarkdown(data.text, {id: data.repo}))

      default:
        cb(null, self.serveBuffer(400, req._t('error.UnknownAction', data)))
      }
    })
  })
}

G.serveFile = function (req, dirs, outside) {
  var filename = path.resolve.apply(path, [__dirname].concat(dirs))
  // prevent escaping base dir
  if (!outside && filename.indexOf('../') === 0)
    return this.serveBuffer(403, req._t("error.403Forbidden"))

  return u.readNext(function (cb) {
    fs.stat(filename, function (err, stats) {
      cb(null, err ?
        err.code == 'ENOENT' ? this.serve404(req)
        : this.serveBuffer(500, err.message)
      : u.ifModifiedSince(req, stats.mtime) ?
        pull.once([304])
      : stats.isDirectory() ?
        this.serveBuffer(403, req._t('error.DirectoryNotListable'))
      : cat([
        pull.once([200, {
          'Content-Type': getContentType(filename),
          'Content-Length': stats.size,
          'Last-Modified': stats.mtime.toGMTString()
        }]),
        toPull(fs.createReadStream(filename))
      ]))
    }.bind(this))
  }.bind(this))
}

G.serveBuffer = function (code, buf, contentType, headers) {
  headers = headers || {}
  headers['Content-Type'] = contentType || 'text/plain; charset=utf-8'
  headers['Content-Length'] = Buffer.byteLength(buf)
  return pull.values([
    [code, headers],
    buf
  ])
}

G.serve404 = function (req) {
  return this.serveBuffer(404, req._t("error.404NotFound"))
}

G.serveRedirect = function (req, path) {
  return this.serveBuffer(302,
    '<!doctype><html><head>' +
    '<title>' + req._t('Redirect') + '</title></head><body>' +
    '<p><a href="' + u.escape(path) + '">' +
      req._t('Continue') + '</a></p>' +
    '</body></html>', 'text/html; charset=utf-8', {Location: path})
}

G.serveMarkdown = function (text, repo) {
  return this.serveBuffer(200, markdown(text, repo),
    'text/html; charset=utf-8')
}

G.renderError = function (err, tag) {
  tag = tag || 'h3'
  return '<' + tag + '>' + err.name + '</' + tag + '>' +
    '<pre>' + u.escape(err.stack) + '</pre>'
}

G.renderTry = function (read) {
  var self = this
  var ended
  return function (end, cb) {
    if (ended) return cb(ended)
    read(end, function (err, data) {
      if (err === true)
        cb(true)
      else if (err) {
        ended = true
        cb(null, self.renderError(err))
      } else
        cb(null, data)
    })
  }
}

G.serveTemplate = function (req, title, code, read) {
  var self = this
  if (read === undefined)
    return this.serveTemplate.bind(this, req, title, code)
  var q = req._u.query.q && u.escape(req._u.query.q) || ''
  var app = 'git ssb'
  var appName = this.ssbAppname
  if (req._t) app = req._t(app)
  return cat([
    pull.values([
      [code || 200, {
        'Content-Type': 'text/html'
      }],
      '<!doctype html><html><head><meta charset=utf-8>',
      '<title>' + (title || app) + '</title>',
      '<link rel=stylesheet href="/static/styles.css"/>',
      '<link rel=stylesheet href="/highlight/foundation.css"/>',
      '</head>\n',
      '<body>',
      '<header>'
    ]),
    self.isPublic ? null : u.readOnce(function (cb) {
      self.about(self.myId, function (err, about) {
        if (err) return cb(err)
        cb(null,
          '<a href="' + u.encodeLink(self.myId) + '">' +
            (about.image ?
              '<img class="profile-icon icon-right"' +
              ' src="/' + encodeURIComponent(about.image) + '"' +
              ' alt="' + u.escape(about.name) + '">' : u.escape(about.name)) +
          '</a>')
      })
    }),
    pull.once(
      '<form action="/search" method="get">' +
      '<h1><a href="/">' + app +
        (appName == 'ssb' ? '' : ' <sub>' + appName + '</sub>') +
      '</a></h1> ' +
      '<input class="search-bar" name="q" size="60"' +
        ' placeholder=" Search" value="' + q + '" />' +
      '</form>' +
      '</header>' +
      '<article><hr />'),
    this.renderTry(read),
    pull.once('<hr/><p style="font-size: .8em;">Built with <a href="http://git-ssb.celehner.com">git-ssb-web</a></p></article></body></html>')
  ])
}

G.serveError = function (req, err, status) {
  if (err.message == 'stream is closed')
    this.reconnect && this.reconnect()
  return pull(
    pull.once(this.renderError(err, 'h2')),
    this.serveTemplate(req, err.name, status || 500)
  )
}

G.renderObjectData = function (obj, filename, repo, rev, path) {
  var ext = u.getExtension(filename)
  return u.readOnce(function (cb) {
    u.readObjectString(obj, function (err, buf) {
      buf = buf.toString('utf8')
      if (err) return cb(err)
      cb(null, (ext == 'md' || ext == 'markdown')
        ? markdown(buf, {repo: repo, rev: rev, path: path})
        : buf.length > 1000000 ? ''
        : renderCodeTable(buf, ext))
    })
  })
}

function renderCodeTable(buf, ext) {
  return '<pre><table class="code">' +
    u.highlight(buf, ext).split('\n').map(function (line, i) {
      i++
      return '<tr id="L' + i + '">' +
        '<td class="code-linenum">' + '<a href="#L' + i + '">' + i + '</td>' +
        '<td class="code-text">' + line + '</td></tr>'
    }).join('') +
    '</table></pre>'
}

/* Feed */

G.renderFeed = function (req, feedId, filter) {
  var query = req._u.query
  var opts = {
    reverse: !query.forwards,
    lt: query.lt && +query.lt || Date.now(),
    gt: query.gt ? +query.gt : -Infinity,
    id: feedId
  }
  return pull(
    feedId ? this.ssb.createUserStream(opts) : this.ssb.createFeedStream(opts),
    pull.filter(function (msg) {
      var c = msg.value.content
      return c.type in msgTypes
        || (c.type == 'post' && c.repo && c.issue)
    }),
    typeof filter == 'function' ? filter(opts) : filter,
    pull.take(100),
    this.addAuthorName(),
    query.forwards && u.pullReverse(),
    paginate(
      function (first, cb) {
        if (!query.lt && !query.gt) return cb(null, '')
        var gt = feedId ? first.value.sequence : first.value.timestamp + 1
        query.gt = gt
        query.forwards = 1
        delete query.lt
        cb(null, '<a href="?' + qs.stringify(query) + '">' +
          req._t('Next') + '</a>')
      },
      paramap(this.renderFeedItem.bind(this, req), 8),
      function (last, cb) {
        query.lt = feedId ? last.value.sequence : last.value.timestamp - 1
        delete query.gt
        delete query.forwards
        cb(null, '<a href="?' + qs.stringify(query) + '">' +
          req._t('Previous') + '</a>')
      },
      function (cb) {
        if (query.forwards) {
          delete query.gt
          delete query.forwards
          query.lt = opts.gt + 1
        } else {
          delete query.lt
          query.gt = opts.lt - 1
          query.forwards = 1
        }
        cb(null, '<a href="?' + qs.stringify(query) + '">' +
          req._t(query.forwards ? 'Older' : 'Newer') + '</a>')
      }
    )
  )
}

G.renderFeedItem = function (req, msg, cb) {
  var self = this
  var c = msg.value.content
  var msgDate = moment(new Date(msg.value.timestamp)).fromNow()
  var msgDateLink = u.link([msg.key], msgDate, false, 'class="date"')
  var author = msg.value.author
  var authorLink = u.link([msg.value.author], msg.authorName)
  switch (c.type) {
    case 'git-repo':
      var done = multicb({ pluck: 1, spread: true })
      self.getRepoName(author, msg.key, done())
      if (c.upstream) {
        return self.getMsg(c.upstream, function (err, upstreamMsg) {
          if (err) return cb(null, self.serveError(req, err))
          self.getRepoName(upstreamMsg.author, c.upstream, done())
          done(function (err, repoName, upstreamName) {
            cb(null, '<section class="collapse">' +
              req._t('Forked', {
                name: authorLink,
                upstream: u.link([c.upstream], upstreamName),
                repo: u.link([msg.key], repoName)
              }) + ' ' + msgDateLink + '</section>')
          })
        })
      } else {
        return done(function (err, repoName) {
          if (err) return cb(err)
          var repoLink = u.link([msg.key], repoName)
          cb(null, '<section class="collapse">' +
            req._t('CreatedRepo', {
              name: authorLink,
              repo: repoLink
            }) + ' ' + msgDateLink + '</section>')
        })
      }
    case 'git-update':
      return self.getRepoName(author, c.repo, function (err, repoName) {
        if (err) return cb(err)
        var repoLink = u.link([c.repo], repoName)
        cb(null, '<section class="collapse">' +
          req._t('Pushed', {
            name: authorLink,
            repo: repoLink
          }) + ' ' + msgDateLink + '</section>')
      })
    case 'issue':
    case 'pull-request':
      var issueLink = u.link([msg.key], u.messageTitle(msg))
      return self.getMsg(c.project, function (err, projectMsg) {
        if (err) return cb(null,
          self.repos.serveRepoNotFound(req, c.repo, err))
        self.getRepoName(projectMsg.author, c.project,
          function (err, repoName) {
            if (err) return cb(err)
            var repoLink = u.link([c.project], repoName)
            cb(null, '<section class="collapse">' +
              req._t('OpenedIssue', {
                name: authorLink,
                type: req._t(c.type == 'pull-request' ?
                  'pull request' : 'issue.'),
                title: issueLink,
                project: repoLink
              }) + ' ' + msgDateLink + '</section>')
          })
      })
    case 'about':
      return cb(null, '<section class="collapse">' +
        req._t('Named', {
          author: authorLink,
          target: '<tt>' + u.escape(c.about) + '</tt>',
          name: u.link([c.about], c.name)
        }) + '</section>')
    case 'post':
      return this.pullReqs.get(c.issue, function (err, pr) {
        if (err) return cb(err)
        var type = pr.msg.value.content.type == 'pull-request' ?
          'pull request' : 'issue.'
        var changed = self.issues.isStatusChanged(msg, pr)
        return cb(null, '<section class="collapse">' +
          req._t(changed == null ? 'CommentedOn' :
              changed ? 'ReopenedIssue' : 'ClosedIssue', {
            name: authorLink,
            type: req._t(type),
            title: u.link([pr.id], pr.title, true)
          }) +
          (c.text ? '<blockquote>' + markdown(c.text) + '</blockquote>' : '') +
          '</section>')
      })
    default:
      return cb(null, u.json(msg))
  }
}

/* Index */

G.serveIndex = function (req) {
  return this.serveTemplate(req)(this.renderFeed(req))
}

/* Message */

G.serveMessage = function (req, id, path) {
  var self = this
  return u.readNext(function (cb) {
    self.ssb.get(id, function (err, msg) {
      if (err) return cb(null, self.serveError(req, err))
      var c = msg.content || {}
      switch (c.type) {
        case 'git-repo':
          return self.getRepo(id, function (err, repo) {
            if (err) return cb(null, self.serveError(req, err))
            cb(null, self.repos.serveRepoPage(req, GitRepo(repo), path))
          })
        case 'git-update':
          return self.getRepo(c.repo, function (err, repo) {
            if (err) return cb(null,
              self.repos.serveRepoNotFound(req, c.repo, err))
            cb(null, self.repos.serveRepoUpdate(req,
              GitRepo(repo), id, msg, path))
          })
        case 'issue':
          return self.getRepo(c.project, function (err, repo) {
            if (err) return cb(null,
              self.repos.serveRepoNotFound(req, c.project, err))
            self.issues.get(id, function (err, issue) {
              if (err) return cb(null, self.serveError(req, err))
              cb(null, self.repos.issues.serveRepoIssue(req,
                GitRepo(repo), issue, path))
            })
          })
        case 'pull-request':
          return self.getRepo(c.repo, function (err, repo) {
            if (err) return cb(null,
              self.repos.serveRepoNotFound(req, c.project, err))
            self.pullReqs.get(id, function (err, pr) {
              if (err) return cb(null, self.serveError(req, err))
              cb(null, self.repos.pulls.serveRepoPullReq(req,
                GitRepo(repo), pr, path))
            })
          })
        case 'issue-edit':
          if (ref.isMsgId(c.issue)) {
            return self.pullReqs.get(c.issue, function (err, issue) {
              if (err) return cb(err)
              self.getRepo(issue.project, function (err, repo) {
                if (err) {
                  if (!repo) return cb(null,
                    self.repos.serveRepoNotFound(req, c.repo, err))
                  return cb(null, self.serveError(req, err))
                }
                cb(null, self.repos.serveIssueOrPullRequest(req, GitRepo(repo),
                  issue, path, id))
              })
            })
          }
          // fallthrough
        case 'post':
          if (ref.isMsgId(c.issue) && ref.isMsgId(c.repo)) {
            // comment on an issue
            var done = multicb({ pluck: 1, spread: true })
            self.getRepo(c.repo, done())
            self.pullReqs.get(c.issue, done())
            return done(function (err, repo, issue) {
              if (err) {
                if (!repo) return cb(null,
                  self.repos.serveRepoNotFound(req, c.repo, err))
                return cb(null, self.serveError(req, err))
              }
              cb(null, self.repos.serveIssueOrPullRequest(req, GitRepo(repo),
                issue, path, id))
            })
          } else if (ref.isMsgId(c.root)) {
            // comment on issue from patchwork?
            return self.getMsg(c.root, function (err, root) {
              if (err) return cb(null, self.serveError(req, err))
              var repoId = root.content.repo || root.content.project
              if (!ref.isMsgId(repoId))
                return cb(null, self.serveGenericMessage(req, id, msg, path))
              self.getRepo(repoId, function (err, repo) {
                if (err) return cb(null, self.serveError(req, err))
                switch (root.content && root.content.type) {
                  case 'issue':
                    return self.issues.get(c.root, function (err, issue) {
                      if (err) return cb(null, self.serveError(req, err))
                      return cb(null,
                        self.repos.issues.serveRepoIssue(req,
                          GitRepo(repo), issue, path, id))
                    })
                  case 'pull-request':
                    return self.pullReqs.get(c.root, function (err, pr) {
                      if (err) return cb(null, self.serveError(req, err))
                      return cb(null,
                        self.repos.pulls.serveRepoPullReq(req,
                          GitRepo(repo), pr, path, id))
                    })
                }
              })
            })
          }
          // fallthrough
        default:
          if (ref.isMsgId(c.repo))
            return self.getRepo(c.repo, function (err, repo) {
              if (err) return cb(null,
                self.repos.serveRepoNotFound(req, c.repo, err))
              cb(null, self.repos.serveRepoSomething(req,
                GitRepo(repo), id, msg, path))
            })
          else
            return cb(null, self.serveGenericMessage(req, id, msg, path))
      }
    })
  })
}

G.serveGenericMessage = function (req, id, msg, path) {
  return this.serveTemplate(req, id)(pull.once(
    '<section><h2>' + u.link([id]) + '</h2>' +
    u.json(msg) +
    '</section>'))
}

/* Search */

G.serveSearch = function (req) {
  var self = this
  var q = String(req._u.query.q || '')
  if (!q) return this.serveIndex(req)
  var qId = q.replace(/^ssb:\/*/, '')
  if (ref.type(qId))
    return this.serveRedirect(req, encodeURIComponent(qId))

  var search = new RegExp(q, 'i')
  return this.serveTemplate(req, req._t('Search') + ' &middot; ' + q, 200)(
    this.renderFeed(req, null, function (opts) {
      return function (read) {
        return pull(
          many([
            self.getMsgs('about', opts),
            read
          ]),
          pull.filter(function (msg) {
            var c = msg.value.content
            return (
              search.test(msg.key) ||
              c.text && search.test(c.text) ||
              c.name && search.test(c.name) ||
              c.title && search.test(c.title))
          })
        )
      }
    })
  )
}

G.getMsgs = function (type, opts) {
  return this.ssb.messagesByType({
    type: type,
    reverse: opts.reverse,
    lt: opts.lt,
    gt: opts.gt,
  })
}

G.serveBlobNotFound = function (req, repoId, err) {
  return this.serveTemplate(req, req._t('error.BlobNotFound'), 404)(pull.once(
    '<h2>' + req._t('error.BlobNotFound') + '</h2>' +
    '<p>' + req._t('error.BlobNotFoundInRepo', {
      repo: u.link([repoId])
    }) + '</p>' +
    '<pre>' + u.escape(err.stack) + '</pre>'
  ))
}

G.serveRaw = function (length, contentType) {
  var headers = {
    'Content-Type': contentType || 'text/plain; charset=utf-8',
    'Cache-Control': 'max-age=31536000'
  }
  if (length != null)
    headers['Content-Length'] = length
  return function (read) {
    return cat([pull.once([200, headers]), read])
  }
}

G.getBlob = function (req, key, cb) {
  var blobs = this.ssb.blobs
  blobs.want(key, function (err, got) {
    if (err) cb(err)
    else if (!got) cb(new Error(req._t('error.MissingBlob', {key: key})))
    else cb(null, blobs.get(key))
  })
}

G.serveBlob = function (req, key) {
  var self = this
  return u.readNext(function (cb) {
    self.getBlob(req, key, function (err, read) {
      if (err) cb(null, self.serveError(req, err))
      else if (!read) cb(null, self.serve404(req))
      else cb(null, identToResp(read))
    })
  })
}

function identToResp(read) {
  var ended, type, queue
  var id = ident(function (_type) {
    type = _type && mime.lookup(_type)
  })(read)
  return function (end, cb) {
    if (ended) return cb(ended)
    if (end) id(end, function (end) {
      cb(end === true ? null : end)
    })
    else if (queue) {
      var _queue = queue
      queue = null
      cb(null, _queue)
    }
    else if (!type)
      id(null, function (end, data) {
        if (ended = end) return cb(end)
        queue = data
        cb(null, [200, {
          'Content-Type': type || 'text/plain; charset=utf-8',
          'Cache-Control': 'max-age=31536000'
        }])
      })
    else
      id(null, cb)
  }
}