git ssb

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/* ssb-about
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 * factored out of ssb-notifier
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 *
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 * TODO:
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 * - publish as own module
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 * - handle live updates and reconnecting
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 * - deprecate when ssb-names is used in scuttlebot
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 */
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var pull = require('pull-stream')
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var cat = require('pull-cat')
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var asyncMemo = require('asyncmemo')
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module.exports = function (sbot, id) {
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  var getAbout = asyncMemo(getAboutFull, sbot, id)
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  getAbout.getName = function (id, cb) {
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    getAbout(id, function (err, about) {
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      cb(err, about && about.name)
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    })
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  }
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  getAbout.getImage = function (id, cb) {
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    getAbout(id, function (err, about) {
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      cb(err, about && about.image)
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    })
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  }
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  return getAbout
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}
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function truncate(str, len) {
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  str = String(str)
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  return str.length < len ? str : str.substr(0, len-1) + '…'
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}
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// Get About info (name and icon) for a feed.
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function getAboutFull(sbot, source, dest, cb) {
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  var info = {}
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  var target = dest.target || dest
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  var owner = dest.owner || dest
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  pull(
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    cat([
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      // First get About info that we gave them.
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      sbot.links({
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        source: source,
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        dest: target,
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        rel: 'about',
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        values: true,
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        reverse: true
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      }),
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      // If that isn't enough, then get About info that they gave themselves.
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      sbot.links({
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        source: owner,
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        dest: target,
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        rel: 'about',
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        values: true,
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        reverse: true
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      }),
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    ]),
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    pull.filter(function (msg) {
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      return msg && msg.value.content
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    }),
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    pull.drain(function (msg) {
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      if (info.name && info.image)
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        return gotIt()
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      var c = msg.value.content
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      if (!info.name && c.name)
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        info.name = c.name
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      if (!info.image && c.image)
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        info.image = c.image.link
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    }, gotIt)
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  )
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  function gotIt(err) {
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    if (!cb) {
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      if (err && err !== true)
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        console.error(err)
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      return
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    }
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    var _cb = cb
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    cb = null
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    if (err && err !== true) return _cb(err)
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    if (!info.name) info.name = truncate(target, 20)
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    _cb(null, info)
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  }
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  // Keep updated as changes are made
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  pull(
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    sbot.links({
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      dest: target,
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      rel: 'about',
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      live: true,
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      values: true,
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      gte: Date.now()
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    }),
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    pull.drain(function (msg) {
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      var c = msg.value.content
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      if (msg.value.author == source || msg.value.author == owner) {
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        // TODO: give about from source (self) priority over about from owner
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        if (c.name)
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          info.name = c.name
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        if (c.image)
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          info.image = c.image
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      }
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    }, function (err) {
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      if (err) console.error(err)
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    })
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  )
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}
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