Add pages to create, view, and edit Gatherings

1 files changed, 271 insertions, 0 deletions

diff --git a/lib/about.js b/lib/about.js
index 1e41691..c905d61 100644
--- a/lib/about.js
+++ b/lib/about.js
@@ -81,6 +81,277 @@ function computeTopAbout(aboutByFeed) {
 }
 
 About.prototype.get = function (dest, cb) {
+  if (dest[0] === '@') return this.getSocial(dest, cb)
+  return this.getCausal(dest, cb)
+}
+
+function copy(obj) {
+  if (obj === null || typeof obj !== 'object') return obj
+  var o = {}
+  for (var k in obj) o[k] = obj[k]
+  return o
+}
+
+function premapAbout(msg) {
+  var value = {
+    about: {},
+    mentions: {},
+    branches: {},
+    sources: {},
+    ts: msg.ts
+  }
+  var c = msg.value.content
+  if (!c) return value
+
+  if (c.branch) {
+    msg.branches.map(function (id) {
+      value.branches[id] = true
+    })
+  }
+
+  if (!c.about && c.root) return value
+  value.about = {}
+  var author = msg.value.author
+  var source = {id: msg.key, seq: msg.value.sequence}
+  for (var k in c) switch(k) {
+    case 'type':
+    case 'about':
+    case 'branch':
+      break
+    case 'recps':
+      // get recps from root message only
+      if (!c.root && !c.about) {
+        value.recps = {}
+        u.toLinkArray(c.recps).forEach(function (link) {
+          value.recps[link.link] = link
+        })
+      }
+      break
+    case 'mentions':
+      value.mentions = {}
+      u.toLinkArray(c.mentions).map(function (link) {
+        value.mentions[link.link] = link
+      })
+      break
+    case 'image':
+      var link = u.toLink(c.image)
+      if (!link) break
+      value.about.image = link.link
+      value.about.imageLink = link
+      var sources = value.sources.image || (value.sources.image = [])
+      sources[author] = source
+      break
+    case 'attendee':
+      var attendee = u.linkDest(c.attendee)
+      if (attendee && attendee === author) {
+        // TODO: allow users adding other users as attendees?
+        var attendeeLink = copy(u.toLink(c.attendee))
+        attendeeLink.source = msg.key
+        value.attending = {}
+        value.attending[attendee] = attendeeLink.remove ? null : attendeeLink }
+      break
+    default:
+      // TODO: handle arrays
+      value.about[k] = c[k]
+      var sources = value.sources[k] || (value.sources[k] = {})
+      sources[author] = source
+  }
+  return value
+}
+
+function reduceAbout(values, lastValue) {
+  var newValue = {
+    about: {},
+    mentions: {},
+    branches: {},
+    sources: {}
+  }
+  values.sort(compareByTs).concat(lastValue).forEach(function (value) {
+    if (!value) return
+    if (value.ts) {
+      if (!newValue.ts || value.ts > newValue.ts) {
+        newValue.ts = value.ts
+      }
+    }
+    if (value.attending) {
+      var attending = newValue.attending || (newValue.attending = {})
+      for (var k in value.attending) {
+        attending[k] = value.attending[k]
+      }
+    }
+    if (value.mentions) for (var k in value.mentions) {
+      newValue.mentions[k] = value.mentions[k]
+    }
+    if (value.branches) for (var k in value.branches) {
+      newValue.branches[k] = value.branches[k]
+    }
+    if (value.recps) {
+      // note: zero recps is still private. truthy recps indicates private
+      var recps = newValue.recps || (newValue.recps = {})
+      for (var k in value.recps) {
+        newValue.recps[k] = value.recps[k]
+      }
+    }
+    if (value.about) for (var k in value.about) {
+      // TODO: use merge heuristics
+      newValue.about[k] = value.about[k]
+      if (lastValue && lastValue.about[k]) {
+        if (value === lastValue) {
+          newValue.sources[k] = lastValue.sources[k]
+        } else {
+          // message setting a property resets the property's sources from branches
+        }
+      } else {
+        var newSources = newValue.sources[k] || (newValue.sources[k] = {})
+        var sources = value.sources[k]
+        for (var feed in sources) {
+          if (newSources[feed] && newSources[feed].seq > sources[feed].seq) {
+            // assume causal order in user's own feed.
+            // this condition shouldn't be reached if messages are in feed order
+            console.error('skip', k, feed, sources[feed].id, newSources[feed].id)
+            continue
+          }
+          newSources[feed] = sources[feed]
+        }
+      }
+    }
+  })
+  return newValue
+}
+
+function postmapAbout(value) {
+  var about = {
+    ts: value.ts,
+    _sources: {}
+  }
+  for (var k in value.sources) {
+    var propSources = about._sources[k] = []
+    for (var feed in value.sources[k]) {
+      propSources.push(value.sources[k][feed].id)
+    }
+  }
+  if (value.mentions) {
+    about.mentions = []
+    for (var k in value.mentions) {
+      about.mentions.push(value.mentions[k])
+    }
+  }
+  if (value.attending) {
+    about.attendee = []
+    for (var k in value.attending) {
+      var link = value.attending[k]
+      if (link) about.attendee.push(link)
+    }
+  }
+  if (value.branches) about.branch = Object.keys(value.branches)
+  if (value.recps) {
+    about.recps = []
+    for (var k in value.recps) {
+      about.recps.push(value.recps[k])
+    }
+  }
+  if (value.about) for (var k in value.about) {
+    about[k] = value.about[k]
+  }
+  return about
+}
+
+function compareByTs(a, b) {
+  return a.ts - b.ts
+}
+
+About.prototype.getCausal = function (dest, cb) {
+  var self = this
+  var backlinks = {}
+  var seen = {}
+  var queue = []
+  var aboutAtMsgs = {}
+  var now = Date.now()
+  function enqueue(msg) {
+    if (!seen[msg.key]) {
+      seen[msg.key] = true
+      queue.push(msg)
+    }
+  }
+  function isMsgIdDone(id) {
+    return !!aboutAtMsgs[id]
+  }
+  function isMsgReady(msg) {
+    return msg.branches.every(isMsgIdDone)
+  }
+  function dequeue() {
+    var msg = queue.filter(isMsgReady).sort(compareByTs)[0]
+    if (!msg) return console.error('thread error'), queue.shift()
+    var i = queue.indexOf(msg)
+    queue.splice(i, 1)
+    return msg
+  }
+  pull(
+    cat([
+      dest[0] === '%' && self.app.pullGetMsg(dest),
+      self.app.sbot.links({
+        rel: 'about',
+        dest: dest,
+        values: true,
+        private: true,
+        meta: false
+      }),
+      self.app.sbot.links({
+        rel: 'root',
+        dest: dest,
+        values: true,
+        private: true,
+        meta: false
+      })
+    ]),
+    pull.unique('key'),
+    self.app.unboxMessages(),
+    pull.drain(function (msg) {
+      var c = msg.value.content
+      if (!c) return
+      msg = {
+        key: msg.key,
+        ts: Math.min(now,
+          Number(msg.timestamp) || Infinity,
+          Number(msg.value.timestamp || c.timestamp) || Infinity),
+        value: msg.value,
+        branches: u.toLinkArray(c.branch).map(u.linkDest)
+      }
+      if (!msg.branches.length) {
+        enqueue(msg)
+      } else msg.branches.forEach(function (id) {
+        var linksToMsg = backlinks[id] || (backlinks[id] = [])
+        linksToMsg.push(msg)
+      })
+    }, function (err) {
+      if (err) return cb(err)
+      while (queue.length) {
+        var msg = dequeue()
+        var abouts = msg.branches.map(function (id) { return aboutAtMsgs[id] })
+        aboutAtMsgs[msg.key] = reduceAbout(abouts, premapAbout(msg))
+        var linksToMsg = backlinks[msg.key]
+        if (linksToMsg) linksToMsg.forEach(enqueue)
+      }
+      var headAbouts = []
+      var headIds = []
+      for (var id in aboutAtMsgs) {
+        if (backlinks[id]) continue
+        headIds.push(id)
+        headAbouts.push(aboutAtMsgs[id])
+      }
+      headAbouts.sort(compareByTs)
+      var about = postmapAbout(reduceAbout(headAbouts))
+      about.branch = headIds
+      cb(null, about)
+    })
+  )
+}
+
+function getValue(obj) {
+  return obj.value
+}
+
+About.prototype.getSocial = function (dest, cb) {
   var self = this
   var myAbout = []
   var aboutByFeed = {}