Store replies to posts, show under the post body

First step towards #35.

Also deletes the boolean/array portions when doing export, since these
aren't supported by manual CSV.

Todo:

- Clean up reply links on post deletion
- Allow target post author to delete reply links
- Add a "reply" link under the post to encourage replying
- Pagination?  Top-level "my replies" tab?
- Enable/disable reply links per-post

It'd be nice to be able to block reply links from a specific user
entirely.  (Ie, maybe they're not bannable, but they are annoying, more
like a mute feature.)  The user would still be able to post the reply
link, but it wouldn't show up anywhere.

lib/posts.js

@@ -7,6 +7,7 @@ var conf = require('./conf');
 
 var crypto = require('crypto');
 var utils = require('./utils');
+var url = require('url');
 
 var MAX_POSTS = 10;
 
@@ -16,6 +17,43 @@ var getTime = function () {
   return Math.floor(Date.now() / 1000);
 };
 
+var internalLinkRe = function () {
+  // The better to inline you with...
+  var key = '(post![0-9]+-[0-9a-f]+|user![0-9a-f-]{36}![0-9]+-[0-9a-f]+)';
+  var pattern = 'https?://[^/\\s]+/post/' + key;
+  return new RegExp(pattern);
+};
+
+// find replies that look like links to other posts in the system.
+// to be "internal" must have this hostname
+var getInternalLinks = function (reply, host) {
+  if (!host) return false;
+
+  reply = reply.trim();
+  if (!reply) return false;
+
+  var urls = reply.trim().split(/\s+/);
+
+  var internalLinks = urls.map(function (r) {
+    var parsed = r.match(internalLinkRe());
+    if (!parsed) return false;
+
+    var u = url.parse(parsed[0]);
+    if (u.host === host) {
+      // internal link.  Just save the postid.
+      return parsed[1].replace(/^(post!|user![^!]+!)(.*)$/, '$2');
+    } else {
+      console.error('not an internal link host=%j u=%j', host, u);
+    }
+
+    return false;
+  }).filter(function (r) {
+    return r;
+  });
+
+  return internalLinks;
+}
+
 exports.add = function (request, reply) {
   var time = getTime();
   var uid = request.session.get('uid');
@@ -34,10 +72,13 @@ exports.add = function (request, reply) {
     return reply(Boom.wrap(err, 400));
   }
 
+  var host = request.headers.host;
+
   var postItem = {
     uid: uid,
     name: name,
     created: time,
+    replyto: getInternalLinks(request.payload.reply, host),
     reply: utils.autoLink(request.payload.reply) || '',
     content: utils.autoLink(request.payload.content, {
       htmlEscapeNonEntities: true,
@@ -47,18 +88,31 @@ exports.add = function (request, reply) {
 
   var postid = time + '-' + crypto.randomBytes(1).toString('hex');
 
+  var done = function (err) {
+    if (err) {
+      return reply(Boom.wrap(err, 400));
+    }
+    reply.redirect('/posts');
+  };
+
   var savePost = function () {
     db.put('user!' + request.session.get('uid') + '!' + postid, postItem, function (err) {
       if (err) {
-        return reply(Boom.wrap(err, 400));
+        return done(err);
       }
 
       db.put('post!' + postid, postItem, function (err) {
         if (err) {
-          return reply(Boom.wrap(err, 400));
+          return done(err);
         }
 
-        reply.redirect('/posts');
+        saveReply(postItem, function (err) {
+          if (err) {
+            return done(err);
+          }
+
+          reply.redirect('/posts');
+        });
       });
     });
   };
@@ -84,6 +138,44 @@ exports.add = function (request, reply) {
   getId();
 };
 
+var saveReply = function (postItem, next) {
+  if (!postItem.replyto) {
+    return process.nextTick(next);
+  }
+
+  var count = postItem.replyto.length;
+  if (!count) {
+    return process.nextTick(next);
+  }
+
+  var postid = postItem.postid;
+
+  postItem.replyto.forEach(function (target) {
+    // content and replies get big.  We just need a few basics.
+    // TODO(isaacs): Look up target post to make sure it's valid.
+    // TODO(isaacs): put target UID on this object for moderation privs.
+    var replyItem = {
+      uid: postItem.uid,
+      name: postItem.name,
+      created: postItem.created
+    };
+
+    db.put('replyto!' + target + '!' + postid, replyItem, function (err) {
+      then(err);
+    });
+  });
+
+  var error;
+  var then = function (err) {
+    if (err) {
+      error = err;
+    }
+    if (--count <= 0) {
+      return next(error);
+    }
+  };
+}
+
 var setDate = function (created) {
   return moment(created * 1000).format('MMM Do, YYYY - HH:mm a');
 };
@@ -295,6 +387,7 @@ exports.getRecentForUser = function (uid, request, next) {
 };
 
 exports.del = function (request, reply) {
+  // TODO(isaacs): delete replies to and from this post.
   if (request.session && (request.session.get('uid') === request.payload.uid) || request.session.get('op')) {
     var keyArr = request.params.key.split('!');
     var time = keyArr[keyArr.length - 1];
@@ -328,12 +421,54 @@ exports.get = function (request, reply) {
 
     post.created = setDate(post.created);
 
-    reply.view('post', {
-      analytics: conf.get('analytics'),
-      id: request.params.key,
-      session: request.session.get('uid') || false,
-      op: request.session.get('op'),
-      post: post
+    getReplyPosts(post, function (err, post) {
+      if (err) {
+        return reply(Boom.wrap(err, 404));
+      }
+
+      reply.view('post', {
+        analytics: conf.get('analytics'),
+        id: request.params.key,
+        session: request.session.get('uid') || false,
+        op: request.session.get('op'),
+        post: post
+      });
     });
   });
 };
+
+// TODO(isaacs): Pagination.  Maybe only show the first 100 here,
+// but have them all in a top-level "replies" tab?
+var getReplyPosts = function (post, next) {
+  var streamOpt = {
+    gte: 'replyto!' + post.postid,
+    lte: 'replyto!' + post.postid + '\xff',
+    limit: 100
+  };
+
+  var replies = [];
+  var rs = db.createReadStream(streamOpt);
+
+  rs.on('data', function (reply) {
+    var val = reply.value;
+    var key = reply.key;
+
+    var reply = key.match(/^replyto![^!]+!([^!]+)$/);
+    if (!reply) return;
+    reply = reply[1];
+    if (!reply) return;
+
+    var html = '\n<a href="/post/post!' + reply + '" rel="nofollow">' +
+      setDate(val.created) + '</a> - ' +
+      '<a href="/user/' + val.uid + '">' + val.name + '</a>';
+
+    replies.push(html);
+  });
+
+  rs.on('end', function () {
+    post.replies = replies.join('');
+    next(null, post);
+  });
+
+  rs.on('error', next);
+};

lib/profile.js

@@ -304,6 +304,9 @@ exports.exportPosts = function (request, reply) {
       if (!post.value.postid) {
         post.value.postid = String(post.value.created);
       }
+      // Manual CSV encoding doesn't handle arrays or booleans
+      delete post.value.replyto;
+      delete post.value.showreplies;
       return post.value;
     });
 

public/styl/global.styl

@@ -434,6 +434,7 @@ article .posted {
 .content article p.reply {
   font-style: italic;
   margin-bottom: 0;
+  margin-top: 15px;
 }
 
 .delete-account {