WIP: draft payload processing

app/controllers/incoming_controller.rb

@@ -4,8 +4,40 @@ class IncomingController < ApplicationController
 
   def github
     # parse the JSON payload, that we get as string, to a hash
-    useable_body = JSON.parse(request.body.read).to_h
+    json_body = JSON.parse(request.body.read)
 
-    Raven.capture_message('Received hook', extra: useable_body)
+    Raven.capture_message('Received hook', extra: useable_body.to_h)
+
+    # parse the payload and trigger different actions
+    # todo: update the github app to provide us a token that we can validate
+    event_type = request.headers['X-GitHub-Event']
+    case event_type
+    when 'pull_request'
+      parse_pull_request(json_body)
+      # else # in case we handle all events, we should log unhandled payloads
+      #  Raven.capture_message('Unhandled payload', extra: useable_body.to_h)
+    end
+  end
+
+  # this is now a valid route and sucks balls
+  # should this be part of the PullRequest model?
+  # How do we serialize the payload to a PullRequest model / how do we sync with our redis/database
+  def parse_pull_request(payload)
+    # TODO: does it make sense to parse payload['action'] here?
+
+    # get all labels on a PR
+    labels = payload['pull_request']['labels']
+    # github-wide unique ids
+    repository_id = payload['repository']['id']
+    pr_id = payload = payload['pull_request']['id']
+    # check if a PR is mergeable or not. Set/remove the related label
+    if payload['pull_request']['mergeable']
+      # isn't mergeable, we need to set a label if it isn't already present
+      add_label_on_repo('needs-rebase', repository_id) unless github.repo_label?('needs-rebase', repository_id)
+      add_label_on_pr('needs-rebase', repository_id, pr_id) unless labels.any? { |label| label[:name] == 'bla' }
+    elsif labels.any? { |label| label['name'] == 'needs-rebase' }
+      # is mergeable, we need to remove a label if it is present
+      remove_label_on_pr('needs-rebase', repository_id, pr_id)
+    end
   end
 end

app/lib/github.rb

@@ -5,4 +5,38 @@ def self.client
       access_token: Rails.application.credentials.github[Rails.env.to_sym][:bot_token]
     )
   end
+
+  # some convenience methods
+  # todo: store labels as json/yaml. We already have someting similar in the plumbing repo
+
+  def remove_label_on_pr(label, repository)
+    client.remove_label(repository, pr, label)
+  end
+
+  def add_label_on_pr(label, repository, pr_id)
+    # We assume that the label exists on the repository
+    client.add_labels_to_an_issue(repository, pr_id, [label])
+  end
+
+  def add_labels_on_pr(labels, repository, pr_id)
+    # We assume that the labels exists on the repository
+    client.add_labels_to_an_issue(repository, pr_id, labels)
+  end
+
+  def remove_label_on_repo(label, repository)
+    # this method should only get the label name and do a lookup of the rest (see line 10)
+    # https://octokit.github.io/octokit.rb/Octokit/Client/Labels.html#add_label-instance_method
+    # todo: how to add a description
+    cient.add_label(repository, label, 'cccccc')
+  end
+
+  def add_label_on_repo(label, repository)
+    cient.delete_label!(repository, label)
+  end
+
+  def repo_label?(label, repository)
+    # check if a repository already has a specific label
+    # we could also catch Octokit::NotFound:
+    client.label(repository, label) ? true : false
+  end
 end