7 files changed, 233 insertions, 0 deletions
diff --git a/lib/gitlab/chat_commands/base_command.rb b/lib/gitlab/chat_commands/base_command.rb
new file mode 100644
index 00000000000..e59d69b72b9
--- /dev/null
+++ b/lib/gitlab/chat_commands/base_command.rb
@@ -0,0 +1,49 @@
+module Gitlab
+  module ChatCommands
+    class BaseCommand
+      QUERY_LIMIT = 5
+
+      def self.match(_text)
+        raise NotImplementedError
+      end
+
+      def self.help_message
+        raise NotImplementedError
+      end
+
+      def self.available?(_project)
+        raise NotImplementedError
+      end
+
+      def self.allowed?(_user, _ability)
+        true
+      end
+
+      def self.can?(object, action, subject)
+        Ability.allowed?(object, action, subject)
+      end
+
+      def execute(_)
+        raise NotImplementedError
+      end
+
+      def collection
+        raise NotImplementedError
+      end
+
+      attr_accessor :project, :current_user, :params
+
+      def initialize(project, user, params = {})
+        @project, @current_user, @params = project, user, params.dup
+      end
+
+      private
+
+      def find_by_iid(iid)
+        resource = collection.find_by(iid: iid)
+
+        readable?(resource) ? resource : nil
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/chat_commands/command.rb b/lib/gitlab/chat_commands/command.rb
new file mode 100644
index 00000000000..0ec358debc7
--- /dev/null
+++ b/lib/gitlab/chat_commands/command.rb
@@ -0,0 +1,62 @@
+module Gitlab
+  module ChatCommands
+    class Command < BaseCommand
+      COMMANDS = [
+        Gitlab::ChatCommands::IssueShow,
+        Gitlab::ChatCommands::IssueCreate,
+        Gitlab::ChatCommands::Deploy,
+      ].freeze
+
+      def execute
+        command, match = match_command
+
+        if command
+          if command.allowed?(project, current_user)
+            present command.new(project, current_user, params).execute(match)
+          else
+            access_denied
+          end
+        else
+          help(help_messages)
+        end
+      end
+
+      private
+
+      def match_command
+        match = nil
+        service = available_commands.find do |klass|
+          match = klass.match(command)
+        end
+
+        [service, match]
+      end
+
+      def help_messages
+        available_commands.map(&:help_message)
+      end
+
+      def available_commands
+        COMMANDS.select do |klass|
+          klass.available?(project)
+        end
+      end
+
+      def command
+        params[:text]
+      end
+
+      def help(messages)
+        Mattermost::Presenter.help(messages, params[:command])
+      end
+
+      def access_denied
+        Mattermost::Presenter.access_denied
+      end
+
+      def present(resource)
+        Mattermost::Presenter.present(resource)
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/chat_commands/deploy.rb b/lib/gitlab/chat_commands/deploy.rb
new file mode 100644
index 00000000000..0eed1fce0dc
--- /dev/null
+++ b/lib/gitlab/chat_commands/deploy.rb
@@ -0,0 +1,57 @@
+module Gitlab
+  module ChatCommands
+    class Deploy < BaseCommand
+      include Gitlab::Routing.url_helpers
+
+      def self.match(text)
+        /\Adeploy\s+(?<from>.*)\s+to+\s+(?<to>.*)\z/.match(text)
+      end
+
+      def self.help_message
+        'deploy <environment> to <target-environment>'
+      end
+
+      def self.available?(project)
+        project.builds_enabled?
+      end
+
+      def self.allowed?(project, user)
+        can?(user, :create_deployment, project)
+      end
+
+      def execute(match)
+        from = match[:from]
+        to = match[:to]
+
+        actions = find_actions(from, to)
+        return unless actions.present?
+
+        if actions.one?
+          play!(from, to, actions.first)
+        else
+          Result.new(:error, 'Too many actions defined')
+        end
+      end
+
+      private
+
+      def play!(from, to, action)
+        new_action = action.play(current_user)
+
+        Result.new(:success, "Deployment from #{from} to #{to} started. Follow the progress: #{url(new_action)}.")
+      end
+
+      def find_actions(from, to)
+        environment = project.environments.find_by(name: from)
+        return unless environment
+
+        environment.actions_for(to).select(&:starts_environment?)
+      end
+
+      def url(subject)
+        polymorphic_url(
+          [ subject.project.namespace.becomes(Namespace), subject.project, subject ])
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/chat_commands/issue_command.rb b/lib/gitlab/chat_commands/issue_command.rb
new file mode 100644
index 00000000000..f1bc36239d5
--- /dev/null
+++ b/lib/gitlab/chat_commands/issue_command.rb
@@ -0,0 +1,17 @@
+module Gitlab
+  module ChatCommands
+    class IssueCommand < BaseCommand
+      def self.available?(project)
+        project.issues_enabled? && project.default_issues_tracker?
+      end
+
+      def collection
+        project.issues
+      end
+
+      def readable?(issue)
+        self.class.can?(current_user, :read_issue, issue)
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/chat_commands/issue_create.rb b/lib/gitlab/chat_commands/issue_create.rb
new file mode 100644
index 00000000000..99c1382af44
--- /dev/null
+++ b/lib/gitlab/chat_commands/issue_create.rb
@@ -0,0 +1,26 @@
+module Gitlab
+  module ChatCommands
+    class IssueCreate < IssueCommand
+      def self.match(text)
+        # we can not match \n with the dot by passing the m modifier as than 
+        # the title and description are not seperated
+        /\Aissue\s+create\s+(?<title>[^\n]*)\n*(?<description>(.|\n)*)/.match(text)
+      end
+
+      def self.help_message
+        'issue create <title>\n<description>'
+      end
+
+      def self.allowed?(project, user)
+        can?(user, :create_issue, project)
+      end
+
+      def execute(match)
+        title = match[:title]
+        description = match[:description].to_s.rstrip
+
+        Issues::CreateService.new(project, current_user, title: title, description: description).execute
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/chat_commands/issue_show.rb b/lib/gitlab/chat_commands/issue_show.rb
new file mode 100644
index 00000000000..f5bceb038e5
--- /dev/null
+++ b/lib/gitlab/chat_commands/issue_show.rb
@@ -0,0 +1,17 @@
+module Gitlab
+  module ChatCommands
+    class IssueShow < IssueCommand
+      def self.match(text)
+        /\Aissue\s+show\s+(?<iid>\d+)/.match(text)
+      end
+
+      def self.help_message
+        "issue show <id>"
+      end
+
+      def execute(match)
+        find_by_iid(match[:iid])
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/chat_commands/result.rb b/lib/gitlab/chat_commands/result.rb
new file mode 100644
index 00000000000..324d7ef43a3
--- /dev/null
+++ b/lib/gitlab/chat_commands/result.rb
@@ -0,0 +1,5 @@
+module Gitlab
+  module ChatCommands
+    Result = Struct.new(:type, :message)
+  end
+end