Move services for collecting items to Finders

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

6 files changed, 285 insertions, 0 deletions

diff --git a/app/finders/README.md b/app/finders/README.md
new file mode 100644
index 00000000000..6fbf0e2f4c1
--- /dev/null
+++ b/app/finders/README.md
@@ -0,0 +1,24 @@
+# Finders
+
+This type of classes responsible for collectiong items based on different conditions.
+To prevent lookup methods in models like this: 
+
+```
+class Project
+  def issues_for_user_filtered_by(user, filter)
+    # A lot of logic not related to project model itself
+  end
+end
+
+issues = project.issues_for_user_filtered_by(user, params)
+```
+
+Better use this: 
+
+```
+selector = Finders::Issues.new
+
+issues = selector.execute(project, user, filter)
+```
+
+It will help keep models thiner
diff --git a/app/finders/base_finder.rb b/app/finders/base_finder.rb
new file mode 100644
index 00000000000..d20716fb170
--- /dev/null
+++ b/app/finders/base_finder.rb
@@ -0,0 +1,137 @@
+# BaseFinder
+#
+# Used to filter Issues and MergeRequests collections by set of params
+#
+# Arguments:
+#   klass - actual class like Issue or MergeRequest
+#   current_user - which user use
+#   params:
+#     scope: 'created-by-me' or 'assigned-to-me' or 'all'
+#     state: 'open' or 'closed' or 'all'
+#     group_id: integer
+#     project_id: integer
+#     milestone_id: integer
+#     assignee_id: integer
+#     search: string
+#     label_name: string
+#     sort: string
+#
+class BaseFinder
+  attr_accessor :current_user, :params
+
+  def execute(current_user, params)
+    @current_user = current_user
+    @params = params
+
+    items = init_collection
+    items = by_scope(items)
+    items = by_state(items)
+    items = by_group(items)
+    items = by_project(items)
+    items = by_search(items)
+    items = by_milestone(items)
+    items = by_assignee(items)
+    items = by_label(items)
+    items = sort(items)
+  end
+
+  private
+
+  def init_collection
+    table_name = klass.table_name
+
+    if project
+      if project.public? || (current_user && current_user.can?(:read_project, project))
+        project.send(table_name)
+      else
+        []
+      end
+    elsif current_user && params[:authorized_only].presence
+      klass.of_projects(current_user.authorized_projects)
+    else
+      klass.of_projects(Project.accessible_to(current_user))
+    end
+  end
+
+  def by_scope(items)
+    case params[:scope]
+    when 'created-by-me', 'authored' then
+      items.where(author_id: current_user.id)
+    when 'all' then
+      items
+    when 'assigned-to-me' then
+      items.where(assignee_id: current_user.id)
+    else
+      raise 'You must specify default scope'
+    end
+  end
+
+  def by_state(items)
+    case params[:state]
+    when 'closed'
+      items.closed
+    when 'all'
+      items
+    when 'opened'
+      items.opened
+    else
+      raise 'You must specify default state'
+    end
+  end
+
+  def by_group(items)
+    if params[:group_id].present?
+      items = items.of_group(Group.find(params[:group_id]))
+    end
+
+    items
+  end
+
+  def by_project(items)
+    if params[:project_id].present?
+      items = items.of_projects(params[:project_id])
+    end
+
+    items
+  end
+
+  def by_search(items)
+    if params[:search].present?
+      items = items.search(params[:search])
+    end
+
+    items
+  end
+
+  def sort(items)
+    items.sort(params[:sort])
+  end
+
+  def by_milestone(items)
+    if params[:milestone_id].present?
+      items = items.where(milestone_id: (params[:milestone_id] == '0' ? nil : params[:milestone_id]))
+    end
+
+    items
+  end
+
+  def by_assignee(items)
+    if params[:assignee_id].present?
+      items = items.where(assignee_id: (params[:assignee_id] == '0' ? nil : params[:assignee_id]))
+    end
+
+    items
+  end
+
+  def by_label(items)
+    if params[:label_name].present?
+      items = items.tagged_with(params[:label_name])
+    end
+
+    items
+  end
+
+  def project
+    Project.where(id: params[:project_id]).first if params[:project_id].present?
+  end
+end
diff --git a/app/finders/issues_finder.rb b/app/finders/issues_finder.rb
new file mode 100644
index 00000000000..8e0c606249e
--- /dev/null
+++ b/app/finders/issues_finder.rb
@@ -0,0 +1,22 @@
+# Finders::Issues class
+#
+# Used to filter Issues collections by set of params
+#
+# Arguments:
+#   current_user - which user use
+#   params:
+#     scope: 'created-by-me' or 'assigned-to-me' or 'all'
+#     state: 'open' or 'closed' or 'all'
+#     group_id: integer
+#     project_id: integer
+#     milestone_id: integer
+#     assignee_id: integer
+#     search: string
+#     label_name: string
+#     sort: string
+#
+class IssuesFinder < BaseFinder
+  def klass
+    Issue
+  end
+end
diff --git a/app/finders/merge_requests_finder.rb b/app/finders/merge_requests_finder.rb
new file mode 100644
index 00000000000..3727149c8fb
--- /dev/null
+++ b/app/finders/merge_requests_finder.rb
@@ -0,0 +1,22 @@
+# Finders::MergeRequest class
+#
+# Used to filter MergeRequests collections by set of params
+#
+# Arguments:
+#   current_user - which user use
+#   params:
+#     scope: 'created-by-me' or 'assigned-to-me' or 'all'
+#     state: 'open' or 'closed' or 'all'
+#     group_id: integer
+#     project_id: integer
+#     milestone_id: integer
+#     assignee_id: integer
+#     search: string
+#     label_name: string
+#     sort: string
+#
+class MergeRequestsFinder < BaseFinder
+  def klass
+    MergeRequest
+  end
+end
diff --git a/app/finders/notes_finder.rb b/app/finders/notes_finder.rb
new file mode 100644
index 00000000000..384316e14b7
--- /dev/null
+++ b/app/finders/notes_finder.rb
@@ -0,0 +1,17 @@
+class NotesFinder
+  def execute(project, current_user, params)
+    target_type = params[:target_type]
+    target_id   = params[:target_id]
+
+    case target_type
+    when "commit"
+      project.notes.for_commit_id(target_id).not_inline.fresh
+    when "issue"
+      project.issues.find(target_id).notes.inc_author.fresh
+    when "merge_request"
+      project.merge_requests.find(target_id).mr_and_commit_notes.inc_author.fresh
+    when "snippet"
+      project.snippets.find(target_id).notes.fresh
+    end
+  end
+end
diff --git a/app/finders/projects_finder.rb b/app/finders/projects_finder.rb
new file mode 100644
index 00000000000..bfaba758788
--- /dev/null
+++ b/app/finders/projects_finder.rb
@@ -0,0 +1,63 @@
+class ProjectsFinder
+  def execute(current_user, options)
+    group = options[:group]
+
+    if group
+      group_projects(current_user, group)
+    else
+      all_projects(current_user)
+    end
+  end
+
+  private
+
+  def group_projects(current_user, group)
+    if current_user
+      if group.users.include?(current_user)
+        # User is group member
+        #
+        # Return ALL group projects
+        group.projects
+      else
+        projects_members = UsersProject.where(
+          project_id: group.projects,
+          user_id: current_user
+        )
+
+        if projects_members.any?
+          # User is a project member
+          #
+          # Return only:
+          #   public projects
+          #   internal projects
+          #   joined projects
+          #
+          group.projects.where(
+            "projects.id IN (?) OR projects.visibility_level IN (?)",
+            projects_members.pluck(:project_id),
+            Project.public_and_internal_levels
+          )
+        else
+          # User has no access to group or group projects
+          #
+          # Return only:
+          #   public projects
+          #   internal projects
+          #
+          group.projects.public_and_internal_only
+        end
+      end
+    else
+      # Not authenticated
+      #
+      # Return only:
+      #   public projects
+      group.projects.public_only
+    end
+  end
+
+  def all_projects
+    # TODO: implement
+    raise 'Not implemented yet'
+  end
+end