class Projects::BranchesController < Projects::ApplicationController
  include ActionView::Helpers::SanitizeHelper
  include SortingHelper

  # Authorize
  before_action :require_non_empty_project, except: :create
  before_action :authorize_download_code!
  before_action :authorize_push_code!, only: [:new, :create, :destroy, :destroy_all_merged]

  # Support legacy URLs
  before_action :redirect_for_legacy_index_sort_or_search, only: [:index]

  def index
    respond_to do |format|
      format.html do
        @sort = params[:sort].presence || sort_value_recently_updated
        @mode = params[:state].presence || 'overview'
        @overview_max_branches = 5

        # Fetch branches for the specified mode
        fetch_branches_by_mode

        @refs_pipelines = @project.pipelines.latest_successful_for_refs(@branches.map(&:name))
        @merged_branch_names = repository.merged_branch_names(@branches.map(&:name))

        # n+1: https://gitlab.com/gitlab-org/gitaly/issues/992
        Gitlab::GitalyClient.allow_n_plus_1_calls do
          @max_commits = @branches.reduce(0) do |memo, branch|
            diverging_commit_counts = repository.diverging_commit_counts(branch)
            [memo, diverging_commit_counts[:behind], diverging_commit_counts[:ahead]].max
          end
        end

        render
      end
      format.json do
        branches = BranchesFinder.new(@repository, params).execute
        branches = Kaminari.paginate_array(branches).page(params[:page])
        render json: branches.map(&:name)
      end
    end
  end

  def recent
    @branches = @repository.recent_branches
  end

  def create
    branch_name = sanitize(strip_tags(params[:branch_name]))
    branch_name = Addressable::URI.unescape(branch_name)

    redirect_to_autodeploy = project.empty_repo? && project.deployment_platform.present?

    result = CreateBranchService.new(project, current_user)
        .execute(branch_name, ref)

    success = (result[:status] == :success)

    if params[:issue_iid] && success
      issue = IssuesFinder.new(current_user, project_id: @project.id).find_by(iid: params[:issue_iid])
      SystemNoteService.new_issue_branch(issue, @project, current_user, branch_name) if issue
    end

    respond_to do |format|
      format.html do
        if success
          if redirect_to_autodeploy
            redirect_to url_to_autodeploy_setup(project, branch_name),
              notice: view_context.autodeploy_flash_notice(branch_name)
          else
            redirect_to project_tree_path(@project, branch_name)
          end
        else
          @error = result[:message]
          render action: 'new'
        end
      end

      format.json do
        if success
          render json: { name: branch_name, url: project_tree_url(@project, branch_name) }
        else
          render json: result[:messsage], status: :unprocessable_entity
        end
      end
    end
  end

  def destroy
    @branch_name = Addressable::URI.unescape(params[:id])
    result = DeleteBranchService.new(project, current_user).execute(@branch_name)

    respond_to do |format|
      format.html do
        flash_type = result[:status] == :error ? :alert : :notice
        flash[flash_type] = result[:message]

        redirect_to project_branches_path(@project), status: 303
      end

      format.js { render nothing: true, status: result[:return_code] }
      format.json { render json: { message: result[:message] }, status: result[:return_code] }
    end
  end

  def destroy_all_merged
    DeleteMergedBranchesService.new(@project, current_user).async_execute

    redirect_to project_branches_path(@project),
      notice: 'Merged branches are being deleted. This can take some time depending on the number of branches. Please refresh the page to see changes.'
  end

  private

  def ref
    if params[:ref]
      ref_escaped = sanitize(strip_tags(params[:ref]))
      Addressable::URI.unescape(ref_escaped)
    else
      @project.default_branch || 'master'
    end
  end

  def url_to_autodeploy_setup(project, branch_name)
    project_new_blob_path(
      project,
      branch_name,
      file_name: '.gitlab-ci.yml',
      commit_message: 'Set up auto deploy',
      target_branch: branch_name,
      context: 'autodeploy'
    )
  end

  def redirect_for_legacy_index_sort_or_search
    # Normalize a legacy URL with redirect
    if request.format != :json && !params[:state].presence && [:sort, :search, :page].any? { |key| params[key].presence }
      redirect_to project_branches_filtered_path(@project, state: 'all'), notice: 'Update your bookmarked URLs as filtered/sorted branches URL has been changed.'
    end
  end

  def fetch_branches_by_mode
    if @mode == 'overview'
      # overview mode
      @active_branches, @stale_branches = BranchesFinder.new(@repository, sort: sort_value_recently_updated).execute.partition(&:active?)
      # Here we get one more branch to indicate if there are more data we're not showing
      @active_branches = @active_branches.first(@overview_max_branches + 1)
      @stale_branches = @stale_branches.first(@overview_max_branches + 1)
      @branches = @active_branches + @stale_branches
    else
      # active/stale/all view mode
      @branches = BranchesFinder.new(@repository, params.merge(sort: @sort)).execute
      @branches = @branches.select { |b| b.state.to_s == @mode } if %w[active stale].include?(@mode)
      @branches = Kaminari.paginate_array(@branches).page(params[:page])
    end
  end
end