require 'mime/types'

module API
  class CommitStatuses < Grape::API
    params do
      requires :id, type: String, desc: 'The ID of a project'
    end
    resource :projects, requirements: API::PROJECT_ENDPOINT_REQUIREMENTS do
      include PaginationParams

      before { authenticate! }

      desc "Get a commit's statuses" do
        success Entities::CommitStatus
      end
      params do
        requires :sha,   type: String, desc: 'The commit hash'
        optional :ref,   type: String, desc: 'The ref'
        optional :stage, type: String, desc: 'The stage'
        optional :name,  type: String, desc: 'The name'
        optional :all,   type: String, desc: 'Show all statuses, default: false'
        use :pagination
      end
      get ':id/repository/commits/:sha/statuses' do
        authorize!(:read_commit_status, user_project)

        not_found!('Commit') unless user_project.commit(params[:sha])

        pipelines = user_project.pipelines.where(sha: params[:sha])
        statuses = ::CommitStatus.where(pipeline: pipelines)
        statuses = statuses.latest unless to_boolean(params[:all])
        statuses = statuses.where(ref: params[:ref]) if params[:ref].present?
        statuses = statuses.where(stage: params[:stage]) if params[:stage].present?
        statuses = statuses.where(name: params[:name]) if params[:name].present?
        present paginate(statuses), with: Entities::CommitStatus
      end

      desc 'Post status to a commit' do
        success Entities::CommitStatus
      end
      params do
        requires :sha,         type: String,  desc: 'The commit hash'
        requires :state,       type: String,  desc: 'The state of the status',
                               values: %w(pending running success failed canceled)
        optional :ref,         type: String,  desc: 'The ref'
        optional :target_url,  type: String,  desc: 'The target URL to associate with this status'
        optional :description, type: String,  desc: 'A short description of the status'
        optional :name,        type: String,  desc: 'A string label to differentiate this status from the status of other systems. Default: "default"'
        optional :context,     type: String,  desc: 'A string label to differentiate this status from the status of other systems. Default: "default"'
        optional :coverage,    type: Float,   desc: 'The total code coverage'
      end
      post ':id/statuses/:sha' do
        authorize! :create_commit_status, user_project

        commit = @project.commit(params[:sha])
        not_found! 'Commit' unless commit

        # Since the CommitStatus is attached to Ci::Pipeline (in the future Pipeline)
        # We need to always have the pipeline object
        # To have a valid pipeline object that can be attached to specific MR
        # Other CI service needs to send `ref`
        # If we don't receive it, we will attach the CommitStatus to
        # the first found branch on that commit

        ref = params[:ref]
        ref ||= @project.repository.branch_names_contains(commit.sha).first
        not_found! 'References for commit' unless ref

        name = params[:name] || params[:context] || 'default'

        pipeline = @project.pipeline_for(ref, commit.sha)
        unless pipeline
          pipeline = @project.pipelines.create!(
            source: :external,
            sha: commit.sha,
            ref: ref,
            user: current_user,
            protected: @project.protected_for?(ref))
        end

        status = GenericCommitStatus.running_or_pending.find_or_initialize_by(
          project: @project,
          pipeline: pipeline,
          name: name,
          ref: ref,
          user: current_user,
          protected: @project.protected_for?(ref)
        )

        optional_attributes =
          attributes_for_keys(%w[target_url description coverage])

        status.update(optional_attributes) if optional_attributes.any?
        render_validation_error!(status) if status.invalid?

        begin
          case params[:state]
          when 'pending'
            status.enqueue!
          when 'running'
            status.enqueue
            status.run!
          when 'success'
            status.success!
          when 'failed'
            status.drop!(:api_failure)
          when 'canceled'
            status.cancel!
          else
            render_api_error!('invalid state', 400)
          end

          MergeRequest.where(source_project: @project, source_branch: ref)
            .update_all(head_pipeline_id: pipeline) if pipeline.latest?

          present status, with: Entities::CommitStatus
        rescue StateMachines::InvalidTransition => e
          render_api_error!(e.message, 400)
        end
      end
    end
  end
end