require 'mime/types'

module API
  class Commits < Grape::API
    include PaginationParams

    COMMIT_ENDPOINT_REQUIREMENTS = API::PROJECT_ENDPOINT_REQUIREMENTS.merge(sha: API::NO_SLASH_URL_PART_REGEX)

    before { authorize! :download_code, user_project }

    params do
      requires :id, type: String, desc: 'The ID of a project'
    end
    resource :projects, requirements: API::PROJECT_ENDPOINT_REQUIREMENTS do
      desc 'Get a project repository commits' do
        success Entities::RepoCommit
      end
      params do
        optional :ref_name, type: String, desc: 'The name of a repository branch or tag, if not given the default branch is used'
        optional :since,    type: DateTime, desc: 'Only commits after or on this date will be returned'
        optional :until,    type: DateTime, desc: 'Only commits before or on this date will be returned'
        optional :path,     type: String, desc: 'The file path'
        use :pagination
      end
      get ':id/repository/commits' do
        path   = params[:path]
        before = params[:until]
        after  = params[:since]
        ref    = params[:ref_name] || user_project.try(:default_branch) || 'master'
        offset = (params[:page] - 1) * params[:per_page]

        commits = user_project.repository.commits(ref,
                                                  path: path,
                                                  limit: params[:per_page],
                                                  offset: offset,
                                                  before: before,
                                                  after: after)

        commit_count =
          if path || before || after
            user_project.repository.count_commits(ref: ref, path: path, before: before, after: after)
          else
            # Cacheable commit count.
            user_project.repository.commit_count_for_ref(ref)
          end

        paginated_commits = Kaminari.paginate_array(commits, total_count: commit_count)

        present paginate(paginated_commits), with: Entities::RepoCommit
      end

      desc 'Commit multiple file changes as one commit' do
        success Entities::RepoCommitDetail
        detail 'This feature was introduced in GitLab 8.13'
      end
      params do
        requires :branch, type: String, desc: 'Name of the branch to commit into. To create a new branch, also provide `start_branch`.'
        requires :commit_message, type: String, desc: 'Commit message'
        requires :actions, type: Array[Hash], desc: 'Actions to perform in commit'
        optional :start_branch, type: String, desc: 'Name of the branch to start the new commit from'
        optional :author_email, type: String, desc: 'Author email for commit'
        optional :author_name, type: String, desc: 'Author name for commit'
      end
      post ':id/repository/commits' do
        authorize! :push_code, user_project

        attrs = declared_params
        attrs[:branch_name] = attrs.delete(:branch)
        attrs[:start_branch] ||= attrs[:branch_name]

        result = ::Files::MultiService.new(user_project, current_user, attrs).execute

        if result[:status] == :success
          commit_detail = user_project.repository.commit(result[:result])
          present commit_detail, with: Entities::RepoCommitDetail
        else
          render_api_error!(result[:message], 400)
        end
      end

      desc 'Get a specific commit of a project' do
        success Entities::RepoCommitDetail
        failure [[404, 'Commit Not Found']]
      end
      params do
        requires :sha, type: String, desc: 'A commit sha, or the name of a branch or tag'
      end
      get ':id/repository/commits/:sha', requirements: COMMIT_ENDPOINT_REQUIREMENTS do
        commit = user_project.commit(params[:sha])

        not_found! 'Commit' unless commit

        present commit, with: Entities::RepoCommitDetail
      end

      desc 'Get the diff for a specific commit of a project' do
        failure [[404, 'Commit Not Found']]
      end
      params do
        requires :sha, type: String, desc: 'A commit sha, or the name of a branch or tag'
      end
      get ':id/repository/commits/:sha/diff', requirements: COMMIT_ENDPOINT_REQUIREMENTS do
        commit = user_project.commit(params[:sha])

        not_found! 'Commit' unless commit

        commit.raw_diffs.to_a
      end

      desc "Get a commit's comments" do
        success Entities::CommitNote
        failure [[404, 'Commit Not Found']]
      end
      params do
        use :pagination
        requires :sha, type: String, desc: 'A commit sha, or the name of a branch or tag'
      end
      get ':id/repository/commits/:sha/comments', requirements: COMMIT_ENDPOINT_REQUIREMENTS do
        commit = user_project.commit(params[:sha])

        not_found! 'Commit' unless commit
        notes = user_project.notes.where(commit_id: commit.id).order(:created_at)

        present paginate(notes), with: Entities::CommitNote
      end

      desc 'Cherry pick commit into a branch' do
        detail 'This feature was introduced in GitLab 8.15'
        success Entities::RepoCommit
      end
      params do
        requires :sha, type: String, desc: 'A commit sha, or the name of a branch or tag to be cherry picked'
        requires :branch, type: String, desc: 'The name of the branch'
      end
      post ':id/repository/commits/:sha/cherry_pick', requirements: COMMIT_ENDPOINT_REQUIREMENTS do
        authorize! :push_code, user_project

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

        branch = user_project.repository.find_branch(params[:branch])
        not_found!('Branch') unless branch

        commit_params = {
          commit: commit,
          start_branch: params[:branch],
          branch_name: params[:branch]
        }

        result = ::Commits::CherryPickService.new(user_project, current_user, commit_params).execute

        if result[:status] == :success
          branch = user_project.repository.find_branch(params[:branch])
          present user_project.repository.commit(branch.dereferenced_target), with: Entities::RepoCommit
        else
          render_api_error!(result[:message], 400)
        end
      end

      desc 'Post comment to commit' do
        success Entities::CommitNote
      end
      params do
        requires :sha, type: String, desc: 'A commit sha, or the name of a branch or tag on which to post a comment'
        requires :note, type: String, desc: 'The text of the comment'
        optional :path, type: String, desc: 'The file path'
        given :path do
          requires :line, type: Integer, desc: 'The line number'
          requires :line_type, type: String, values: %w(new old), default: 'new', desc: 'The type of the line'
        end
      end
      post ':id/repository/commits/:sha/comments', requirements: COMMIT_ENDPOINT_REQUIREMENTS do
        commit = user_project.commit(params[:sha])
        not_found! 'Commit' unless commit

        opts = {
          note: params[:note],
          noteable_type: 'Commit',
          commit_id: commit.id
        }

        if params[:path]
          commit.raw_diffs(limits: false).each do |diff|
            next unless diff.new_path == params[:path]
            lines = Gitlab::Diff::Parser.new.parse(diff.diff.each_line)

            lines.each do |line|
              next unless line.new_pos == params[:line] && line.type == params[:line_type]
              break opts[:line_code] = Gitlab::Diff::LineCode.generate(diff.new_path, line.new_pos, line.old_pos)
            end

            break if opts[:line_code]
          end

          opts[:type] = LegacyDiffNote.name if opts[:line_code]
        end

        note = ::Notes::CreateService.new(user_project, current_user, opts).execute

        if note.save
          present note, with: Entities::CommitNote
        else
          render_api_error!("Failed to save note #{note.errors.messages}", 400)
        end
      end
    end
  end
end
