# frozen_string_literal: true

module Gitlab
  module GithubImport
    module Representation
      class DiffNote
        include Representable

        NOTEABLE_ID_REGEX = %r{/pull/(?<iid>\d+)}i

        expose_attribute :noteable_id, :commit_id, :file_path,
          :diff_hunk, :author, :created_at, :updated_at,
          :original_commit_id, :note_id, :end_line, :start_line,
          :side, :in_reply_to_id, :discussion_id, :subject_type

        # Builds a diff note from a GitHub API response.
        #
        # note - An instance of `Hash` containing the note details.
        def self.from_api_response(note, additional_data = {})
          matches = note[:html_url].match(NOTEABLE_ID_REGEX)

          unless matches
            raise(
              ArgumentError,
              "The note URL #{note[:html_url].inspect} is not supported"
            )
          end

          user = Representation::User.from_api_response(note[:user]) if note[:user]
          hash = {
            noteable_id: matches[:iid].to_i,
            file_path: note[:path],
            commit_id: note[:commit_id],
            original_commit_id: note[:original_commit_id],
            diff_hunk: note[:diff_hunk],
            author: user,
            note: note[:body],
            created_at: note[:created_at],
            updated_at: note[:updated_at],
            note_id: note[:id],
            end_line: note[:line],
            start_line: note[:start_line],
            side: note[:side],
            in_reply_to_id: note[:in_reply_to_id],
            discussion_id: DiffNotes::DiscussionId.new(note).find_or_generate,
            subject_type: note[:subject_type]
          }

          new(hash)
        end

        # Builds a new note using a Hash that was built from a JSON payload.
        def self.from_json_hash(raw_hash)
          hash = Representation.symbolize_hash(raw_hash)

          hash[:author] &&= Representation::User.from_json_hash(hash[:author])

          new(hash)
        end

        attr_accessor :merge_request

        # attributes - A Hash containing the raw note details. The keys of this
        #              Hash must be Symbols.
        def initialize(attributes)
          @attributes = attributes

          @note_formatter = DiffNotes::SuggestionFormatter.new(
            note: attributes[:note],
            start_line: attributes[:start_line],
            end_line: attributes[:end_line]
          )
        end

        def noteable_type
          DiffNotes::DiscussionId::NOTEABLE_TYPE
        end

        def contains_suggestion?
          @note_formatter.contains_suggestion?
        end

        def note
          @note_formatter.formatted_note
        end

        def line_code
          # on the GitHub side it is possible to leave a comment on a file
          # or on a line. When the comment is left on a file there is no
          # diff hunk, but LegacyDiffNote requires line_code to be always present
          # and DiffFile requires it for text files
          # so it is set as the first line for any type of file (image, binary, text)
          return Gitlab::Git.diff_line_code(file_path, 1, 1) if on_file?

          diff_line = Gitlab::Diff::Parser.new.parse(diff_hunk.lines).to_a.last
          Gitlab::Git.diff_line_code(file_path, diff_line.new_pos, diff_line.old_pos)
        end

        # Returns a Hash that can be used to populate `notes.st_diff`, removing
        # the need for requesting Git data for every diff note.
        # Used when importing with LegacyDiffNote
        def diff_hash
          {
            diff: diff_hunk,
            new_path: file_path,
            old_path: file_path,

            # These fields are not displayed for LegacyDiffNote notes, so it
            # doesn't really matter what we set them to.
            a_mode: '100644',
            b_mode: '100644',
            new_file: false
          }
        end

        # Used when importing with DiffNote
        def diff_position
          position_params = {
            diff_refs: merge_request.diff_refs,
            old_path: file_path,
            new_path: file_path
          }

          Gitlab::Diff::Position.new(position_params.merge(diff_line_params))
        end

        def github_identifiers
          {
            note_id: note_id,
            noteable_iid: noteable_id,
            noteable_type: noteable_type
          }
        end

        private

        def diff_line_params
          if addition?
            { new_line: end_line, old_line: nil }
          else
            { new_line: nil, old_line: end_line }
          end
        end

        def addition?
          side == 'RIGHT'
        end

        def on_file?
          subject_type == 'file'
        end
      end
    end
  end
end
