module LanguageServer
  module Protocol
    module Interface
      #
      # The change text document notification's parameters.
      #
      class DidChangeTextDocumentParams
        def initialize(text_document:, content_changes:)
          @attributes = {}

          @attributes[:textDocument] = text_document
          @attributes[:contentChanges] = content_changes

          @attributes.freeze
        end

        #
        # The document that did change. The version number points
        # to the version after all provided content changes have
        # been applied.
        #
        # @return [VersionedTextDocumentIdentifier]
        def text_document
          attributes.fetch(:textDocument)
        end

        #
        # The actual content changes. The content changes describe single state changes
        # to the document. So if there are two content changes c1 (at array index 0) and
        # c2 (at array index 1) for a document in state S then c1 moves the document from
        # S to S' and c2 from S' to S''. So c1 is computed on the state S and c2 is computed
        # on the state S'.
        #
        # To mirror the content of a document using change events use the following approach:
        # - start with the same initial content
        # - apply the 'textDocument/didChange' notifications in the order you receive them.
        # - apply the `TextDocumentContentChangeEvent`s in a single notification in the order
        #   you receive them.
        #
        # @return [TextDocumentContentChangeEvent[]]
        def content_changes
          attributes.fetch(:contentChanges)
        end

        attr_reader :attributes

        def to_hash
          attributes
        end

        def to_json(*args)
          to_hash.to_json(*args)
        end
      end
    end
  end
end
