# frozen_string_literal: true

require "open3"
require "lutaml/uml/formatter/base"
require "lutaml/layout/graph_viz_engine"

module Lutaml
  module Uml
    module Formatter
      class Graphviz < Base
        class Attributes < Hash
          def to_s
            to_a
              .reject { |(_k, val)| val.nil? }
              .map { |(a, b)| "#{a}=#{b.inspect}" }
              .join(" ")
          end
        end

        ACCESS_SYMBOLS = {
          "public"    => "+",
          "protected" => "#",
          "private"   => "-",
        }.freeze
        DEFAULT_CLASS_FONT = "Helvetica".freeze

        VALID_TYPES = %i[
          dot
          xdot
          ps
          pdf
          svg
          svgz
          fig
          png
          gif
          jpg
          jpeg
          json
          imap
          cmapx
        ].freeze

        def initialize(attributes = {})
          super

          @graph = Attributes.new
          # Associations lines style, `true` gives curved lines
          # https://graphviz.org/doc/info/attrs.html#d:splines
          @graph["splines"] = "ortho"
          # Padding between outside of picture and nodes
          @graph["pad"] = 0.5
          # Padding between levels
          @graph["ranksep"] = "1.2.equally"
          # Padding between nodes
          @graph["nodesep"] = "1.2.equally"
          # TODO: set rankdir
          # @graph['rankdir'] = 'BT'

          @edge = Attributes.new
          @edge["color"] = "gray50"

          @node = Attributes.new
          @node["shape"] = "box"

          @type = :dot
        end

        attr_reader :graph
        attr_reader :edge
        attr_reader :node

        def type=(value)
          super

          @type = :dot unless VALID_TYPES.include?(@type)
        end

        def format(node)
          dot = super.lines.map(&:rstrip).join("\n")

          generate_from_dot(dot)
        end

        def escape_html_chars(text)
          text
            .gsub(/</, "&#60;")
            .gsub(/>/, "&#62;")
            .gsub(/\[/, "&#91;")
            .gsub(/\]/, "&#93;")
        end

        def format_field(node)
          symbol = ACCESS_SYMBOLS[node.visibility]
          result = "#{symbol}#{node.name}"
          if node.type
            keyword = node.keyword ? "«#{node.keyword}»" : ""
            result += " : #{keyword}#{node.type}"
          end
          if node.cardinality
            result += "[#{node.cardinality[:min]}..#{node.cardinality[:max]}]"
          end
          result = escape_html_chars(result)
          result = "<U>#{result}</U>" if node.static

          result
        end

        def format_method(node)
          symbol = ACCESS_SYMBOLS[node.access]
          result = "#{symbol} #{node.name}"
          if node.arguments
            arguments = node.arguments.map do |argument|
              "#{argument.name}#{" : #{argument.type}" if argument.type}"
            end.join(", ")
          end

          result << "(#{arguments})"
          result << " : #{node.type}" if node.type
          result = "<U>#{result}</U>" if node.static
          result = "<I>#{result}</I>" if node.abstract

          result
        end

        def format_relationship(node)
          graph_parent_name = generate_graph_name(node.owner_end)
          graph_node_name = generate_graph_name(node.member_end)
          attributes = generate_graph_relationship_attributes(node)
          graph_attributes = " [#{attributes}]" unless attributes.empty?

          %{#{graph_parent_name} -> #{graph_node_name}#{graph_attributes}}
        end

        def generate_graph_relationship_attributes(node)
          attributes = Attributes.new
          if %w[dependency realizes].include?(node.member_end_type)
            attributes["style"] = "dashed"
          end
          attributes["dir"] = if node.owner_end_type && node.member_end_type
                                "both"
                              elsif node.owner_end_type
                                "back"
                              else
                                "direct"
                              end
          attributes["label"] = node.action if node.action
          if node.owner_end_attribute_name
            attributes["headlabel"] = format_label(
              node.owner_end_attribute_name,
              node.owner_end_cardinality
            )
          end
          if node.member_end_attribute_name
            attributes["taillabel"] = format_label(
              node.member_end_attribute_name,
              node.member_end_cardinality
            )
          end

          attributes["arrowtail"] = case node.owner_end_type
                                    when "composition"
                                      "diamond"
                                    when "aggregation"
                                      "odiamond"
                                    when "direct"
                                      "vee"
                                    else
                                      "onormal"
                                    end

          attributes["arrowhead"] = case node.member_end_type
                                    when "composition"
                                      "diamond"
                                    when "aggregation"
                                      "odiamond"
                                    when "direct"
                                      "vee"
                                    else
                                      "onormal"
                                    end
          # swap labels and arrows if `dir` eq to `back`
          if attributes["dir"] == "back"
            attributes["arrowhead"], attributes["arrowtail"] =
              [attributes["arrowtail"], attributes["arrowhead"]]
            attributes["headlabel"], attributes["taillabel"] =
              [attributes["taillabel"], attributes["headlabel"]]
          end
          attributes
        end

        def format_label(name, cardinality = {})
          res = "+#{name}"
          if cardinality.nil? ||
              (cardinality["min"].nil? || cardinality["max"].nil?)
            return res
          end

          "#{res} #{cardinality['min']}..#{cardinality['max']}"
        end

        def format_member_rows(members, hide_members)
          unless !hide_members && members && members.length.positive?
            return <<~HEREDOC.chomp
              <TABLE BORDER="0" CELLPADDING="0" CELLSPACING="0">
                <TR><TD ALIGN="LEFT"></TD></TR>
              </TABLE>
            HEREDOC
          end

          field_rows = members.map do |field|
            %{<TR><TD ALIGN="LEFT">#{format_field(field)}</TD></TR>}
          end
          field_table = <<~HEREDOC.chomp
            <TABLE BORDER="0" CELLPADDING="0" CELLSPACING="0">
              #{field_rows.map { |row| ' ' * 10 + row }.join("\n")}
            </TABLE>
          HEREDOC
          field_table << "\n" << " " * 6
          field_table
        end

        def format_class(node, hide_members)
          name = ["<B>#{node.name}</B>"]
          name.unshift("«#{node.keyword}»") if node.keyword
          name_html = <<~HEREDOC
            <TABLE BORDER="0" CELLPADDING="0" CELLSPACING="0">
              #{name.map { |n| %(<TR><TD ALIGN="CENTER">#{n}</TD></TR>) }.join('\n')}
            </TABLE>
          HEREDOC

          field_table = format_member_rows(node.attributes, hide_members)
          method_table = format_member_rows(node.methods, hide_members)
          table_body = [name_html, field_table, method_table].map do |type|
            next if type.nil?

            <<~TEXT
              <TR>
                <TD>#{type}</TD>
              </TR>
            TEXT
          end

          <<~HEREDOC.chomp
            <TABLE BORDER="0" CELLBORDER="1" CELLSPACING="0" CELLPADDING="10">
              #{table_body.compact.join("\n")}
            </TABLE>
          HEREDOC
        end

        def format_document(node)
          @fontname = node.fontname || DEFAULT_CLASS_FONT
          @node["fontname"] = "#{@fontname}-bold"

          if node.fidelity
            hide_members = node.fidelity["hideMembers"]
            hide_other_classes = node.fidelity["hideOtherClasses"]
          end
          classes = (node.classes +
                      node.enums +
                      node.data_types +
                      node.primitives).map do |class_node|
            graph_node_name = generate_graph_name(class_node.name)

            <<~HEREDOC
              #{graph_node_name} [
                shape="plain"
                fontname="#{@fontname || DEFAULT_CLASS_FONT}"
                label=<#{format_class(class_node, hide_members)}>]
            HEREDOC
          end.join("\n")
          associations = node.classes.map(&:associations).compact.flatten +
            node.associations
          if node.groups
            associations = sort_by_document_groupping(node.groups,
                                                      associations)
          end
          classes_names = node.classes.map(&:name)
          associations = associations.map do |assoc_node|
            if hide_other_classes &&
                !classes_names.include?(assoc_node.member_end)
              next
            end

            format_relationship(assoc_node)
          end.join("\n")

          classes = classes.lines.map { |line| "  #{line}" }.join.chomp
          associations = associations
            .lines.map { |line| "  #{line}" }.join.chomp

          <<~HEREDOC
            digraph G {
              graph [#{@graph}]
              edge [#{@edge}]
              node [#{@node}]

            #{classes}

            #{associations}
            }
          HEREDOC
        end

        protected

        def sort_by_document_groupping(groups, associations)
          result = []
          groups.each do |batch|
            batch.each do |group_name|
              associations
                .select { |assc| assc.owner_end == group_name }
                .each do |association|
                  result.push(association) unless result.include?(association)
                end
            end
          end
          associations.each do |association|
            result.push(association) unless result.include?(association)
          end
          result
        end

        def generate_from_dot(input)
          Lutaml::Layout::GraphVizEngine.new(input: input).render(@type)
        end

        def generate_graph_name(name)
          name.gsub(/[^0-9a-zA-Z]/i, "")
        end
      end
    end
  end
end