module Rigor::ModuleGraph::Viewer::Html

# File lib/rigor/module_graph/viewer/html.rb, line 161
def add_external_endpoints(meta, edges, parent_for)
  edges.flat_map { |e| [e.from, e.to] }.uniq.each do |name|
    meta[name] ||= node_data(
      id: name, kind: "external", path: nil, line: nil,
      parent_for: parent_for
    )
  end
end

# File lib/rigor/module_graph/viewer/html.rb, line 73
def build_data(edges:, nodes:, path_mode:, open_with:,
               collapse: [], groups: nil)
  # Decide each node's parent compound (if any) before
  # walking the node / edge sets, so member nodes can
  # have their visible label shortened to drop the
  # namespace prefix.
  parent_for = compute_parents(edges, nodes, collapse, groups)

  node_meta = build_node_meta(nodes, parent_for, path_mode)
  add_external_endpoints(node_meta, edges, parent_for)

  # Cytoscape treats any node referenced as a `parent` as
  # a compound (group) automatically. We still emit an
  # explicit entry per compound so it gets a label and
  # `kind: "compound"` styling — and so the JSON dataset
  # is self-contained for debugging.
  compound_nodes = parent_for.values.uniq.compact.map do |label|
    { data: { id: label, name: label, kind: "compound" } }
  end

  {
    # Compound nodes first so Cytoscape sees the parents
    # before their children during element registration.
    nodes: compound_nodes + node_meta.values.map { |n| { data: n } },
    edges: edges.each_with_index.map do |edge, i|
      {
        data: {
          id: "e#{i}",
          source: edge.from,
          target: edge.to,
          kind: edge.kind,
          confidence: edge.confidence
        }
      }
    end,
    options: { open_with: open_with&.to_s }
  }
end

# File lib/rigor/module_graph/viewer/html.rb, line 138
def build_node_meta(nodes, parent_for, path_mode)
  meta = {}
  nodes.each do |node|
    next unless CONSTANT_KINDS.include?(node.kind)

    key = fully_qualified(node)
    # First definition wins; class re-opens still resolve
    # to one Cytoscape node, matching the dedup contract
    # in `Edge#dedup_key`.
    meta[key] ||= node_data(
      id: key, kind: node.kind,
      path: path_for(node.path, path_mode), line: node.line,
      parent_for: parent_for
    )
  end
  meta
end

# File lib/rigor/module_graph/viewer/html.rb, line 133
def collect_names(edges, nodes)
  (edges.flat_map { |e| [e.from, e.to] } +
   nodes.flat_map { |n| CONSTANT_KINDS.include?(n.kind) ? [fully_qualified(n)] : [] }).uniq
end

# File lib/rigor/module_graph/viewer/html.rb, line 116
def compute_parents(edges, nodes, collapse, groups)
  if groups && !groups.empty?
    groups.dup
  else
    prefixes = Array(collapse).map(&:to_s).reject(&:empty?).sort_by { |p| -p.length }
    return {} if prefixes.empty?

    all_names = collect_names(edges, nodes)
    parent_for = {}
    all_names.each do |name|
      match = prefixes.find { |p| name.start_with?("#{p}::") }
      parent_for[name] = match if match
    end
    parent_for
  end
end

# File lib/rigor/module_graph/viewer/html.rb, line 195
def fully_qualified(node)
  owner = node.owner
  owner && !owner.empty? ? "#{owner}::#{node.name}" : node.name
end

# File lib/rigor/module_graph/viewer/html.rb, line 174
def node_data(id:, kind:, path:, line:, parent_for:)
  parent = parent_for[id]
  data = {
    id: id,
    name: parent ? short_label(id, parent) : id,
    kind: kind,
    path: path,
    line: line
  }
  data[:parent] = parent if parent
  data
end

# File lib/rigor/module_graph/viewer/html.rb, line 200
def path_for(path, mode)
  return nil if path.nil? || mode == :none

  case mode
  when :absolute then File.expand_path(path)
  when :relative then path
  end
end

# File lib/rigor/module_graph/viewer/html.rb, line 51
def render(edges:, nodes:, title:, subtitle: nil,
           path_mode: :relative, open_with: nil,
           collapse: [], groups: nil)
  data = build_data(
    edges: edges, nodes: nodes,
    path_mode: path_mode, open_with: open_with,
    collapse: collapse, groups: groups
  )
  template = ERB.new(File.read(TEMPLATE_PATH), trim_mode: "-")
  template.result_with_hash(
    title: title,
    subtitle: subtitle,
    data_json: safe_json(data),
    css: File.read(CSS_PATH),
    cytoscape: File.read(CYTOSCAPE_JS_PATH),
    viewer: File.read(VIEWER_JS_PATH)
  )
end

# File lib/rigor/module_graph/viewer/html.rb, line 213
def safe_json(value)
  JSON.generate(value).gsub("</", "<\\/")
end

# File lib/rigor/module_graph/viewer/html.rb, line 191
def short_label(id, parent)
  id.sub(/\A#{Regexp.escape(parent)}::/, "")
end