obsidian_canvas_to_list.rb

require 'json'

canvas = JSON.parse(STDIN.read, symbolize_names: true)

all_ids = canvas[:nodes].map { |n| n[:id] }
dest_ids = canvas[:edges].map {|e| e[:toNode] }.uniq
root_ids = all_ids - dest_ids

nodes_by_id = canvas[:nodes].to_h {|n| [n[:id],n] }
graph = canvas[:edges].group_by {|e| e[:fromNode] }.transform_values { |vv| vv.map {|v| v[:toNode] }}

tree = {}

walked_nodes = Set.new

root_ids.each do |root_id|
  queue = [[root_id, tree]]

  loop do
    break if queue.empty?

    node_id, tree_pointer = queue.shift
    walked_nodes.add(node_id)
    tree_pointer[node_id] = {}

    neighbors = graph[node_id]
    next if neighbors.nil?
    neighbors.each do |neighbor_id|
      unless walked_nodes.include?(neighbor_id)
        queue.push([neighbor_id, tree_pointer[node_id]])
      end
    end
  end
end

def print_tree(nodes_by_id ,tree, indent)
  tree.map do |node_id, children|
    node = nodes_by_id[node_id]
    spaces = '  '*indent
    if node[:text]
      puts node[:text].lines.map.with_index{|l,i| i==0 ? "#{spaces}- #{l}" : "#{spaces}  #{l}"}
    elsif node[:label]
      puts "#{spaces}- #{node[:"label"]}"
    elsif node[:file]
      puts "#{spaces}- [[#{node[:file]}]]"
    elsif node[:url]
      puts "#{spaces}- #{node[:"url"]}"
    else
      puts "#{'  '*indent}- #{node.to_json}"
    end
    print_tree(nodes_by_id, children, indent+1)
  end
end

print_tree(nodes_by_id, tree, 0)