library(igraph)

# 1) Read DOT file
dot <- readLines("ductNet.dot", warn = FALSE)

# 2) Basic cleanup
dot <- sub("//.*$", "", dot)        # remove // comments
dot <- trimws(dot)
dot <- dot[nzchar(dot)]             # drop empty lines

# 3) Keep only edge lines (directed -> or undirected --)
edge_lines <- dot[grepl("->|--", dot)]

# 4) Extract from/to (handles optional quotes and ignores attributes like [label=...])
m <- regexec('^\\s*"?([^"\\s]+)"?\\s*(->|--)\\s*"?([^"\\s\\[;]+)"?', edge_lines)
mm <- regmatches(edge_lines, m)

edges_df <- data.frame(
  from = vapply(mm, function(x) if (length(x) >= 2) x[2] else NA_character_, ""),
  to   = vapply(mm, function(x) if (length(x) >= 4) x[4] else NA_character_, ""),
  stringsAsFactors = FALSE
)

edges_df <- na.omit(edges_df)

# 5) Build igraph
directed_flag <- any(grepl("->", edge_lines))  # if any directed edges exist
g <- graph_from_data_frame(edges_df, directed = directed_flag)

# 6) Plot
plot(g, layout = layout_as_tree(g, root = which(V(g)$name == "A")))
# 6) Save as JPEG

library(DiagrammeR)

graph <- create_graph() |>
  add_edges_from_table(
    table = g,
    from_col = from,
    to_col = to
  )
graph <- add_global_graph_attrs(graph, "layout", "dot", "graph")
graph <- add_global_graph_attrs(graph, "rankdir", "TB", "graph")

render_graph(graph)


jpeg("map.jpg", width = 1200, height = 900, res = 150)

plot(
  g,
  layout = layout_as_tree(g, root = which(V(g)$name == "A")),
  vertex.size = 30,
  vertex.label.cex = 1.2,
  edge.arrow.size = 0.6
)

dev.off()