// -*- coding: utf-8 -*-
// Copyright (C) 2011, 2012, 2014-2021 Laboratoire de Recherche
// et Développement de l'Epita (LRDE).
// Copyright (C) 2003, 2004  Laboratoire d'Informatique de Paris 6 (LIP6),
// département Systèmes Répartis Coopératifs (SRC), Université Pierre
// et Marie Curie.
//
// This file is part of Spot, a model checking library.
//
// Spot is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
//
// Spot is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
// or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
// License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

#include "config.h"
#include <ostream>
#include <sstream>
#include <stdexcept>
#include <spot/tl/print.hh>
#include <spot/twa/twagraph.hh>
#include <spot/twaalgos/dot.hh>
#include <spot/twa/bddprint.hh>
#include <spot/misc/escape.hh>
#include <spot/twa/formula2bdd.hh>
#include <spot/twaalgos/sccinfo.hh>
#include <spot/kripke/fairkripke.hh>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <ctype.h>
#include <utility>

using namespace std::string_literals;

namespace spot
{
  namespace
  {
    constexpr int MAX_BULLET = 20;

    static constexpr const char palette[][8] =
      {
        "#1F78B4", /* blue */
        "#FF4DA0", /* pink */
        "#FF7F00", /* orange */
        "#6A3D9A", /* purple */
        "#33A02C", /* green */
        "#E31A1C", /* red */
        "#C4C400", /* yellowish */
        "#505050", /* gray */
        "#6BF6FF", /* light blue */
        "#FF9AFF", /* light pink */
        "#FF9C67", /* light orange */
        "#B2A4FF", /* light purple */
        "#A7ED79", /* light green */
        "#FF6868", /* light red */
        "#FFE040", /* light yellowish */
        "#C0C090", /* light gray */
      };

    constexpr int palette_mod = sizeof(palette) / sizeof(*palette);

    class dotty_output final
    {
      // Keep all 0/false-initialized values together.
      std::vector<std::string>* sn_ = nullptr;
      std::map<unsigned, unsigned>* highlight_edges_ = nullptr;
      std::map<unsigned, unsigned>* highlight_states_ = nullptr;
      bool highlight_states_show_num_ = false;
      std::vector<std::pair<unsigned, unsigned>>* sprod_ = nullptr;
      std::vector<unsigned>* orig_ = nullptr;
      std::set<unsigned>* incomplete_ = nullptr;
      std::string* name_ = nullptr; // title for the graph
      std::string* graph_name_ = nullptr; // name for the digraph
      std::map<std::pair<int, int>, int> univ_done;
      std::vector<bool> true_states_;
      std::vector<bool>* state_player_;

      acc_cond::mark_t inf_sets_ = {};
      acc_cond::mark_t fin_sets_ = {};
      unsigned opt_shift_sets_ = 0;
      enum { ShapeAuto = 0, ShapeCircle, ShapeEllipse,
             ShapeRectangle } opt_shape_ = ShapeAuto;
      const char* extrastyle = "";
      bool opt_force_acc_trans_ = false;
      bool opt_vertical_ = false;
      bool opt_name_ = false;
      bool opt_show_acc_ = true;
      bool mark_states_ = false;
      bool dcircles_ = false;
      bool opt_scc_ = false;
      bool opt_html_labels_ = false;
      bool opt_color_sets_ = false;
      bool opt_state_labels_ = false;
      bool uppercase_k_seen_ = false;
      bool opt_rainbow = false;
      bool opt_bullet = false;
      bool opt_bullet_but_buchi = false;
      bool opt_all_bullets = false;
      bool opt_ordered_edges_ = false;
      bool opt_numbered_edges_ = false;
      bool opt_hide_true_states_ = false;
      bool opt_orig_show_ = false;
      bool max_states_given_ = false; // related to max_states_
      bool opt_latex_ = false;
      bool opt_showlabel_ = true;
      const char* nl_ = "\\n";
      const char* label_pre_ = "label=\"";
      char label_post_ = '"';
      bool opt_id_ = false;
      std::string opt_id_graph_;

      const_twa_graph_ptr aut_;
      std::string opt_font_;
      std::string opt_node_color_;
      std::ostream& os_;
      bool inline_state_names_ = true;
      unsigned max_states_ = -1U; // related to max_states_given_

      bool opt_shared_univ_dest_ = true;
      bool opt_mealy_ = false;
      bdd opt_mealy_output_;

    public:

      unsigned max_states()
      {
        return max_states_;
      }

      bool max_states_given()
      {
        return max_states_given_;
      }

      void find_true_states()
      {
        unsigned n = aut_->num_states();
        true_states_.resize(n, false);
        auto& g = aut_->get_graph();
        auto& acc = aut_->acc();
        for (unsigned s = 0; s < n; ++s)
          {
            auto& ss = g.state_storage(s);
            if (ss.succ == ss.succ_tail)
              {
                auto& es = g.edge_storage(ss.succ);
                if (es.cond == bddtrue

                    && es.src == es.dst
                    && acc.accepting(es.acc))
                  true_states_[s] = true;
              }
          }
      }


      void
      parse_opts(const char* options)
      {
        const char* orig = options;
        while (char c = *options++)
          switch (c)
            {
            case '.':
              {
                // Copy the value in a string, so future calls to
                // parse_opts do not fail if the environment has
                // changed.  (This matters particularly in an ipython
                // notebook, where it is tempting to redefine
                // SPOT_DOTDEFAULT.)
                static std::string def = []()
                  {
                    auto s = getenv("SPOT_DOTDEFAULT");
                    return s ? s : "";
                  }();
                // Prevent infinite recursions...
                if (orig == def.c_str())
                  throw std::runtime_error
                    ("SPOT_DOTDEFAULT should not contain '.'");
                if (!def.empty())
                  parse_opts(def.c_str());
                break;
              }
            case '+':
              {
                char* end;
                opt_shift_sets_ = strtoul(options, &end, 10);
                if (options == end)
                  throw std::runtime_error
                    ("missing number after '+' in print_dot() options");
                options = end;
                break;
              }
            case '<':
              {
                char* end;
                max_states_ = strtoul(options, &end, 10);
                if (options == end)
                  throw std::runtime_error
                    ("missing number after '<' in print_dot() options");
                if (max_states_ == 0)
                  {
                    max_states_ = -1U;
                    max_states_given_ = false;
                  }
                else
                  {
                    max_states_given_ = true;
                  }
                options = end;
                break;
              }
            case '#':
              opt_numbered_edges_ = true;
              break;
            case '1':
              inline_state_names_ = false;
              break;
            case 'a':
              opt_show_acc_ = true;
              break;
            case 'A':
              opt_show_acc_ = false;
              break;
            case 'b':
              opt_bullet = true;
              opt_bullet_but_buchi = false;
              break;
            case 'B':
              opt_bullet = true;
              opt_bullet_but_buchi = true;
              break;
            case 'c':
              opt_shape_ = ShapeCircle;
              break;
            case 'C':
              if (*options != '(')
                throw std::runtime_error
                  ("invalid node color specification for print_dot()");
              {
                auto* end = strchr(++options, ')');
                if (!end)
                  throw std::runtime_error
                    ("invalid node color specification for print_dot()");
                opt_node_color_ = std::string(options, end - options);
                options = end + 1;
              }
              break;
            case 'd':
              opt_orig_show_ = true;
              break;
            case 'e':
              opt_shape_ = ShapeEllipse;
              break;
            case 'E':
              opt_shape_ = ShapeRectangle;
              break;
            case 'f':
              if (*options != '(')
                throw std::runtime_error
                  ("invalid font specification for print_dot()");
              {
                auto* end = strchr(++options, ')');
                if (!end)
                  throw std::runtime_error
                    ("invalid font specification for print_dot()");
                opt_font_ = std::string(options, end - options);
                options = end + 1;
              }
              break;
            case 'g':           // "graphs" are unlabeled automata
              opt_showlabel_ = false;
              break;
            case 'h':
              opt_vertical_ = false;
              break;
            case 'i':
              if (*options == '(')
                {
                  auto* end = strchr(++options, ')');
                  if (!end)
                    throw std::runtime_error
                      ("unclosed \"i(...\" for print_dot()");
                  opt_id_graph_ = std::string(options, end - options);
                options = end + 1;
                }
              opt_id_ = true;
              break;
            case 'k':
              opt_state_labels_ = true;
              break;
            case 'K':
              opt_state_labels_ = false;
              uppercase_k_seen_ = true;
              break;
            case 'n':
              opt_name_ = true;
              break;
            case 'N':
              opt_name_ = false;
              break;
            case 'o':
              opt_ordered_edges_ = true;
              break;
            case 'r':
              opt_color_sets_ = true;
              opt_rainbow = true;
              break;
            case 'R':
              opt_color_sets_ = true;
              opt_rainbow = false;
              break;
            case 's':
              opt_scc_ = true;
              break;
            case 'u':
              opt_hide_true_states_ = true;
              break;
            case 'v':
              opt_vertical_ = true;
              break;
            case 't':
              opt_force_acc_trans_ = true;
              break;
            case 'x':
              opt_latex_ = true;
              break;
            case 'y':
              opt_shared_univ_dest_ = false;
              break;
            default:
              throw std::runtime_error
                ("unknown option for print_dot(): "s + c);
            }
        if (opt_color_sets_ && !opt_latex_)
          opt_html_labels_ = true;
        if (opt_html_labels_)
          {
            nl_ = "<br/>";
            label_pre_ = "label=<";
            label_post_ = '>';
          }
        if (opt_latex_)
          {
            nl_ = "\\\\{}";
            label_pre_ = "texlbl=\"";
            label_post_ = '"';
          }

      }

      dotty_output(std::ostream& os, const char* options)
        : os_(os)
      {
        parse_opts(options ? options : ".");
      }

      bool uppercase_k_seen() const
      {
        return uppercase_k_seen_;
      }

      const char*
      html_set_color(int v) const
      {
        if (opt_rainbow)
          return palette[v % palette_mod];
        // Color according to Fin/Inf
        if (inf_sets_.has(v))
          {
            if (fin_sets_.has(v))
              return palette[2];
            else
              return palette[0];
          }
        else
          {
            return palette[1];
          }
      }

      void
      output_set(std::ostream& os, int v) const
      {
        v += opt_shift_sets_;
        if (opt_html_labels_)
          os << "<font color=\"" << html_set_color(v) << "\">";
        if (!opt_latex_ && opt_bullet && (v >= 0) & (v <= MAX_BULLET))
          {
            static const char* const tab[MAX_BULLET + 1] = {
              "⓿", "❶", "❷", "❸",
              "❹", "❺", "❻", "❼",
              "❽", "❾", "❿", "⓫",
              "⓬", "⓭", "⓮", "⓯",
              "⓰", "⓱", "⓲", "⓳",
              "⓴",
            };
            os << tab[v];
          }
        else if (opt_latex_ && opt_bullet)
          {
            os << "\\accset{" << v << '}';
          }
        else
          {
            os << v;
          }
        if (opt_html_labels_)
          os << "</font>";
      }


      void
      output_mark(acc_cond::mark_t a) const
      {
        if (!opt_all_bullets)
          {
            if (opt_latex_)
              os_ << "\\{";
            else
              os_ << '{';
          }
        const char* space = "";
        for (auto v: a.sets())
          {
            if (!opt_all_bullets)
              os_ << space;
            output_set(os_, v);
            space = ",";
          }
        if (!opt_all_bullets)
          {
            if (opt_latex_)
              os_ << "\\}";
            else
              os_ << '}';
          }
      }


      std::ostream&
      escape_for_output(std::ostream& os, const std::string& s) const
      {
        if (opt_html_labels_)
          return escape_html(os, s);
        if (opt_latex_)
          return escape_latex(os, s);
        return escape_str(os, s);
      }

      std::ostream&
      format_label(std::ostream& os, formula f) const
      {
        if (opt_latex_)
          {
            print_sclatex_psl(os << '$', f) << '$';
            return os;
          }
        // GraphViz (2.40.1) has a strict limit of 16k for label
        // length.  The limit we use below is more conservative,
        // because (1) escaping the html element in the string
        // (e.g., "&" -> "&amp;") can increase it a lot, and (2)
        // a label of size 2048 is already unreasonable to display.
        std::string s = str_psl(f);
        if (s.size() > 2048)
          s = "(label too long)";
        return escape_for_output(os, s);
      }

      std::ostream&
      format_label(std::ostream& os, bdd label) const
      {
        return format_label(os, bdd_to_formula(label, aut_->get_dict()));
      }

      std::ostream&
      format_state_label(std::ostream& os, unsigned s) const
      {
        bdd label = bddfalse;
        for (auto& t: aut_->out(s))
          {
            label = t.cond;
            break;
          }
        if (label == bddfalse
            && incomplete_ && incomplete_->find(s) != incomplete_->end())
            return os << "...";
        return format_label(os, label);
      }

      std::ostream&
      format_mealy(std::ostream& os,
                   bdd in,
                   bdd out) const
      {
        format_label(os, in);
        if (opt_html_labels_)
          os << "</TD><TD>/</TD><TD ALIGN=\"LEFT\" BGCOLOR=\"#ffe5f1\">";
        else
          os << " / ";
        format_label(os, out);
        return os;
      }

      std::ostream&
      format_mealy(std::ostream& os, bdd cond) const
      {
        if (opt_html_labels_)
          os << ("<TABLE BORDER=\"0\"><TR><TD ALIGN=\"RIGHT\""
                 " BGCOLOR=\"#e9f4fb\">");
        // Is the label is separable?
        bdd in = bdd_exist(cond, opt_mealy_output_);
        bdd out = bdd_existcomp(cond, opt_mealy_output_);
        if (cond == (in & out))
          {
            format_mealy(os, in, out);
          }
        else
          {
            // Otherwise, present it as a sum of separable labels.
            std::map<bdd, bdd, bdd_less_than_stable> in_out;
            bdd sup = bdd_support(cond);
            for (bdd cond: minterms_of(cond, sup))
              {
                bdd in = bdd_exist(cond, opt_mealy_output_);
                bdd out = bdd_existcomp(cond, opt_mealy_output_);
                if (auto p = in_out.emplace(in, out); !p.second)
                  p.first->second |= out;
              }
            std::map<bdd, bdd, bdd_less_than_stable> out_in;
            for (auto [in, out]: in_out)
              if (auto p = out_in.emplace(out, in); !p.second)
                p.first->second |= in;
            bool first = true;
            for (auto [out, in]: out_in)
              {
                if (!first)
                  {
                    if (opt_html_labels_)
                      os << ("</TD></TR><TR><TD ALIGN=\"RIGHT\""
                             " BGCOLOR=\"#e9f4fb\">");
                    else
                      os << '\n';
                  }
                format_mealy(os, in, out);
                first = false;
              }
          }
        return os;
      }

      std::string string_dst(int dst, int color_num = -1)
      {
        std::ostringstream tmp_dst;
        tmp_dst << dst;
        if (!opt_shared_univ_dest_ && color_num >= 0)
          tmp_dst << '.' << color_num;
        return tmp_dst.str();
      }

      template<typename U, typename V>
      void print_true_state(U to, V from) const
      {
        os_ << "  T" << to << 'T' << from << " [label=\"\", style=invis, ";
        os_ << (opt_vertical_ ? "height=0]\n" : "width=0]\n");
      }

      void
      print_dst(int dst, bool print_edges = false,
                const char* style = nullptr, int color_num = -1)
      {
        int& univ = univ_done[std::make_pair(dst, color_num)];
        if (univ == 2)
          return;
        std::string dest = string_dst(dst, color_num);
        if (univ == 0)
          os_ << "  " << dest
              << " [label=<>,shape=point,width=0.05,height=0.05]\n";
        if (print_edges)
          {
            for (unsigned d: aut_->univ_dests(dst))
              {
                bool dst_is_hidden_true_state =
                  opt_hide_true_states_ && true_states_[d];
                if (dst_is_hidden_true_state)
                  print_true_state(d, dest);
                os_ << "  " << dest << " -> ";
                if (dst_is_hidden_true_state)
                  os_ << 'T' << d << 'T' << dest;
                else
                  os_ << d;
                if ((style && *style) || opt_id_)
                  {
                    os_ << " [";
                    const char* sep = "";
                    if (style && *style)
                      {
                        os_ << style;
                        sep = ",";
                      }
                    if (opt_id_)
                      os_ << sep << "id=\"E" << dest << 'E' << d << '\"';
                    os_ << ']';
                  }
                os_ << '\n';
              }
            univ = 2;
          }
        else
          {
            univ = 1;
          }
      }

      void print_acceptance_for_human()
      {
        std::string accstr = aut_->acc().name("d");
        if (accstr.empty())
          return;
        os_ << nl_ << '[' << accstr << ']';
      }

      void
      start()
      {
        if (opt_html_labels_)
          std::tie(inf_sets_, fin_sets_) =
            aut_->get_acceptance().used_inf_fin_sets();
        // UTF-8 has no glyphs for circled numbers larger than MAX_BULLET.
        if (opt_bullet && (aut_->num_sets() <= MAX_BULLET || opt_latex_))
          opt_all_bullets = true;
        os_ << "digraph \"";
        if (graph_name_)
          escape_str(os_, *graph_name_);
        os_ << "\" {\n";
        if (opt_latex_)
          {
            os_ << "  d2tgraphstyle=\"every node/.style={align=center}\"\n";
            if (opt_bullet)
              {
                os_ << ("  d2tdocpreamble=\""
                        "\\DeclareRobustCommand{\\accset}[1]{"
                        "\\tikz[baseline=(num.base)]{\\node[fill=")
                    << (opt_color_sets_ ? "accset#1" : "black")
                    << (",draw=white,text=white,thin,circle,inner sep=1pt,"
                        "font=\\bfseries\\sffamily] (num) {#1};}}");
                if (opt_color_sets_)
                  {
                    unsigned n = aut_->num_sets();
                    for (unsigned i = 0; i < n; ++i)
                      os_ << "\n\\definecolor{accset" << i << "}{HTML}{"
                          << (html_set_color(i) + 1) << '}';
                  }
                if (opt_bullet)
                  os_ << "\"\n";
              }
          }
        if (!opt_vertical_)
          os_ << "  rankdir=LR\n";
        if (highlight_states_show_num_)
          os_ << "  forcelabels=true\n";
        if (name_ || opt_show_acc_)
          {
            os_ << "  " << label_pre_;
            if (name_)
              escape_for_output(os_, *name_);
            if (opt_show_acc_)
              {
                if (!dcircles_)
                  {
                    if (name_)
                      os_ << nl_;
                    auto& acc = aut_->get_acceptance();
                    auto outset = [this](std::ostream& os, int v)
                                  {
                                    this->output_set(os, v);
                                  };
                    if (opt_html_labels_)
                      acc.to_html(os_, outset);
                    else if (opt_latex_)
                      acc.to_latex(os_ << '$', outset) << '$';
                    else
                      acc.to_text(os_, outset);

                  }
                print_acceptance_for_human();
              }
            os_ << label_post_ << '\n';
            os_ << "  labelloc=\"t\"\n";
          }
        switch (opt_shape_)
          {
          case ShapeCircle:
            os_ << "  node [shape=\"circle\"]\n";
            break;
          case ShapeEllipse:
            // Ellipse is the default shape used by GraphViz, but
            // with set width and height so it's a circle when possible.
            os_ << "  node [shape=\"ellipse\",width=\"0.5\",height=\"0.5\"]\n";
            break;
          case ShapeRectangle:
            os_ << "  node [shape=\"box\",style=\"rounded\",width=\"0.5\"]\n";
            break;
          case ShapeAuto:
            SPOT_UNREACHABLE();
          }
        if (!opt_node_color_.empty())
          os_ << "  node [style=\"filled" << extrastyle << "\", fillcolor=\""
              << opt_node_color_ << "\"]\n";
        if (!opt_font_.empty())
          os_ << "  fontname=\"" << opt_font_
              << "\"\n  node [fontname=\"" << opt_font_
              << "\"]\n  edge [fontname=\"" << opt_font_
              << "\"]\n";
        if (opt_id_)
          {
            if (!opt_id_graph_.empty())
              escape_str(os_ << "  id=\"", opt_id_graph_) << "\"\n";
            os_ << "  node [id=\"S\\N\"]\n";
          }
        // Always copy the environment variable into a static string,
        // so that we (1) look it up once, but (2) won't crash if the
        // environment is changed.
        static std::string extra = []()
          {
            auto s = getenv("SPOT_DOTEXTRA");
            return s ? s : "";
          }();
        // Any extra text passed in the SPOT_DOTEXTRA environment
        // variable should be output at the end of the "header", so
        // that our setup can be overridden.
        if (!extra.empty())
          os_ << "  " << extra << '\n';
        os_ << "  I [label=\"\", style=invis, ";
        os_ << (opt_vertical_ ? "height" : "width");
        int init = (int) aut_->get_init_state_number();
        os_ << "=0]\n  I -> " << init;
        if (init >= 0)
          os_ << '\n';
        else
          os_ << " [arrowhead=onormal]\n";
      }

      void
      end()
      {
        os_ << '}' << std::endl;
      }

      bool print_state_name(std::ostream& os, unsigned s,
                            bool force_text = false) const
      {
        if (sn_ && s < sn_->size() && !(*sn_)[s].empty())
          {
            if (force_text)
              escape_str(os, (*sn_)[s]);
            else
              escape_for_output(os, (*sn_)[s]);
          }
        else if (sprod_)
          {
            os << (*sprod_)[s].first << ',' << (*sprod_)[s].second;
          }
        else
          {
            return false;
          }
        return true;
      }

      void
      process_state(unsigned s)
      {
        os_ << "  " << s << " [" << label_pre_;

        if (!(inline_state_names_ && print_state_name(os_, s)))
          os_ << s;
        if (orig_ && s < orig_->size())
          os_ << " (" << (*orig_)[s] << ')';

        bool include_state_labels =
          opt_state_labels_ && (inline_state_names_ || opt_latex_);
        if (mark_states_ && !dcircles_)
          {
            acc_cond::mark_t acc = {};
            for (auto& t: aut_->out(s))
              {
                acc = t.acc;
                break;
              }

            if (acc)
              {
                os_ << nl_;
                output_mark(acc);
              }
            if (include_state_labels)
              format_state_label(os_ << nl_, s);
            os_ << label_post_;
          }
        else
          {
            if (include_state_labels)
              format_state_label(os_ << nl_, s);
            os_ << label_post_;
            // Use state_acc_sets(), not state_is_accepting() because
            // on co-Büchi automata we want to mark the rejecting
            // states.
            if (dcircles_ && aut_->state_acc_sets(s))
              os_ << ", peripheries=2";
          }
        if (state_player_ && state_player_->size() > s && (*state_player_)[s])
          os_ << ", shape=\"diamond\"";
        if (highlight_states_)
          {
            auto iter = highlight_states_->find(s);
            if (iter != highlight_states_->end())
              {
                os_ << ", style=\"bold" << extrastyle;
                if (!opt_node_color_.empty())
                  os_ << ",filled";
                os_ << "\", color=\"" << palette[iter->second % palette_mod]
                    << '"';
                if (highlight_states_show_num_)
                  os_ << ", xlabel=\"[" << iter->second << "]\"";
              }
          }
        if (!inline_state_names_ && (sn_ || sprod_ || opt_state_labels_)
            && !opt_latex_)
          {
            std::ostringstream os;
            bool nonempty = print_state_name(os, s, true);
            if (opt_state_labels_)
              {
                if (nonempty)
                  os << '\n';
                format_state_label(os, s);
                nonempty = true;
              }
            if (nonempty)
              os_ << ", tooltip=\"" << os.str() << '"';
          }
        os_ << "]\n";
        if (incomplete_ && incomplete_->find(s) != incomplete_->end())
          os_ << "  u" << s << (" [label=\"...\", shape=none, "
                                "width=0, height=0, "
                                "tooltip=\"hidden successors\"]\n  ")
              << s << " -> u" << s << (" [style=dashed, "
                                       "tooltip=\"hidden successors\"]\n");
      }

      void
      process_link(const twa_graph::edge_storage_t& t, int number,
                   bool print_edges)
      {
        bool dst_is_hidden_true_state =
          (t.dst < true_states_.size()) && true_states_[t.dst];

        if (print_edges)
          {
            if (dst_is_hidden_true_state)
              print_true_state(t.dst, t.src);
            os_ << "  " << t.src << " -> ";
            if (dst_is_hidden_true_state)
              os_ << 'T' << t.dst << 'T' << t.src;
            else
              os_  << (int)t.dst;
            if (aut_->is_univ_dest(t.dst) && highlight_edges_
                && !opt_shared_univ_dest_ && !dst_is_hidden_true_state)
              {
                auto idx = aut_->get_graph().index_of_edge(t);
                auto iter = highlight_edges_->find(idx);
                if (iter != highlight_edges_->end())
                  os_ << '.' << iter->second % palette_mod;
              }
            os_ << " [" << label_pre_;
            if (!opt_state_labels_ && opt_showlabel_)
              {
                if (opt_mealy_)
                  format_mealy(os_, t.cond);
                else
                  format_label(os_, t.cond);
              }
            if (!mark_states_)
              if (auto a = t.acc)
                {
                  if (!opt_state_labels_ && opt_showlabel_)
                    {
                      if (opt_mealy_ && opt_html_labels_)
                        os_ << "</TD></TR><TR><TD COLSPAN=\"3\">";
                      else
                        os_ << nl_;
                    }
                  output_mark(a);
                }
            if (opt_mealy_ && opt_html_labels_)
              os_ << "</TD></TR></TABLE>>";
            else
              os_ << label_post_;
            if (opt_ordered_edges_ || opt_numbered_edges_)
              {
                os_ << ", taillabel=\"";
                if (opt_ordered_edges_)
                  os_ << number;
                if (opt_ordered_edges_ && opt_numbered_edges_)
                  os_ << ' ';
                if (opt_numbered_edges_)
                  os_ << '#' << aut_->get_graph().index_of_edge(t);
                os_ << '"';
              }
            if (opt_id_)
              {
                unsigned index = aut_->get_graph().index_of_edge(t);
                os_ << ", id=\"E" << index << '"';
                // Somehow \E must appear as \\E in tooltip in
                // graphviz 2.43.0; this looks like a bug.
                os_ << ", tooltip=\"\\\\E\\n#" << index << '"';
              }
          }
        std::string highlight;
        int color_num = -1;
        if (highlight_edges_)
          {
            auto idx = aut_->get_graph().index_of_edge(t);
            auto iter = highlight_edges_->find(idx);
            if (iter != highlight_edges_->end())
              {
                std::ostringstream o;
                o << "style=bold, color=\""
                  << palette[iter->second % palette_mod]
                  << '"';
                highlight = o.str();
                if (print_edges)
                  os_ << ", " << highlight;
                if (!opt_shared_univ_dest_)
                  color_num = iter->second % palette_mod;
              }
          }
        if (print_edges)
          {
            if (aut_->is_univ_dest(t.dst))
              os_ << ", arrowhead=onormal";
            os_ << "]\n";
          }
        if (aut_->is_univ_dest(t.dst))
          print_dst(t.dst, print_edges, highlight.c_str(), color_num);
      }

      void print(const const_twa_graph_ptr& aut)
      {
        aut_ = aut;
        if (opt_hide_true_states_)
          find_true_states();

        sn_ = aut->get_named_prop<std::vector<std::string>>("state-names");
        // We have no names.  Do we have product sources?
        if (!sn_)
          {
            sprod_ = aut->get_named_prop
              <std::vector<std::pair<unsigned, unsigned>>>
              ("product-states");
            if (sprod_ && aut->num_states() != sprod_->size())
              sprod_ = nullptr;
          }

        if (opt_orig_show_)
          orig_ = aut->get_named_prop<std::vector<unsigned>>("original-states");
        if (opt_state_labels_)
          {
            // Verify that we can use state labels for this automaton.
            unsigned n = aut->num_states();
            for (unsigned s = 0; s < n; ++s)
              {
                bool first = true;
                bdd cond = bddfalse;
                for (auto& t: aut->out(s))
                  if (first)
                    {
                      cond = t.cond;
                      first = false;
                    }
                  else if (t.cond != cond)
                    {
                      opt_state_labels_ = false;
                      break;
                    }
              }
          }
        highlight_edges_ =
          aut->get_named_prop<std::map<unsigned, unsigned>>("highlight-edges");
        highlight_states_ =
          aut->get_named_prop<std::map<unsigned, unsigned>>("highlight-states");
        if (highlight_states_)
          {
            // If we use more than palette_mod/2 colors, we will use
            // some extra markers to distinguish colors.
            auto e = highlight_states_->end();
            highlight_states_show_num_ =
              std::find_if(highlight_states_->begin(), e,
                           [](auto p){
                             return p.second >= palette_mod / 2;
                           }) != e;
          }
        // setup Mealy machine rendering.
        if (!aut->get_named_prop<std::vector<bool>>("state-player"))
          if (auto p = aut->get_named_prop<bdd>("synthesis-outputs"))
            {
              if (aut->acc().is_t())
                opt_show_acc_ = false;
              bdd out = *p;
              opt_mealy_output_ = out;
              opt_mealy_ = true;
            }
        incomplete_ =
          aut->get_named_prop<std::set<unsigned>>("incomplete-states");
        state_player_ =
          aut_->get_named_prop<std::vector<bool>>("state-player");
        graph_name_ = aut_->get_named_prop<std::string>("automaton-name");
        if (opt_name_)
          name_ = graph_name_;
        mark_states_ = (!opt_force_acc_trans_
                        && aut_->prop_state_acc().is_true()
                        && aut_->num_sets() > 0);
        dcircles_ = (mark_states_
                     && (!opt_bullet || opt_bullet_but_buchi)
                     && (aut_->acc().is_buchi() || aut_->acc().is_co_buchi()));
        if (opt_shape_ == ShapeAuto)
          {
            if ((inline_state_names_ && (sn_ || sprod_ || opt_state_labels_))
                || (opt_state_labels_ && opt_latex_)
                || aut->num_states() > 1000
                || (mark_states_ && !dcircles_)
                || orig_)
              {
                opt_shape_ = ShapeRectangle;
                // If all state names are very short, prefer ellipses.
                if (!opt_state_labels_ && !orig_
                    && !(mark_states_ && !dcircles_)
                    && ((sn_ && std::all_of(sn_->begin(), sn_->end(),
                                            [](const std::string& s)
                                            { return s.size() <= 4; }))
                        || (sprod_ && std::all_of(sprod_->begin(),
                                                  sprod_->end(),
                                                  [](auto p)
                                                  {
                                                    return (p.first < 100
                                                            && p.second < 100);
                                                  }))))
                  opt_shape_ = ShapeEllipse;
              }
            else if (aut->num_states() > 10)
              {
                opt_shape_ = ShapeEllipse;
              }
            else
              {
                opt_shape_ = ShapeCircle;
              }
          }
        if (opt_shape_ == ShapeRectangle)
          extrastyle = ",rounded";
        auto si =
          std::unique_ptr<scc_info>(opt_scc_ ? new scc_info(aut) : nullptr);

        start();
        if (si)
          {
            if (aut->is_existential())
              si->determine_unknown_acceptance();

            unsigned sccs = si->scc_count();
            for (unsigned i = 0; i < sccs; ++i)
              {
                os_ << "  subgraph cluster_" << i << " {\n";

                // Color the SCC to indicate whether is it accepting.
                if (!si->is_useful_scc(i))
                  os_ << "  color=grey\n";
                else if (si->is_trivial(i))
                  os_ << "  color=black\n";
                else if (si->is_accepting_scc(i))
                  os_ << "  color=green\n";
                else if (si->is_rejecting_scc(i))
                  os_ << "  color=red\n";
                else
                  // May only occur if the call to
                  // determine_unknown_acceptance() above is removed.
                  os_ << "  color=orange\n";
                if (opt_id_)
                  os_ << "  id=\"SCC" << i << "\"\n";

                if (name_ || opt_show_acc_)
                  {
                    // Reset the label, otherwise the graph label would
                    // be inherited by the cluster.
                    os_ << (opt_latex_ ? "  texlbl=\"\"\n" : "  label=\"\"\n");
                  }
                for (auto s: si->states_of(i))
                  {
                    if (opt_hide_true_states_ && true_states_[s])
                      continue;
                    process_state(s);
                    int trans_num = 0;
                    unsigned scc_of_s = si->scc_of(s);
                    for (auto& t : aut_->out(s))
                      for (unsigned d: aut_->univ_dests(t.dst))
                        if (si->scc_of(d) == scc_of_s)
                          {
                            process_link(t, trans_num++, false);
                            break;
                          }
                  }
                os_ << "  }\n";
              }
          }
        int init = (int) aut_->get_init_state_number();
        if (init < 0)
          print_dst(init, true);
        unsigned ns = aut_->num_states();
        for (unsigned n = 0; n < ns; ++n)
          {
            if (opt_hide_true_states_ && true_states_[n])
              continue;
            if (!si || !si->reachable_state(n))
              process_state(n);
            int trans_num = 0;
            for (auto& t: aut_->out(n))
              process_link(t, trans_num++, true);
          }
        end();
      }
    };
  } // anonymous namespace

  std::ostream&
  print_dot(std::ostream& os, const const_twa_ptr& g, const char* options)
  {
    dotty_output d(os, options);
    // Enable state labels for Kripke structure.
    if (std::dynamic_pointer_cast<const fair_kripke>(g)
        && !d.uppercase_k_seen())
      d.parse_opts("k");
    auto aut = std::dynamic_pointer_cast<const twa_graph>(g);
    if (!aut || (d.max_states_given() && aut->num_states() >= d.max_states()))
      aut = make_twa_graph(g, twa::prop_set::all(), true, d.max_states() - 1);
    d.print(aut);
    return os;
  }

  namespace
  {
    class dotty_aig final
    {
      public:
      bool vertical = true;
      bool latex = false;
      std::ostream& os_;

      void
      parse_opts(const char *options)
      {
        while (char c = *options++)
          switch (c)
          {
          case 'h':
          {
            vertical = false;
            break;
          }
          case 'v':
          {
            vertical = true;
            break;
          }
          default:
            throw std::runtime_error("unknown option for print_dot(): "s + c);
          }
      }

      dotty_aig(std::ostream &os, const char *options)
          : os_(os)
      {
        parse_opts(options ? options : "");
      }

      void print(const aig_ptr &circuit)
      {
        if (!circuit)
          return;
        const auto& in_names = circuit->input_names();
        const auto& out_names = circuit->output_names();

        auto num_latches = circuit->num_latches();
        auto latches = circuit->next_latches();
        auto num_inputs = circuit->num_inputs();
        auto num_outputs = circuit->num_outputs();
        auto outputs = circuit->outputs();
        auto num_gates = circuit->num_gates();
        auto gates = circuit->gates();

        auto add_edge = [](std::ostream &stream, const unsigned src,
                           const unsigned dst) {
          auto src_gate = src & ~1;
          stream << "  " << src_gate << " -> " << dst;
          if (src & 1)
            stream << " [arrowhead=dot]";
          stream << '\n';
        };

        if (vertical)
          os_ << "digraph \"\" {\n  rankdir = BT\n";
        else
          os_ << "digraph \"\" {\n  rankdir = LR\n";

        os_ << "  {\n    rank = same\n"
          "    node [shape=box,style=filled,fillcolor=\"#ffe6cc\"]\n";
        for (unsigned i = 0; i < num_latches; ++i)
          {
            auto first_m_mod = circuit->latch_var(i) & ~1;
            os_ << "    " << first_m_mod << " [label=\"L" << i << "_out\"]\n";
          }
        os_ << "  }\n";
        if (num_gates)
          {
            os_ << "  node [shape=circle,style=solid]\n";
            for (unsigned i = 0; i < num_gates; ++i)
              if ((gates[i].first != 0) && (gates[i].second != 0))
                os_ << "  " << circuit->gate_var(i) << '\n';
          }
        bool has_false = false;
        if (num_latches)
          {
            os_ << "  {\n    rank=same\n"
              "    node [shape=box,style=filled,"
              "fillcolor=\"#ffe6cc\",label=\"\\N_in\"]\n";
            for (unsigned i = 0; i < num_latches; ++i)
              {
                os_ << "    L" << i << '\n';
                if (latches[i] <= 1)
                  has_false = true;
              }
            os_ << "  }\n";
          }
        const char* out_pos = vertical ? ":s" : ":w";
        const char* rotate = vertical ? "" : ",orientation=-90";
        if (num_outputs)
          {
            os_ << "  {\n    rank = sink\n    "
              "node [shape=invtriangle,style=filled,fillcolor=\"#ffe5f1\""
                << rotate << "]\n";
            for (unsigned i = 0; i < num_outputs; ++i)
              {
                os_ << "    o" << i << " [label=\"" << out_names[i] << "\"]\n";
                if (outputs[i] <= 1)
                  has_false = true;
              }
            os_ << "  }\n";
          }
        if (num_inputs | has_false)
          {
            os_ << "  {\n    rank=source\n"
              "    node [shape=triangle,style=filled,fillcolor=\"#e9f4fb\""
                << rotate << "]\n";
            for (unsigned i = 0; i < num_inputs; ++i)
              os_ << "    " << circuit->input_var(i)
                  << " [label=\"" << in_names[i] << "\"]\n";
            if (has_false)
              os_ <<
                "    0 [shape=box,fillcolor=\"#ffe6cc\",label=\"False\"]\n";
            os_ << "  }\n";
          }
        for (unsigned i = 0; i < num_outputs; ++i)
          {
            auto z = outputs[i];
            os_ << "  " << (z & ~1) << " -> o" << i << out_pos;
            if (z & 1)
              os_ << " [arrowhead=dot]";
            os_ << '\n';
          }
        for (unsigned i = 0; i < num_latches; ++i)
          {
            os_ << "  " << (latches[i] & ~1) << " -> L" << i;
            if (latches[i] & 1)
              os_ << " [arrowhead=dot]";
            os_ << '\n';
          }
        for (unsigned i = 0; i < num_gates; ++i)
          if ((gates[i].first != 0) && (gates[i].second != 0))
            {
              auto gate_var = circuit->gate_var(i);
              add_edge(os_, gates[i].first, gate_var);
              add_edge(os_, gates[i].second, gate_var);
            }
        os_ << "}\n";
      }
    };
  }

  std::ostream &
  print_dot(std::ostream &os, aig_ptr circuit, const char* options)
  {
    dotty_aig d(os, options);
    if (!circuit)
      return os;
    d.print(circuit);
    return os;
  }

}
