/* Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is also distributed with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.

   This program 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, version 2.0, for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */


#include "my_global.h"

#ifdef HAVE_SPATIAL

#include "sql_string.h"
#include "gcalc_tools.h"
#include "gstream.h"                            // Gis_read_stream
#include "spatial.h"
#include "sql_class.h"                          // THD

#define float_to_coord(d) ((double) d)


/*
  Adds new shape to the relation.
  After that it can be used as an argument of an operation.
*/

gcalc_shape_info Gcalc_function::add_new_shape(uint32 shape_id,
                                               shape_type shape_kind)
{
  shapes_buffer.q_append((uint32) shape_kind);
  return n_shapes++;
}


/*
  Adds new operation to the constructed relation.
  To construct the complex relation one has to specify operations
  in prefix style.
*/

void Gcalc_function::add_operation(op_type operation, uint32 n_operands)
{
  uint32 op_code= (uint32 ) operation + n_operands;
  function_buffer.q_append(op_code);
}


/*
  Sometimes the number of arguments is unknown at the moment the operation
  is added. That allows to specify it later.
*/

void Gcalc_function::add_operands_to_op(uint32 operation_pos, uint32 n_operands)
{
  uint32 op_code= uint4korr(function_buffer.ptr() + operation_pos) + n_operands;
  function_buffer.write_at_position(operation_pos, op_code);
}


void Gcalc_function::set_operands_to_op(uint32 operation_pos, uint32 n_operands)
{
  uint32 op_code= (uint4korr(function_buffer.ptr() + operation_pos) & op_any) +
                  n_operands;
  function_buffer.write_at_position(operation_pos, op_code);
}


/*
  Just like the add_operation() but the result will be the inverted
  value of an operation.
*/

void Gcalc_function::add_not_operation(op_type operation, uint32 n_operands)
{
  uint32 op_code= ((uint32) op_not | (uint32 ) operation) + n_operands;
  function_buffer.q_append(op_code);
}


int Gcalc_function::single_shape_op(shape_type shape_kind, gcalc_shape_info *si)
{
  if (reserve_shape_buffer(1) || reserve_op_buffer(1))
    return 1;
  *si= add_new_shape(0, shape_kind);
  add_operation(op_shape, *si);
  return 0;
}


/*
  Specify how many arguments we're going to have.
*/

int Gcalc_function::reserve_shape_buffer(uint n_shapes)
{
  return shapes_buffer.reserve(n_shapes * shape_buffer_item_size, 512);
}


/*
  Specify how many operations we're going to have.
*/

int Gcalc_function::reserve_op_buffer(uint n_ops)
{
  return function_buffer.reserve(n_ops * function_buffer_item_size, 512);
}


int Gcalc_function::alloc_states()
{
  if (function_buffer.reserve((n_shapes+1) * sizeof(int)))
    return 1;
  i_states= (int *) (function_buffer.ptr() + ALIGN_SIZE(function_buffer.length()));
  return 0;
}



#ifndef DBUG_OFF
/**
  Return spatial operation name from its numeric code.
*/
const char *Gcalc_function::op_name(int code)
{
  enum op_type type= (enum op_type) code;
  switch (type)
  {
  case op_shape:          return "op_shape";
  case op_not:            return "op_not";
  case op_union:          return "op_union";
  case op_intersection:   return "op_intersection";
  case op_symdifference:  return "op_symdifference";
  case op_difference:     return "op_difference";
  case op_backdifference: return "op_backdifference";
  case op_any:            return "op_any";
  }
  return "op_unknown";
}


const char *Gcalc_function::shape_name(int code)
{
  switch (code)
  {
  case shape_point: return   "shape_point";
  case shape_line:  return   "shape_line";
  case shape_polygon: return "shape_polygon";
  case shape_hole:    return "shape_hole";
  }
  return "shape_unknown";
}


/**
  Trace spatial operation buffer into debug log
  and optionally into client side warnings.
*/
void Gcalc_function::debug_print_function_buffer()
{
  int i, nelements= function_buffer.length() / function_buffer_item_size;
  THD *thd= current_thd;
  DBUG_PRINT("info", ("nelements=%d", nelements));
  for (i= 0; i < nelements; i++)
  {
    int c_op= uint4korr(function_buffer.ptr() + function_buffer_item_size * i);
    int func=  (c_op & op_any);
    int mask= (c_op & op_not) ? 1 : 0;
    int n_ops= c_op & ~op_any;
    const char *c_op_name= op_name(func);
    const char *s_name= (func == op_shape) ?
                         shape_name(uint4korr(shapes_buffer.ptr() +
                         shape_buffer_item_size * n_ops)) : "";
    DBUG_PRINT("info", ("[%d]=%d c_op=%d (%s) mask=%d n_ops=%d",
                       i, c_op, func, c_op_name, mask, n_ops));
    if (thd->get_gis_debug())
      push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN,
                          ER_UNKNOWN_ERROR, "[%d] %s[%d]%s",
                          i, c_op_name, n_ops, s_name);
  }
}
#endif


int Gcalc_function::count_internal()
{
  int c_op= uint4korr(cur_func);
  op_type next_func= (op_type) (c_op & op_any);
  int mask= (c_op & op_not) ? 1:0;
  int n_ops= c_op & ~op_any;
  int result;

  cur_func+= function_buffer_item_size;
  if (next_func == op_shape)
    return i_states[c_op & ~(op_any | op_not)] ^ mask;

  result= count_internal();

  while (--n_ops)
  {
    int next_res= count_internal();
    switch (next_func)
    {
      case op_union:
        result= result | next_res;
        break;
      case op_intersection:
        result= result & next_res;
        break;
      case op_symdifference:
        result= result ^ next_res;
        break;
      case op_difference:
        result= result & !next_res;
        break;
      case op_backdifference:
        result= (!result) & next_res;
        break;
      default:
        DBUG_ASSERT(FALSE);
    };
  }

  return result ^ mask;
}


/*
  Clear the state of the object.
*/

void Gcalc_function::reset()
{
  n_shapes= 0;
  shapes_buffer.length(0);
  function_buffer.length(0);
}


int Gcalc_function::find_function(Gcalc_scan_iterator &scan_it)
{
  while (scan_it.more_points())
  {
    if (scan_it.step())
      return -1;
    Gcalc_scan_events ev= scan_it.get_event();
    const Gcalc_scan_iterator::point *evpos= scan_it.get_event_position();
    if (ev & (scev_point | scev_end | scev_two_ends))
      continue;

    clear_state();
    for (Gcalc_point_iterator pit(&scan_it); pit.point() != evpos; ++pit)
    {
      gcalc_shape_info si= pit.point()->get_shape();
      if ((get_shape_kind(si) == Gcalc_function::shape_polygon))
        invert_state(si);
    }
    invert_state(evpos->get_shape());

    if (ev == scev_intersection)
    {
      const Gcalc_scan_iterator::point *evnext= evpos->c_get_next();
      if ((get_shape_kind(evpos->get_shape()) !=
             Gcalc_function::shape_polygon)             ||
          (get_shape_kind(evnext->get_shape()) !=
             Gcalc_function::shape_polygon))
        invert_state(evnext->get_shape());
    }

    if (count())
      return 1;
  }
  return 0;
}


int Gcalc_operation_transporter::single_point(Gcalc_shape_status *st,
                                              double x, double y)
{
  DBUG_PRINT("info", ("Gcalc_operation_transporter::single_point: %g %g", x, y));
  gcalc_shape_info si;
  return m_fn->single_shape_op(Gcalc_function::shape_point, &si) ||
         int_single_point(si, x, y);
}


int Gcalc_operation_transporter::start_line(Gcalc_shape_status *st)
{
  DBUG_PRINT("info", ("Gcalc_operation_transporter::start_line"));
  int_start_line();
  return m_fn->single_shape_op(Gcalc_function::shape_line, &m_si);
}


int Gcalc_operation_transporter::complete_line(Gcalc_shape_status *st)
{
  DBUG_PRINT("info", ("Gcalc_operation_transporter::complete_line"));
  int_complete_line();
  return 0;
}


int Gcalc_operation_transporter::start_poly(Gcalc_shape_status *st)
{
  DBUG_PRINT("info", ("Gcalc_operation_transporter::start_poly"));
  int_start_poly();
  return m_fn->single_shape_op(Gcalc_function::shape_polygon, &m_si);
}


int Gcalc_operation_transporter::complete_poly(Gcalc_shape_status *st)
{
  DBUG_PRINT("info", ("Gcalc_operation_transporter::complete_poly"));
  int_complete_poly();
  return 0;
}


int Gcalc_operation_transporter::start_ring(Gcalc_shape_status *st)
{
  DBUG_PRINT("info", ("Gcalc_operation_transporter::start_ring"));
  int_start_ring();
  return 0;
}


int Gcalc_operation_transporter::complete_ring(Gcalc_shape_status *st)
{
  DBUG_PRINT("info", ("Gcalc_operation_transporter::complete_ring"));
  int_complete_ring();
  return 0;
}


int Gcalc_operation_transporter::add_point(Gcalc_shape_status *st,
                                           double x, double y)
{
  DBUG_PRINT("info", ("Gcalc_operation_transporter::add_point %g %g", x, y));
  return int_add_point(m_si, x, y);
}


int Gcalc_operation_transporter::start_collection(Gcalc_shape_status *st,
                                                  int n_objects)
{
  DBUG_PRINT("info", ("Gcalc_operation_transporter::start_collection"));
  if (m_fn->reserve_shape_buffer(n_objects) || m_fn->reserve_op_buffer(1))
    return 1;
  m_fn->add_operation(Gcalc_function::op_union, n_objects);
  return 0;
}


int Gcalc_operation_transporter::complete_collection(Gcalc_shape_status *st)
{
  DBUG_PRINT("info", ("Gcalc_operation_transporter::complete_collection"));
  return 0;
}


int Gcalc_operation_transporter::collection_add_item(Gcalc_shape_status
                                                     *st_collection,
                                                     Gcalc_shape_status
                                                     *st_item)
{
  DBUG_PRINT("info", ("Gcalc_operation_transporter::collection_add_item"));
  return 0;
}


int Gcalc_result_receiver::start_shape(Gcalc_function::shape_type shape)
{
  DBUG_ENTER("Gcalc_result_receiver::start_shape");
  DBUG_PRINT("info", ("%s", Gcalc_function::shape_name(shape)));
  if (buffer.reserve(4*2, 512))
    DBUG_RETURN(1);
  cur_shape= shape;
  shape_pos= buffer.length();
  buffer.length(shape_pos + ((shape == Gcalc_function::shape_point) ? 4:8));
  n_points= 0;
  shape_area= 0.0;

  DBUG_RETURN(0);
}


int Gcalc_result_receiver::add_point(double x, double y)
{
  DBUG_ENTER("Gcalc_result_receiver::add_point");
  DBUG_PRINT("info", ("xy=(%g,%g)", x, y));
  if (n_points && x == prev_x && y == prev_y)
    DBUG_RETURN(0);

  if (!n_points++)
  {
    prev_x= first_x= x;
    prev_y= first_y= y;
    DBUG_RETURN(0);
  }

  shape_area+= prev_x*y - prev_y*x;

  if (buffer.reserve(8*2, 512))
    DBUG_RETURN(1);
  buffer.q_append(prev_x);
  buffer.q_append(prev_y);
  prev_x= x;
  prev_y= y;
  DBUG_RETURN(0);
}


int Gcalc_result_receiver::complete_shape()
{
  DBUG_ENTER("Gcalc_result_receiver::complete_shape");
  DBUG_PRINT("info", ("n_points=%u", (uint) n_points));
  if (n_points == 0)
  {
    buffer.length(shape_pos);
    DBUG_RETURN(0);
  }
  if (n_points == 1)
  {
    if (cur_shape == Gcalc_function::shape_hole ||
        cur_shape == Gcalc_function::shape_polygon)
    {
      /*
        All points of a hole (or a polygon) have the same 
        coordinates - remove the shape.
      */
      buffer.length(shape_pos);
      DBUG_RETURN(0);
    }
    if (cur_shape != Gcalc_function::shape_point)
    {
      cur_shape= Gcalc_function::shape_point;
      buffer.length(buffer.length()-4);
    }
  }
  else
  {
    if (cur_shape == Gcalc_function::shape_point)
    {
      DBUG_RETURN(1);
    }

    DBUG_ASSERT(cur_shape != Gcalc_function::shape_point);
    if (cur_shape == Gcalc_function::shape_hole ||
        cur_shape == Gcalc_function::shape_polygon)
    {
      shape_area+= prev_x*first_y - prev_y*first_x;
      /* Remove a hole (or a polygon) if its area == 0. */
      if (fabs(shape_area) < 1e-8)
      {
        buffer.length(shape_pos);
        DBUG_RETURN(0);
      }
      if (prev_x == first_x && prev_y == first_y)
      {
        n_points--;
        buffer.write_at_position(shape_pos + 4, n_points);
        goto do_complete;
      }
    }
    buffer.write_at_position(shape_pos+4, n_points);
  }

  if (buffer.reserve(8*2, 512))
    DBUG_RETURN(1);
  buffer.q_append(prev_x);
  buffer.q_append(prev_y);
  
do_complete:
  buffer.write_at_position(shape_pos, (uint32) cur_shape);

  if (!n_shapes++)
  {
    DBUG_ASSERT(cur_shape != Gcalc_function::shape_hole);
    common_shapetype= cur_shape;
  }
  else if (cur_shape == Gcalc_function::shape_hole)
  {
    ++n_holes;
  }
  else if (!collection_result && (cur_shape != common_shapetype))
  {
      collection_result= true;
  }
  DBUG_PRINT("info",
             ("n_shapes=%u cur_shape=%s common_shapetype=%s",
              (uint) n_shapes, Gcalc_function::shape_name(cur_shape),
              Gcalc_function::shape_name(common_shapetype)));
  DBUG_RETURN(0);
}


int Gcalc_result_receiver::single_point(double x, double y)
{
  DBUG_PRINT("info", ("single_point xy=(%g,%g)", x, y));
  return start_shape(Gcalc_function::shape_point) ||
         add_point(x, y) ||
         complete_shape();
}


int Gcalc_result_receiver::done()
{
  DBUG_ENTER("Gcalc_result_receiver::done");
  DBUG_RETURN(0);
}


void Gcalc_result_receiver::reset()
{
  DBUG_ENTER("Gcalc_result_receiver::reset");
  buffer.length(0);
  collection_result= FALSE;
  n_shapes= n_holes= 0;
  DBUG_VOID_RETURN;
}


int Gcalc_result_receiver::get_result_typeid()
{
  DBUG_ENTER("Gcalc_result_receiver::get_result_typeid");
  if (!n_shapes)
    DBUG_RETURN(0);

  if (collection_result)
    DBUG_RETURN(Geometry::wkb_geometrycollection);
  switch (common_shapetype)
  {
    case Gcalc_function::shape_polygon:
      DBUG_RETURN((n_shapes - n_holes == 1) ? Geometry::wkb_polygon :
                                              Geometry::wkb_multipolygon);
    case Gcalc_function::shape_point:
      DBUG_RETURN((n_shapes == 1) ? Geometry::wkb_point :
                                    Geometry::wkb_multipoint);
    case Gcalc_function::shape_line:
      DBUG_RETURN((n_shapes == 1) ? Geometry::wkb_linestring :
                                    Geometry::wkb_multilinestring);
    default:
      DBUG_ASSERT(0);
  }
  DBUG_RETURN(0);
}


Gcalc_operation_reducer::Gcalc_operation_reducer(size_t blk_size) :
  Gcalc_dyn_list(blk_size, sizeof(res_point)),
  m_res_hook((Gcalc_dyn_list::Item **)&m_result),
  m_first_active_thread(NULL)
{
  // We use sizeof(res_point) in constructor, the other items must be smaller
  DBUG_ASSERT(sizeof(res_point) >= sizeof(active_thread));
}


void Gcalc_operation_reducer::init(Gcalc_function *fn, modes mode)
{
  DBUG_ENTER("Gcalc_result_receiver::init");
  m_fn= fn;
  m_mode= mode;
  m_first_active_thread= NULL;
  DBUG_VOID_RETURN;
}


Gcalc_operation_reducer::
Gcalc_operation_reducer(Gcalc_function *fn, modes mode, size_t blk_size) :
  Gcalc_dyn_list(blk_size, sizeof(res_point)),
  m_res_hook((Gcalc_dyn_list::Item **)&m_result)
{
  DBUG_ENTER("Gcalc_operation_reducer::Gcalc_operation_reducer");
  init(fn, mode);
  DBUG_VOID_RETURN;
}


inline int Gcalc_operation_reducer::continue_range(active_thread *t,
						const Gcalc_heap::Info *p)
{
  DBUG_ENTER("Gcalc_operation_reducer::continue_range");
  DBUG_ASSERT(t->result_range);
  res_point *rp= add_res_point(p);
  if (!rp)
    DBUG_RETURN(1);
  rp->glue= NULL;
  rp->down= t->rp;
  t->rp->up= rp;
  t->rp= rp;
  DBUG_RETURN(0);
}


inline int Gcalc_operation_reducer::continue_i_range(active_thread *t,
						  const Gcalc_heap::Info *p,
						  double x, double y)
{
  DBUG_ENTER("Gcalc_operation_reducer::continue_i_range");
  DBUG_ASSERT(t->result_range);
  res_point *rp= add_res_i_point(p, x, y);
  if (!rp)
    DBUG_RETURN(1);
  rp->glue= NULL;
  rp->down= t->rp;
  t->rp->up= rp;
  t->rp= rp;
  DBUG_RETURN(0);
}

inline int Gcalc_operation_reducer::start_range(active_thread *t,
					     const Gcalc_heap::Info *p)
{
  DBUG_ENTER("Gcalc_operation_reducer::start_range");
  res_point *rp= add_res_point(p);
  if (!rp)
    DBUG_RETURN(1);
  rp->glue= rp->down= NULL;
  t->result_range= 1;
  t->rp= rp;
  DBUG_RETURN(0);
}

inline int Gcalc_operation_reducer::start_i_range(active_thread *t,
					       const Gcalc_heap::Info *p,
					       double x, double y)
{
  DBUG_ENTER("Gcalc_operation_reducer::start_i_range");
  res_point *rp= add_res_i_point(p, x, y);
  if (!rp)
    DBUG_RETURN(1);
  rp->glue= rp->down= NULL;
  t->result_range= 1;
  t->rp= rp;
  DBUG_RETURN(0);
}

inline int Gcalc_operation_reducer::end_range(active_thread *t,
					   const Gcalc_heap::Info *p)
{
  DBUG_ENTER("Gcalc_operation_reducer::end_range");
  res_point *rp= add_res_point(p);
  if (!rp)
    DBUG_RETURN(1);
  rp->glue= rp->up= NULL;
  rp->down= t->rp;
  t->rp->up= rp;
  t->result_range= 0;
  DBUG_RETURN(0);
}

inline int Gcalc_operation_reducer::end_i_range(active_thread *t,
					     const Gcalc_heap::Info *p,
					     double x, double y)
{
  DBUG_ENTER("Gcalc_operation_reducer::end_i_range");
  res_point *rp= add_res_i_point(p, x, y);
  if (!rp)
    DBUG_RETURN(1);
  rp->glue= rp->up= NULL;
  rp->down= t->rp;
  t->rp->up= rp;
  t->result_range= 0;
  DBUG_RETURN(0);
}

int Gcalc_operation_reducer::start_couple(active_thread *t0, active_thread *t1,
				       const Gcalc_heap::Info *p,
                                       const active_thread *prev_range)
{
  DBUG_ENTER("Gcalc_operation_reducer::start_couple");
  res_point *rp0, *rp1;
  if (!(rp0= add_res_point(p)) || !(rp1= add_res_point(p)))
    DBUG_RETURN(1);
  rp0->glue= rp1;
  rp1->glue= rp0;
  rp0->down= rp1->down= NULL;
  t0->rp= rp0;
  t1->rp= rp1;
  if (prev_range)
  {
    rp0->set_outer_poly(prev_range->thread_start());
    t1->set_thread_start(prev_range->thread_start());
  }
  else
  {
    rp0->set_outer_poly(NULL);
    t0->set_thread_start(rp0);
  }
  DBUG_RETURN(0);
}

int Gcalc_operation_reducer::start_i_couple(active_thread *t0, active_thread *t1,
					 const Gcalc_heap::Info *p0,
					 const Gcalc_heap::Info *p1,
					 double x, double y,
                                         const active_thread *prev_range)
{
  DBUG_ENTER("Gcalc_operation_reducer::start_i_couple");
  res_point *rp0, *rp1;
  if (!(rp0= add_res_i_point(p0, x, y)) || !(rp1= add_res_i_point(p1, x, y)))
    DBUG_RETURN(1);
  rp0->glue= rp1;
  rp1->glue= rp0;
  rp0->down= rp1->down= NULL;
  t0->result_range= t1->result_range= 1;
  t0->rp= rp0;
  t1->rp= rp1;
  if (prev_range)
  {
    rp0->set_outer_poly(prev_range->thread_start());
    t1->set_thread_start(prev_range->thread_start());
  }
  else
  {
    rp0->set_outer_poly(NULL);
    t0->set_thread_start(rp0);
  }
  DBUG_RETURN(0);
}

int Gcalc_operation_reducer::end_couple(active_thread *t0, active_thread *t1,
				     const Gcalc_heap::Info *p)
{
  DBUG_ENTER("Gcalc_operation_reducer::end_couple");
  res_point *rp0, *rp1;
  if (!t1->result_range)
    DBUG_RETURN(1);
  if (!(rp0= add_res_point(p)) || !(rp1= add_res_point(p)))
    DBUG_RETURN(1);
  rp0->down= t0->rp;
  rp1->down= t1->rp;
  rp1->glue= rp0;
  rp0->glue= rp1;
  rp0->up= rp1->up= NULL;
  t0->rp->up= rp0;
  t1->rp->up= rp1;
  t0->result_range= t1->result_range= 0;
  DBUG_RETURN(0);
}

int Gcalc_operation_reducer::end_i_couple(active_thread *t0, active_thread *t1,
				       const Gcalc_heap::Info *p0,
				       const Gcalc_heap::Info *p1,
				       double x, double y)
{
  DBUG_ENTER("Gcalc_operation_reducer::end_i_couple");
  res_point *rp0, *rp1;
  if (!(rp0= add_res_i_point(p0, x, y)) || !(rp1= add_res_i_point(p1, x, y)))
    DBUG_RETURN(1);
  rp0->down= t0->rp;
  rp1->down= t1->rp;
  rp1->glue= rp0;
  rp0->glue= rp1;
  rp0->up= rp1->up= NULL;
  t0->result_range= t1->result_range= 0;
  t0->rp->up= rp0;
  t1->rp->up= rp1;
  DBUG_RETURN(0);
}

int Gcalc_operation_reducer::add_single_point(const Gcalc_heap::Info *p)
{
  DBUG_ENTER("Gcalc_operation_reducer::add_single_point");
  res_point *rp= add_res_single_point(p);
  if (!rp)
    DBUG_RETURN(1);
  rp->glue= rp->up= rp->down= NULL;
  DBUG_RETURN(0);
}

int Gcalc_operation_reducer::add_i_single_point(const Gcalc_heap::Info *p,
					     double x, double y)
{
  DBUG_ENTER("Gcalc_operation_reducer::add_i_single_point");
  res_point *rp= add_res_i_point(p, x, y);
  if (!rp)
    DBUG_RETURN(1);
  rp->glue= rp->up= rp->down= NULL;
  DBUG_RETURN(0);
}

int Gcalc_operation_reducer::
handle_lines_intersection(active_thread *t0, active_thread *t1,
			  const Gcalc_heap::Info *p0, const Gcalc_heap::Info *p1,
			  double x, double y)
{
  DBUG_ENTER("Gcalc_operation_reducer::handle_lines_intersection");
  DBUG_PRINT("info", ("p=(%g,%g,#%u) p1=(%g,%g,#%u) xy=(%g,%g)",
                      p0->x, p0->y, p0->shape, p1->x, p1->y, p1->shape, x, y));
  m_fn->invert_state(p0->shape);
  m_fn->invert_state(p1->shape);
  int intersection_state= m_fn->count();
  if ((t0->result_range | t1->result_range) == intersection_state)
    DBUG_RETURN(0);

  if (t0->result_range &&
      (end_i_range(t0, p1, x, y) || start_i_range(t0, p1, x, y)))
    DBUG_RETURN(1);

  if (t1->result_range &&
      (end_i_range(t1, p0, x, y) || start_i_range(t1, p0, x, y)))
    DBUG_RETURN(1);

  if (intersection_state &&
      add_i_single_point(p0, x, y))
    DBUG_RETURN(1);
    
  DBUG_RETURN(0);
}

inline int Gcalc_operation_reducer::
handle_line_polygon_intersection(active_thread *l, const Gcalc_heap::Info *pl,
				 int line_state, int poly_state,
				 double x, double y)
{
  DBUG_ENTER("Gcalc_operation_reducer::handle_line_polygon_intersection");
  DBUG_PRINT("info", ("p=(%g,%g,#%u) xy=(%g,%g)",
                      pl->x, pl->y, pl->shape, x, y));
  int range_after= ~poly_state & line_state;
  if (l->result_range == range_after)
    DBUG_RETURN(0);
  DBUG_RETURN(range_after ? start_i_range(l, pl, x, y) :
                            end_i_range(l, pl, x, y));
}

static inline void switch_athreads(Gcalc_operation_reducer::active_thread *t0,
				   Gcalc_operation_reducer::active_thread *t1,
				   Gcalc_dyn_list::Item **hook)
{
  *hook= t1;
  t0->next= t1->next;
  t1->next= t0;
}

inline int Gcalc_operation_reducer::
handle_polygons_intersection(active_thread *t0, active_thread *t1,
			     Gcalc_dyn_list::Item **t_hook,
			     const Gcalc_heap::Info *p0,
			     const Gcalc_heap::Info *p1,
			     int prev_state, double x, double y,
                             const active_thread *prev_range)
{
  DBUG_ENTER("Gcalc_operation_reducer::handle_polygons_intersection");
  DBUG_PRINT("info", ("p0=(%g,%g,#%u) p1=(%g,%g,#%u) xy=(%g,%g)",
                      p0->x, p0->y, p0->shape, p1->x, p1->y, p1->shape, x, y));
  m_fn->invert_state(p0->shape);
  int state_11= m_fn->count();
  m_fn->invert_state(p1->shape);
  int state_2= m_fn->count();
  int state_01= prev_state ^ t0->result_range;
  if ((prev_state == state_01) && (prev_state == state_2))
  {
    if (state_11 == prev_state)
    {
      switch_athreads(t0, t1, t_hook);
      DBUG_RETURN(0);
    }
    DBUG_RETURN(start_i_couple(t0, t1, p0, p1, x, y, prev_range));
  }
  if (prev_state == state_2)
  {
    if (state_01 == state_11)
    {
      if (m_mode & polygon_selfintersections_allowed)
      {
	switch_athreads(t0, t1, t_hook);
	DBUG_RETURN(0);
      }
      if (prev_state != (m_mode & prefer_big_with_holes))
        DBUG_RETURN(continue_i_range(t0, p0, x, y) ||
                    continue_i_range(t1, p1, x, y));
      DBUG_RETURN(end_i_couple(t0, t1, p0, p1, x, y) ||
                  start_i_couple(t0, t1, p0, p1, x, y, prev_range));
    }
    else
      DBUG_RETURN(end_i_couple(t0, t1, p0, p1, x, y));
  }
  if (state_01 ^ state_11)
  {
    switch_athreads(t0, t1, t_hook);
    DBUG_RETURN(0);
  }

  active_thread *thread_to_continue;
  const Gcalc_heap::Info *way_to_go;
  if (prev_state == state_01)
  {
    thread_to_continue= t1;
    way_to_go= p1;
  }
  else 
  {
    thread_to_continue= t0;
    way_to_go= p0;
  }
  DBUG_RETURN(continue_i_range(thread_to_continue, way_to_go, x, y));
}

int Gcalc_operation_reducer::count_slice(Gcalc_scan_iterator *si)
{
  DBUG_ENTER("Gcalc_operation_reducer::count_slice");
  Gcalc_point_iterator pi(si);
  active_thread *cur_t= m_first_active_thread;
  Gcalc_dyn_list::Item **at_hook= (Gcalc_dyn_list::Item **)&m_first_active_thread;
  const active_thread *prev_range;
  int prev_state;

  if (si->get_event() & (scev_point | scev_end | scev_two_ends))
  {
    for (; pi.point() != si->get_event_position(); ++pi, cur_t= cur_t->get_next())
      at_hook= &cur_t->next;

    switch (si->get_event())
    {
      case scev_point:
      {
        DBUG_PRINT("Gcalc_operation_reducer", ("event=scev_point"));
        if (cur_t->result_range &&
            continue_range(cur_t, pi.get_pi()))
          DBUG_RETURN(1);
        break;
      }
      case scev_end:
      {
        DBUG_PRINT("Gcalc_operation_reducer", ("event=scev_end"));
        if (cur_t->result_range &&
            end_range(cur_t, pi.get_pi()))
          DBUG_RETURN(1);
        *at_hook= cur_t->next;
        free_item(cur_t);
        break;
      }
      case scev_two_ends:
      {
        DBUG_PRINT("Gcalc_operation_reducer", ("event=scev_two_ends"));
        active_thread *cur_t1= cur_t->get_next();
        if (cur_t->result_range &&
            end_couple(cur_t, cur_t1, pi.get_pi()))
          DBUG_RETURN(1);

        *at_hook= cur_t1->next;
        free_list(cur_t, &cur_t1->next);
        break;
      }
      default:
        DBUG_ASSERT(0);
    }
    DBUG_RETURN(0);
  }

  prev_state= 0;
  prev_range= 0;

  m_fn->clear_state();
  for (; pi.point() != si->get_event_position(); ++pi, cur_t= cur_t->get_next())
  {
    if (m_fn->get_shape_kind(pi.get_shape()) == Gcalc_function::shape_polygon)
    {
      m_fn->invert_state(pi.get_shape());
      prev_state^= cur_t->result_range;
    }
    at_hook= &cur_t->next;
    if (cur_t->result_range)
      prev_range= prev_state ? cur_t : 0;
  }

  switch (si->get_event())
  {
  case scev_thread:
  {
    DBUG_PRINT("info", ("event=scev_thread"));
    active_thread *new_t= new_active_thread();
    if (!new_t)
      DBUG_RETURN(1);
    m_fn->invert_state(pi.get_shape());
    new_t->result_range= prev_state ^ m_fn->count();
    new_t->next= *at_hook;
    *at_hook= new_t;
    if (new_t->result_range &&
	start_range(new_t, pi.get_pi()))
      DBUG_RETURN(1);
    break;
  }
  case scev_two_threads:
  {
    DBUG_PRINT("info", ("event=scev_two_threads"));
    active_thread *new_t0, *new_t1;
    int fn_result;
    if (!(new_t0= new_active_thread()) || !(new_t1= new_active_thread()))
      DBUG_RETURN(1);
    
    m_fn->invert_state(pi.get_shape());
    fn_result= m_fn->count();
    new_t0->result_range= new_t1->result_range= prev_state ^ fn_result;
    new_t1->next= *at_hook;
    new_t0->next= new_t1;
    *at_hook= new_t0;
    if (new_t0->result_range &&
	start_couple(new_t0, new_t1, pi.get_pi(), prev_range))
      DBUG_RETURN(1);
    break;
  }
  case scev_intersection:
  {
    DBUG_PRINT("info", ("event=scev_intersection"));
    active_thread *cur_t1= cur_t->get_next();
    const Gcalc_heap::Info *p0, *p1;
    p0= pi.get_pi();
    ++pi;
    p1= pi.get_pi();
    bool line0= m_fn->get_shape_kind(p0->shape) == Gcalc_function::shape_line;
    bool line1= m_fn->get_shape_kind(p1->shape) == Gcalc_function::shape_line;

    if (!line0 && !line1) /* two polygons*/
    {
      if (handle_polygons_intersection(cur_t, cur_t1, at_hook, p0, p1,
				       prev_state, pi.get_x(), si->get_y(),
                                       prev_range))
        DBUG_RETURN(1);
    }
    else if (line0 && line1)
    {
      if (!prev_state &&
	  handle_lines_intersection(cur_t, cur_t1,
				    p0, p1, pi.get_x(), si->get_y()))
        DBUG_RETURN(1);
      switch_athreads(cur_t, cur_t1, at_hook);
    }
    else
    {
      int poly_state;
      int line_state;
      const Gcalc_heap::Info *line;
      active_thread *line_t;
      m_fn->invert_state(p0->shape);
      if (line0)
      {
	line_state= m_fn->count();
	poly_state= prev_state;
	line= p0;
	line_t= cur_t1;
      }
      else
      {
	poly_state= m_fn->count();
	m_fn->invert_state(p1->shape);
	line_state= m_fn->count();
	line= p1;
	line_t= cur_t;
      }
      if (handle_line_polygon_intersection(line_t, line,
					   line_state, poly_state,
					   pi.get_x(), si->get_y()))
        DBUG_RETURN(1);
      switch_athreads(cur_t, cur_t1, at_hook);
    }
    break;
  }
  case scev_single_point:
  {
    DBUG_PRINT("info", ("event=scev_single_point"));
    m_fn->invert_state(pi.get_shape());
    if ((prev_state ^ m_fn->count()) &&
	add_single_point(pi.get_pi()))
      DBUG_RETURN(1);
    break;
  }
  default:
    DBUG_ASSERT(0);
  }

  DBUG_RETURN(0);
}

int Gcalc_operation_reducer::count_all(Gcalc_heap *hp)
{
  DBUG_ENTER("Gcalc_operation_reducer::count_all");
  Gcalc_scan_iterator si;
  si.init(hp);
  while (si.more_points())
  {
    if (si.step())
      DBUG_RETURN(1);
    if (count_slice(&si))
      DBUG_RETURN(1);
  }
  DBUG_RETURN(0);
}

inline void Gcalc_operation_reducer::free_result(res_point *res)
{
  DBUG_ENTER("Gcalc_result_receiver::free_result");
  if ((*res->prev_hook= res->next))
  {
    res->get_next()->prev_hook= res->prev_hook;
  }
  free_item(res);
  DBUG_VOID_RETURN;
}


inline int Gcalc_operation_reducer::get_single_result(res_point *res,
						   Gcalc_result_receiver *storage)
{
  DBUG_ENTER("Gcalc_operation_reducer::get_single_result");
  if (res->intersection_point)
  {
    if (storage->single_point(float_to_coord(res->x),
			      float_to_coord(res->y)))
      DBUG_RETURN(1);
  }
  else
    if (storage->single_point(res->x, res->y))
      DBUG_RETURN(1);
  free_result(res);
  DBUG_RETURN(0);
}


int Gcalc_operation_reducer::get_result_thread(res_point *cur,
                                               Gcalc_result_receiver *storage,
                                               int move_upward)
{
  DBUG_ENTER("Gcalc_operation_reducer::get_result_thread");
  res_point *next;
  bool glue_step= false;
  res_point *first_poly_node= cur;
  double x, y;
  while (cur)
  {
    if (!glue_step)
    {
      if (cur->intersection_point)
      {
        x= float_to_coord(cur->x);
        y= float_to_coord(cur->y);
      }
      else
      {
	x= cur->pi->x;
        y= cur->pi->y;
      }
      if (storage->add_point(x, y))
        DBUG_RETURN(1);
    }
    
    next= move_upward ? cur->up : cur->down;
    if (!next && !glue_step)
    {
      next= cur->glue;
      move_upward^= 1;
      glue_step= true;
      if (next)
	next->glue= NULL;
    }
    else
      glue_step= false;

    cur->first_poly_node= first_poly_node;
    free_result(cur);
    cur= next;
  }
  DBUG_RETURN(0);
}


int Gcalc_operation_reducer::get_polygon_result(res_point *cur,
                                                Gcalc_result_receiver *storage)
{
  DBUG_ENTER("Gcalc_operation_reducer::get_polygon_result");
  res_point *glue= cur->glue;
  if(glue)
  {
    if(glue->up)
      glue->up->down= NULL;
    free_result(glue);
    cur->glue= NULL;
  }
  DBUG_RETURN(get_result_thread(cur, storage, 1) ||
              storage->complete_shape());
}


int Gcalc_operation_reducer::get_line_result(res_point *cur,
                                             Gcalc_result_receiver *storage)
{
  DBUG_ENTER("Gcalc_operation_reducer::get_line_result");
  res_point *next;
  int move_upward= 1;
  if (cur->glue)
  {
    /* Here we have to find the beginning of the line */
    next= cur->up;
    move_upward= 1;
    while (next)
    {
      cur= next;
      next= move_upward ? next->up : next->down;
      if (!next)
      {
	next= cur->glue;
	move_upward^= 1;
      }
    }
  }

  DBUG_RETURN(get_result_thread(cur, storage, move_upward) ||
              storage->complete_shape());
}


static int chunk_info_cmp(const Gcalc_result_receiver::chunk_info *a1,
                          const Gcalc_result_receiver::chunk_info *a2)
{
  if (a1->first_point != a2->first_point)
    return a1->first_point < a2->first_point ? -1 : 1;
  if (a1->is_poly_hole != a2->is_poly_hole)
    return a1->is_poly_hole < a2->is_poly_hole ? -1 : 1;
  return (int) a1->order - (int) a2->order;
}


#ifndef DBUG_OFF
void Gcalc_result_receiver::chunk_info::dbug_print() const
{
  DBUG_PRINT("info", ("first_point=%p order=%d position=%d length=%d",
                      first_point, (int) order, (int) position, (int) length));
}
#endif


/**
  Rearrange the result shape chunks according to the required order.
*/
int Gcalc_result_receiver::reorder_chunks(chunk_info *chunks, int nchunks)
{
  DBUG_ENTER("Gcalc_result_receiver::sort_polygon_rings");

  String tmp;
  uint32 reserve_length= buffer.length();
  if (tmp.reserve(reserve_length, MY_ALIGN(reserve_length, 512)))
    DBUG_RETURN(1);

  // Put shape data in the required order
  for (chunk_info *chunk= chunks, *end= chunks + nchunks; chunk < end; chunk++)
  {
#ifndef DBUG_OFF
    chunk->dbug_print();
#endif
    tmp.append(buffer.ptr() + chunk->position, (size_t) chunk->length);
  }
  // Make sure all chunks were put
  DBUG_ASSERT(tmp.length() == buffer.length());
  // Get all data from tmp and unlink tmp from its buffer.
  buffer.takeover(tmp);
  DBUG_RETURN(0);
}


int Gcalc_operation_reducer::get_result(Gcalc_result_receiver *storage)
{
  DBUG_ENTER("Gcalc_operation_reducer::get_result");
  Dynamic_array<Gcalc_result_receiver::chunk_info> chunks;
  bool polygons_found= false;
  int counter= 0;

  *m_res_hook= NULL;
  while (m_result)
  {
    /**
      Handle cyclic graph scenario. This can occur due to invalid input
      geometry. Ideally the comparison should be with length of the string.
      We have choosen an arbitory number suitable for practical usecase's
      due to the complexity involved in checking with the length.
    */
    counter++;
    if (counter > 10000)
      DBUG_RETURN(1);

    Gcalc_function::shape_type shape;
    Gcalc_result_receiver::chunk_info chunk;

    chunk.first_point= m_result;
    chunk.order= chunks.elements();
    chunk.position= storage->position();
    chunk.is_poly_hole= false;

    if (!m_result->up)
    {
      if (get_single_result(m_result, storage))
	DBUG_RETURN(1);
      goto end_shape;
    }
    
    shape= m_fn->get_shape_kind(m_result->pi->shape);
    if (shape == Gcalc_function::shape_polygon)
    {
      polygons_found= true;
      if (m_result->get_outer_poly()) // Inner ring (hole)
      {
        chunk.first_point= m_result->get_outer_poly();
        chunk.is_poly_hole= true;
        shape= Gcalc_function::shape_hole;
      }
      storage->start_shape(shape);
      if (get_polygon_result(m_result, storage))
        DBUG_RETURN(1);
      chunk.first_point= ((res_point*) chunk.first_point)->first_poly_node;
    }
    else
    {
      storage->start_shape(shape);
      if (get_line_result(m_result, storage))
        DBUG_RETURN(1);
    }

end_shape:
    chunk.length= storage->position() - chunk.position;
    chunks.append(chunk);
  }

  /*
    In case if some polygons where found, we need to reorder polygon rings
    in the output buffer to make all hole rings go after their outer rings.
  */
  if (polygons_found && chunks.elements() > 1)
  {
    chunks.sort(chunk_info_cmp);
    if (storage->reorder_chunks(chunks.front(), chunks.elements()))
      DBUG_RETURN(1);
  }
  
  m_res_hook= (Gcalc_dyn_list::Item **)&m_result;
  storage->done();
  DBUG_RETURN(0);
}


void Gcalc_operation_reducer::reset()
{
  DBUG_ENTER("Gcalc_operation_reducer::reset");
  free_list(m_result, m_res_hook);
  m_res_hook= (Gcalc_dyn_list::Item **)&m_result;
  free_list(m_first_active_thread);
  DBUG_VOID_RETURN;
}

#endif /*HAVE_SPATIAL*/

