#!/usr/bin/perl -w
# Copyright 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 Kevin Ryde
# This file is part of Math-PlanePath.
#
# Math-PlanePath 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, or (at your option) any later
# version.
#
# Math-PlanePath 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 Math-PlanePath.  If not, see <http://www.gnu.org/licenses/>.
use 5.004;
use strict;
use Test;
plan tests => 659;
use lib 't';
use MyTestHelpers;
BEGIN { MyTestHelpers::nowarnings(); }
use Math::PlanePath::TerdragonCurve;
#------------------------------------------------------------------------------
# VERSION
{
  my $want_version = 129;
  ok ($Math::PlanePath::TerdragonCurve::VERSION, $want_version,
      'VERSION variable');
  ok (Math::PlanePath::TerdragonCurve->VERSION,  $want_version,
      'VERSION class method');
  ok (eval { Math::PlanePath::TerdragonCurve->VERSION($want_version); 1 },
      1,
      "VERSION class check $want_version");
  my $check_version = $want_version + 1000;
  ok (! eval { Math::PlanePath::TerdragonCurve->VERSION($check_version); 1 },
      1,
      "VERSION class check $check_version");
  my $path = Math::PlanePath::TerdragonCurve->new;
  ok ($path->VERSION,  $want_version, 'VERSION object method');
  ok (eval { $path->VERSION($want_version); 1 },
      1,
      "VERSION object check $want_version");
  ok (! eval { $path->VERSION($check_version); 1 },
      1,
      "VERSION object check $check_version");
}
#------------------------------------------------------------------------------
# digit rotations used by xy_to_n_list()
{
  my @digit_to_x = ([0,2,1],  [0,-1,-2],  [0,-1, 1]);
  my @digit_to_y = ([0,0,1],  [0, 1, 0],  [0,-1,-1]);
  foreach my $a (0,1,2) {
    my $x = $digit_to_x[0]->[$a];
    my $y = $digit_to_y[0]->[$a];
    ($x,$y) = (($x+3*$y)/-2,  # rotate +120
               ($x-$y)/2);
    ok ($x == $digit_to_x[1]->[$a], 1);
    ok ($y == $digit_to_y[1]->[$a], 1);
    ($x,$y) = (($x+3*$y)/-2,  # rotate +120
               ($x-$y)/2);
    ok ($x == $digit_to_x[2]->[$a], 1);
    ok ($y == $digit_to_y[2]->[$a], 1);
  }
}
#------------------------------------------------------------------------------
# xyxy_to_n()
{
  my $path = Math::PlanePath::TerdragonCurve->new;
  ok ($path->xyxy_to_n(0,0, 2,0),  0);
  ok ($path->xyxy_to_n(0,0, 1,1),  undef);
}
#------------------------------------------------------------------------------
# xy_to_n_list()
{
  my $path = Math::PlanePath::TerdragonCurve->new (arms => 2);
  {
    my @n_list = $path->xy_to_n_list(1,1);
    ok (join(',',@n_list), '3,4,10');
  }
  {
    my @n_list = $path->xy_to_n_list(-1,1);
    ok (join(',',@n_list), '5,11');
  }
}
# at 0,0
foreach my $arms (1 .. 6) {
  my $path = Math::PlanePath::TerdragonCurve->new (arms => $arms);
  my @got_n_list = $path->xy_to_n_list(0,0);
  my $got_n_list = join(',',@got_n_list);
  my $want_n_list = join(',', 0 .. $arms-1);
  ok ($got_n_list, $want_n_list);
}
{
  # arms=6 points shown in the POD
  #
  #             --- 8,13,31 ---------------- 7,12,30 ---
  #               /        \               /         \
  #  \           /          \             /           \          /
  #   \         /            \           /             \        /
  # --- 9,14,32 ------------- 0,1,2,3,4,5 -------------- 6,17,35 ---
  #   /         \            /           \             /        \
  #  /           \          /             \           /          \
  #               \        /               \         /
  #            --- 10,15,33 ---------------- 11,16,34 ---
  my $path = Math::PlanePath::TerdragonCurve->new (arms => 6);
  foreach my $elem ([-1, 1, '8,13,31'],
                    [ 1, 1, '7,12,30'],
                    [-2, 0, '9,14,32'],
                    [ 0, 0, '0,1,2,3,4,5'],
                    [ 2, 0, '6,17,35'],
                    [-1,-1, '10,15,33'],
                    [ 1,-1, '11,16,34'],
                   ) {
    my ($x,$y, $want_n_list) = @$elem;
    my @got_n_list = $path->xy_to_n_list($x,$y);
    my $got_n_list = join(',',@got_n_list);
    ok ($got_n_list, $want_n_list);
  }
}
#------------------------------------------------------------------------------
# level_to_n_range()
{
  my $path = Math::PlanePath::TerdragonCurve->new;
  { my ($n_lo,$n_hi) = $path->level_to_n_range(0);
    ok ($n_lo, 0);
    ok ($n_hi, 1); }
  { my ($n_lo,$n_hi) = $path->level_to_n_range(1);
    ok ($n_lo, 0);
    ok ($n_hi, 3); }
  { my ($n_lo,$n_hi) = $path->level_to_n_range(2);
    ok ($n_lo, 0);
    ok ($n_hi, 9); }
}
{
  my $path = Math::PlanePath::TerdragonCurve->new (arms => 5);
  { my ($n_lo,$n_hi) = $path->level_to_n_range(0);
    ok ($n_lo, 0);
    ok ($n_hi, (3**0 + 1)*5 - 1); }
  { my ($n_lo,$n_hi) = $path->level_to_n_range(1);
    ok ($n_lo, 0);
    ok ($n_hi, (3**1 + 1)*5 - 1); }
  { my ($n_lo,$n_hi) = $path->level_to_n_range(2);
    ok ($n_lo, 0);
    ok ($n_hi, (3**2 + 1)*5 - 1); }
}
#------------------------------------------------------------------------------
# xy_to_n_list()
{
  my $path = Math::PlanePath::TerdragonCurve->new;
  foreach my $elem ([ 1,  '1' ],
                    [ 2,  '2,5' ],
                    [ 3,  '3' ],
                    [ 4,  '4,7' ],
                    [ 5,  '2,5' ],
                    [ 6,  '6,15' ],
                    [ 7,  '4,7' ],
                    [ 8,  '8,11,14' ],
                    [ 11,  '8,11,14' ],
                    [ 14,  '8,11,14' ],
                   ) {
    my ($n, $want_n_list) = @$elem;
    my ($x,$y) = $path->n_to_xy ($n);
    my @got_n_list = $path->xy_to_n_list ($x,$y);
    my $got_n_list = join(',',@got_n_list);
    ok ($got_n_list, $want_n_list);
  }
}
#------------------------------------------------------------------------------
# turn sequence claimed in the pod
{
  # per KochCurve.t, 0=straight, 1=+120 degrees, 2=+240 degrees
  sub dxdy_to_dir3 {
    my ($dx,$dy) = @_;
    if ($dy == 0) {
      if ($dx == 2) { return 0/2; }
      # if ($dx == -2) { return 3; }
    }
    if ($dy == 1) {
      # if ($dx == 1) { return 1; }
      if ($dx == -1) { return 2/2; }
    }
    if ($dy == -1) {
      # if ($dx == 1) { return 5; }
      if ($dx == -1) { return 4/2; }
    }
    die "unrecognised $dx,$dy";
  }
  sub path_n_dir {
    my ($path, $n) = @_;
    my ($dx,$dy) = $path->n_to_dxdy($n) or die "Oops, no point at ",$n;
    return dxdy_to_dir3 ($dx, $dy);
  }
  # return 0 for left, 1 for right
  sub path_n_turn {
    my ($path, $n) = @_;
    my $prev_dir = path_n_dir ($path, $n-1);
    my $dir = path_n_dir ($path, $n);
    return ($dir - $prev_dir + 3) % 3;  # "+3" to stay +ve for "use integer"
  }
  # return 1 for left, 2 for right
  sub calc_n_turn {
    my ($n) = @_;
    die if $n == 0;
    while (($n % 3) == 0) {
      $n = int($n/3); # skip low 0s
    }
    return ($n % 3);  # next digit is the turn
  }
  # # return 0 for left, 1 for right
  # sub calc_n_next_turn {
  #   my ($n) = @_;
  #   my $mask = $n ^ ($n+1);      # low bits 000111..11
  #   my $z = $n & ($mask + 1);    # the solitary bit above it
  #   my $turn = ($z == 0 ? 0 : 1);
  #   return $turn;
  # }
  my $path = Math::PlanePath::TerdragonCurve->new;
  my $bad = 0;
  foreach my $n ($path->n_start + 1 .. 500) {
    {
      my $path_turn = path_n_turn ($path, $n);
      my $calc_turn = calc_n_turn ($n);
      if ($path_turn != $calc_turn) {
        MyTestHelpers::diag ("turn n=$n  path $path_turn calc $calc_turn");
        last if $bad++ > 10;
      }
    }
    # {
    #   my $path_turn = path_n_turn ($path, $n+1);
    #   my $calc_turn = calc_n_next_turn ($n);
    #   if ($path_turn != $calc_turn) {
    #     MyTestHelpers::diag ("next turn n=$n  path $path_turn calc $calc_turn");
    #     last if $bad++ > 10;
    #   }
    # }
  }
  ok ($bad, 0, "turn sequence");
}
#------------------------------------------------------------------------------
# n_start, x_negative, y_negative
{
  my $path = Math::PlanePath::TerdragonCurve->new;
  ok ($path->n_start, 0, 'n_start()');
  ok ($path->x_negative, 1, 'x_negative()');
  ok ($path->y_negative, 1, 'y_negative()');
  ok ($path->class_x_negative, 1, 'class_x_negative()');
  ok ($path->class_y_negative, 1, 'class_y_negative()');
}
{
  my @pnames = map {$_->{'name'}}
    Math::PlanePath::TerdragonCurve->parameter_info_list;
  ok (join(',',@pnames), 'arms');
}
#------------------------------------------------------------------------------
# first few points
{
  my @data = (
              [ 0, 0,0 ],
              [ 1, 2,0 ],
              [ 2, 1,1 ],
              [ 3, 3,1 ],
              [ 4, 2,2 ],
              [ 5, 1,1, 'rep' ],
              [ 6, 0,2 ],
              [ 0.25,  0.5, 0 ],
              [ 1.25,  1.75, 0.25 ],
              [ 2.25,  1.5, 1 ],
              [ 3.25,  2.75, 1.25 ],
             );
  my $path = Math::PlanePath::TerdragonCurve->new;
  foreach my $elem (@data) {
    my ($n, $x,$y, $rep) = @$elem;
    {
      # n_to_xy()
      my ($got_x, $got_y) = $path->n_to_xy ($n);
      if ($got_x == 0) { $got_x = 0 }  # avoid "-0"
      if ($got_y == 0) { $got_y = 0 }
      ok ($got_x, $x, "n_to_xy() x at n=$n");
      ok ($got_y, $y, "n_to_xy() y at n=$n");
    }
    if ($n==int($n) && ! $rep) {
      # xy_to_n()
      my $got_n = $path->xy_to_n ($x, $y);
      ok ($got_n, $n, "xy_to_n() n at x=$x,y=$y");
    }
    {
      $n = int($n);
      my ($got_nlo, $got_nhi) = $path->rect_to_n_range (0,0, $x,$y);
      ok ($got_nlo <= $n, 1, "rect_to_n_range() nlo=$got_nlo at n=$n,x=$x,y=$y");
      ok ($got_nhi >= $n, 1, "rect_to_n_range() nhi=$got_nhi at n=$n,x=$x,y=$y");
    }
  }
}
#------------------------------------------------------------------------------
# random rect_to_n_range()
foreach my $arms (1 .. 4) {
  my $path = Math::PlanePath::TerdragonCurve->new (arms => $arms);
  ok ($path->arms_count, $arms, 'arms_count()');
  for (1 .. 5) {
    my $bits = int(rand(25));     # 0 to 25, inclusive
    my $n = int(rand(2**$bits));  # 0 to 2^bits, inclusive
    my ($x,$y) = $path->n_to_xy ($n);
    my $rev_n = $path->xy_to_n ($x,$y);
    ok (defined $rev_n, 1, "xy_to_n($x,$y) arms=$arms reverse n, got undef");
    my ($n_lo, $n_hi) = $path->rect_to_n_range ($x,$y, $x,$y);
    ok ($n_lo <= $n, 1,
        "rect_to_n_range() arms=$arms n=$n at xy=$x,$y cf got n_lo=$n_lo");
    ok ($n_hi >= $n, 1,
        "rect_to_n_range() arms=$arms n=$n at xy=$x,$y cf got n_hi=$n_hi");
  }
}
#------------------------------------------------------------------------------
# random n_to_xy() fracs
foreach my $arms (1 .. 4) {
  my $path = Math::PlanePath::TerdragonCurve->new (arms => $arms);
  for (1 .. 20) {
    my $bits = int(rand(25));         # 0 to 25, inclusive
    my $n = int(rand(2**$bits)) + 1;  # 1 to 2^bits, inclusive
    my ($x1,$y1) = $path->n_to_xy ($n);
    my ($x2,$y2) = $path->n_to_xy ($n+$arms);
    foreach my $frac (0.25, 0.5, 0.75) {
      my $want_xf = $x1 + ($x2-$x1)*$frac;
      my $want_yf = $y1 + ($y2-$y1)*$frac;
      my $nf = $n + $frac;
      my ($got_xf,$got_yf) = $path->n_to_xy ($nf);
      ok ($got_xf, $want_xf, "n_to_xy($nf) arms=$arms frac $frac, x");
      ok ($got_yf, $want_yf, "n_to_xy($nf) arms=$arms frac $frac, y");
    }
  }
}
#------------------------------------------------------------------------------
exit 0;