#! /usr/bin/perl
use warnings;
use strict;
use 5.010;
use WWW::Mechanize::GZip;
use HTML::TableExtract;
use HTML::TableExtract qw(tree);
use open ':std', OUT => ':utf8';
use Prompt::Timeout;
use constant TIMEOUT  => 3;
use constant MAXTRIES => 16;

my $site = 'http://www.fourmilab.ch/yoursky/cities.html';
my $mech = 'WWW::Mechanize::GZip'->new;
$mech->get($site);
$mech->follow_link( text => 'Portland OR' );
my $lub = 2457204.63659;    #least upper bound
my $glb = 2457207.63659;    #greatest lower bound
my @right;
my @left;
my @julian;
$mech->set_fields(qw'date 2');
my ( $vstr, $jstr ) = ( 5, 3 );

my $upper = $lub;
my $lower = $glb;
my $equal;
my $equal_sec;
my $now_string = localtime;
my $filename   = 'planet5.txt';
open( my $jh, '>>', $filename ) or die "Could not open file '$filename' $!";
say $jh "Script executed at $now_string";
say $jh join "\t", "venus", "jupiter", "julian date";
my $attempts = 1;

while ( ( $jstr != $vstr ) ) {

  my $default = ( ( $attempts >= MAXTRIES ) ) ? 'N' : 'Y';
  my $answer = prompt( "Make query number $attempts?", $default, TIMEOUT );
  exit if $answer =~ /^N/i;
  my $guess = median( $upper, $lower );
  say "guess is $guess";
  push @julian, $guess;
  $mech->set_fields( jd => $guess );
  $mech->click_button( value => "Update" );
  my $te = 'HTML::TableExtract'->new;
  $te->parse( $mech->content );
  my $table      = ( $te->tables )[3];
  my $table_tree = $table->tree;
  my $venus      = $table_tree->cell( 4, 1 )->as_text;
  my $jupiter    = $table_tree->cell( 7, 1 )->as_text;
  $vstr = string_to_second($venus);
  say "vstr is $vstr";
  push @right, $vstr;
  $jstr = string_to_second($jupiter);
  say "jstr is $jstr";
  push @left, $jstr;
  say $jh join "\t", $vstr, $jstr, $guess;

  if ( $jstr > $vstr ) {
    $upper = $guess;
  }
  elsif ( $vstr > $jstr ) {
    $lower = $guess;
  }
  else {
    $equal = $guess;
    say "equal, while condition should fail $equal";
    $equal_sec = $vstr;
  }
  $te->delete;
  $attempts++;
}
my $equal_ra = second_to_string($equal_sec);
say "equal_ra is $equal_ra";
say $jh "equal seconds is $equal_sec and equal ra is $equal_ra";
say "right is @right";
say "left is @left";
say "julian is @julian";

## Determine last best guess that was unequal
my $ind1 = get_index( \@right );
say "ind is $ind1";
say "v is $right[$ind1] and jul is $julian[$ind1]";
if ( $ind1 >= 0 ) {
  $upper = $julian[$ind1];
}
else {
  $upper = $lub;
}
say "upper is $upper";
$lower = $julian[-1];
say "lower is $lower";

## find upper bound of convergence range
$attempts = 1;
while ( ( abs( $upper - $lower ) > .000005 ) ) {

  my $default = ( ( $attempts >= MAXTRIES ) ) ? 'N' : 'Y';
  my $answer = prompt( "Make query number $attempts?", $default, TIMEOUT );
  exit if $answer =~ /^N/i;
  my $guess = median( $upper, $lower );
  say "guess is $guess";
  $mech->set_fields( jd => $guess );
  $mech->click_button( value => "Update" );
  my $te = 'HTML::TableExtract'->new;
  $te->parse( $mech->content );
  my $table      = ( $te->tables )[3];
  my $table_tree = $table->tree;
  my $venus      = $table_tree->cell( 4, 1 )->as_text;
  my $jupiter    = $table_tree->cell( 7, 1 )->as_text;
  $vstr = string_to_second($venus);
  say "vstr is $vstr";
  $jstr = string_to_second($jupiter);
  say "jstr is $jstr";
  say $jh join "\t", $vstr, $jstr, $guess;

  if ( $vstr > $jstr ) {
    $upper = $guess;
  }
  elsif ( $vstr == $jstr ) {
    $lower = $guess;
  }
  else {
    die "retrograde motion or bad data";
  }
  $te->delete;
  $attempts++;
}
say "after upper contraction, upper is $upper";
say "after upper contraction, lower is $lower";
my $end_time = $lower;
say $jh join "\t", $upper, $end_time;

## Determine last best guess that was unequal
$ind1 = low_index( \@left );
say "ind is $ind1";
say "v is $left[$ind1] and jul is $julian[$ind1]";
if ( $ind1 >= 0 ) {
  $upper = $julian[$ind1];
}
else {
  $upper = $glb;
}
$lower = $julian[-1];
say "lower is $lower";
## find beginning  bound of convergence range
$attempts = 1;
while ( ( abs( $upper - $lower ) > .000005 ) ) {

  my $default = ( ( $attempts >= MAXTRIES ) ) ? 'N' : 'Y';
  my $answer = prompt( "Make query number $attempts?", $default, TIMEOUT );
  exit if $answer =~ /^N/i;
  my $guess = median( $upper, $lower );
  say "guess is $guess";
  $mech->set_fields( jd => $guess );
  $mech->click_button( value => "Update" );
  my $te = 'HTML::TableExtract'->new;
  $te->parse( $mech->content );
  my $table      = ( $te->tables )[3];
  my $table_tree = $table->tree;
  my $venus      = $table_tree->cell( 4, 1 )->as_text;
  my $jupiter    = $table_tree->cell( 7, 1 )->as_text;
  $vstr = string_to_second($venus);
  say "vstr is $vstr";
  $jstr = string_to_second($jupiter);
  say "jstr is $jstr";
  say $jh join "\t", $vstr, $jstr, $guess;

  if ( $vstr < $jstr ) {
    $upper = $guess;
  }
  elsif ( $vstr == $jstr ) {
    $lower = $guess;
  }
  else {
    die "retrograde motion or bad data";
  }
  $te->delete;
  $attempts++;
}
say "after begin contraction, upper is $upper";
say "after begin contraction, lower is $lower";
my $begin_time = $upper;
say $jh join "\t", $lower, $begin_time;
my $middle = median( $begin_time, $end_time );
say "middle is $middle";
my $duration = $end_time - $begin_time;
say "duration is $duration";
say $jh "middle: $middle\t duration: $duration";

# get final disposition
$mech->set_fields( jd => $middle );
$mech->set_fields(qw'lat 35 ns North');
$mech->set_fields(qw'lon 80 ew East');
my $te = 'HTML::TableExtract'->new;
$te->parse( $mech->content );
my $table      = ( $te->tables )[3];
my $table_tree = $table->tree;

my $vdistance = $table_tree->cell( 4, 3 )->as_text;
my $jdistance = $table_tree->cell( 7, 3 )->as_text;
say $jh "vdistance is $vdistance";
say $jh "jdistance is $jdistance";

my $table2 = ( $te->tables )[1];

my $table_tree2 = $table2->tree;
my $table_text2 = $table_tree2->as_text;
say "table text2 is $table_text2";
my $utc1 = $table_tree->cell( 1, 1 )->as_text;
say $jh "utc1 is $utc1";
my $utc2 = $table_tree->cell( 1, 0 )->as_text;
say $jh "utc2 is $utc2";

#my $utc = $mech->value(utc);
#say "utc is $utc";

sub median {
  my ( $up, $low ) = @_;
  my $return = ( $up + $low ) / 2.0;
  return $return;
}

sub string_to_second {
  my $string = shift;
  my $return = 9000;
  if ( my $success = $string =~ /^(\d*)h\s+(\d*)m\s+(\d*)s$/ ) {
    $return = 3600 * $1 + 60 * $2 + $3;
  }
  else {
    say "string was misformed";
  }
  return $return;
}

sub second_to_string {
  my $seconds   = shift;
  my $hours     = int( $seconds / 3600 );
  my $remainder = $seconds % 3600;
  my $minutes   = int( $remainder / 60 );
  my $sec       = $remainder % 60;
  my $return    = join '', $hours, 'h ', $minutes, 'm ', $sec, 's';
  return $return;
}

sub get_index {
  my ($ref_right) = shift;
  my @right       = @$ref_right;
  my $return      = -1;
  my $eq          = $right[-1];
  say "right is @right";
  say "eq is $eq";
  for my $i ( 0 .. $#right ) {
    if ( $right[$i] <= $eq ) {
      next;
    }
    else {
      $return = $i;
      say "i is $i";
    }
  }
  say "right is @right";
  return $return;
}

sub low_index {
  my ($ref_right) = shift;
  my @right       = @$ref_right;
  my $return      = -1;
  my $eq          = $right[-1];
  say "right is @right";
  say "eq is $eq";
  for my $i ( 0 .. $#right ) {
    if ( $right[$i] >= $eq ) {
      next;
    }
    else {
      $return = $i;
      say "i is $i";
    }
  }
  say "right is @right";
  return $return;
}


##</code><code>##

Script executed at Mon Jun 29 02:10:13 2015
venus	jupiter	julian date
34790	34686	2457206.13659
34682	34653	2457205.38659
34628	34636	2457205.01159
34655	34644	2457205.19909
34641	34640	2457205.10534
34634	34638	2457205.058465
34638	34639	2457205.0819025
34640	34640	2457205.09362125
equal seconds is 34640 and equal ra is 9h 37m 20s
34640	34640	2457205.09948062
34641	34640	2457205.10241031
34641	34640	2457205.10094547
34641	34640	2457205.10021305
34641	34640	2457205.09984684
34641	34640	2457205.09966373
34641	34640	2457205.09957218
34640	34640	2457205.0995264
34641	34640	2457205.09954929
34640	34640	2457205.09953785
34640	34640	2457205.09954357
34640	34640	2457205.09954643
2457205.09954929	2457205.09954643
34639	34640	2457205.08776187
34639	34640	2457205.09069156
34639	34640	2457205.09215641
34640	34640	2457205.09288883
34639	34640	2457205.09252262
34639	34640	2457205.09270572
34640	34640	2457205.09279728
34640	34640	2457205.0927515
34640	34640	2457205.09272861
34639	34640	2457205.09271717
34639	34640	2457205.09272289
34639	34640	2457205.09272575
2457205.09272861	2457205.09272575
middle: 2457205.09613609	 duration: 0.0068206787109375
vdistance is 0.512
jdistance is 6.083
utc1 is 
utc2 is