#! /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;
}